Article

Efficient Breeding System for Red-fleshed Apple Based on Linkage with S(3)-RNase Allele in 'Pink Pearl'

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Abstract

We have used a red-fleshed apple cultivar, Malus ·domestica Pink Pearl, and its progeny, 'JPP 35', as paternal parents for producing new red-fleshed cultivars suitable for fresh use or processing such as pie fillings, dried apple, apple juice, or cider. In this process, we found that the S3-RNase allele of 'Pink Pearl' was linked to its red flesh trait. It was suggested that this trait might be controlled by a new gene apart from the MYB10 (MdMYB10) gene. Using 'JPP 35' (S-RNase allele genotype; S3S7) produced by 'Jonathan' (S7S9) · 'Pink Pearl' (S3Sx) as a paternal parent, we developed a system for producing red-fleshed progenies suitable for fresh use. That is, 96% and 86% of progenies from 'Shinano Sweet' (S1S7) · 'JPP35' (S3S7) and 'Orin' (S2S7) · 'JPP35' (S3S7) containing the S3-RNase allele, respectively, showed the red flesh trait. Similarly, red-fleshed progenies suitable for apple pie or natural red juice could be produced by 'Jonathan' (S7S9) · 'JPP35' (S3S7).

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... Recently, we found that the R6 promoter was not observed at the promoter region of MdMYB in red-fleshed apple cultivars Pink Pearl ('Surprise' · unknown pollen parent, selected in 1944), JPP35 ('Jonathan' · 'Pink Pearl'), and any of their progenies with the red flesh trait (Sekido et al., 2010a). Although the molecular mechanism of their red coloration is largely unknown, we indicated that the red flesh trait in 'Pink Pearl' is tightly linked with its S 3 -RNase allele (Sekido et al., 2010a). ...
... Recently, we found that the R6 promoter was not observed at the promoter region of MdMYB in red-fleshed apple cultivars Pink Pearl ('Surprise' · unknown pollen parent, selected in 1944), JPP35 ('Jonathan' · 'Pink Pearl'), and any of their progenies with the red flesh trait (Sekido et al., 2010a). Although the molecular mechanism of their red coloration is largely unknown, we indicated that the red flesh trait in 'Pink Pearl' is tightly linked with its S 3 -RNase allele (Sekido et al., 2010a). Because the flesh and skin color trait within the Rni locus (the site of MdMYB 1 and 10) located in linkage group 9, not 17 of the S-allele location, and which is called the S-locus (Chagné et al., 2007;Maliepaard et al., 1998), the red flesh trait in 'Pink Pearl' seemed to be controlled by a different type of MYB transcription factor close to the S 3 -RNase allele. ...
... Accurate linkage between red flesh trait and S 3 -RNase in 'Pink Pearl'. Previously, we indicated that 67 of 70 (96%) and 51 of 58 (88%) progenies from 'Shinano Sweet' (S 1 S 7 ) · 'JPP 35' (S 3 S 7 ) and 'Orin' (S 2 S 7 ) · 'JPP 35' (S 3 S 7 ), respectively, showed the red flesh color because the S 3 -RNase allele of 'Pink Pearl' was linked to its red flesh trait (Sekido et al., 2010a). At that time, we proposed that some progenies with white flesh color would turn white-pink after full maturity. ...
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Article
We re-investigated the flesh color and S-genotypes of progenies of red-fleshed apple cultivar JPP35, which was produced by 'Jonathan' × 'Pink Pearl', and clarified that 100% and 96% of progenies from 'Shinano Sweet' (S 1S 7) × 'JPP35' (S 3S 7) and 'Orin' (S 2S 7) × 'JPP35' (S 3S 7) containing S3-RNase allele, respectively, showed the red flesh trait. Using this tight linkage between red flesh trait and self- and cross-compatibility relating allele such as S 3-RNase allele, we showed suitable cultivar combinations for efficient production of various red-fleshed apples. We also identified an unknown S-RNase allele in 'Pink Pearl' as S 11 and determined its partial genomic sequence, including a complete intron with its known S 3-RNase allele.
... The Etter apple only has pink flesh in the cortex, and the red pigmentation is not found in the leaves, stems, or other vegetative tissues. This was later defined as the Type 2 phenotype 109 . The pioneering work of Hansen and Etter in creating the two types of red- fleshed apple laid the foundation for the breeding of red- fleshed apple worldwide. ...
... In Japan, Sekido et al. have been breeding Type 2 red-fleshed apples since 1989. The red-fleshed apple cultivar "Pink Pearl" and its progeny "JPP35" ("Jonathan" × "Pink Pearl") were used as paternal parents to produce new red-fleshed cultivars 109 . In Germany, the Type 2 red-fleshed apple "Weirouge" was bred in Wei- henstephan and first registered in 1997 110 . ...
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Article
Flavonoids play essential roles in human health. Apple (Malus domestica Borkh.), one of the most widely produced and economically important fruit crops in temperate regions, is a significant source of flavonoids in the human diet and is among the top nutritionally rated and most widely consumed fruits worldwide. Epidemiological studies have shown that the consumption of apples, which are rich in a variety of free and easily absorbable flavonoids, is associated with a decreased risk of various diseases. However, apple production is challenged by serious inbreeding problems. The narrowing of the hereditary base has resulted in apples with poor nutritional quality and low flavonoid contents. Recently, there have been advances in our understanding of the roles that Malus sieversii (Ledeb.) M.Roem has played in the process of apple domestication and breeding. In this study, we review the origin of cultivated apples and red-fleshed apples, and discuss the genetic diversity and construction of the core collections of M. sieversii. We also discuss current research progress and breeding programs on red-skinned and red-fleshed apples and summarize the exploitation and utilization of M. sieversii in the breeding of high-flavonoid, and red-fleshed apples. This study highlights a valuable pattern of horticultural crop breeding using wild germplasm resources. The future challenges and directions of research on the molecular mechanisms of flavonoid accumulation and high-flavonoid apple breeding are discussed.
... trait ( Sekido et al., 2010 ). Using this information, we developed a searching system for cultivars ( Fig. 2 ). ...
... Note: Z S-RNase genotypes are fromIgarashi et al., (2010),Sekido et al., (2010),Umemura et al., (2011) andMatsumoto et al., (2015) . ...
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Article
As apple possesses self-incompatibility, knowledge of the S-genotypes is very important for apple breeding and cultivation. We investigated the S-RNase genotypes of 13 type 2 red-fleshed apple cultivars and 8 lineages. All of the investigated type 2 red-fleshed apples contained the S3-RNase allele closely linked to the red-fleshed trait. We made a search system for ovule parents to efficiently produce new type 2 red-fleshed cultivars based on the S-RNase allele information (http://www.agr.nagoya-u.ac.jp/∼hort/apple/red/). More than 90% of progenies from crossing a selected white-fleshed ovule parent with a type 2 red-fleshed pollen parent are expected to show the red-fleshed phenotype. We also compiled a database of the S-RNase genotypes of more than 1 000 apple cultivars, including a survey system of cultivar combinations showing those that were fully incompatible, semicompatible and fully compatible, written in Chinese (http://www.agr.nagoya-u.ac.jp/∼hort/apple/ch/) and Japanese (http://www.agr.nagoya-u.ac.jp/∼hort/apple/ja/). Keywords: Malus × domestica, type 2 red-fleshed, S-RNase, genotype, cultivar combination, self-incompatibility
... In contrast, MdMYB110a which controls the development of red coloration only in the fruit flesh in linkage group 17 (Chagné et al., 2013;Umemura et al., 2013). Moreover, the red-fleshed trait of type 2 apples was found to be linked to the S 3 -RNase allele (Sekido et al., 2010). In type 2 apples, the coloration of skin and fruit flesh is controlled by different MdMYBA/1/10 and MdMYB110a genes (Umemura et al., 2013). ...
... Hatsuyama personal communication; Takos et al., 2006); therefore, its skin, flesh, and core show red coloration due to MdMYB10R6. In contrast, 'Kurenainoyume' does not possess MdMYB10R6, but two functional MdMYB10R1 (=MdMYBA/1) alleles (Igarashi et al., 2011), which contribute to red skin coloration, and it is assumed that 'Kurenainoyume' has at least one MdMYB110a allele, considering the red flesh phenotype and the presence of the S 3 -RNase allele (Chagné et al., 2013;Sekido et al., 2010;Umemura et al., 2013). ...
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Article
We investigated the effect of fruit bagging treatment using three kinds of paper bags differing in light permeability on the red coloration of skin, flesh, and core in type 2 red-fleshed ‘Kurenainoyume’ apples by comparison with type 1 ‘Goshogawara’ apples. Skin coloration of both ‘Goshogawara’ and ‘Kurenainoyume’ was affected by light and the effect was more marked in ‘Kurenainoyume’ than ‘Goshogawara’. In contrast, the effect of fruit bagging treatment on the red coloration of the core was limited in ‘Goshogawara’, while core coloration was not observed in ‘Kurenainoyume’ type 2 apples. Flesh coloration was observed even under dark conditions in both cultivars, and the light tended to enhance the flesh coloration to some extent in both cultivars. Since fruit bagging treatment is a prerequisite for ‘Kurenainoyume’ to prevent cork spot-like physiological disorder (CSPD) in the skin, we optimized the fruit bagging treatment conditions using a light impermeable double-layered paper bag (2-layer bag), considering both prevention of CSPD and the red coloration of ‘Kurenainoyume’ skin and flesh. Bag-removal at 25, 35, and 45 days before harvest (DBH), resulted in good skin and flesh coloration without CSPD incidence. Moreover, there was no significant difference in fresh weight, soluble solid, or malic acid contents compared with the non-bagging control. Therefore, we recommend bag-removal from 25 to 45 DBH for ‘Kurenainoyume’ as a practical cultivation technique.
... Because breeding of new apple cultivars takes a long time and requires a large space for the planting of trees, establishment of an early screening system is essential. Although we previously devel- oped a breeding system of type 2 red-fleshed apple based on the linkage of the MdMYB110a and S 3 -RNase alleles (Sekido et al., 2010;Umemura et al., 2011), a more accurate screening system is desired because genetic recombination between the MdMYB110a and S locus occurs at a certain frequency (Umemura et al., 2013). ...
... Most Malus species exhibit a gametophytic self-incompatibility system controlled by the S locus, and this system employs S-RNase as the pistil determinant (for a review, see Sassa, 2016). The efficient breeding system of type 2 red-fleshed apples that we developed previously took advantage of the genetic linkage of the S 3 -RNase allele and the MdMYB110a gene (Sekido et al., 2010;Umemura et al., 2011). In this breeding system, we used 'Shinano Sweet' (S 1 S 7 ) and 'JPP35 (S 3 S 7 ) as maternal and paternal parents, respectively. ...
Article
Apples are rich source of phenolic compounds exhibiting a strong antioxidant activity. Although type 2 red-fleshed apples highly accumulate health-promoting anthocyanins, accumulation profiles of other phenolic compounds had not been investigated. The objective of this study was to characterize the accumulation profiles of eight phenolic compounds in five type 2 red-fleshed apple varieties with different color intensities in their cortex. Quantification of the phenolic compounds revealed that not only cyanidin-3-galactoside but also chlorogenic acid and epicatechin are the dominant phenolic compounds in type 2 red-fleshed cultivars except for a red flesh lineage showing a white cortex. Bioinformatic analysis further revealed that cultivars with a deep red flesh accumulated caffeic acid and procyanidin B2, but cultivars with a pale-red flesh accumulated catechin and epicatechin. In pale-red flesh cultivars, the correlation between the expression of MdMYB110a gene responsible for the type 2 red flesh phenotype and the two phenylpropanoid pathway genes MdC3H and MdLAR were also observed during the fruit development. Taken together, these results indicate that there is a significant variation in the contents of phenolic compounds between type 2 red-fleshed cultivars and suggest the possibility that biosynthesis of some phenolic compounds other than anthocyanins is also regulated through MdMYB110a. In addition, for selecting type 2 red-fleshed cultivars efficiently, we also reported the development of a dCAPS marker which can detect functional MdMYB110a allele accurately.
... For these reasons, the investigation of anthocyanin biosynthesis in fruit has become a popular area of research, with the aim of more efficiently developing novel fruit cultivars with a higher anthocyanin content (Xie et al. 2011). In addition to well-known Communicated by D. Chagné anthocyanin-rich fruits, such as blueberries or cranberries, other fruits with red flesh, such as kiwis (Jaeger and Harker 2005), oranges (Xu et al. 2009), apples (Sekido et al. 2010;Volz et al. 2009), plums (Cevallos-Casals et al. 2006), and cherries (Sooriyapathirana et al. 2010), are considered in varietal innovation programs, which generally integrate plant genomics and classical breeding methods. ...
... These authors demonstrated that R 6 is responsible for increasing MYB10 transcript levels and the subsequent ectopic accumulation of anthocyanins. However, a study by Sekido et al. (2010) showed that the red-flesh trait of the apple cultivar 'Pink Pearl' might be controlled by a gene other than MdMYB10. The gene they identified that controls the red-flesh trait is close to the S3-RNase allele in LG17. ...
Article
Anthocyanin-rich peaches, because of their antioxidant properties and their strong attractiveness to consumers, are increasingly considered in French peach varietal innovation programs that integrate plant genomics and classical breeding. In this study, we describe a new blood-flesh trait identified in the ‘Wu Yue Xian’ peach accession from China. ‘Wu Yue Xian’ exhibits a fully red mesocarp during the later stages of fruit development, both with green midrib leaf and normal growth of the tree. This blood-flesh phenotype clearly differs from that determined by a single recessive locus (bf) in ‘Harrow Blood’, a clone showing blood-flesh in both immature and mature fruit associated with red midrib leaf and reduced tree height. We have then provided genetic evidence that blood-flesh phenotype of ‘Wu Yue Xian’ was controlled by a single dominant locus, designated DBF (Dominant Blood- Flesh), in four successive families derived from this accession. A genetic linkage map of the blood-flesh parent (‘D6090’) of the fourth population was constructed, including 102 SSRs spanning a total distance of 562.3 cM in eight linkage groups. Whereas the bf locus is located to linkage group 4, we mapped DBF to the top of linkage group 5, thus proving that DBF and bf loci are not alleles. Among 64 predicted genes in the DBF region (505 kbp), three genes of the dihydroflavonol-4- reductase family were identified as good candidates for the control of the DBF trait. Furthermore, SSR markers flanking DBF, such as AMPP157 and AMPPG178, supply a good basis to implement marker-assisted selection for this trait.
... It has been explained that carrots contain bioactive compounds such as carotenoids, flavonoids, phenolic acids, polyacetylenes, and ascorbic acid, which have been proposed to have immunomodulatory effects; therefore, chemists may develop bioactive compounds isolated from carrots in the future. There has been a lot of development of genetically modified plant to enhance the amount of phytonutrients and biomarkers for dietary health, for example, red-fleshed apples rich in anthocyanins (Espley et al., 2013;Sekido et al., 2010), therefore researchers in this area of expertise such as biologists may develop genetically modified carrots high in β-carotene in order to enriched the nutritional benefit of carrots. ...
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Carrots (Daucus carota L.) are vegetables proven to have nutraceutical effects and beneficial for health due to its natural bioactive substances. One of the potential of carrots to maintain optimum health status is by regulating immune response. This literature review summarized the proposed immunomodulatory mechanisms of the antioxidant properties of carrot’s β-carotene and other bioactive compounds such as phenolic acid, flavonoid, polyacetylene and ascorbic acid via the anti-inflammatory, antioxidant and overall (innate and adaptive) immune response modulation. Overall, carrot’s bioactive compounds regulated pro-inflammatory and anti-inflammatory cytokines, reduced oxidative stress by decreasing the reactive oxygen species accumulation and improving antioxidant capacity and the expression of genes in order to prevent more damaging oxidative destruction. Carrots also modulated the immune components by regulating leukocytes, antigens, immunoglobulins, and histamine levels. Thus, the immunomodulatory activity makes carrots as a functional food source that has the potential to prevent and treat various diseases.
... Thus far, it has been shown that some peach and plum cultivars can rival the anthocyanin, total phenolics, and antioxidant activity of blueberries (Byrne, 2005). In the case of developing red flesh among normally green, yellow, and white tree fruit (apples, pears, peaches, plums) cultivars, there appear to be a few major genes that condition this anthocyanin production in various fruits (Sekido et al., 2010). Currently, several fruit breeding programs are exploring or developing berry and tree fruit crops with greater levels of anthocyanins (Byrne, 2005). ...
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Chapter
Cassava (Manihot esculenta Crantz) is one of the important tropical tuber crops and cultured for it tuberous roots rich in starch. It belongs to the family Euphorbiaceae. Cassava originated in South America and was domesticated less than ten thousand years ago with confirmation of primordial farming in Brazil, Peru, Columbia and Venezuela. Cassava was introduced from Brazil to India by the Portuguese in the part of the Kerala state, during the 17th century. Cassava is considered as the future food security crop as regards to its biological efficiency coupled with ability to sustain under changing climate especially during drought (by shedding leaves) and to grow well in marginal soils. The diversity in cassava genotypes accounts for differences in end-product properties and would require characterization of cassava varieties for suitability of culinary and processing. Hi-tech starch factories for pre-gelatinized starch, acid-modified thin boiling starch, oxidized and cationic starches, textile grade modified starch with good tensile and adhesive strength, and paper grade starch with ink water resistance are the potential future avenues for cassava marketing. Strengthening the research base to produce modified starches with stable viscosity, freeze-thaw stability, film-forming properties, better suspension characteristics, etc. to suit many food applications will further enhance the prospects of cassava
... Thus far, it has been shown that some peach and plum cultivars can rival the anthocyanin, total phenolics, and antioxidant activity of blueberries (Byrne, 2005). In the case of developing red flesh among normally green, yellow, and white tree fruit (apples, pears, peaches, plums) cultivars, there appear to be a few major genes that condition this anthocyanin production in various fruits (Sekido et al., 2010). Currently, several fruit breeding programs are exploring or developing berry and tree fruit crops with greater levels of anthocyanins (Byrne, 2005). ...
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Chapter
Genomic research with collection and assessment of the biodiversity in the genus are likely to ensure the future of the Musa crop. The potential to breed superior hybrids has been demonstrated, and there are numerous opportunities for improving both the process and the product, and for realizing impact from already developed hybrids. Breeding techniques and recombinant DNA approach necessitate detailed knowledge of the genetics and genomics of the bananas.
... Unexpectedly, the endangered wild apple, M. niedzwetzkyana (red fleshed apple), was assigned primarily to the cluster of the cultivated apple genotypes, although the assignment pattern was more complex at K5 sharing its genetic affinity the highest with TalE and TalW (Figure 1a,b). The red fleshed apple is regarded as an important genetic resources of apple breeding programs due to its distinctive pink coloration with the high anthocyanin content [70], yet the plant only resides in a few extremely restricted areas making it vulnerable to extinction [71]. The species is currently listed as "Endangered" on the IUCN RED LIST (https://www.iucnredlist.org). ...
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Article
There is growing attention given to gene flow between crops and the wild relatives as global landscapes have been rapidly converted into agricultural farm fields over the past century. Crop-to-wild introgression may advance the extinction risks of rare plants through demographic swamping and/or genetic swamping. Malus sieversii, the progenitor of the apple, is exclusively distributed along the Tien Shan mountains. Habitat fragmentation and hybridization between M. sieversii and the cultivated apples have been proposed to be the causal mechanism of the accelerated extinction risk. We examined the genetic diversity pattern of eleven wild and domesticated apple populations and assessed the gene flow between M. sieversii and the cultivated apples in Ka-zakhstan using thirteen nuclear microsatellite loci. On average, apple populations harbored fairly high within-population diversity, whereas population divergences were very low suggesting likely influence of human-mediated dispersal. Assignment results showed a split pattern between the cultivated and wild apples and frequent admixture among the apple populations. Coupled with the inflated contemporary migration rates, the admixture pattern might be the signature of increased human intervention within the recent past. Our study highlighted the prevalent crop to wild gene flow of apples occurring in Kazakhstan, proposing an accelerated risk of genetic swamping.
... Only a few genotypes are known in which the red fruit flesh colouration is not associated with red skin and leaf colour. One out of these genotypes is 'Pink Pearl' that does not contain the R6 promoter element (Sekido et al., 2010). The red fruit flesh colouration of these type 2 red-fleshed apples appears to be controlled by MdMYB110a, a paralogue of MdMYB10 that is located on LG 17 Umemura et al., 2013). ...
Chapter
This book covers the biotechnology of all the major perennial fruit and nut species, including Actinidia spp., Anacardium occidentale , Mangifera indica , Pistacia vera , Annona spp., Cocos nucifera , Elaeis guineensis , Phoenix dactylifera , Ananas comosus , Carica papaya , Garcinia mangostana , Diospyros kaki , Vaccinium spp., Castanea spp., Carya illinoinensis , Juglans regia , Persea americana , Theobroma cacao , Musa spp., Psidium guajava , Olea europaea , Averrhoa carambola , Passiflora spp., Eriobotrya japonica , Fragaria × ananassa , Malus × domestica , Prunus persica , Prunus armeniaca , Prunus domestica , Prunus spp., Prunus dulcis , Pyrus spp., Cydonia spp., Rubus spp., Citrus spp., Dimocarpus longan , Litchi chinensis , and Vitis spp. This book also covers biotechnologies and also traditional ones, such as regeneration pathways, protoplast culture, in vitro mutagenesis, and ploidy manipulation that have been applied to many of these species. The species are organized by plant family to facilitate comparisons among related ones. Each species is discussed in relation to its family and its related wild forms, and most are accompanied by full colour illustrations. This book is a vital resource for those working on the improvement of perennial fruit, nut and plantation crops.
... Plants rich in anthocyanins are Vaccinium species, such as blueberry, cranberry, and bilberry; Rubus berries, including black raspberry, red raspberry, and blackberry; blackcurrant, cherry, Concord grape, muscadine grape, red cabbage, and violet petals. Red-fleshed peaches and apples contain anthocyanins (Cevallos-Casals et al., 2006;Sekido et al., 2010). ...
... To date, extensive traditional breeding has been carried, and related red apple varieties have been gradually obtained. However, only a little pink occurs in the outer cortex, leaves, stems, and other vegetative tissues do not show red (Sekido et al. 2010). Therefore, the comprehensive analysis of anthocyanin synthesis in all tissues in the present study will provide a theoretical basis for breeding studies, and could speed up the pace of red apple breeding by the early identification of seedlings. ...
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Malus niedzwetzkyana (Dieck) Langenf is a special germplasm in which all tissues are rich in anthocyanins. In recent years, M. niedzwetzkyana has gained popularity among consumers because of its healthy pulp composition and beautiful fruit color. Despite its valuable features, many functionally transcribed genes involved in anthocyanin biosynthesis have not been comprehensively explored. In addition, the genetic similarity research of M. niedzwetzkyana was also inconclusive. Over many years, our group has collected 153 Malus samples at home and abroad; therefore, we carried anthocyanin synthesis research using -omics and genetic similarity analysis with simple sequence repeat (SSR) markers. Transcriptome sequencing provided more specific sequences for SSR analysis. The results showed that M. niedzwetzkyana had higher similarity to M. sieversii (Ledeb) Roem in China than in other countries. In addition, we identified 83 unigenes involved in anthocyanin synthesis, which could be used in the early identification of red apple breeding seedlings, and to speed up the breeding of cultivated red apples.
... 12−16 In addition, apart from consumer preference for red skin and the fact that the concentration of phenolic compounds is much greater in the skin of apples than in the flesh, 3 many people discard the peel before eating the apple mainly for cultural reasons. 17,18 Furthermore, there is a heightened public interest in potential crops for coloring food naturally 19 without transgenic or cysgenic programs because consumers' attitudes toward genetically modified foods are mainly negative. 20 Hence, strongly colored fruit and vegetables are attractive for both fresh fruit and juice processing companies to increase and expand their range of products. ...
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The main objective of this study was to evaluate the impact of the season on the apple phytochemical composition (phenolic compounds, triterpenes, and organic and ascorbic acids). For this proposal four red-fleshed and five white-fleshed apple varieties from two consecutive seasons (2015 and 2016) were studied. A significant interaction with the season in some compounds was observed. The total phenolic content in the apple flesh from 2015 was higher than 2016 probably related with the lower rainfall during the harvest period in 2015 that could have favored hydric stress in the apple trees. The impact of the season on the apple skin was different. The 2016 season was characterized by higher maximum and minimum temperatures resulting in higher content of flavonols, triterpenes and organic acids. Anthocyanin concentration in both flesh and skin of the red-fleshed apples showed no clear relation to the season and each variety showed an individual pattern.
... On the other hand, the type-II accumulation pattern is independent of MdMYB10. In varieties such as 'Pink Pearl' and 'JPP35′, the red color of the fruit flesh is rather regulated by MdMYB110a (Chagné et al., 2013), which is a dominant allele genetically linked to the S3-RNase locus that is responsible for self-incompatibility (Sekido et al., 2010;Umemura et al., 2013). ...
Article
Anthocyanins are naturally occurring flavonoids derived from the phenylpropanoid pathway. There is increasing evidence of the preventative and protective roles of anthocyanins against a broad range of pathologies, including different cancer types and metabolic diseases. However, most of the fresh produce available to consumers typically contains only small amounts of anthocyanins, mostly limited to the epidermis of plant organs. Therefore, transgenic and non-transgenic approaches have been proposed to enhance the levels of this phytonutrient in vegetables, fruits, and cereals. Here, were review the current literature on the anthocyanin biosynthesis pathway in model and crop species, including the structural and regulatory genes involved in the differential pigmentation patterns of plant structures. Furthermore, we explore the genetic regulation of anthocyanin biosynthesis and the reasons why it is strongly repressed in specific cell types, in order to create more efficient breeding strategies to boost the biosynthesis and accumulation of anthocyanins in fresh fruits and vegetables.
... Identification of the regulatory gene (MYB10) for red apple skin and flesh color brought a new subject of interest in the fruit industry (Espley et al., 2007;Takos et al., 2006). Since then, research is being conducted on breeding of red-fleshed apples to develop cultivars with elevated concentrations of anthocyanins (Espley et al., 2013;Sekido, Hayashi, Yamada, Shiratake, & Matsumoto, 2010). Unlike in whitefleshed apples, anthocyanins in red-fleshed apples are concentrated both in the skin and flesh, with cyanidin-3-galactoside being predominant, hence the substantial content. ...
Article
The influence of combined pulsed electric fields (PEF) and mild temperature on the inactivation of Escherichia coli, Salmonella enteritidis, and Saccharomyces cerevisiae suspended in a novel cloudy red apple juice (Malus pumila Niedzwetzkyana (Dieck)) was investigated to define treatment conditions that meet the U.S. Food and Drug Administration (FDA) regulation for fruit juice pasteurization. There was significant microbial inactivation (p < .05) with increased experimental treatment conditions (electric field strength: 25–35 kV/cm, treatment time: 86–258 µs, post‐treatment temperature: 30–50 °C). The highest level of inactivation for E. coli, S. enteritidis, and S. cerevisiae was 5.21, 6.02, and 5.49 log reduction, respectively. PEF treatment at 35 kV/cm for 258 µs combined with heating at 50 °C was selected as pasteurization conditions. Pasteurization did not cause significant changes (p < .05) in pH, titratable acidity, total soluble solids, conductivity, and particle size of cloudy red apple juice, in comparison with conventional treatment. Practical applications Red‐fleshed apples are increasingly becoming a subject of interest in the fruit industry due to their remarkable anthocyanin content. However, mere identification or development of novel fruits is insufficient for the fruit juice industry to cater for consumer demand. There is need to combine this with novel processing technologies that ensure preservation of the desired unique quality attributes. This study indicated that combined PEF and mild heat can be successfully applied for the pasteurization of a novel cloudy red apple juice without significantly affecting important juice properties such as pH, acidity, conductivity, and particle size. This work provides a basis for new product development as numerous red‐fleshed apple cultivars are being developed and PEF technology is progressing toward industrial application.
... 13 In addition, although the concentration of phenolic compounds is much greater in the peel of apples than in the flesh, 2 a million pounds of peel is thrown away every year (the waste product of applesauce and canned apple manufacture), and also some people (no information was found on that subject in the literature) and cultures discard the peel before eating. 14 Moreover, there is a rapidly increasing interest in potential crops for coloring food naturally 15 without transgenic or cysgenic programs because consumers' purchasing behavior regarding genetically modified food is mainly negative. 16 Hence, colored fruits and vegetables are attractive for both fresh fruit and juice processing companies to grow and diversify their markets. ...
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Article
This study is an exhaustive chemical characterization of the phenolic compounds, triterpenes, and organic and ascorbic acids in red-fleshed apple varieties obtained by different breeding programs and using five traditional and new white-fleshed apple cultivars as reference. To carry out these analyses, solid-liquid extraction (SLE) and ultraperformance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) were used. The results showed that the red-fleshed apples contained, in either the flesh or peel, higher amounts of phenolic acids (chlorogenic acid), anthocyanins (cyanidin-3-O-galactoside), dihydrochalcones (phloretin xylosyl glucoside), and organic acids (malic acid) but a lower amount of flavan-3-ols than the white-fleshed apples. These quantitative differences could be related to an up-regulation of anthocyanins, dihydrochalcones, and malic acid and a down-regulation of flavan-3-ols (anthocyanin precursors) in both the flesh and peel of the red-fleshed apple varieties. The reported results should be considered preliminary because the complete phytochemical characterization of the red-fleshed apple cultivars will be extended to consecutive harvest seasons.
... Type 2 red-fleshed apples derived from "Pink Pearl" show a green-leaf and red-fleshed phenotype, and their cortex is specifically pigmented at the late stage of fruit development ( Figure 5) [43]. We found that the red-fleshed trait of "Pink Pearl" is tightly linked with its 3 -allele located within the S-locus responsible for the gametophytic self-and cross-incompatibility system in apple [44]. Using this tight linkage, we found suitable cultivar combinations for efficient production of various red-fleshed apples (Table 2). ...
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Article
Breeding and cultivation of new apple cultivars are among the most attractive and important issues for apple researchers. As almost all apple cultivars exhibit gametophytic self-incompatibility (GSI), cross-pollination between genetically different cultivars and species is essential not only for stable fruit production, but also for breeding of new cultivars. For cross-pollination by insect or hand pollination, pollen viability and pistil fertility are key factors, but also the mechanism of GSI has to be taken into account. This paper reviews the germination rate of pollen after storage in different conditions, at different periods of flowering, and in combination with pistil fertility and cross-compatibility among wild-, crab-, and cultivated apples. Furthermore, suitable cultivar combinations for new attractive apple cultivars based on GSI are explored. Especially, details about S-genotypes of apple cultivars, which are present in recent cultivar catalogues, are introduced together with a newly established on-line searchable database of S-genotypes of cultivars, wild apples and crab apples that shows incompatibility, semicompatibility, and full-compatibility.
... Interestingly, 'Surprise' and cultivar descendent have less extreme red coloration than the wild species M. sieversii f. niedzwetzkyana (Anonymous, 2013;Borrie and Chaussee, 2011). Although 'Pink Pearl' has red colored fruit flesh, it does not contain the R6 promoter of the MdMYB10 gene (Sekido et al., 2010). Recently, it was shown that the red flesh trait of type 2 genotypes might be controlled by the gene MdMYB110a, a paralogue of MdMYB10 which is located on LG 17 (Chagne et al., 2013;Umemura et al., 2013). ...
Article
Red fruit flesh is a desirable trait in apple breeding, because red-fleshed apples are a novelty and therefore considered to be more attractive to consumers and contain more health beneficial compounds. The red fruit flesh coloration is based on an increased level of cyanidin 3-galactoside, an anthocyanin whose biosynthesis is regulated by the MYB-type transcription factors MdMYB10 or MdMYB110a, respectively. A repeated segment in the MdMYB10 promoter allele R6 results in a gain-of-function mutation visible as red pigmentation of fruit skin and flesh and all vegetative tissues. Red-fleshed apple genotypes containing this R6 allele belong to the type 1 red-fleshed apple, which is known to be linked to some negative traits like astringent taste and internal flesh browning disorder. In type 2 red-fleshed apples the fruit flesh coloration is not inevitably linked with skin and leaf color. This red-fleshed apple phenotype, which is a result of increased expression of MdMYB110a, seems to be more useful for breeding, but it can be found rather seldom. In the present study 357 Malus accessions of the German Malus Germplasm Collection were evaluated for red fruit flesh coloration and the presence of the MdMYB10 R1 (not mutated) and R6 promoter alleles. Among them a total of 40 accessions were identified which contain the R6 allele. 37 accessions showed a red coloration of the fruit flesh. All these accessions belong to type 1 red-fleshed apple. No type 2 red-fleshed apple could be found. Three accessions with R6 allele had non-red-fleshed apples. 312 other non-red-fleshed accessions contained only the R1 allele. Five non-red-fleshed accessions contained a new promoter allele with an unexpected size of ~1kbp. Sequencing of this allele detected the insertion of a non-autonomous apple transposon.
... We confirmed this presumed allelotype and pigmentation in independent accessions of this variety from both the USDA collection and CCG. In addition, the absence of the MdMYB10 R 6 allele in 'Pink Pearl' was recently noted by Sekido et al. (2010), who additionally determined that red flesh in this variety resulted from a dominant allele linked to the self-incompatibility S-locus. 'Pink Pearl' was selected prior to 1944 as an open-pollinated seedling of 'Surprise' (USDA ARS National Genetic Resources Program 2011). ...
Article
Anthocyanins are flavonoid pigments imparting red, blue, or purple pigmentation to fruits, flowers and foliage. These compounds are powerful antioxidants in vitro, and are widely believed to contribute to human health. The fruit of the domestic apple (Malus x domestica) is a popular and important source of nutrients, and is considered one of the top ‘functional foods’—those foods that have inherent health-promoting benefits beyond basic nutritional value. The pigmentation of typical red apple fruits results from accumulation of anthocyanin in the skin. However, numerous genotypes of Malus are known that synthesize anthocyanin in additional fruit tissues including the core and cortex (flesh). Red-fleshed apple genotypes are an attractive starting point for development of novel varieties for consumption and nutraceutical use through traditional breeding and biotechnology. However, cultivar development is limited by lack of characterization of the diversity of genetic backgrounds showing this trait. We identified and cataloged red-fleshed apple genotypes from four Malus diversity collections representing over 3,000 accessions including domestic cultivars, wild species, and named hybrids. We found a striking range of flesh color intensity and pattern among accessions, including those carrying the MYB10 R 6 allele conferring ectopic expression of a key transcriptional regulator of anthocyanin biosynthesis. Although MYB10 R 6 was strongly associated with red-fleshed fruit among genotypes, this allele was neither sufficient nor required for this trait in all genotypes. Nearly all red-fleshed accessions tested could be traced back to ‘Niedzwetzkyana’, a presumed natural form of M. sieversii native to central Asia.
... The detected QTL explained 31.0% of the phenotypic variation. This finding is consistent with the recent mapping of the self-incompatibility locus (Celton et al., 2009), also linked with red flesh in cv Pink Pearl (Sekido et al., 2010;Umemura et al., 2011) on LG 17 (Maliepaard et al., 1998). ...
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Article
Anthocyanin accumulation is coordinated in plants by a number of conserved transcription factors. In apple (Malus x domestica, Borkh.) a R2R3 MYB transcription factor has been shown to control fruit flesh and foliage anthocyanin pigmentation (MYB10), and fruit skin colour (MYB1). However, the pattern of expression and allelic variation at these loci does not explain all anthocyanin-related apple phenotypes. One such example is an open-pollinated seedling of 'Sangrado' that has green foliage and develops red flesh in the fruit cortex late in maturity. We used methods that combine plant breeding, molecular biology and genomics to identify duplicated MYB transcription factors that could control this phenotype. We then demonstrated that the red flesh cortex phenotype is associated with enhanced expression of MYB110a, a paralogue of MYB10. Functional characterisation of MYB110a showed that it was able to up-regulate anthocyanin biosynthesis in tobacco. The chromosomal location of MYB110a is consistent with a whole genome duplication event that occurred during evolution of apple within the Maloideae family. Both MYB10 and MYB110a have conserved function in some cultivars but they differ in their expression pattern and response to fruit maturity.
... In this case, the identification of alleles responsible for anthocyanin biosynthesis in apple skin and flesh and of molecular markers associated with them will facilitate the selection of progeny plants with anthocyaninrich fruits in a breeding programme. Recently, a new gene, apart from MdMYB10, associated to a molecular marker was found to be responsible for triggering anthocyanin synthesis in flesh of apple fruits [106]. In general, molecular markers have the advantage to allow easy identification of homozygous and heterozygous progeny without need to verify the phenotype of fruits; they are not influenced by environmental cues or epigenetic effects and can reduce introgression of undesired traits. ...
Article
Anthocyanins represent the major red, purple, violet and blue pigments in many flowers and fruits. They attract pollinators and seed dispersers and defend plants against abiotic and biotic stresses. Anthocyanins are produced by a specific branch of the flavonoid pathway, which is differently regulated in monocot and dicot species. In the monocot maize, the anthocyanin biosynthesis genes are activated as a single unit by a ternary complex of MYB-bHLH-WD40 transcription factors (MBW complex). In the dicot Arabidopsis, anthocyanin biosynthesis genes can be divided in two subgroups: early biosynthesis genes (EBGs) are activated by co-activator independent R2R3-MYB transcription factors, whereas late biosynthesis genes (LBGs) require an MBW complex. In addition to this, a complex regulatory network of positive and negative feedback mechanisms controlling anthocyanin synthesis in Arabidopsis has been described. Recent studies have broadened our understanding of the regulation of anthocyanin synthesis in flowers and fruits, indicating that a regulatory system based on the cooperation of MYB, bHLH and WD40 proteins that control floral and fruit pigmentation is common to many dicot species.
Article
Introduction: Red-fleshed apples (Malus spp.) are one of the rarest apple genotypes in the world and the accumulation of a high amount of anthocyanin, is the main cause of the redness of their fruit flesh. Anthocyanins are among important flavonoids and due to antioxidative activity, scavenge reactive oxygen species, and hence, are considered as one of the health-promoting nutraceuticals in the human diet. The amount of anthocyanins depends upon the expression of the transcription factors that are regulating their metabolic pathway. Among these transcription factors are the members of the MYB gene family. MdMYB10, belonging to this gene family in apple, has been shown to have a significant role in controlling the amount of anthocyanin production and redness in fruit flesh. The expression of MdMYB10 and consequently, the production of MdMYB10 proteins has positive feedback on its own expression. This happens due to a 23 bp microsatellite tandemly repeated 5 times in its promoter region (called allele R6) which is a target sequence for MdMYB10 acting as a positive regulator. This structure invokes the overexpression of MdMYB10 which in turn increases the expression of anthocyanin producing enzymes and finally the amount of anthocyanin in all organs of the apple plant including fruit flesh. The apple Malus pumila var. Niedzwetzkyana and its derivatives have been reported to have such a structure in the promoter region of the MdMYB10 gene. The length of the R6 allele is 496 bp, while the R1 allele is only 392 bp long. However, in some cases, a locus linked to the S3 allele of the S-RNase gene has been proposed to be responsible for the redness of the fruit flesh in some genotypes. It has been reported that even the offspring of these plants have had red-fleshed fruits. Materials and Methods: To study the mechanism of the redness of the fruit flesh in some local genotypes, genomic DNA was extracted using the CTAB method from the leaf samples obtained from 9 red- and white-fleshed apple genotypes including Red Delicious, Golden Delicious, Miandoab, Makamik (Khalatpoushan), Bud 9, Varzighan, and Ivand. Then the allelotype of the promoter region of the MdMYB10 gene as well as the existence of S3 allele at S-RNase locus was investigated using polymerase chain reaction. For amplification of the target sequences, MdMYB10 and S3 specific primers were exploited and 1% agarose gel electrophoresis of the amplified fragments was used for observing and scoring the bands. All steps were repeated seven times. Results and Discussion: The results in this research showed that the white-fleshed genotypes (Red Delicious, Golden Delicious, and Granny Smith) were lacking any R6 allele at the promoter region of the MdMYB10 gene and were R1R1 homozygotes, while the red-fleshed genotypes (Miandoab, Makamik (Khalatpoushan), Bud 9, and Varzighan) had at least one R6 allele at the mentioned promoter region as well as a S3 allele in the self-incompatibility locus S-RNase. These results were in accordance with the previous reports. Therefore, these samples could be traced back to Malus pumila var. Niedzwetzkyana. Evaluating the S-RNase locus in these genotypes illustrated that Granny Smith (as positive control), Golden Delicious (as positive control), Makamik (Khalatpoushan), Miandoab, Varzeghan, Bud 9 and tissue culture sample, showing a band around 500 bp (smaller) had S3 allele, while for Ivand and Red Delicious (as negative control) no S3 band was obtained. For the tissue culture sample which was R1R1 at the promoter region and S3 at S-RNase locus, it was postulated that flesh-redness may be due to the locus linked to the S3 allele. We also got an unknown R band for the Ivand genotype when analyzing for the MdMYB10 promoter region. The sequencing of in the future studies, may help to unravel the mechanism by which shoot-redness happens in this genotype. Conclusion: The development of highly potent and novel cultivars for the fast-evolving market is indispensable in the plant breeding field. In this way, breeding apple plant, as an important temperate fruit with a long postharvest life, for redness of fruit flesh can be considered as a noticeable case. We could confirm in this research that in the endemic, red-fleshed apples, R6 may be responsible for their high anthocyanin production. However, the S3-RNase-linked locus should also be considered in marker-assisted breeding methods for this trait. Therefore, these red-fleshed genotypes are highly recommended to be employed in the national breeding programs for increasing the anthocyanin content of apple fruits.
Chapter
Apple (Malus × domestica Borkh.) is one of the most widely produced and economically important fruits in temperate regions. Fruit color development in apples is a major focus for both breeders and researchers as consumers associate brightly colored red apples with ripeness and good flavor. In this chapter, we will discuss research efforts on the coloration of the apple fruit, including the development of important genomic databases to identify important genomic regions and genes, genetic and transcriptional factors that regulate pigment accumulation, environmental factors influencing anthocyanin synthesis, and current goals for breeding for red-skinned and red-fleshed apples. We will also cover key transcription factors, such as MYB, bHLH, and WD40 that are involved in the regulation of anthocyanin synthesis and of fruit color development in apples. We will also discuss the regulation of apple color development by external environmental factors such as light, temperature, and water. Furthermore, we will offer insights into the molecular mechanisms underlying anthocyanin biosynthesis in apples. This knowledge will provide valuable guidance for the breeding of high-quality red-skinned and red-fleshed apple cultivars.
Article
Apple (Malus domestica Borkh.) is one of the most widely produced and economically important fruits in temperate regions. Fruit color development in apple is a major focus for both breeders and researchers as consumers associate brightly colored red apples with ripeness and a good flavor. In recent years, great progress has been made in the research of apple fruit color development, but its development mechanism has not been systematic dissected from the aspects of genetics, transcription or environmental factors. Here, we summarize research on the coloration of apple fruit, including the development of important genomic databases to identify important genomic regions and genes, genetic and transcriptional factors that regulate pigment accumulation, environmental factors that affect anthocyanin synthesis, and the current breeding progress of red-skinned and red-fleshed apples. We describe key transcription factors, such as MYB, bHLH, and WD40, which are involved in the regulation of anthocyanin synthesis and fruit color development in apple. We also discuss the regulation of apple color by external environmental factors such as light, temperature, and water. The aim of this review is to provide insights into the molecular mechanisms underlying anthocyanin biosynthesis in apple. This information will provide significant guidance for the breeding of high-quality red-skinned and red-fleshed apple varieties.
Article
Red-fleshed apples are popular due to their high anthocyanin content. MdMYB10 and its homologs are known to be important regulators of anthocyanin synthesis in apple, but the roles of other transcription factors are not well understood. Here, we explored the role of MdWRKY11 in regulating anthocyanin synthesis in apple flesh. Overexpression of MdWRKY11 in apple callus could significantly promote anthocyanin accumulation, and the expression of some MYB transcription factors and structural genes increased significantly. In binding analyses, MdWRKY11 bound to W-box cis-elements in the promoters of MdMYB10, MdMYB11, and MdUFGT. However, MdWRKY11 did not interact with MdMYB10, MdbHLH3, or MdWD40 proteins, the members of the MBW complex. Sequence analyses revealed that another W-box cis-element was present in the promoter of MdHY5 (encoding a photoresponse factor) and MdWRKY11 was able to bind to the promoter of MdHY5 and promote its activity. Our findings clarify the role of MdWRKY11 in anthocyanin synthesis in red-fleshed apple and imply that other novel genes may be involved in anthocyanin synthesis.
Article
Forest ecosystems are rich in biodiversity and provide valuable ecosystem services, but are declining worldwide. Malus niedzwetzkyana , an Endangered wild relative of domesticated apples, is an important component of the walnut–fruit forests of Central Asia. Its iconic pink blossom and genetic properties give it special cultural and scientific significance, but livestock grazing and firewood collection threaten its survival. The conservation of the species and its native forest ecosystem is critical and urgent. This study provides information on the ecology and population of M. niedzwetzkyana and the threats affecting its habitat, improving our understanding of its distribution and proposing measures to reduce threats. We collected ecological data and assessed population structure and threats at four forest sites in southern Kyrgyzstan. We mapped 149 individuals, creating the largest known dataset for this species. We developed species distribution models for M. niedzwetzkyana to identify climatically suitable regions and potential areas for restoration. Sary-Chelek Biosphere Reserve contained the largest expanse of pristine forest and the most stable M. niedzwetzkyana population, followed by Kara-Alma Forestry Unit. Forests in the Gava Forestry Unit and Dashman Reserve were most extensively damaged by humans and livestock. The wild apple's favoured habitat was south-west facing slopes with a gradient < 30° and a relatively open canopy. Overall, the study population was vulnerable to extinction with limited regeneration potential. We recommend short-term population enhancement through planting projects and increased protection of individuals in pristine sites. Community-based conservation initiatives should be prioritized in extensively damaged sites, and larger-scale reforestation of these forests needs to be considered.
Chapter
One hypothesis to account for the dramatic increase of inflammatory driven diseases, such as cancer, cardiovascular disease, obesity, diabetes, and others, across the world is the coincidental displacement of fruits and vegetables in the diet with processed foods as populations in the developing world rapidly acculturate to a more affluent lifestyle. Fruits are rich sources of antioxidant and anti-inflammatory natural compounds that offset many of the biological events leading to the development of the above-mentioned chronic diseases. In this review, potentially cancer-protective phytochemicals in fruits are reviewed to describe the research approaches, the range of chemistry and mechanisms seen in the study of the health benefits of fruit phytochemicals. Furthermore, given the rapid increase in research, public’s interest in the health benefits of food, and the government’s and food industry’s efforts to develop and promote healthy foods, fruit breeders have begun to investigate the feasibility of developing health-enhanced fruit cultivars. Thus far, there appears to be ample genetic variability within fruit crops to develop cultivars with higher levels of plant phytochemicals, such as total phenolics, anthocyanins, and antioxidant activity. Nevertheless, selecting breeding targets is elusive as there is little information on which specific phytochemical or combination of phytochemicals and the levels needed to effectively enhance the health of the consuming public.
Chapter
Fruit breeding is a long-term process which takes a minimum of about a decade from the original cross to a finished cultivar. Thus, much thought needs to go into which objectives to be emphasized in the breeding. Although certain objectives, such as yield and basic quality, are always important, the overall lifestyle, environmental, marketing, and production trends affect the objectives that breeders emphasize in their programs as they strive to anticipate the future needs of the fruit industry. The importance of each trend varies with the crop and environment. The major trends are to develop cultivars which simplify orchard practices, have increased resistance to biotic and abiotic stress, extend the adaptation zones of the crop, create new fruit types, create fruit cultivars with enhanced health benefits, and provide consistently high quality.
Article
In apple, two MYB transcription factors MdMYB10 (R6:MdMYB10) and MdMYB110a have been shown to be responsible for the type 1 and type 2 red flesh traits, respectively. While type 1 red-fleshed apples are characterized by a red coloration not only in fruit flesh but also in vegetative tissues such as leaves and flowers, red pigmentation in type 2 red-fleshed apples is limited at the fruit flesh. We have searched cultivars containing both functional MdMYB10 and MdMYB110a and then tried to breed new cultivars containing both functional genes by cross-pollination of ‘Geneva’ (type 1) and ‘Pink Pearl’ (type 2). The cultivar having both genes should exhibit superior characteristics, such as a stable red flesh trait throughout fruit maturity, as type 1 reduces its colouring until maturity, whereas type 2 increases until maturity. We could not identify red-fleshed cultivars having both genes; moreover, only one plant of 80 F1 progeny having both genes died in its juvenile stage. From the results, it was suggested that some sort of breeding depression must have occurred. We analysed the expression patterns of the genes within two F1 plants having either MdMYB10 or MdMYB110a gene and found that the expression pattern of MdMYB110a was different from that observed in ‘JPP35’ (‘Jonathan’ × ‘Pink Pearl’). The MdMYB110a gene in the No. 2804 F1 plant derived from ‘Pink Pearl’ × ‘Geneva’ was expressed in the flesh from the beginning of the red coloration through maturity, and seemed to cause upregulation, not only the latter half, but also the first half of the gene in the anthocyanin pathway.
Article
Anthocyanins, which contribute red coloration to apple skin, are recognized for their antioxidant properties. Some apple cultivars also accumulate anthocyanins in fruit flesh. In this study, we analyzed the inheritance of coloration traits in fruit skin, fruit flesh, and leaves as well as their candidate gene, and searched for quantitative trait loci (QTLs) for fruit maturity linked to the red flesh trait in ‘Maypole’, using a ‘Fuji’ × ‘Maypole’ F1 population. Phenotypic segregation in the F1 population indicated that red skin, striped skin, red flesh, and red leaf traits are each controlled by separate single dominant genes and that red leaves co-segregated with red flesh. Of these, a striped skin trait derived from ‘Fuji’ corresponded to the MdMYBA genotype, known to regulate anthocyanin synthesis in fruit skin, suggesting that this genotype may be responsible for fruit skin coloring patterns. The red leaf/red flesh trait derived from ‘Maypole’ co-segregated with the MdMYB10 R6 promoter. MdMYBA and MdMYB10 were located in the same region at the bottom of linkage group (LG) 9 on the same genetic material, supporting that these genes are allelic. Analysis of the relationship between red coloration and fruit maturity revealed that fruits of red-fleshed progeny tended to mature earlier than those of white-fleshed progeny. A major QTL accounting for 35.6% of the total variance (logarithm of odds [LOD] = 8.94) was detected near the MdMYB10 locus in ‘Maypole’, indicating that the factor controlling earliness of fruit maturity is tightly linked to the red leaf/red flesh trait.
Article
We have succeeded in isolating an MdMYB110a_JP gene responsible for a red-fleshed trait from a fruit of apple cultivar ‘JPP35’ (‘Jonathan’ × ‘Pink Pearl’). The isolated MdMYB110a_JP gene was located on chromosome (ch.) 17, which was different from the location of known MdMYB1/10 gene of ch.9, and ‘JPP35’ and ‘Pink Pearl’ did not contain the known R 6 :MdMYB10 allele responsible for the red-skin and red-fleshed trait. The MdMYB110a_JP was expressed strongly and weakly in the cortex and core of ‘JPP35’ fruit, respectively, at the time of coloring start in flesh, and also weakly in flower buds. Following the MdMYB110a_JP expression, the expression of the genes, MdCHS and MdLDOX, that encode the enzymes of the flavonoid pathway, was induced in flesh of ‘JPP35’ in accordance with anthocyanin accumulation. In contrast, the MdMYB110a_JP gene was not expressed in any tissues in red-skin and white-fleshed ‘Fuji’, and in red-skin and red-fleshed ‘Maypole’. Instead, MdMYB1-1 allele responsible for red-skin trait was expressed in red-skin of ‘Fuji’ and ‘JPP35’, and R 6 :MdMYB10 allele responsible for red-skin and red-flesh trait was expressed in red-core and red-cortex in ‘Maypole’ as expected. Moreover, 35S:MdMYB110a_JP transgenic apple ‘JM2’ showed a red-foliage phenotype depending on the MdMYB110a_JP expression level. From the results, it was strongly suggested that the red-fleshed phenotype of ‘JPP35’ fruit was caused by up-regulation of the genes of anthocyanin pathway induced by the MdMYB110a_JP gene.
Conference Paper
Modern multi-level metallisation schemes offer the possibility of many innovative structures for frequency characterisation and de-embedding. In this paper we perform a detailed characterisation of several such structures up to 50 GHz and show their application to measurements of a high performance HBT device. We further propose a consistency check, by comparing independent DC and s-parameter measurements, to gain further confidence in the de-embedding operations.
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Linkage maps for the apple cultivars ‘Prima’ and ‘Fiesta’ were constructed using RFLP, RAPD, isozyme, AFLP, SCAR and microsatellite markers in a ‘Prima’בFiesta’ progeny of 152 individuals. Seventeen linkage groups, putatively corresponding to the seventeen haploid apple chromosomes, were obtained for each parent. These maps were aligned using 67 multi-allelic markers that were heterozygous in both parents. A large number of duplicate RFLP loci was observed and, in several instances, linked RFLP markers in one linkage group showed corresponding linkage in another linkage group. Distorted segregation was observed mainly in two regions of the genome, especially in the male parent alleles. Map positions were provided for resistance genes to scab and rosy leaf curling aphid (Vf and Sd 1, respectively) for the fruit acidity gene Ma and for the self-incompatibility locus S. The high marker density and large number of mapped codominant RFLPs and some microsatellite markers make this map an ideal reference map for use in other progenies also and a valuable tool for the mapping of quantitative trait loci.
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Mutations in the genes encoding for either the biosynthetic or transcriptional regulation of the anthocyanin pathway have been linked to color phenotypes. Generally, this is a loss of function resulting in a reduction or a change in the distribution of anthocyanin. Here, we describe a rearrangement in the upstream regulatory region of the gene encoding an apple (Malus x domestica) anthocyanin-regulating transcription factor, MYB10. We show that this modification is responsible for increasing the level of anthocyanin throughout the plant to produce a striking phenotype that includes red foliage and red fruit flesh. This rearrangement is a series of multiple repeats, forming a minisatellite-like structure that comprises five direct tandem repeats of a 23-bp sequence. This MYB10 rearrangement is present in all the red foliage apple varieties and species tested but in none of the white fleshed varieties. Transient assays demonstrated that the 23-bp sequence motif is a target of the MYB10 protein itself, and the number of repeat units correlates with an increase in transactivation by MYB10 protein. We show that the repeat motif is capable of binding MYB10 protein in electrophoretic mobility shift assays. Taken together, these results indicate that an allelic rearrangement in the promoter of MYB10 has generated an autoregulatory locus, and this autoregulation is sufficient to account for the increase in MYB10 transcript levels and subsequent ectopic accumulation of anthocyanins throughout the plant.
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Although an association between chilling tolerance and aquaporins has been reported, the exact mechanisms involved in this relationship remain unclear. We compared the expression profiles of aquaporin genes between a chilling-tolerant and a low temperature-sensitive rice variety using real-time PCR and identified seven genes that closely correlated with chilling tolerance. Chemical treatment experiments, by which rice plants were induced to lose their chilling tolerance, implicated the PIP1 (plasma membrane intrinsic protein 1) subfamily member genes in chilling tolerance. Of these members, changes in expression of the OsPIP1;3 gene suggested this to be the most closely related to chilling tolerance. Although OsPIP1;3 showed a much lower water permeability than members of the OsPIP2 family, OsPIP1;3 enhanced the water permeability of OsPIP2;2 and OsPIP2;4 when co-expressed with either of these proteins in oocytes. Transgenic rice plants (OE1) overexpressing OsPIP1;3 showed an enhanced level of chilling tolerance and the ability to maintain high OsPIP1;3 expression levels under low temperature treatment, similar to that of chilling-tolerant rice plants. We assume that OsPIP1;3, constitutively overexpressed in the leaf and root of transgenic OE1 plants, interacts with members of the OsPIP2 subfamily, thereby improving the plants' water balance under low temperatures and resulting in the observed chilling tolerance of the plants.
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Apple trees display gametophytic self-incompatibility which is controlled by a series of polymorphic S-alleles. To resolve the discrepancies in S-allele assignment that appeared in the literature, we have re-examined the identity of S-alleles known from domestic apple cultivars. Upon an alignment of S-allele nucleotide sequences, we designed allele-specific primer pairs to selectively amplify a single S-allele per reaction. Alternatively, highly similar S-alleles that were co-amplified with the same primer pair were discriminated through their distinct restriction digestion pattern. This is an extension of our previously developed allele-specific PCR amplification approach to reveal the S-genotypes in apple cultivars. Amplification parameters were optimised for the unique detection of the 15 apple S-alleles of which the nucleotide sequences are known. Both the old cultivars with a known S-genotype and a number of more common cultivars were assayed with this method. In most cases, our data coincided with those obtained through phenotypic and S-RNase analysis. However, three S-alleles were shown to relate to RNases that were previously proposed as being encoded by distinct S-alleles. For another S-allele the corresponding gene product has not been discriminated. Consequently, we propose the re-numbering of these four S-alleles. Furthermore, two alleles that were previously identified as S(27a) and S(27b) now received a distinct number, despite their identical S-specificity. To ease widespread future analysis of S-genotypes, we identified common cultivars that may function as a witness for bearing a particular S-allele. We discuss the assignment of new S-alleles which should help to avoid further confusion.
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Anthocyanins are secondary metabolites found in higher plants that contribute to the colors of flowers and fruits. In apples (Malus domestica Borkh.), several steps of the anthocyanin pathway are coordinately regulated, suggesting control by common transcription factors. A gene encoding an R2R3 MYB transcription factor was isolated from apple (cv Cripps' Pink) and designated MdMYB1. Analysis of the deduced amino acid sequence suggests that this gene encodes an ortholog of anthocyanin regulators in other plants. The expression of MdMYB1 in both Arabidopsis (Arabidopsis thaliana) plants and cultured grape cells induced the ectopic synthesis of anthocyanin. In the grape (Vitis vinifera) cells MdMYB1 stimulated transcription from the promoters of two apple genes encoding anthocyanin biosynthetic enzymes. In ripening apple fruit the transcription of MdMYB1 was correlated with anthocyanin synthesis in red skin sectors of fruit. When dark-grown fruit were exposed to sunlight, MdMYB1 transcript levels increased over several days, correlating with anthocyanin synthesis in the skin. MdMYB1 gene transcripts were more abundant in red skin apple cultivars compared to non-red skin cultivars. Several polymorphisms were identified in the promoter of MdMYB1. A derived cleaved amplified polymorphic sequence marker designed to one of these polymorphisms segregated with the inheritance of skin color in progeny from a cross of an unnamed red skin selection (a sibling of Cripps' Pink) and the non-red skin cultivar Golden Delicious. We conclude that MdMYB1 coordinately regulates genes in the anthocyanin pathway and the expression level of this regulator is the genetic basis for apple skin color.
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Anthocyanin concentration is an important determinant of the colour of many fruits. In apple (Malus x domestica), centuries of breeding have produced numerous varieties in which levels of anthocyanin pigment vary widely and change in response to environmental and developmental stimuli. The apple fruit cortex is usually colourless, although germplasm does exist where the cortex is highly pigmented due to the accumulation of either anthocyanins or carotenoids. From studies in a diverse array of plant species, it is apparent that anthocyanin biosynthesis is controlled at the level of transcription. Here we report the transcript levels of the anthocyanin biosynthetic genes in a red-fleshed apple compared with a white-fleshed cultivar. We also describe an apple MYB transcription factor, MdMYB10, that is similar in sequence to known anthocyanin regulators in other species. We further show that this transcription factor can induce anthocyanin accumulation in both heterologous and homologous systems, generating pigmented patches in transient assays in tobacco leaves and highly pigmented apple plants following stable transformation with constitutively expressed MdMYB10. Efficient induction of anthocyanin biosynthesis in transient assays by MdMYB10 was dependent on the co-expression of two distinct bHLH proteins from apple, MdbHLH3 and MdbHLH33. The strong correlation between the expression of MdMYB10 and apple anthocyanin levels during fruit development suggests that this transcription factor is responsible for controlling anthocyanin biosynthesis in apple fruit; in the red-fleshed cultivar and in the skin of other varieties, there is an induction of MdMYB10 expression concurrent with colour formation during development. Characterization of MdMYB10 has implications for the development of new varieties through classical breeding or a biotechnological approach.
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Red coloration of apple (Malus × domestica) skin is an important determinant of consumer preference and marketability. Anthocyanins are responsible for this coloration, and their accumulation is positively correlated with the expression level of anthocyanin biosynthetic genes. Regulation of expression of these genes is believed to be controlled by MYB transcription factors, and the MYB transcription factors involved in the activation of anthocyanin biosynthetic genes have been isolated in various plants. In the present study, we isolated and characterized a MYB transcription factor gene (MdMYBA) from apple skin. Characterization of MdMYBA demonstrated that (i) MdMYBA expression was specifically regulated depending on the tissue and cultivar/species; (ii) its expression level was much higher in a deep-red cultivar (‘Jonathan’) than in a pale-red cultivar (‘Tsugaru’); (iii) when cauliflower mosaic virus 35S::MdMYBA was introduced into the cotyledons of apple seedlings by means of a transient assay, reddish-purple spots were induced, and MdMYBA also induced anthocyanin accumulation in reproductive tissues of transgenic tobacco; (iv) the expression of MdMYBA was induced by UV-B irradiation and low-temperature treatment, both of which are known to be important in the promotion of anthocyanin accumulation in apple skin; (v) MdMYBA bound specifically to an anthocyanidin synthase (MdANS) promoter region in a gel-shift assay; and (vi) MdMYBA was mapped to the near region of the BC226-STS (a1) marker for the red skin color locus (Rf). These results suggest that MdMYBA is a key regulatory gene in anthocyanin biosynthesis in apple skin.
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Integrating plant genomics and classical breeding is a challenge for both plant breeders and molecular biologists. Marker-assisted selection (MAS) is a tool that can be used to accelerate the development of novel apple varieties such as cultivars that have fruit with anthocyanin through to the core. In addition, determining the inheritance of novel alleles, such as the one responsible for red flesh, adds to our understanding of allelic variation. Our goal was to map candidate anthocyanin biosynthetic and regulatory genes in a population segregating for the red flesh phenotypes. We have identified the Rni locus, a major genetic determinant of the red foliage and red colour in the core of apple fruit. In a population segregating for the red flesh and foliage phenotype we have determined the inheritance of the Rni locus and DNA polymorphisms of candidate anthocyanin biosynthetic and regulatory genes. Simple Sequence Repeats (SSRs) and Single Nucleotide Polymorphisms (SNPs) in the candidate genes were also located on an apple genetic map. We have shown that the MdMYB10 gene co-segregates with the Rni locus and is on Linkage Group (LG) 09 of the apple genome. We have performed candidate gene mapping in a fruit tree crop and have provided genetic evidence that red colouration in the fruit core as well as red foliage are both controlled by a single locus named Rni. We have shown that the transcription factor MdMYB10 may be the gene underlying Rni as there were no recombinants between the marker for this gene and the red phenotype in a population of 516 individuals. Associating markers derived from candidate genes with a desirable phenotypic trait has demonstrated the application of genomic tools in a breeding programme of a horticultural crop species.
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We determined the genomic DNA sequences of two new S-RNase alleles, S-si5 and S-ad5, in apple. Both consisted of 232 deduced amino acids, and contained five conserved domains (C1, C2, C3, RC4, and C5), and an intron specific to S-RNase genes of the Rosaceae, at the appropriate positions. We developed a PCR-RFLP method to identify these alleles, and clarified their occurrence in several Malus species, such as M. orientalis (W1-11-13; I.D. number 90104; S-si5), M. sieversii (W1-10-49; ID number 90100; S-si5), and M. sylvestris (ID number 88076; S-ad5) and cultivars, such as Adersleber Calville' (S-ad5) and 'Cox's Pomona' (S-ad5). Cross-pollination tests confirmed that S-si5 and S-ad5 were functionally distinct in spite of their identical rosaceous hypervariable region (RHV), which appears to be critical for S-allele discrimination in the Rosaceae. We recommend use of the next available numbers, S-33 and S-34, instead of S-si5 and S-ad5, respectively, since the allele annotations are only transitory. This is the first known case in apple in which two S-RNase alleles containing an identical RHV act as different alleles.
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An S25-RNase gene in the pistil responsible for self-incompatibility within the apple (Malus x domestica Borkh.) was cloned from a McIntosh cultivar. We developed an S25-allele-specific polymerase chain reaction and digestion (PCR-digestion) method using specific primers and the restriction enzyme BamHI. We investigated the S-allele genotypes of 18 'McIntosh' progeny.
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S3-, S5-, S9- (=Sc-), Sf-, Sg- and Sh (=S24)-alleles in the wild apple were deduced by using S-allele-specific-polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analyses. Within the alleles, the deduced amino acid sequence of Sg'-RNase in Sg-allele of Malus transitoria differed by one amino acid from that of Sg-RNase in Sg-allele of M. × domestica 'Indo'. From the cross pollination analysis of M. transitoria and M. × domestica 'Indo', and S-allele-specific-PCR-RFLP analyses of their progenies, it was indicated that the pistil Sg'RNase in M. transitoria rejected the pollen of Sg-allele from 'Indo'. A difference of one amino acid within the RHV region produced by natural mutation was not enough to generate a new S-allele. This is the first report in the literature concerning S-allele diversification in the apple.
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We examined S-allele genotypes of ten apple cultivars and species to determine their possible usefulness as pollenizers for all apple cultivars. 'Dolgo' did not contain any known S-RNases encoded at the S-locus, suggesting its possible usefulness as a pollenizer for almost all apple cultivars. We also identified and confirmed the S-allele genotypes of 18 apple cultivars by polymerase chain reaction (PCR)-digestion analysis. The S-genotype of 'Kiou' (S1S7), 'Korei' (S3S28), 'Korin' (S1S9), 'Kotoku' (S1S28), 'Kyokkou (S7S25), 'Lobo' (S1S7), 'Mahe 7' (S2S7), 'Mellow' (S2S3), 'Takahara' (S3S9) and 'Warabi' (S9S28) were confirmed by pollination results. These cultivars seemed not to have originated from the expected seed or pollen parents or, in the case of 'Lobo', might have been mislabelled. Finally, we identified the S-allele genotypes of 'Prima' (S2S10), 'Querina' (S3S9) and 'Yoko' x 'Prima' (S3S10), which are resistant to scab.
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We analysed the S-RNase genotypes of 23 crab apple (Malus spp.) pollinators and 102 cultivars of domestic apple (Malus pumila Mill.) by PCR amplification and digestion. Within the 23 pollinators, four pollinators, 'Hopa', 'Jack', 'Pink Perfection' and 'Profusion B', each had two unidentified S-RNase alleles. These cultivars should be useful pollinators for all domestic cultivars. Twenty-one of the domestic cultivars exhibited S-genotypes contrary to those expected from their supposed parentage, suggesting that one or both reported parents were wrong. We confirmed many of the S-RNase genotypes by pollination tests.
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Accurate knowledge of the S-genotypes of apple cultivars is important for use in a breeding programme. We analysed the S-RNase genotypes of 65 apple (Malus × domestica Borkh.) cultivars grown in Japan that had 'Cox's Orange Pippin', 'Jonathan', or 'Delicious' as their progenitors, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses. In this process, we developed a PCR-RFLP method to identify the S 6-and S 21-RNase alleles that may be present in 'Cox's Pomona'. We showed that one of the alleged parents of 'Allington Pippin', 'Cox's Pomona', 'Merton Worcester', and 'Webster' might be wrong. We also showed that the S 16a-and S 16b-RNase alleles were functionally identical, and that 'Komitsu' was produced by a cross between 'Jonathan' × 'Starking Delicious'.
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The S-allele genotype of 25 apple cultivars and selections were determined by the polymerase chain reaction (PCR)-digestion identification method. 'Adam's Pearmain' was assigned as S1S3, which differed from previous assignments as S10S11 by pollination tests (Kobel et al., 1939) and as S10AS11 by stylar protein analyses (Boskovic and Tobutt, 1999). Genome analyses and our pollination tests confirmed the S1S3 genotype. 'Hida', 'Scarlet', 'Sekihikari' and 'Yukari' were assigned as S3S9, S3S 9, S3S30(28) and S2S 9, respectively. The S-genotypes were not matched with any of the expected S-genotypes from supposed parents. Since the S-genotypes were in agreement with those determined by our pollination tests, the applicability of the Sgenotype assignments based on the PCR-digestion identification method was confirmed.
Article
A polymerase chain reaction (PCR)·based method for identifying the S-alleles in the Asian pear [Pyrus pyrifolia (Burm) Nak.] was applied to apple (Malus Xdomestica Borkh.) cultivars. With minor modifications in one of the primers, the fragments from S-genes (S-RNases) with introns were amplified from total DNA of apple cultivars possessing S2-, S3-, S5-, S7- (=Sd-), S9- (=Sc-), Sf- and Sg-allele genotypes. S-genes within S24- (=Sh-) and S26-alleles were also amplified. The PCR amplification step of this method appears to be useful for preliminary investigation of apple S-genotypes, especially for species or cultivars of unknown origin or history. Using the primers, which are a part of a new S-allele, the Se-allele encoding Se-RNase with an intron in the Se-allele was amplified. We cloned the cDNA of Se-RNase, and developed a PCR-restriction fragment length polymorphism (RFLP) analysis method for Se-allele identification. S-allele genotypes of seven apple cultivars were investigated.
Article
The S-locus genes in the pistil (S-RNases) were cloned from the apple (Malusxdomestica Borkh.) cultivar Akane (S-genotype SdSh from pollination analysis). The Sd- and Sh-RNase corresponded to S7- and S24-RNase, which have been cloned from 'Idared' and 'Braeburn', respectively. Sh-RNase was very similar to Sf- and Sg-RNases at the deduced amino acid-sequence levels (93%). We developed an S-allele specific polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis method for distinguishing the Sh from Sf and Sg, and the Sh-alleles of 'Akane', 'Touhoku 2', 'Vista Bella', and 'Worcester Pearmain' were identified. We also identified the S-allele genotypes of 16 apple cultivars.
Article
S-allele genotypes of nine apple (Malus xdomestica Borkh.) cultivars were identified using S-allele-specific polymerase chain reaction (PCR)-restriction fragment-length polymorphism (RFLP) analysis. A new S-allele, Sg, was proposed to be present in 'American Summer Pearmain', 'Indo', 'Kitanosachi', and 'Meku 10'. This allele is very similar to Sf at the nucleotide sequence (92%) and deduced amino acid sequence (94%) levels.
Article
We determined partial genomic sequences including a hypervariable HVa (RHV) region and introns of the S6-, S12-, S13-, S14-, S17-, S19-, and S21-RNases of apple. Previously, it was suggested by Broothaerts (2003) that the S6 corresponded to S25 in ‘McIntosh’/‘Wijcik’ and ‘Tydeman’s Early Worcester’, and S19 corresponded to S28. However, S6 and S19 are different from the S25 and S28, respectively. The determined sequences of the S6 and S12, and S17 and S19 are identical, and these four alleles seem to act as the same allele. We newly assigned S6a in place of S6 and S12, and S6b in place of S17 and S19 from the results of sequence analyses, not pollination tests. The sequences of S13 and S14 were also identical. We also newly assigned S11 in place of S13 and S14. We had speculated that S21 would correspond to St by PCR-digestion analysis, however, the determined sequence of S21 was different from St.
Article
Apple exhibits gametophytic self-incom-patibility (GSI). GSI is controlled by a single locus, the S-locus. In this type of self-incom-patibility, pollen tube growth is arrested in the style when the pollen shares the same S-allele with the pistil (de Nettancourt, 1977). The S-alleles in the pistil encode ribonu-cleases, called S-RNases. To date, six S-RNases (S c , S d , S e , S f , S g , and S h) have been cloned in Japan (Kitahara et al., 1999, 2000; Matsumoto and Kitahara, 2000; Sassa et al., 1996), and eight S-RNases (S 2 , S 3 , S 5 , S 7 , S 9 , S 24 , S 26 , and S 27) in Europe (Broothaerts et al., 1995; Janssens et al., 1995; Verdoodt et al., 1998). Two pairs of S-RNases, S c and S 9 , and S h and S 24 , are identical at the deduced amino acid sequence level. Recently, the S-alleles of 'McIntosh' were identified as S i S z by pollination and progeny analysis (Komori et al., 1999), and as S 10 S 25 by the stylar ribonuclease bands (Boskovic and Tobutt, 1999). In the present study, the cDNA sequence encoding the S i -RNase was deter-mined; the same allele is designated S 10 in Europe. We developed a S i (=S 10)-allele-spe-cific PCR-digestion analysis method, and de-termined that S i (=S 10) is present in 'McIntosh' and five other cultivars. Abstract. An S-allele cDNA was cloned from pistils of 'McIntosh' apple (Malus ×domestica Borkh.). The allele, designated S i in Japan and S 10 in Europe, is an S-RNase that is very similar (94%) to the S 3 -RNase at the deduced amino acid sequence level. This allele can be detected by amplification using the polymerase chain reaction (PCR) and specific primers, followed by digestion with restriction enzyme EheI. The S 10 allele was discovered in 'Empire', 'Maypole', 'Shinano Red', 'Spencer', and 'Vista Bella'. The S-allele cDNAs sequenced to date are listed with their Japanese and European designations.
Article
Repetitive DNA sequences present in the grapevine genome were investigated as probes for distinguishing species and cultivars. Microsatellite sequences, minisatellite sequences, tandemly arrayed genes and highly repetitive grapevine sequences were studied. The relative abundance of microsatellite and minisatellite DNA in the genome varied with the repeat sequence and determined their usefulness in detecting RFLPs. Cloned Vitis ribosomal repeat units were characterised and showed length heterogeneity (9.14-12.15 kb) between and within species. A highly repetitive DNA sequence isolated from V. vinifera was found to be specific only to those species classified as Euvitis. DNA polymorphisms were found between Vitis species and between cultivars of V. vinifera with all classes of repeat DNA sequences studied. DNA sequences suitable for DNA fingerprinting gave genotype-specific patterns for all of the cultivars and species examined. The DNA polymorphisms detected indicates a moderate to high level of heterozygosity in grapevine cultivars.
Article
S-genotypes of 13 apple (Malus x domestica Borkh.) cultivars and 10 progenies of 'Megumi' were identified by S-allele-specific PCR-RFLP analysis. The S-genotypes of 'Gala' and 'Fuji' were reconfirmed by the analysis. The S-genotypes of 'Kinsei' (S 2 S 9) and 'Kizashi' (S 2 S 3), were inconsistent with expected S-genotypes of their parents, indicating that they are derivatives from some other pollen parents having S 9 - or S 3 -allele. 'Tsugaru', 'Akagi', and 'Youkou' seem to have been produced by using pollen parents possessing S 7 -, S 7 - or S 9 - allele, respectively. The S-genotype of self-compatible 'Megumi' was identified as S 2 S 9; no mutation occurred within either of the S-genes. The reciprocal crosses between 'Megumi' and 'Hatsuaki' (S 3 S 9) resulted in fruits with seeds, whereas those between 'Megumi' and 'Redgold' (S 2 S 9) or 'Megumi' and 'Kinsei' (S 2 S 9) resulted in no seeds. These results indicate that the self-compatibility of 'Megumi' is not attributable to defects within the S-genes.
Article
Using degenerate primers designed based on the conserved regions of the reported SLF/SFB genes, more than a dozen of different cDNA clones were isolated from pollen of three different apple S-genotypes by reverse transcription (RT)-PCR. The 5′- and 3′-rapid amplification of cDNA end in combination with RT-PCR allowed isolation of two full-length cDNAs, whose corresponding genes (RJ28-2 and Mg15, later renamed SLF 1 and SLF 2 ) were specifically expressed in pollen in an S-haplotype-specific manner. PCR analysis of seven different cultivars further showed the linkage between SLF 1 and S 1 -RNase and between SLF 2 and S 2 -RNase. The predicted ORFs of the two genes encode two F-box proteins of 393 amino acids in length with 70% amino acid identity. These features are consistent with the supposition that SLF 1 and SLF 2 are good candidates for pollen S-genes. Phylogenetic trees for the SLF/SFB and S-RNase proteins reported in the Solanaceae, Scrophulariaceae and Rosaceae (including apple) were constructed. It was found that the SLFs and S-RNases from apple were more closely related to those from Petunia (a genus of the Solanaceae) and Antirrhinum (a genus of the Scrophulariaceae) than to those from Prunus (a genus of the Rosaceae), implying a potential co-evolution between SLF/SFB and S-RNase. Furthermore, six SLF-like genes that shared a high level of sequence similarity (amino acid identity from 68 to 72%) to SLFs were also isolated. Among them, RJ28, Jt24 and Jt24-4 were confirmed to be expressed specifically in pollen in an S-haplotype-unspecific manner. These results are discussed in relation to the possible evolution of the SLF/SFB in S-RNase-based self-incompatible species.
Article
Complementary DNA clones representing two alleles of the self-incompatibility (S) locus of apple (Malus x domestica Borkh.) have been isolated and characterised. One of the alleles corresponds to a 29 kDa ribonuclease (S-RNase) that was purified from pistil tissue. On northern blots, both cDNAs hybridized to a transcript that was only present in pistils and not in the other plant tissues analysed. Corresponding genomic sequences, amplified by PCR, were found to contain a single intron of 138 bp and 1100 bp respectively. Comparison of both sequences shows that the cDNAs encode mature proteins containing 65% of identical residues. Eight invariable cysteine residues, conserved regions around two histidines thought to play a role in RNA catalysis, and a number of other distinct residues are conserved between the apple S-RNases and similar proteins in the family Solanaceae. As this is the first report of sequences of S-alleles from a species belonging to a family that is not related with the Solanaceae, the structural features of S-RNases deduced from a comparison of their sequences are discussed.
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Male humpbacks modify their sexual displays when exposed to man-made noise.
Article
Consumption of fruits and vegetables has been shown to be effective in the prevention of chronic diseases. These benefits are often attributed to the high antioxidant content of some plant foods. Apples are commonly eaten and are large contributors of phenolic compounds in European and North American diets. The peels of apples, in particular, are high in phenolics. During applesauce and canned apple manufacture, the antioxidant-rich peels of apples are discarded. To determine if a useful source of antioxidants is being wasted, the phytochemical content, antioxidant activity, and antiproliferative activity of the peels of four varieties of apples (Rome Beauty, Idared, Cortland, and Golden Delicious) commonly used in applesauce production in New York state were investigated. The values of the peels were compared to those of the flesh and flesh + peel components of the apples. Within each variety, the total phenolic and flavonoid contents were highest in the peels, followed by the flesh + peel and the flesh. Idared and Rome Beauty apple peels had the highest total phenolic contents (588.9 +/- 83.2 and 500.2 +/- 13.7 mg of gallic acid equivalents/100 g of peels, respectively). Rome Beauty and Idared peels were also highest in flavonoids (306.1 +/- 6.7 and 303.2 +/- 41.5 mg of catechin equivalents/100 g of peels, respectively). Of the four varieties, Idared apple peels had the most anthocyanins, with 26.8 +/- 6.5 mg of cyanidin 3-glucoside equivalents/100 g of peels. The peels all had significantly higher total antioxidant activities than the flesh + peel and flesh of the apple varieties examined. Idared peels had the greatest antioxidant activity (312.2 +/- 9.8 micromol of vitamin C equivalents/g of peels). Apple peels were also shown to more effectively inhibit the growth of HepG(2) human liver cancer cells than the other apple components. Rome Beauty apple peels showed the most bioactivity, inhibiting cell proliferation by 50% at the low concentration of 12.4 +/- 0.4 mg of peels/mL. The high content of phenolic compounds, antioxidant activity, and antiproliferative activity of apple peels indicate that they may impart health benefits when consumed and should be regarded as a valuable source of antioxidants.
  • R V Espley
  • R P Hellens
  • J Putterill
  • D E Stevenson
  • S Kutty-Amma
  • A C Allan
Espley, R.V., R.P. Hellens, J. Putterill, D.E. Stevenson, S. Kutty-Amma, and A.C. Allan. 2007. Red colouration in apple fruit is due to the activity of the MYB transcription factor, MdMYB10. Plant J. 49:414-427.
S-RNase genotypes of wild apples necessary for utilization as pollenizers
  • S Matsumoto
  • J Morita
  • K Abe
  • H Bessho
  • K Yamada
  • K Shiratake
  • H Fukui
Matsumoto, S., J. Morita, K. Abe, H. Bessho, K. Yamada, K. Shiratake, and H. Fukui. 2009. S-RNase genotypes of wild apples necessary for utilization as pollenizers. Hort. Environ. Biotechnol. 50:213-216.