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ABSTRACT: Lupinus mariae-josephi H. Pascual is an intriguing lupin species recently discovered in the Mediterranean region. New data from seed coat micromorphology,
cytology, and DNA sequences were generated in order to extend our knowledge on this species and to examine its evolutionary
relationships within Lupinus. This species shows morphological similarities with the Mediterranean smooth seeded species of sections Micranthi and Lutei. It shares the same chromosome number 2n=52 with the latter Old World taxa, but also with unifoliolate lupins from Florida. Besides, L. mariae-josephi exhibited a seed coat micromorphology “intermediate” between the rough and the smooth seed coat types. Phylogenetic analyses
using ITS and ETS nrDNA spacers, and the LEGCYC1A locus supported L. mariae-josephi as a distinct Old World line, placed out of the Scabrispermae, but without clear placement amongst the Mediterranean smooth-seeded lineages. Unexpectedly, LEGCYC1A data revealed phylogenetic affinities between L. mariae-josephi and L. villosus, a unifoliolate North American lupin that might have experienced a reticulated evolutionary process. All together, the data
underline the phylogenetic interest of L. mariae-josephi in Lupinus and the need of additional investigations in order to definitely elucidate its enigmatic status. Moreover, as L. mariae-josephi is one of the rare Old World lupins strictly restricted to poor basic soils, it opens new perspectives of ecological and
agronomic interests in the wide areas of poor calcareous soils in the Mediterranean region.
KeywordsChromosome number–
Lupinus mariae-josephi
–Old World lupins–Phylogenetic placement–Seed coat microstructure
Genetic Resources and Crop Evolution 04/2012; 58(1):101-114. · 1.55 Impact Factor
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ABSTRACT: SymRK is one of the key genes involved in initial steps of legume symbiotic association with fungi (mycorrhization) and nitrogen-fixing bacteria (nodulation). A large portion of the sequence encoding the extracellular domain of SYMRK was obtained for 38 lupine accessions and 2 outgroups in order to characterize this region, to evaluate its phylogenetic utility, and to examine whether its molecular evolutionary pattern is correlated with rhizobial diversity and specificity in Lupinus. The data suggested that, in Lupinus, SymRK is a single copy gene that shows good phylogenetic potential. Accordingly, SymRK provided additional support to previous molecular phylogenies, and shed additional light on relationships within the Old World group of Lupinus, especially among the African species. Similar to results of other studies, analyses of SymRK sequences were unable to resolve placement of the Florida unifoliolate lineage, whose relationship was weakly supported to either the Old or the New World lupines. Our data are consistent with strong purifying selection operating on SymRK in Lupinus, preserving rather than diversifying its function. Thus, although SymRK was demonstrated to be a vital gene in the early stages of the root-bacterial symbiotic associations, no evidence from present analyses indicate that this gene is involved in changes in rhizobial specificity in Lupinus.
Molecular Phylogenetics and Evolution 07/2011; 60(1):49-61. · 3.61 Impact Factor
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ABSTRACT: The compatible solute hypothesis posits that maintaining osmotic equilibrium under conditions of high salinity requires synthesis of organic compounds, uptake of potassium ions, and partial exclusion of NaCl. To assess whether osmotic adaptation in Limonium latifolium proceeds according to this hypothesis, a comprehensive analysis of solute accumulation during NaCl treatments was conducted. Determination of prevailing inorganic ions and establishment of the metabolic profiles for low M(r) organic substances revealed that contrary to the mentioned hypothesis the major contributors to osmolarity were constituted by inorganic solutes. Independent of salinity, only 25% of this osmolarity resulted from organic solutes such as Suc and hexoses. Proline (Pro), beta-alanine betaine, and choline-O-sulfate were minor contributors to osmolarity. Compatible inositols also occurred, especially chiro-inositol, characterized for the first time in this species, to our knowledge. Principal component analysis showed that only a limited number of metabolic reconfigurations occurred in response to dynamic changes in salinity. Under such conditions only sugars, chiro-inositol, and Pro behave as active osmobalancers. Analysis of metabolic profiles during acclimatization to either mild salinity or nonsaline conditions showed that organic solute accumulation is predominantly controlled by constitutive developmental programs, some of which might be slightly modulated by salinity. Osmolarity provided under such conditions can be sufficient to maintain turgor in salinized seedlings. Compartmental analysis of Pro and beta-alanine betaine in leaf tissues demonstrated that these solutes, mainly located in vacuoles under nonsaline conditions, could be partly directed to the cytosol in response to salinization. Thus they did not conform with the predictions of the compatible solute hypothesis.
Plant physiology 08/2007; 144(3):1598-611. · 6.53 Impact Factor
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ABSTRACT: Arginine decarboxylase (ADC) is a key enzyme involved in the synthesis of polyamines, which have been implicated in developmental processes and stress responses in higher plants. An ancestral ADC gene appears to have been duplicated at the origin of the Brassicaceae family, thus yielding two paralogues in the derived taxa. ADC gene structure was investigated in Pringlea antiscorbutica R. Br., a geographically isolated Brassicaceae species that is endemic from the subantarctic region. P. antiscorbutica exhibits several biochemical and physiological adaptations related to this cold and harsh environment, including high levels of polyamines, which is unusual in higher plants, and especially high levels of agmatine, the product of the ADC-catalysed reaction. Various ADC clones were obtained from P. antiscorbutica. Sequence and phylogenetic analysis showed that all these clones fitted with the presence of two paralogues, PaADC1 and PaADC2, in P. antiscorbutica. Expression of these ADC paralogues was analyzed in P. antiscorbutica during vegetative development and response to stress. Whereas PaADC2 was expressed at both seedling and mature stages, PaADC1 transcripts were hardly detected during early development and were significantly expressed in mature plants. Moreover, PaADC2, but not PaADC1, expression was up-regulated in response to chilling and salt stress at seedling stage. Analysis of 5' regulatory regions of these ADC genes revealed several differences in putative cis-regulatory elements, which could be associated with specific expression patterns. These results were compared to ADC paralogue expression in Arabidopsis thaliana and are discussed in the evolutionary context of genetic diversity resulting from gene duplication.
Gene 12/2004; 342(2):199-209. · 2.34 Impact Factor
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ABSTRACT: The compatible solute hypothesis posits that maintaining osmotic equilibrium under conditions of high salinity requires synthesis of organic compounds, uptake of potassium ions, and partial exclusion of NaCl. To assess whether osmotic adaptation in Limonium latifolium proceeds according to this hypothesis, a comprehensive analysis of solute accumulation during NaCl treatments was conducted. Determination of prevailing inorganic ions and establishment of the metabolic profiles for low M(r) organic substances revealed that contrary to the mentioned hypothesis the major contributors to osmolarity were constituted by inorganic solutes. Independent of salinity, only 25% of this osmolarity resulted from organic solutes such as Suc and hexoses. Proline (Pro), beta-alanine betaine, and choline-O-sulfate were minor contributors to osmolarity. Compatible inositols also occurred, especially chiro-inositol, characterized for the first time in this species, to our knowledge. Principal component analysis showed that only a limited number of metabolic reconfigurations occurred in response to dynamic changes in salinity. Under such conditions only sugars, chiro-inositol, and Pro behave as active osmobalancers. Analysis of metabolic profiles during acclimatization to either mild salinity or nonsaline conditions showed that organic solute accumulation is predominantly controlled by constitutive developmental programs, some of which might be slightly modulated by salinity. Osmolarity provided under such conditions can be sufficient to maintain turgor in salinized seedlings. Compartmental analysis of Pro and beta-alanine betaine in leaf tissues demonstrated that these solutes, mainly located in vacuoles under nonsaline conditions, could be partly directed to the cytosol in response to salinization. Thus they did not conform with the predictions of the compatible solute hypothesis.
Plant Physiology.
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ABSTRACT: The legume genus, Lupinus, has many notable properties that make it interesting from a scientific perspective, including its basal position in the evolution of Papilionoid legumes. As the most economically important legume species, L. angustifolius L. (narrow-leafed lupin) has been subjected to much genetic analysis including linkage mapping and genomic library development. Cytogenetic analysis has been hindered by the large number of small morphologically uniform chromosomes (2n = 40). Here, we present a significant advance: the development of chromosome-specific cytogenetic markers and assignment of the first genetic linkage groups (LGs) to chromosomal maps of L. angustifolius using the bacterial artificial chromosome (BAC)-fluorescence in situ hybridization approach. Twelve clones produced single-locus signals that "landed" on 7 different chromosomes. Based on BAC-end sequences of those clones, genetic markers were generated. Eight clones localized on 3 chromosomes, allowed these chromosomes to be assigned to 3 LGs. An additional single-locus clone may be useful to combine an unassigned group (Cluster-2) with main LGs. This work provides a strong foundation for future identification of all chromosomes with specific markers and for complete integration of narrow-leafed lupin LGs. This resource will greatly facilitate the chromosome assignment and ordering of sequence contigs in sequencing the L. angustifolius genome.
The Journal of heredity 102(2):228-36. · 2.05 Impact Factor
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ABSTRACT: Fifty-one species belonging to 16 families of halophytes have been collected in salty areas surrounding the Seyfe Lake in Central Anatolia (Turkey). Their plant/sodicity relationships and the involvement of nitrogenous solutes in their osmotic adjustment have been more specifically investigated in order to compare adaptative traits involved in their salt tolerance with those well-known occurring in halophytes from marine salt marshes. The internal molecular ratio between [K+]int and [K+ + Na+]int was found to be low in the shoots of dicots due to important abilities to accumulate Na+. In contrast this ratio was higher in the monocots, this being due to low contents of Na+ not to high ones of K+. This suggests specific traits which allow the dicots to absorb, accumulate and compartmentalize Na+ in order to provide cheap osmotic particles for osmotic adjustment. In terms of putative compatible solutes derived from primary nitrogen metabolism the study has been restricted to free proline and glycine betaine. It reveals that the 51 species investigated could be discriminated according to their capacity to accumulate, under natural saline conditions, either proline or glycine betaine or both of these compounds. It was also shown that species that behaved as glycine betaine accumulators behaved as poor proline accumulators and vice versa. This might suggest that in a number of species exhibiting attributes for glycine betaine production the level of free proline could be under the negative control of that of glycine betaine. A number of other nitrogenous osmolytes, such as Δ1-acetylornithine, β-alanine betaine and choline-O-sulfate were also found in certain species. Plantago maritima previously found to accumulate sorbitol in response to saline conditions was shown here to coaccumulate proline and glycine betaine in addition to sorbitol which was also found to be abundant. Phenetic analysis of the set of data obtained allow to discriminate two main clusters of halophytic species refering mainly to the traits associated with proline and (or) glycine betaine accumulation. As expected, the majority of the Chenopodiaceae, exhibited a distinct behavior within cluster II, based on their dual ability to store Na+ and glycine betaine. Some species of this family did not conform with this model. Thus, it becomes clear that salt tolerance in halophytic plants which might partly result from the cooperativity of a number of well-conserved mechanisms could also result from specific processes that could be modulated by the saline environment.
Environmental and Experimental Botany.
