María Alejandra Moya-León

María Alejandra Moya-León
Universidad de Talca · Instituto Ciencias Biologicas

About

75
Publications
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1,666
Citations
Citations since 2017
15 Research Items
1014 Citations
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2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200

Publications

Publications (75)
Article
Full-text available
Xyloglucan endotransglycosylase/hydrolases (XTHs) are cell wall enzymes with hydrolase (XEH) and/or endotransglycosylase (XET) activities. As they are involved in the modification of the xyloglucans, a type of hemicellulose present in the cell wall, they are believed to be very important in different processes, including growth, development, and fr...
Article
Expansins are cell wall proteins associated to several processes, including changes in the cell wall during ripening of fruit, which matches softening of the fruit. We have previously reported an increase in expression of specific expansins transcripts during softening of Fragaria chiloensis fruit. Here we characterized three α-expansins. Their ful...
Article
Xyloglucan endotransglycosylase/hydrolases (XTH) may have endotransglycosylase (XET) and/or hydrolase (XEH) activities. Previous studies confirmed XET activity for PrXTH1 protein from radiata pine. XTHs could interact with many hemicellulose substrates, but the favorite substrate of PrXTH1 is still unknown. The prediction of union type and energy s...
Article
Full-text available
Fragaria chiloensis is a strawberry endemic from Chile with attractive white-pink fruit, pleasant aroma and taste. However, this fruit has a limited post-harvest period due to fast softening. Several transcription factors (TFs) are involved in the regulation of fruit ripening, and members of the NAC family have been implicated in cell wall remodeli...
Article
Full-text available
Background Fragaria vesca or ‘woodland strawberry’ has emerged as an attractive model for the study of ripening of non-climacteric fruit. It has several advantages, such as its small genome and its diploidy. The recent availability of the complete sequence of its genome opens the possibility for further analysis and its use as a reference species....
Article
Xyloglucan endotransglycosylase/hydrolases (XTH) may have endotransglycosylase (XET) and/or hydrolase (XEH) activities. Previous studies suggest that XTHs might play a key role in ripening of Fragaria chiloensis fruit as FcXTH1 transcripts increase as fruit softens. FcXTH1 protein sequence contains a conserved N-glycosylation site adjacent to catal...
Article
The fungus Penicillium purpurogenum degrades plant cell walls by the action of cellulolytic, xylanolytic and pectinolytic enzymes. The α-D-galactosidase is one of the enzymes which may act on pectin degradation. This enzyme has several biotechnological and medical applications. The aim of this work was to better understand the molecular mechanism o...
Article
A distinct type of postharvest skin browning on apple (Malus domestica Borkh.) fruit called "stain" is a frequent disorder in ‘Fuji’ grown under high light and elevated temperatures.Symptoms typically develop only on sun-exposed sections of the fruit regardless of the presence of sunburn symptoms, and sometimes only in the margins of this area.The...
Article
White Chilean strawberries (Fragaria chiloensis) are non-climacteric fruits, with an exotic colour and aroma. In order to discover genes involved in the development of these fruits, we identified a fragment of a gene encoding a Late Embryogenesis Abundant (LEA) domain protein, FcLDP1, that was expressed in early stages of fruit development, particu...
Article
Full-text available
Abstract Stem reorientation in response to inclination in trees has commanded the attention of the research community widely, but the molecular mechanisms of the response are still unknown. The most accepted theory is auxin redistribution in affected tissues. Flavonols have been reported as potent inhibitors of polar auxin transport; however, no re...
Article
Full-text available
The Chilean strawberry fruit has high content of antioxidants and polyphenols. Previous studies evidenced antioxidant properties by in vitro methods. However, the antioxidant effect and its impact as functional food on animal health have not been evaluated. In this study, rats were fed with a Chilean strawberry aqueous extract (4 g/kg of animal per...
Article
Full-text available
Symposium 20 - PABMB: Teaching biochemistry in a connected world Chair: Miguel Castanho, Universidade de Lisboa, PortugalAbstract:The new paradigm of higher education requires new teaching strategies to meet the learning objectives of biochemistry courses. Teaching biochemistry in the current state of science and society requires a special motivati...
Article
Alcohol acyltransferases (AAT) catalyze the esterification reaction of alcohols and acyl-CoA into esters in fruits and flowers. Despite the high divergence between AAT enzymes, two important and conserved motifs are shared: the catalytic HxxxD motif, and the DFGWG motif. The latter is proposed to play a structural role; however, its function remain...
Article
Fruit softening is associated to cell wall modifications produced by a set of hydrolytic enzymes and proteins. Expansins are proteins with no catalytic activity, which have been associated with several processes during plant growth and development. A role for expansins has been proposed during softening of fruits, and many fruit-specific expansins...
Chapter
Full-text available
Anthocyanins are one of the most abundant flavonoid compounds. These pigments, naturally present in fruits and vegetables, provide color and promote health benefits to consumers due to their antioxidant capacity. To date, more than 600 anthocyanins have been identified in nature, all coming from six anthocyanidin aglycones derived from flavylium ba...
Article
Fragaria chiloensis ssp. chiloensis has two native botanical forms. Fruits from both botanical forms, Fragaria chiloensis ssp. chiloensis f. chiloensis (native white strawberry) and f. patagonica (native red strawberry), were collected from Bio-Bio Region, and a comparative study in the biosynthesis and pigment accumulation was performed from achen...
Article
Full-text available
The cell wall is a dynamic structure that can be modified by different conditions during growth. Stem inclina- tion induces biochemical changes and chemical modifications in the cell walls of conifers driving plant stem reorientation. Different enzymes take part in cell wall remodeling, including xyloglucan endotransglycosylase/hydrolase (XTH). Thi...
Article
Postharvest sunscald on apples is a physiological disorder that develops on the skin during cold storage. The symptoms develop only on sun-exposed sections of the fruit with or without sun-injury and they appear as superficial dark-brown patches. In order to determine the role of different antioxidant systems in sunscald development, fruit with dif...
Article
Xyloglucan endotransglycosylase/hydrolase (XTH) enzymes are involved in the remodeling of plant cell wall hemicelluloses. With the aim to study the involvement of XTHs in strawberry fruit ripening, two cDNAs (FaXTH1 and FaXTH2) coding putative XTH proteins were cloned and the expression level of both genes was analyzed on different plant tissues an...
Article
Aroma in Vasconcellea pubescens fruit is determined by esters, which are the products of catalysis by alcohol acyltransferase (VpAAT1). VpAAT1 protein structure displayed the conserved HxxxD motif facing the solvent channel in the center of the structure. To gain insight into the role of these catalytic residues, kinetic and site-directed mutagenes...
Article
Fragaria chiloensis (L.) Mill. is one of the parent of the commercial strawberry, and has emerged as a variety for breeding purposes. Botrytis cinerea infection is one of the most important infectious diseases for cultivated plant species, producing important losses in yield as well as fruit quality. Plants and fruits of Chilean strawberry have sho...
Article
Alcohol acyltransferases (AAT) play a key role in ester biosynthesis. In Cucumis melo var. cantalupensis, AATs are encoded by a gene family of four members (CmAAT1-4). CmAAT1, CmAAT3 and CmAAT4 are capable of synthesizing esters, being CmAAT1 the most active. CmAAT2 is inactive and has a 268-alanine residue instead of a threonine which is present i...
Article
Full-text available
Teaching biochemistry in the current state of science and society requires a special motivation for learning, especially for students where Biochemistry is one of the courses on their careers. The traditional way of teaching, based on the teacher-student relationship, mostly unidirectional, does not fulfil the needs imposed in this era. Considering...
Article
Full-text available
Loss of verticality in conifers affects the nor-mal wood development by inducing changes and chemical modifications in tree stems called compression wood. It is known that ethylene influences the response during this abnormal wood-forming process. The expression pattern of genes involved in the ethylene biosynthesis pathway during gravitropic respo...
Article
Tropical papaya (Carica papaya) and mountain papaya (Vasconcellea pubescens) fruits are characterised for their strong and particular aroma. The aroma of both fruits is different and dominated by esters, which are synthesised by alcohol acyltransferases (AATs). The ability to produce esters is contrasting, V. pubescens (VpAAT1) being a very active...
Article
The effect of postharvest dips of CaCl2 and/or naphthalene acetic acid (NAA) on quality parameters, cell wall composition and expression of cell wall-modifying genes of Fragaria chiloensis fruits were evaluated. After treatments, the fruit was cold stored and samples were evaluated at 0 d, 5 d and after 8 d, plus 2 d at room temperature. No differe...
Article
Aroma in fruits is an important attribute of quality determined by a set of volatile compounds. Tropical papaya (Carica papaya) and mountain papaya (Vasconcellea pubescens) fruit are characterized for their strong and particular aroma. Their aroma is different and dominated by esters, compounds which are synthesized by alcohol acyltransferases (AAT...
Article
Aroma in fruits is an important attribute of quality determined by a set of volatile compounds. Tropical papaya (Carica papaya) and mountain papaya (Vasconcellea pubescens) fruit are characterized for their strong and particular aroma. Their aroma is different and dominated by esters, compounds which are synthesized by alcohol acyltransferases (AAT...
Article
Chilean strawberry (Fragaria chiloensis) is a berry fruit with excellent organoleptic properties, however its fast softening limits its commercialization. Fruit softening is related to cell wall degradation and several related enzymes have been studied in strawberries, including xyloglucan endotransglycosylase/hydrolase (XTH). Two XTH genes have be...
Article
Difference in fruit pigmentation observed between two botanical forms of Fragaria chiloensis ssp. chiloensis (form chiloensis and form patagonica) was studied through transcriptional and chemical approaches. The proportion of different anthocyanins was demonstrated to be characteristic of each botanical form, with pelargonidin 3-glucoside being the...
Article
Chilean strawberry (Fragaria chiloensis), the maternal progenitor of Fragaria×ananassa, has emerged as a new berry fruit with excellent organoleptic characteristics. The fast softening of strawberries is a limiting step for their commercialization. Fruit softening has been shown to be related to cell wall degradation. Several enzymatic activities r...
Article
Fragaria chiloensis, the native Chilean strawberry, is noted for its good fruit quality characters. However, it is a highly perishable fruit due to its rapid softening. With the aim to screen for genes differentially expressed during development and ripening of strawberry fruit, the subtractive suppressive hybridization (SSH) methodology was employ...
Article
Chilean strawberry (Fragaria chiloensis) is arising as a new fruit crop that can diversify the world supply of berries. Fruit softening is thought to be linked to an extensive modification of pectin and hemicellulosic cell wall fractions which in turn is determined to a great extent by the action of some cell wall-modifying enzymes. The objective o...
Article
Mountain papaya ( Vasconcellea pubescens ) is a climacteric fruit that develops a strong and characteristic aroma during ripening. Esters are the main volatile compounds produced by the fruit, and most of them are dependent on ethylene. As esters are synthesized through alcohol acyltransferases (AAT), a full-length cDNA (VpAAT1) was isolated that d...
Article
Full-text available
Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following...
Article
Full-text available
Research was carried out to study the mode of action of diphenylamine (DPA) and 1-methylcyclopropene (1-MCP), on control of superficial scald of Granny Smith apples (Malus domestica Borkh.), and its relation with chemical compounds. Fruit was harvested from a commercial orchard in Chile, 182 and 189 days after full bloom and received the following...
Article
Fragaria chiloensis is characterized for having great aroma and flavor properties. Using headspace-SPME different volatile compounds were identified and quantified during development and ripening of the fruit. The headspace was dominated by esters, butyl acetate, ethyl acetate, ethyl butanoate and ethyl hexanoate being the most abundant in fully ri...
Article
The Chilean strawberry (Fragaria chiloensis) is one of the wild parents of the commercial strawberry (Fragaria × ananassa) and is noted for its good quality. However, its fruits show a higher level of softening between the "large green" and the "turning" stages than that of F. × ananassa, a factor that could affect its shelflife and reduce its keep...
Article
Fruit softening is associated with cell wall modifications produced by a set of hydrolytic enzymes and proteins. Expansins are proteins with no catalytic activity which have been associated with several processes during plant growth and development. A role for expansins has been proposed during fruit softening, and many fruit-specific expansins hav...
Article
The Chilean strawberry fruit (Fragaria chiloensis) has potential as a new exotic berry. The rate of softening differs between F. chiloensis and its related species Fragaria×ananassa. The expression profiles of five expansin genes isolated from F.×ananassa were analyzed during softening of F. chiloensis fruit and the regulatory effect of auxins on t...
Article
Fruit aroma is a complex trait, particularly in terms of the number of different biosynthetic pathways involved, the complexity of the final metabolites, and their regulation. In order to understand the underlying biochemical processes involved in apricot aroma, four cDNAs (Pa-aat, EU784138; Pa-adhEU395433; Pa-pdcEU395434; and Pa-loxEU439430) encod...
Article
One of the most important factors limiting apricot quality is the loss of flavor during storage, particularly overall aroma. To characterize fruit aroma, several techniques have been used, including both instrumental- and sensory-based methodologies. Despite the importance of aroma in fruit quality, limited information is available regarding the ef...
Article
The Chilean strawberry (Fragaria chiloensis) is noted for its good fruit quality characters and is one of the wild parents of the commercial strawberry (Fragaria × ananassa). However, the fruit of the Chilean strawberry shows a higher level of softening than that of F. × ananassa, a factor that can affect its shelf-life and reduce its keeping quali...
Article
Full-text available
Mountain or highland papaya (Vasconcellea pubescens) is a climacteric fruit which develops a strong and characteristic aroma during ripening. The dynamics of aroma volatile production during ripening of whole papaya fruit were analysed by headspace-SPME. The main compounds produced by the fruit were esters (aliphatic and branched) and alcohols: the...
Article
Mountain or highland papaya (Vasconcellea pubescens) is a climacteric fruit which develops a strong and characteristic aroma during ripening. The dynamics of aroma volatile production during ripening of whole papaya fruit were analysed by headspace-SPME. The main compounds produced by the fruit were esters (aliphatic and branched) and alcohols: the...
Article
The hypothesis of this research is that the application of time-frequency analysis to the impulse response of mountain papaya (Vasconcellea pubescens) reduces the variability associated with the firmness index measurement yet retains the benefits of a non-destructive technique. Fruit specimens were nondestructively tested for firmness during 14 day...
Article
The effects of 1-MCP and CA storage in aroma production and consumer acceptance, were investigated during the long-term storage of ‘Packham‘s Triumph’ pears. Pears were harvested 144 (Harvest 1) and 157 days (Harvest 2) after full bloom. The fruit were stored under cold storage (0 °C, 90–95% R.H.), controlled atmospheres (CA, 2.0–2.5 kPa O2 and 1.0...
Conference Paper
Full-text available
Mountain papaya fruits (Vasconcella pubescens) were tested for firmness with a nondestructive acoustic method for 14 days after harvest. The response of each fruit was analyzed with the Fourier transform to obtain a firmness index (FI) based on the second resonant frequency and with the Short Time Fourier Transform (STFT) to obtain a spectrogram fr...
Article
Full-text available
Gomortega keule (Molina) Baillon is an endangered, rare species, the only representative of its genus, and endemic to Central Chile. Populations of this tree are now fragmented and few individuals can be found in any of them. Genetic diversity was studied in 33 individuals from three populations in Cauquenes, a coastal mountain area (35°58'S-72°41'...
Article
Gomortega keule (Molina) Baillon is an endangered, rare species, the only representative of its genus, and endemic to Central Chile. Populations of this tree are now fragmented and few individuals can be found in any of them. Genetic diversity was studied in 33 individuals from three populations in Cauquenes, a coastal mountain area (35�580S-72�410...
Article
The first noticeable event during the ripening of mountain papaya (Vasconcellea pubescens) is the rapid degreening of the skin, followed by climacteric ethylene and flesh softening. When ethylene perception is blocked by 1-methylcyclopropene (1-MCP, 0.3 μl l−1 for 16 h at 20 °C), the increase in ethylene evolution is avoided, and softening and colo...
Article
The identification and characterization of differential gene expression from tissues subjected to stress has gained much attention in plant research. The recognition of elements involved in the response to a particular stress enhances the possibility of promoting crop improvement through direct genetic modification. However, the performance of some...
Article
A novel method using PEG and ammonium sulphate was used to concentrate ACC oxidase from a crude extract prepared from the pulp of ripe fruit of banana (Musa AAA group, Cavendish subgroup). The 145-fold purification of the ACC oxidase to electrophoretic homogeneity was carried out in four chromatographic steps: hydrophobic interaction, anion exchang...
Conference Paper
Fragaria vesca is the first genome sequenced within the Fragaria genus. Due to its high sequence identity it serves as a reference model for species such as the cultivated strawberry (F. x ananassa) and Fragaria chiloensis. Strawberry is a non-climacteric fruit, and its ripening seems to be coordinated by the action of some hormones like auxins (Au...
Conference Paper
Loss of verticality in conifers affects the normal wood development by inducing changes and chemical modifications in tree stems. Ethylene influences the response during this abnormal wood-forming process, and expression pattern of genes involved in the ethylene biosynthesis pathway due to inclination in gymnosperm has been reported in adult trees....

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Projects (3)
Project
I study the role that particular genes play in secondary cell wall formation and degradation. Target genes are those involved in cell wall dynamic but also, I have been involved studying transcription factors.