Development of Cowpea (Vigna unguiculata) Mutant Lines for Dissecting Resilience to Drought Through Physiological and Molecular Crosstalk Analysis
Plant molecular biology reporter, Jun 21, 2024
Additional file 5 of GWAS unveils features between early- and late-flowering pearl millets
Additional file 5.
Bridging the gap in African biodiversity genomics and bioinformatics
Nature Biotechnology
The Open Institute of the African BioGenome Project empowers African scientists and institutions ... more The Open Institute of the African BioGenome Project empowers African scientists and institutions with the skill sets, capacity and infrastructure to advance scientific knowledge and innovation and drive economic growth.
The domesticated Vigna species still need some of the beneficial characters that exist in the wil... more The domesticated Vigna species still need some of the beneficial characters that exist in the wild Vigna species, despite the improvements obtained so far. This study was carried out to enhance our understanding of the Senegalese wild Vigna diversity by exploring the agro-morphological characteristics of some accessions using 22 traits. The phenotyping was carried out in a shaded house for two consecutive rainy seasons (2021 and 2022) using the alpha-lattice experimental design with 55 accessions. Multiple correspondence analysis was carried out based on the qualitative traits, which showed considerable variability for the wild species (Vigna unguiculata var. spontanea, Vigna racemosa, Vigna radiata and the unidentified accession). The quantitative traits were subjected to statistical analysis using descriptive statistics and ANOVA. Our results revealed that ninety-five percent (95%) pod maturity ranged from 74.2 to 125.8 days in accession 3 of V. unguiculata and in accession 92 (V....
Minireview - Genetic transformation of forest trees
ABSTRACT In this review, the recent progress on genetic transformation of forest trees were discu... more ABSTRACT In this review, the recent progress on genetic transformation of forest trees were discussed. Its described also, different applications of genetic engineering for improving forest trees or understanding the mechanisms governing genes expression in woody plants.
Nodulation of transgenic #Casuarina glauca# root
La transformation genetique des casuarinaceae : un outil pour l'etude moleculaire des symbioses actinorhiziennes
Casuarina glauca et allocasuarina verticillata sont deux especes ligneuses de la famille des casu... more Casuarina glauca et allocasuarina verticillata sont deux especes ligneuses de la famille des casuarinaceae capables d'etablir une symbiose fixatrice d'azote avec un actinomycete du sol, frankia. Afin d'introduire des genes etrangers dans ces especes, nous avons choisi deux strategies de transformation. La premiere strategie est basee sur l'utilisation de la souche sauvage a4rs d'agrobacterium rhizogenes pour induire des racines transformees chez c. Glauca. Environ 70% des plantes inoculees au niveau de l'hypocotyle avec a4rs porteuse du gene uida sous le controle du promoteur 35s presentent des racines au point de blessure au bout de trois semaines. La nature transformee de ces racines a ete demontree par l'amplification en chaine par polymerase et par la realisation de tests histochimiques. Apres elimination de la racine principale, 40% des plantes chimeres inoculees par la souche thr de frankia presentent des nodules. L'analyse histochimique de l'expression du gene uida dans les nodules transformes montre une activite gus dans tous les tissus a l'exception des cellules infectees par frankia et des cellules du periderme. Dans la deuxieme strategie nous avons utilise la souche c58c1(pgv2260) desarmee d'agrobacterium tumefaciens comme vecteur de transformation d'a. Verticillata. Des embryons zygotiques matures ont ete blesses puis cocultives avec la souche c58c1(pgv2260) porteuse du gene uida sous le controle du promoteur 35s et du gene marqueur nptii. Environ deux mois apres culture sur milieu nutritif contenant des phytohormones et un marqueur de selection, 21% des embryons ont donne naissance a des cals dont 70% produisent des plantes au bout de six mois. La presence du gene uida dans le genome de ces plantes a ete demontree par analyse qualitative et quantitative de l'activite gus, par amplification en chaine par polymerase des transgenes et par la technique de southern. Des nodules fixateurs d'azote ont ete produits apres inoculation avec la souche allo2 de frankia. Les deux strategies mises au point ont ete utilisees pour analyser l'expression du gene rapporteur gus sous le controle de promoteurs des genes d'hemoglobine symbiotique (lbc3 de soja et hb de parasponia) et non symbiotique (hb de trema) de legumineuses et de non legumineuses chez c. Glauca et a. Verticillata. Les resultats obtenus indiquent que les mecanismes qui gouvernent l'expression de ces genes sont conserves entre non legumineuses, legumineuses et plantes actinorhiziennes
Background Asian rice Oryza sativa, first domesticated in East Asia, has considerable success in ... more Background Asian rice Oryza sativa, first domesticated in East Asia, has considerable success in African fields. When and where this introduction occurred is unclear. Rice varieties of Asian origin may have evolved locally during and after migration to Africa, resulting in unique adaptations, particularly in relation to upland cultivation as frequently practiced in Africa. Methods We investigated the genetic differentiation between Asian and African varieties using the 3000 Rice Genomes SNP dataset. African upland cultivars were first characterized using principal component analysis among 292 tropical Japonica accessions from Africa and Asia. The particularities of African accessions were then explored using two inference techniques, PCA-KDE for supervised classification and chromosome painting, and ELAI for individual allelic dosage monitoring. Key Results Ambiguities of local differentiation between Japonica and other groups pointed at genomic segments that potentially resulted from genetic exchange. Those specific to West African upland accessions were concentrated on chromosome 6 and featured several cAus introgression signals, including a large one between 17.9 and 21.7 Mb. We found iHS statistics in support of positive selection in this region and we provide a list of candidate genes enriched in GO terms that have regulatory functions involved in stress responses that could have facilitated adaptation to harsh upland growing conditions.
An increasing number of candidate genes related to abiotic stress tolerance are being discovered ... more An increasing number of candidate genes related to abiotic stress tolerance are being discovered and proposed to improve the existing cultivars of the high oil-bearing crop sesame (Sesamum indicum L.). However, the in planta functional validation of these genes is remarkably lacking. In this study, we cloned a novel sesame R2-R3 MYB gene SiMYB75 which is strongly induced by drought, sodium chloride (NaCl), abscisic acid (ABA) and mannitol. SiMYB75 is expressed in various sesame tissues, especially in root and its protein is predicted to be located in the nucleus. Ectopic over-expression of SiMYB75 in Arabidopsis notably promoted root growth and improved plant tolerance to drought, NaCl and mannitol treatments. Furthermore, SiMYB75 over-expressing lines accumulated higher content of ABA than wild-type plants under stresses and also increased sensitivity to ABA. Physiological analyses revealed that SiMYB75 confers abiotic stress tolerance by promoting stomatal closure to reduce water loss; inducing a strong reactive oxygen species scavenging activity to alleviate cell damage and apoptosis; and also, up-regulating the expression levels of various stress-marker genes in the ABAdependent pathways. Our data suggested that SiMYB75 positively modulates drought, salt and osmotic stresses responses through ABA-mediated pathways. Thus, SiMYB75 could be a promising candidate gene for the improvement of abiotic stress tolerance in crop species including sesame.
Unlike most of the important food crops, sesame can survive drought but severe and repeated droug... more Unlike most of the important food crops, sesame can survive drought but severe and repeated drought episodes, especially occurring during the reproductive stage, significantly curtail the productivity of this high oil crop. Genome-wide association study was conducted for traits related to drought tolerance using 400 diverse sesame accessions, including landraces and modern cultivars. Ten stable QTLs explaining more than 40% of the phenotypic variation and located on four linkage groups were significantly associated with drought tolerance related traits. Accessions from the tropical area harbored higher numbers of drought tolerance alleles at the peak loci and were found to be more tolerant than those from the northern-area, indicating a long-term genetic adaptation to drought-prone environments. We found that sesame has already fixed important alleles conferring survival to drought which may explain its relative high drought tolerance. However, most of the alleles crucial for productivity and yield maintenance under drought conditions are far from been fixed. This study also revealed that pyramiding the favorable alleles observed at the peak loci is of high potential for enhancing drought tolerance in sesame. In addition, our results highlighted two important pleiotropic QTLs harboring known and unreported drought tolerance genes such as SiABI4, SiTTM3, SiGOLS1, SiNIMIN1 and SiSAM. By integrating candidate gene association study, gene expression, and transgenic experiments, we demonstrated that SiSAM confers drought tolerance by modulating polyamine levels and ROS homeostasis, and a missense mutation in the coding region partly contributes to the natural variation of drought tolerance in sesame.
After decades of research on cowpea, significant amount of omics datasets are available and usefu... more After decades of research on cowpea, significant amount of omics datasets are available and useful in understanding the genetic relationship between Vigna unguiculata ssp. unguiculata and other species belonging to the same genus as well as its genetic variation. Besides, the development of genetic map allowed the chromosome localization of molecular markers associated with disease resistance, seed weight, dehydrin, drought-induced genes, maturity and earliness, and the recent progresses made on cowpea genomic resources development and the availability of a genetic transformation protocol increased the chance to identify more genes and to study their expression. In addition, transcriptomic datasets suggested that many genes are expressed during drought, heating or in nitrogen deficiency conditions as well as during symbiosis and iron storage. Proteomic and metabolomic analyses revealed that the protein and metabolite fractions specifically accumulated in the embryogenic cell suspension and in manganese toxicity conditions, respectively. However, the integration of all these information will promote the improvement of cowpea production.
DNA-based relatedness of cowpea [Vigna unguiculata (L.) Walp.] genotypes using DNA amplification fingerprinting
Physiology and Molecular Biology of Plants, 2000
DAF technology applied to two parental inbred lines (ITS 84-2049 and 524 B) and four other select... more DAF technology applied to two parental inbred lines (ITS 84-2049 and 524 B) and four other selected varieties of cowpea (Mougne, Ndiambour, Mouride and Diogoma) revealed informative and reproducible banding patterns. The different lines showed several common bands but also some specific ones which attest of intra-varietal diversity also revealed by the inheritance of agronomical and botanical traits. The abundance of DNA bands showed that DAF markers are very informative for the determination of genotypic variation in cowpea, and suggests that these markers can be used for breeding purpose to quickly analyze and efficiently identify candidates for crossing. These markers are also an excellent complement to RAPD and RFLP markers already integrated into the cowpea map established at UC Davis California). DAF analysis and PAGE/SS are easy and very powerful technologies to screen the national cowpea germplasm collection in Senegal.
Cowpea
Springer eBooks, 2014
ABSTRACT Cowpea (Vigna unguiculata (L.) Walp.) is an important warm-season legume grown mostly by... more ABSTRACT Cowpea (Vigna unguiculata (L.) Walp.) is an important warm-season legume grown mostly by the poor farmers in the semiarid tropics for human con-sumption and animal feeding. The crop was originated from Africa where it was domesticated from its wild progenitor V. unguiculata subsp. unguiculata var spontanea . In addition, single nucleotide polymorphism markers (SNP) analysis suggested different domestication events from East to West Africa or single domestication process in the fi rst region followed by transportation in the second. On the basis of molecular analyses, the genome organization of the crop was intensively studied, leading to the identifi cation of two gene pools and gene fl ow between cultivated and wild forms or crop to crop can be a threat to the breeding programs. A wide range of biotic (virus, bacteria, fungi, insects, nematodes, and plants) and abiotic (like low phosphorus avail-ability, soil acidity or salinity, drought, and high temperature at night) factors are limiting cowpea production in different parts of the world. To overcome these constraints, diverse programs were implemented for base broadening using interspecifi c hybridization between cowpea and other members of its genus with limited success because of pre-zygotic and post-zygotic barriers. These failures led the investigators to implement protocols to introduce for-eign genes into cowpea. Currently, several genes of interest such as herbicide imazapyr , α-amylase inhibitor 1 (against bruchids), and Cry1Ab and Cry1Ac (against Maruca) have been introduced successfully into commercially
In this review, the recent progress on genetic transformation of forest trees were discussed. Its... more In this review, the recent progress on genetic transformation of forest trees were discussed. Its described also, different applications of genetic engineering for improving forest trees or understanding the mechanisms governing genes expression in woody plants.
Cowpea, Vigna unguiculata (L.) Walp. presents phenotypical variabilities and in order to study th... more Cowpea, Vigna unguiculata (L.) Walp. presents phenotypical variabilities and in order to study the genetic diversity of cultivated Senegalese varieties, two experimental approaches were used. First, a physiological characterization based on nitrogen fixation was used to assess cowpea breeding lines. Inoculation with two Bradyrhizobium strains (NGR234 and ISRA312), showed a difference in nitrogen fixation potential between the cowpea varieties. Diongoma is the highest nitrogen fixing variety, whereas Mouride is the lowest. The second approach employed genetic characterization based on DNA polymorphism to screen. Results suggest that random amplified polymorphic DNA (RAPD) technology can be used to reorganize the national germplasm in order to eliminate the putative duplicates, and to identify elite varieties.
Sesame is an important oilseed crop with a high oil quality. It is prone to drought stress in the... more Sesame is an important oilseed crop with a high oil quality. It is prone to drought stress in the arid and semi-arid areas where it is widely grown. This study aims to decipher the response of tolerant (DT) and sensitive (DS) genotypes to progressive drought based on transcriptome, biochemical and physio-anatomical characterizations. Results indicated that under severe stress, DT relied on a wellfunctioning taproot while DS displayed a disintegrated root due to collapsed cortical cells. This was attributed to a higher accumulation of osmoprotectants and strong activity of antioxidant enzymes especially peroxidases in DT. From roots, DT could supply water to the aboveground tissues to ensure photosynthetic activities and improve endurance under stress. Temporal transcriptome sequencing under drought further confirmed that DT strongly activated genes related to antioxidant activity, osmoprotection and hormonal signaling pathways including abscisic acid and Ethylene. Furthermore, DT displayed unique differentially expressed genes in root functioning as peroxidases, interleukin receptor-associated kinase, heat shock proteins, APETALA2/ethylene-responsive element-binding protein and mitogen activated protein kinase, to effectively scavenge reactive oxygen species and preserve root cell integrity. Finally, 61 candidate genes conferring higher drought tolerance in DT were discovered and may constitute useful resources for drought tolerance improvement in sesame.
ABSTRACT Actinorhizal nodules or actinorhizae represent the most typical example of modified non ... more ABSTRACT Actinorhizal nodules or actinorhizae represent the most typical example of modified non pathogenic roots (nodule lobes), induced by signals synthetized by the microsymbiont. The formation of a nodule lobe occurs in four steps: infection of the root hair by Frankia, formation of the prenodule, initiation and nodule lobe infection. The nodule lobe comprises four distinct zones which are the result of the Frankia acropetal growth and of the differentiation of tissues originating from the apical meristem. In situ hybridization studies of the expression of nif genes of Frankia show that the zone of infected mature cells (zone III) is the zone where the nitrogen fixation is the greatest. Similitudes and differences with organogenesis of the nodules of legumes are displayed and the interest of this primitive symbiosis is emphasized.
Sesame is a survivor crop cultivated for ages in arid areas under high temperatures and limited w... more Sesame is a survivor crop cultivated for ages in arid areas under high temperatures and limited water conditions. Since its entire genome has been sequenced, revealing evolution, and functional characterization of its abiotic stress genes became a hot topic. In this study, we performed a whole-genome identification and analysis of Hsf gene family in sesame. Thirty genes encoding Hsf domain were found and classified into 3 major classes A, B, and C. The class A members were the most representative one and Hsf genes were distributed in 12 of the 16 linkage groups (except the LG 8, 9, 13, and 16). Evolutionary analysis revealed that, segmental duplication events which occurred around 67 MYA, were the primary force underlying Hsf genes expansion in sesame. Comparative analysis also suggested that sesame has retained most of its Hsf genes while its relatives viz. tomato and potato underwent extensive gene losses during evolution. Continuous purifying selection has played a key role in the maintenance of Hsf genes in sesame. Expression analysis of the Hsf genes in sesame revealed their putative involvement in multiple tissue-/developmental stages. Time-course expression profiling of Hsf genes in response to drought stress showed that 90% Hsfs are drought responsive. We infer that classes B-Hsfs might be the primary regulators of drought response in sesame by cooperating with some class A genes. This is the first insight into this gene family and the results provide some gene resources for future gene cloning and functional studies toward the improvement in stress tolerance of sesame.
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