383 research outputs found
On the applicability of the Tubulin-Based Polymorphism (TBP) genotyping method: a comprehensive guide illustrated through the application on different genetic resources in the legume family
Background
Plant discrimination is of relevance for taxonomic, evolutionary, breeding and nutritional studies. To this purpose, evidence is reported to demonstrate TBP (Tubulin-Based-Polymorphism) as a DNA-based method suitable for assessing plant diversity.
Results
Exploiting one of the most valuable features of TBP, that is the convenient and immediate application of the assay to groups of individuals that may belong to different taxa, we show that the TBP method can successfully discriminate different agricultural species and their crop wild relatives within the Papilionoideae subfamily. Detection of intraspecific variability is demonstrated by the genotyping of 27 different accessions of Phaseolus vulgaris.
Conclusions
These data illustrate TBP as a useful and versatile tool for plant genotyping. Since its potential has not yet been fully appreciated by the scientific community, we carefully report all the experimental details of a successful TBP protocol, while describing different applications, so that the method can be replicated in other laboratories
Evolution of secondary metabolites in legumes (Fabaceae)
AbstractLegumes produce a high diversity of secondary metabolites which serve as defence compounds against herbivores and microbes, but also as signal compounds to attract pollinating and fruit-dispersing animals. As nitrogen-fixing organisms, legumes produce more nitrogen containing secondary metabolites than other plant families. Compounds with nitrogen include alkaloids and amines (quinolizidine, pyrrolizidine, indolizidine, piperidine, pyridine, pyrrolidine, simple indole, Erythrina, simple isoquinoline, and imidazole alkaloids; polyamines, phenylethylamine, tyramine, and tryptamine derivatives), non-protein amino acids (NPAA), cyanogenic glucosides, and peptides (lectins, trypsin inhibitors, antimicrobial peptides, cyclotides). Secondary metabolites without nitrogen are phenolics (phenylpropanoids, flavonoids, isoflavones, catechins, anthocyanins, tannins, lignans, coumarins and furanocoumarins), polyketides (anthraquinones), and terpenoids (especially triterpenoid, steroidal saponins, tetraterpenes). While some secondary metabolites have a wide distribution (flavonoids, triterpenes, pinitol), however, others occur in a limited number of taxa. The distributions of secondary metabolites with an irregular occurrence are mapped on a molecular phylogeny of the Fabaceae, reconstructed from a combined data set of nucleotide sequences from rbcL, matK and ITS genes. In most cases, the distribution patterns of secondary metabolites do not agree with the phylogeny of the plants producing them. In contrary, the distribution of many secondary metabolites is patchy and irregular. Thus, the use of phytochemical data to reconstruct a phylogeny of plants is often not informative and can be misleading. The patchy distribution may be due to convergent evolution, a contribution of endophytic fungi or more likely, to an early acquisition of the key genes of secondary metabolism in the evolution of land plants among others by horizontal gene transfer from bacteria. Thus it would be a matter of gene regulation whether these genes are active in some but not all taxa
Nutritional Characteristics of the Seed Protein in 23 Mediterranean Legumes
The search for new sources of plant protein for food and animal feed is driven by an increasing demand in developing countries and the interest in healthy alternatives to animal protein. Seeds from 23 different wild legumes belonging to tribes Gallegeae, Trifolieae, and Loteae were collected in southern Spain and their total amino acid composition was analyzed, by reverse phase-high performance liquid chromatography (RP-HPLC), in order to explore their nutritional value. Protein content in the seeds ranged from 15.5% in Tripodium tetraphyllum to 37.9% and 41.3% in Medicago minima and Medicago polymorpha, respectively. Species belonging to tribe Trifolieae, such as Melilotus elegans and Trifolium spp., showed the most equilibrated amino acid composition and the best theoretical nutritional values, although all species were deficient in sulfur amino acids. The amino acid composition of the seeds from some of these legumes was characterized by high levels of the anticancer non-proteic amino acid canavanine This amino acid was found free in the seeds from some of the species belonging to each of the three tribes included in the present work. Astragalus pelecinus in tribe Gallegea, Trifolium angustifolium in tribe Trifolieae, and Anthyllis vulneraria in tribe Loteae have 3.2%, 3.7%, and 7.2% canavanine, respectively. Seeds from Anthyllis vulneraria, Hymenocarpus lotoides, and Hymenocarpos cornicina have the highest contents in canavanine overall. In conclusion, the seeds from some of these legumes could be used for human consumption and for feeding animals because they contain protein of good nutritional quality. These plants could be useful in domestication and breeding programs for production of new varieties with improved nutritional and functional properties. In addition, some of these species may be of interest as a source of the bioactive compound canavanineinfo:eu-repo/semantics/publishedVersio
Evolutionary Significance Of The Loss Of The Chloroplast‐Dna Inverted Repeat In The Leguminosae Subfamily Papilionoideae
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137404/1/evo05207.pd
Neutral processes related to regional bee commonness and dispersal distances are important predictors of plant–pollinator networks along gradients of climate and landscape conditions
Understanding how niche-based and neutral processes contribute to the spatial varia-tion in plant–pollinator interactions is central to designing effective pollination con-servation schemes. Such schemes are needed to reverse declines of wild bees and other pollinating insects, and to promote pollination services to wild and cultivated plants. We used data on wild bee interactions with plants belonging to the four tribes Loteae, Trifolieae, Anthemideae and either spring- or summer-flowering Cichorieae, sampled systematically along a 682 km latitudinal gradient to build models that allowed us to 1) predict occurrences of pairwise bee–flower interactions across 115 sampling locations, and 2) estimate the contribution of variables hypothesized to be related to niche-based assembly structuring processes (viz. annual mean temperature, landscape diversity, bee sociality, bee phenology and flower preferences of bees) and neutral processes (viz. regional commonness and dispersal distance to conspecifics). While neutral processes were important predictors of plant–pollinator distributions, niche-based processes were reflected in the contrasting distributions of solitary bee and bumble bees along the temperature gradient, and in the influence of bee flower preferences on the distri-bution of bee species across plant types. In particular, bee flower preferences separated bees into three main groups, albeit with some overlap: visitors to spring-flowering Cichorieae; visitors to Anthemideae and summer-flowering Cichorieae; and visitors to Trifolieae and Loteae. Our findings suggest that both neutral and niche-based pro-cesses are significant contributors to the spatial distribution of plant–pollinator inter-actions so that conservation actions in our region should be directed towards areas: Page 2 of 11near high concentrations of known occurrences of regionally rare bees; in mild climatic conditions; and that are surrounded by heterogenous landscapes. Given the observed niche-based differences, the proportion of functionally distinct plants in flower-mixes could be chosen to target bee species, or guilds, of conservation concern. Keywords: ecological networks, machine learning, plant–pollinator interactions, spatial, wild beesNeutral processes related to regional bee commonness and dispersal distances are important predictors of plant–pollinator networks along gradients of climate and landscape conditionspublishedVersionpublishedVersio
Legumes of Forage Value: Their Diversity and Priority for Collection in India
Indian subcontinent is a megacentre of agro-diversity. Legumes have a special place with several native crops and economically important species occurring along forest margins and openings, pastures, grasslands and grazing lands. Several are dual-purpose species for food and feed. However, herbage legumes though major components of grasslands and with a major role in their quality and improvement lack persistence as compared to grasses and their collection, maintenance and conservation assumes importance in the wake of change and loss of habitats of native species and introduction of new germplasm with forage potential. Establishing the correct identity of species is therefore a priority. The major forage legume crops of India (Anon., 2013) belong to Tribes Trifolieae- Trifolium, Medicago, Melilotus among temperate legumes; Phaseoleae- Vigna; and Indigofereae- Cyamopsis tropical, subtropical and arid conditions (Arora and Chandel, 1972). These have a good representation of erect, spreading and viny species with potential for use as forage, soil improvement and use as green manure and often with non-toxic herbage and successfully grown over widely varying environmental conditions making this a morphologically variable and highly diverse germplasm resource. Collecting species of native and introduced species from these habitats that are in a state of flux is important for locating potentially important and unique diversity well adapted to the areas of occurrence.
Several species of forage legumes, both native and introduced (Nayar et al., 2014) were represented as reference specimens of plants collected from the wild or grown in experimental conditions at the National Herbarium of Cultivated Plants (acronym: NHCP). An initiative undertaken was to authenticate the identity of these, and work out characters that could be used for field identification
The systematic significance of testa anatomy in the Leguminosae — an illustrated survey
Seed from all three subfamilies of the Leguminosae was surveyed for anatomical features of the testa which could be used in the systematics of the family. An atlas of testa anatomy is presented, and the possible adaptive significance of certain seed structures is discussed. Seed of the Mimosoideae and Caesalpinioideae remain incompletely separated, but the shape of the micropyle constitutes a useful accessory character. In addition certain genera in these subfamilies have features which are anomalous in the family. Features of the micropyle, cuticle and light line typically characterize the papilionoid seed, but the only characters invariably restricted to this subfamily are hilar features traditionally recognized as such. However, testa anatomy is very useful within the Papilionoideae and certain tribes or groups of phylogenetically related tribes can be recognized by various features of the testa, particularly cuticle sculpturing and micropyle shape. Similarities between mimosoid and caesalpinioid seeds are plesiomorphous, and cannot necessarily imply greater phylogenetic relationship. The occurrence of a direct relationship between epidermal and hypodermal thickness in papilionoid seed suggests an early stabilization of this adaptive structure
Seed Coat Structure in Some Species of Trigonella
Seed coats of nine species of Trigonella, members of Trifolieae, were studied using light and scanning electron microscopy to assess seed coat characters taxonomically. In all species, the testa is of the papillose type except T. geminiflora in which it is of the multi-reticulate type. Based on some of the seed characters such as their shape, size, surface, position of hilum and the features of papillae, a key has been developed to identify different species of this genus. Further, in a highly evolved group like section Bucerates, it has been found that the surface is either papillose without mounds or multi-reticulate. This feature has to be confirmed in more species of this genus
The Basis of Freezing Tolerance Between and Within Species Across Environmental Gradients with a Focus on Arctic, Alpine and Moorland Plants
Freezing events have devastating impacts on crops around the world. Climate change is resulting in more extreme freezing events as well as an increase in winter warm periods and shorter winters which can alter the process of acclimation and deacclimation leading to greater freezing susceptibility. Genes involved in freezing tolerance therefore need to be targeted by crop breeders to improve crop resistance to these events. The CBF family is one of these potential targets due to their presence across the Spermatophyta, including crop species, and their role in acclimation as transcription factors which activate cold response (COR) genes, thereby increasing freezing tolerance. Plants adapted to environments with frequent and very low temperature freezing events, such as arctic and alpine locations may, therefore, already possess modifications to these genes which improve freezing tolerance. The ability of native, dominant cover species to endure and adapt to these climatic changes can also be investigated via the study of variation within CBF over a species range.
CBF sequences were isolated from numerous arctic and alpine species. Several common polymorphisms in key CBF regions were identified and applied to Arabidopsis thaliana CBF1. The effect upon freezing tolerance and CRT/DRE activation of these modified A. thaliana CBF1 sequences were then tested. No definitive conclusions could be drawn, however potential routes of further investigation are highlighted and discussed.
CBF sequences of Empetrum nigrum samples from a wide distribution and both high and low altitude were compared, no differences between sequences which correlated with sample location, were found. However preliminary expression studies indicated a difference in the kinetics of CBF expression between samples from different locations. Further study of CBF expression kinetics within this species is highly recommended.
Routes of further exploration leading to potential targets for crops are discussed, alongside suggested routes of further investigation for Empetrum nigrum and Calluna vulgaris
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