Wild Legumes Research Articles

Genome-wide analysis of the GlutathioneS-Transferase family in wild Medicago ruthenica and drought-tolerant breeding application ofMruGSTU39 gene in cultivated alfalfa.

Transformation of MruGSTU39 in M. ruthenica and alfalfa enhanced growth and survival of transgenic plants by up-regulating GST and glutathione peroxidase activity to detoxify ROS under drought stress. Glutathione S-transferases (GSTs) are ubiquitous supergenefamily which play crucial roles in detoxification of reactive oxygenspecies (ROS). Despite studies on GSTs, few studies have focused on them in perennial, wild plant species with high tolerance to environmental stress. Here, we identified 66 MruGST genes from the genome of Medicago ruthenica, a perennial legume species native to temperate grasslands with high tolerance to environmental stress. These genes were divided into eight classes based on their conserved domains, phylogenetic tree and gene structure, with the tau class being the most numerous. Duplication analysis revealed that GST family in M. ruthenica was expanded by segmental and tandem duplication. Several drought-responsive MruGSTs were identified by transcriptomic analyses. Of them, expression of MruGSTU39 was up-regulated much more in a tolerant accession by drought stress. Transformation of MruGSTU39 in M. ruthenica and alfalfa (Medicago sativa) enhanced growth and survival of transgenic seedlings than their wild-type counterparts under drought. We demonstrated that MruGSTU39 can detoxify ROS to reduce its damage to membrane by up-regulating activities of GST and glutathione peroxidase. Our findings provide full-scaleknowledge on GST family in the wild legume M. ruthenica with high tolerance to drought, and highlight improvement tolerance of legume forages to drought using genomic information of M. ruthenica.

Insights into Emerging Begomovirus-Deltasatellite Complex Diversity: The First Deltasatellite Infecting Legumes.

Simple SummaryLegumes play an important nutritional role in the diets of millions of people, mainly in developing countries, but their productivity is seriously affected by a variety of pathogens including viruses. In the last few decades, a number of whitefly-transmitted viruses have emerged mainly in tropical and subtropical areas worldwide including the DNA-containing begomoviruses. A survey of leguminous plants for the presence of begomoviruses was conducted in Venezuela, an understudied country in this regard, even when a variety of symptoms resembling those caused by begomoviruses has been observed in leguminous crops for 20 years. As a result, begomoviruses belonging to four novel species have been discovered and molecularly characterized. In addition, a novel deltasatellite, a small DNA molecule associated with some begomoviruses, has been found to be associated with cabbage leaf curl virus. This is the first time that a deltasatellite has been found to infect legumes. Our results illustrate the increasing complexity faced by researchers and breeders looking to develop control strategies against these emerging pathogens.Begomoviruses and associated DNA satellites are involved in pathosystems that include many cultivated and wild dicot plants and the whitefly vector Bemisia tabaci. A survey of leguminous plants, both crops and wild species, was conducted in Venezuela, an understudied country, to determine the presence of begomoviruses. Molecular analysis identified the presence of bipartite begomoviruses in 37% of the collected plants. Four of the six begomoviruses identified constituted novel species, and two others had not been previously reported in Venezuela. In addition, a novel deltasatellite (cabbage leaf curl deltasatellite, CabLCD) was found to be associated with cabbage leaf curl virus (CabLCV) in several plant species. CabLCD was the first deltasatellite found to infect legumes and the first found in the New World to infect a crop plant. Agroinoculation experiments using Nicotiana benthamiana plants and infectious viral clones confirmed that CabLCV acts as a helper virus for CabLCD. The begomovirus–deltasatellite complex described here is also present in wild legume plants, suggesting the possible role of these plants in the emergence and establishment of begomoviral diseases in the main legume crops in the region. Pathological knowledge of these begomovirus–deltasatellite complexes is fundamental to develop control methods to protect leguminous crops from the diseases they cause.

Mineral and Protein Screening of Some Wild Legumes of Dilling area (South Kordofan State, Sudan)

Mineral screening was carried out on leaves of seven wild leguminous plants namely: Tamarindus indica, Albizzia amara, Acacia laeta, Senna obtusifolia, Senna occidentalis, Phaseolus adenanthus and Crotalaria saltiana. The leaves have high protein content which ranges between 21.6% for Phaseolus adenanthus and 17.3% for Senna occidentalis. Mineral elements detected in appreciable quantities were Calcium, Magnesium, Potassium, Phosphorus, Sulfur and Iron. Manganese contents were very low and they range between 0.01% for Senna occidentalis and 0.03%for Tamarindus indica, Acacia laeta and Crotalaria saltiana. Analysis showed that these species had different levels of mineral and crude protein.

Next-Generation Sequencing-Based Detection of Common Bean Viruses in Wild Plants from Tanzania and Their Mechanical Transmission to Common Bean Plants.

Viral diseases are a major threat for common bean production. According to recent surveys, >15 different viruses belonging to 11 genera were shown to infect common bean (Phaseolus vulgaris L.) in Tanzania. Virus management requires an understanding of how viruses survive from one season to the next. During this study, we explored the possibility that alternative host plants have a central role in the survival of common bean viruses. We used next-generation sequencing (NGS) techniques to sequence virus-derived small interfering RNAs together with conventional reverse-transcription PCRs (RT-PCRs) to detect viruses in wild plants. Leaf samples for RNA extraction and NGS were collected from 1,430 wild plants around and within common bean fields in four agricultural zones in Tanzania. At least partial genome sequences of viruses potentially belonging to 25 genera were detected. The greatest virus diversity was detected in the eastern and northern zones, whereas wild plants in the Lake zone and especially in the southern highlands zone showed only a few viruses. The RT-PCR analysis of all collected plant samples confirmed the presence of yam bean mosaic virus and peanut mottle virus in wild legume plants. Of all viruses detected, only two viruses, cucumber mosaic virus and a novel bromovirus related to cowpea chlorotic mottle virus and brome mosaic virus, were mechanically transmitted from wild plants to common bean plants. The data generated during this study are crucial for the development of viral disease management strategies and predicting crop viral disease outbreaks in different agricultural regions in Tanzania and beyond.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Physicochemical and functional characterization of trupillo flour (Prosopis juliflora (Sw.) DC) and its inclusion in a food matrix

Introduction: The high protein content has made legumes a raw material of interest in the formulation of different agro-industrial products; the trupillo (Prosopis juliflora) tree is an easily accessible, multipurpose, wild legume that can be used in all its composition, has a high protein value and little commercial level, which is currently being wasted as it is mistakenly considered a weed and that It could be seen as a new alternative that helps in the potentialization of the food sector. Objective: This research aims to functionally characterize trupillo flour (Prosopis juliflora), obtained from leaves and seeds, to include it in a food matrix as a protein extender. Methodology: The experimental design for this research required three phases, i) obtaining, bromatological and functional characterization of leaf flour and trupillo seeds, ii) standardization of formulations for artisan sausages using trupillo flour as a protein source, and iii) bromatological and sensory characterization of the processed sausages. Results: It was found that the flours obtained preserved the characteristic odor and color of each raw material. Particularly, the seed flour presented bromatologically and functionally better protein contents (27.7%), ash (8.04%), swelling capacity (16.7 ml water / g sample), water absorption (7.89 g water / g sample) and water retention capacity (27.9 g water/g sample), for which it was selected to be included in the sausages. In the three formulations made (C, CT and T), there were variations in the color and texture of the sausages, with Formulation T standing out for presenting higher protein content (13.7%). However, consumers preferred Formulation C. Conclusions: These results allow to propose the inclusion of sausage with trupillo flour in the human diet as an alternative to traditional products.

Isolation and characterization of plant growth-promoting endophytic bacteria of wild legumes growing on sandy soils of Binh Thuan province, Vietnam

Isolation and characterization of plant growth-promoting endophytic bacteria of wild legumes growing on sandy soils of Binh Thuan province, Vietnam

Isolation and characterization of plant growth-promoting endophytic bacteria of wild legumes growing on sandy soils of Binh Thuan province, Vietnam

The roots of two legume species (Tephrosia purpurea and Tephrosia villosa) that grew wild on dry sandy soils of Binh Thuan province were sources for isolating plant growth-promoting endophytic bacteria. Semi-solid LGI medium was used for the isolation of nitrogen-fixing bacteria from root extracts. All bacterial isolates isolates were evaluated for their ability to solubilize calcium orthophosphate on solid NBRIP medium and their ability to produce IAA in Burk's liquid medium supplemented with 100 mg/L tryptophan. The possibilities of nitrogen fixation, phosphate solubilization and IAA synthesis were all quantitative examined by colorimetric method. Twenty-two bacterial isolates of T. purpurea and 18 isolates of T. villosa were capable of nitrogen fixation in the range of 1.94 to 2.81 mg/L NH4+, whereas only 18 isolates of T. purpurea and 16 isolates of T. villosa showed phosphate solubilization in the range of 12.30 – 48.90 mg/L P2O5, and IAA production in the range of 0.38 – 12.72 mg/L. Sixteen outstanding bacterial isolates of the two legume species were identified by MALDI-TOF technique. The results showed that 13 isolates had high similarity with five bacterial genera including Klebsiella, Cronobacter, Enterobacter, Burkholderia, and Bacillus with score values in the range of 2.070 – 2.411.

Determination of use value and informant consensus factor on ethnobotanic knowledge about wild legumes used by natives of Wayanad district, Kerala

The present work is aimed to document the traditional knowledge about the various usages of leguminous plants (Fabaceae), by tribals of Wayanad district and its nearer places such as Vanimel and Vilangad villages of Kozhikkode district, Kerala. Ethnobotanical surveys/ interviews/ discossions were carried out in few randomly selected tribal hamlets for the data collection. Among these visits the plants used by tribal communities Paniya and Kattunaikka were focused for documentation. This study reports the data of 80 plants from the family Fabaceae. This report also observed that the tribal communities were deeply depending on various wild legumes for making infrastructures, agricultural utilities, making food/ fuel/ timber/ manure and they solve their health issues to a large extent also by using some wild legume species. Among the eighty species, fifty were used in various medicinal preparations and thirty species were used for dietary needs in combination or alone. At the same time major group of plants are unable to demarcate between food and medicine. Use Value analysis shows that the tree legume species Tamarindus indica is relatively more important with 64 use reports (UV 0.98). Analysis of Informant consensus factor reveals that the homogeneity of knowledge is more for the plants with medicinal properties ( F ic 0.97); whereas maximum heterogeneity ( F ic 0.92) was found about agricultural utilities of plants. According to the results of DMR analysis Dalbergia latifolia ranked first, so that this species is getting more exploited, because it is highly preferable for all five categories studied under DMR analysis. Moreover the present documentation of ethnic knowledge about wild legumes is an attempt to serve as indigenous information for future sustainable utilization and conservation.

The genome of a wild Medicago species provides insights into the tolerant mechanisms of legume forage to environmental stress

BackgroundMedicago ruthenica, a wild and perennial legume forage widely distributed in semi-arid grasslands, is distinguished by its outstanding tolerance to environmental stress. It is a close relative of commonly cultivated forage of alfalfa (Medicago sativa). The high tolerance of M. ruthenica to environmental stress makes this species a valuable genetic resource for understanding and improving traits associated with tolerance to harsh environments.ResultsWe sequenced and assembled genome of M. ruthenica using an integrated approach, including PacBio, Illumina, 10×Genomics, and Hi-C. The assembled genome was 904.13 Mb with scaffold N50 of 99.39 Mb, and 50,162 protein-coding genes were annotated. Comparative genomics and transcriptomic analyses were used to elucidate mechanisms underlying its tolerance to environmental stress. The expanded FHY3/FAR1 family was identified to be involved in tolerance of M. ruthenica to drought stress. Many genes involved in tolerance to abiotic stress were retained in M. ruthenica compared to other cultivated Medicago species. Hundreds of candidate genes associated with drought tolerance were identified by analyzing variations in single nucleotide polymorphism using accessions of M. ruthenica with varying tolerance to drought. Transcriptomic data demonstrated the involvements of genes related to transcriptional regulation, stress response, and metabolic regulation in tolerance of M. ruthenica.ConclusionsWe present a high-quality genome assembly and identification of drought-related genes in the wild species of M. ruthenica, providing a valuable resource for genomic studies on perennial legume forages.

Flora and Phytochorology of Lahij Governorate of Yemen: 1- Systematic Revision of Wild Legumes of the Family Fabaceae

The current study presents a revision of the family Fabaceae in the flora of Lahij Governorate, South Yemen. The recorded taxa were systematically revised and life form, lifespan, and phytogeographical affinities were analyzed. 63 taxa belonging to 20 genera of three subfamilies (Caesalpinioideae, Faboideae, and Mimosoideae) were recorded. For each species, accepted name, synonyms (if any), and local distribution are given. Keys to subfamilies, genera, species, and infra-specific taxa of polymorphic species are provided. The recorded taxa consist of 76.19% perennials and 23.81% annuals. Phanerophytes, chamaephytes, and therophytes were the most frequent life forms. Phytogeographical analysis revealed that the Sudano-Zambezian elements are the most dominant, forming the major constituent (¼ of the recorded plants) of the legume floristic structure. The most diverse genera were Acacia s.l. (13 taxa), Indigofera (12 taxa), Tephrosia (7 taxa), Crotalaria, and Senna (6 taxa each), accounting for about 69.84% of the total taxa recorded. Two species (Acacia hunteri Oliv. and Zygocarpum yemenense (J.B.Gillett) Thulin & Lavin) are endemic to Yemen. Besides, six species (Acacia edgeworthii T. Anders., Acacia johnwoodii Boulos, Cadia purpurea (Picc.) Ait., Crotalaria saltiana Andrews, Indigastrum costatum subsp. goniodes (Hochst. ex Baker) Schrire, and Tephrosia heterophylla Vatke) are considered near endemics.

The Association of Arable Weeds with Modern Wild Cereal Habitats: Implications for Reconstructing the Origins of Plant Cultivation in the Levant

ABSTRACT Reconstructing the origins of plant cultivation in southwest Asia is crucial for understanding associated processes such as the emergence of sedentary communities and domesticated crops. Among the criteria archaeobotanists developed for identifying the earliest plant cultivation, the presence of potential arable weeds found in association with wild cereal and legume remains has been used as a basis for supporting models of prolonged wild plant cultivation before domesticated crops appear. However, the proposed weed floras mainly consist of genus-level identifications that do not differentiate between arable weeds and related species that characterise non-arable habitats. Here we test, for the first time, whether the potential arable weed taxa widely used to identify wild plant cultivation also occur in non-cultivated wild cereal populations. Based on modern survey data from the southern Levant we show that the proposed weed taxa characterise both grasslands and fields. Our findings, therefore, do not support the use of these taxa for reconstructing early cultivation. Instead, for future studies we suggest an approach based on the analysis of plant functional traits related to major agroecological variables such as fertility and disturbance, which has the potential to overcome some of the methodological problems.

Genetic architecture of wild soybean (Glycine soja Sieb. and Zucc.) populations originating from different East Asian regions

East Asian region is home to wild soybean and has high topographic complexity. Measuring genetic diversity and geographical distribution patterns are essential steps to expand the germplasm base. We used SoySNP6K to determine the genetic diversity and population genetic structure of the wild soybean populations from four East-Asian geographies i.e. China, Japan, Korea, and Russian Far East. The wild soybean populations from China, Japan, and Korea are distinct from one another based on genetic structure, whereas the one from Russian Far East was not distinguishable from the Chinese wild soybeans. These populations share three ancestral populations and have a large number of common SNPs. Despite the low genetic diversity scores between the populations, the Chinese accessions had the highest genetic diversity values while the accession from Russian Far East had the lowest. Our analysis also showed that the population is showing a departure from the Hardy–Weinberg equilibrium and there is a possibility of inbreeding for most of the loci. The results showed that the genetic variation follows the geographic distribution within each geographically distinct wild soybeans population. Therefore, a diverse collection of wild soybeans representing all-natural habitats should include representatives from each of these sub-centers. This population would provide important breeding materials to expand the allelic pool of cultivated soybeans through introgression. Based on these criteria, the Chung’s wild legume germplasm collection from Korea provides a good representation of the genetic diversity in wild soybeans for use in soybean breeding programs.

Developments and Prospects in Imperative Underexploited Vegetable Legumes Breeding: A Review.

Vegetable legumes are an essential source of carbohydrates, vitamins, and minerals, along with health-promoting bioactive chemicals. The demand for the use of either fresh or processed vegetable legumes is continually expanding on account of the growing consumer awareness about their well-balanced diet. Therefore, sustaining optimum yields of vegetable legumes is extremely important. Here we seek to present d etails of prospects of underexploited vegetable legumes for food availability, accessibility, and improved livelihood utilization. So far research attention was mainly focused on pulse legumes’ performance as compared to vegetable legumes. Wild and cultivated vegetable legumes vary morphologically across diverse habitats. This could make them less known, underutilized, and underexploited, and make them a promising potential nutritional source in developing nations where malnutrition still exists. Research efforts are required to promote underexploited vegetable legumes, for improving their use to feed the ever-increasing population in the future. In view of all the above points, here we have discussed underexploited vegetable legumes with tremendous potential; namely, vegetable pigeon pea (Cajanus cajan), cluster bean (Cyamopsis tetragonoloba), winged bean (Psophocarpus tetragonolobus), dolichos bean (Lablab purpureus), and cowpea (Vigna unguiculata), thereby covering the progress related to various aspects such as pre-breeding, molecular markers, quantitative trait locus (QTLs), genomics, and genetic engineering. Overall, this review has summarized the information related to advancements in the breeding of vegetable legumes which will ultimately help in ensuring food and nutritional security in developing nations.

Performance of broiler chickens fed graded dietary inclusion levels of moringa (Moringa oleifera) seed cake

The progressive increase in the cost and scarcity of conventional feedstuffs, especially energy and protein sources has resulted into a continuous effort in researching into the possible utilization of the under - exploited wild legumes in poultry feed formulation. Several Researchers had reported on the utilization of Moringa oleifera leaf meal in poultry diets whereas; few reports exist on the utilization of Moringa seed. Therefore, this study wasconducted to evaluate the effect of graded dietary levels of moringa seed cake (MSC) on the performance of broiler chickens. A total of 195, one day old Arbor Acre broiler chicks were randomly assigned into five dietary treatments of moringa seed cake, each treatment having three replicates in a completely randomized design. MSC was included at levels of 0, 5,10, 15 and 20% respectively. Feed and water were given ad- libitum. Proximate composition ofMSC showed that it is high in energy, crude protein and ether extract with3304. 39 ME kcals/ kg, 32.49 % and 17.70%, respectively. Birds fed 5% MSC diet were better than the birds on the other levels of MSC diets in terms of growth and carcass characteristics. The results obtained from growth study revealed a significant declined in, final weight, weight gain, feed intake, and feed conversion ratio as the inclusion levels of MSC increased beyond 5% in thediets. The birds on control diet had the best result in terms of final weight , daily weight gain and daily feed intake of 2974g/bird, 52.4g/bird / day and 107.51g/bird/ day respectively followed by those fed diet containing 5% MSC with 2183.4g/bird, 38.24/bird /day and 95.66g/bird /day respectively. whereas, the birds fed 20% MSC had the least (P>0.05) final weight, daily weight gain and daily feed intake of 560 g/bird, 9.26g/bird /day and 33.51g/bird/day respectively. Carcass characteristics followed similar trend as the growth parameters. Hematological indices showed significant differences across the dietary treatments, however, the results were within the normal range except for the white blood cell. It can therefore be, concluded that the inclusion of MSC in broiler chicken diet should not exceed 5% for optimum growth and general performance.

Multi‐approach comparative study of the two most prevalent genotypes of pea aphid Acyrthosiphon pisum (Hemiptera: Aphididae) in Chile

AbstractThe pea aphid, Acyrthosiphon pisum Harris, is able to colonize various habitats and form genetically distinct biotypes worldwide. In Chile, few genotypes are dominating in space and time and are qualified as “superclones”. Here, we compared in the laboratory different biological features of the most common clones of A. pisum collected from pea (Ap1) and alfalfa (Ap2) fields, in order to gain some insight on their differential ability to colonize broad bean plants. We also studied their probing behavior, profiled their proteome and characterized their community of endosymbionts. We found that the Ap1 genotype performed better on Vicia faba and realized more salivation events in phloem than Ap2. In addition, Ap1 presented a higher prevalence of the endosymbiont Serratia symbiotica. Among the total of 40 proteins that were differentially expressed, 14 and 26 were upregulated in Ap1 and Ap2 genotypes, respectively. The symbionin from Buchnera aphidicola was found to be upregulated in Ap1. A field experiment showed that both genotypes were able to colonize wild legumes, with Ap1 reproducing better on Vicia nigricans than Ap2. However, Ap2 exhibited higher reproduction in the other three wild legumes, suggesting higher invasiveness capacity on wild plants. Variation in the ability to colonize, feeding behavior and the putative involvement of differentially regulated proteins between Ap1 and Ap2 are discussed in relation to their respective endosymbiotic composition, nutritional lifestyle and consequences on their “superclone” status.

Gene Sequences of Potential Targets of Insecticidal PF2 Lectin Identified from the Larval De Novo Transcriptome of the Mexican Bean Weevil (Zabrotes Subfasciatus; Boheman 1833).

Simple SummaryThe Mexican bean weevil Zabrotes subfasciatus is a major insect pest of stored beans. We have previously reported that the PF2 lectin, which is a protein found in the desert wild legume Olneya tesota (Palo Fierro), is toxic to Z. subfasciatus by inhibiting its early larval development. The use of proteomic means allowed us to identify PF2 targets in the midgut of Z. subfasciatus larvae. However, efforts to completely elucidate the insecticidal mechanism of PF2, as well as novel potential targets for insecticidal compounds, have been hindered by the lack of available genomic and proteomic information of non-model insects. Therefore, in this work we massively sequenced and analyzed the transcripts expressed in the larval stage of Z. subfasciatus, which is the first transcriptome reported for this insect. A total of 29,029 transcript sequences were identified, of which 30 sequences encode putative targets of PF2. The functional characteristics and biochemical, biological, or molecular roles for 15,124 sequences were established by means of bioinformatics tools. This study significantly increased the available genetic resources for Zabrotes and related insect species and will be helpful for any kind of future study that requires information on genes or protein sequences.The available genomic and proteomic information of non-model organisms is often underrepresented in public databases hindering their study at molecular, cellular, and physiological levels. Information on Zabrotes subfasciatus (Mexican bean weevil) is poorly represented in databases, yet it is a major pest of common beans. We report the transcriptome of Z. subfasciatus larvae; transcripts were sequenced using an Illumina RNA-Seq technology and assembled de novo identifying 29,029 unigenes with an average size of 1168 bp and an N50 value of 2196 bp. About 15,124 unigenes (52%) were functionally annotated and categorized. Further analysis revealed 30 unigene sequences encoding putative targets of the insecticidal PF2 lectin. The complete deduced amino acid sequences of eight selected proteins potentially related to insecticidal mechanism of Palo Fierro 2 (PF2) were used for predicting probable N-glycosylation sites and analyzing phylogenetic relationships with insect sequences. This work provides a dramatic increase in the genetic resources available for Coleopterans and set the basis for developing future studies on biological aspects and potential control strategies for Z. subfasciatus.

Changing Plant-based Subsistence Practices among Early and Middle Holocene Communities in Eastern Maghreb

ABSTRACT The eastern Maghreb is a key area for understanding environmental and cultural dynamics during the early and middle Holocene. Capsian populations from around 10000–7500 cal BP were among the last foragers in the region. Capsian sites are known as escargotières (land shell middens), and locally called rammadiyat (meaning ashy mound). As taphonomic conditions in Capsian open-air sites generally favour the preservation of resistant materials such as shells and bones rather than fragile plant remains, this study integrates macro-botanical and microfossil evidence from phytoliths, calcitic wood ash pseudomorphs and dung spherulites, since each is influenced by different formation and post-depositional processes. Archaeobotanical results from recent excavations in four Tunisian sites located across the lowland steppe, the Dorsale Mountains and the eastern coast display a wide range of wild plant resources, such as pine, oak, wild legumes, and grasses, in particular Alfa grass. These findings suggest that these plants could have played an important role in Capsian diet, whereas the presence of Alfa grass suggests the use of fibre sources for basketry, matting, building and fuel. Integrated macro-botanical and microfossil records contribute to a better understanding of changing subsistence practices on the threshold of early food-producing systems in north-west Africa.

Phylogeny of Plant Growth-Promoting Actinobacteria Isolated from Legume Nodules in Turkey

Actinobacteria are a biotechnologically important group of microorganisms utilized for their high capacity to synthesize many bioactive substances as well as agriculturally important compounds. In the present study, a culture-dependant approach was employed to isolate actinobacteria from wild legume nodules and their plant growth-promoting activities for indole-3-acetic acid production, atmospheric nitrogen fixation and inorganic phosphate solubilisation was investigated. A molecular approach based on 16S rRNA gene sequence analysis was employed to identify the isolates. After pairwise sequence analysis, six isolates were identified as members of the genera Streptomyces and Micromonospora. All isolates could produce indole-3-acetic acid and utilize atmospheric nitrogen while only one isolate was able to solubilize inorganic phosphate. The isolated actinobacteria are considered to be promising candidates for biological fertilizers especially because of their ability to use atmospheric nitrogen and produce high level of indole-3-acetic acid.

The Effects of Domestication on Secondary Metabolite Composition in Legumes.

Legumes are rich in secondary metabolites, such as polyphenols, alkaloids, and saponins, which are important defense compounds to protect the plant against herbivores and pathogens, and act as signaling molecules between the plant and its biotic environment. Legume-sourced secondary metabolites are well known for their potential benefits to human health as pharmaceuticals and nutraceuticals. During domestication, the color, smell, and taste of crop plants have been the focus of artificial selection by breeders. Since these agronomic traits are regulated by secondary metabolites, the basis behind the genomic evolution was the selection of the secondary metabolite composition. In this review, we will discuss the classification, occurrence, and health benefits of secondary metabolites in legumes. The differences in their profiles between wild legumes and their cultivated counterparts will be investigated to trace the possible effects of domestication on secondary metabolite compositions, and the advantages and drawbacks of such modifications. The changes in secondary metabolite contents will also be discussed at the genetic level to examine the genes responsible for determining the secondary metabolite composition that might have been lost due to domestication. Understanding these genes would enable breeding programs and metabolic engineering to produce legume varieties with favorable secondary metabolite profiles for facilitating adaptations to a changing climate, promoting beneficial interactions with biotic factors, and enhancing health-beneficial secondary metabolite contents for human consumption.

Iron deficient Medicago scutellata grown in nutrient solution at high pH accumulates and secretes large amounts of flavins

Flavin synthesis and secretion is an integral part of the toolbox of root-borne Fe facilitators used by Strategy I species upon Fe deficiency. The Fe-deficiency responses of the wild legume Medicago scutellata grown in nutrient solution have been studied at two different pH values (5.5 and 7.5). Parameters studied include leaf chlorophyll, nutrient solution pH, concentrations and contents of micronutrients, flavin accumulation in roots, flavin export to the medium, and root ferric chelate reductase and acidification activities. Results show that M. scutellata behaves upon Fe deficiency as a Strategy I species, with a marked capacity for synthesizing flavins (riboflavin and three hydroxylated riboflavin derivatives), which becomes more intense at high pH. Results also show that this species is capable of exporting a large amount of flavins to the external medium, both at pH 5.5 and 7.5. This is the first report of a species having a major flavin secretion at pH 7.5, in contrast with the very low flavin secretion found in other flavin-producing species such as Beta vulgaris and M. truncatula. These results provide further support to the hypothesis that flavin secretion is relevant for Fe acquisition at high pH, and open the possibility to improve the Fe-efficiency responses in legumes of agronomic interest.