Project description:Plant-plant associations, notably cereal-legume intercropping, have been proposed in agroecology to better value resources and thus reduce the use of chemical inputs in agriculture. Wheat-pea intercropping allows to decreasing the use of nitrogen fertilization through ecological processes such as niche complementarity and facilitation. Rhizosphere microbial communities may account for these processes, since they play a major role in biogeochemical cycles and impact plant nutrition. Still, knowledge on the effect of intecropping on the rhizosphere microbiota remains scarce. Especially, it is an open question whether rhizosphere microbial communities in cereal-legume intercropping are the sum or not of the microbiota of each plant species cultivated in sole cropping. In the present study, we assessed the impact of wheat and pea in IC on the diversity and structure of their respective rhizosphere microbiota. For this purpose, several cultivars of wheat and pea were cultivated in sole and intercropping. Roots of wheat and pea were collected separately in intercropping for microbiota analyses to allow deciphering the effect of IC on the bacterial community of each plant species/cultivar tested. Our data confirmed the well-known specificity of the rhizosphere effect and further stress the differentiation of bacterial communities between pea genotypes (Hr and hr). As regards the intercropping effect, diversity and structure of the rhizosphere microbiota were comparable to sole cropping. However, a specific co-occurrence pattern in each crop rhizosphere due to intercropping was revealed through network analysis. Bacterial co-occurrence network of wheat rhizosphere in IC was dominated by OTUs belonging to Alphaproteobacteria, Bacteroidetes and Gammaproteobacteria. We also evidenced a common network found in both rhizosphere under IC, indicating the interaction between the plant species; this common network was dominated by Acidobacteria, Alphaproteobacteria, and Bacteroidetes, with three OTUs belonging to Acidobacteria, Betaproteobacteria and Chloroflexi that were identified as keystone taxa. These findings indicate more complex rhizosphere bacterial networks in intercropping. Possible implications of these conclusions are discussed in relation with the functioning of rhizosphere microbiota in intercropping accounting for its beneficial effects.
Project description:Pea (Pisum. sativum L.) is a traditional and important edible legume that can be sorted into grain pea and vegetable pea according to their harvested maturely or not. Vegetable pea by eating the fresh seed is becoming more and more popular in recent years. These two type peas display huge variations of the taste and nutrition, but how seed development and nutrition accumulation of grain pea and vegetable pea and their differences at the molecular level remains poorly understood. To understand the genes and gene networks regulate seed development in grain pea and vegetable pea, high throughput RNA-Seq and bioinformatics analysis were used to compare the transcriptomes of vegetable pea and grain pea developing seed. RNA-Seq generated 18.7 G raw data, which was then de novo assembled into 77,273 unigenes with a mean length of 930 bp. Functional annotation of the unigenes was carried out using the nr, Swiss-Prot, COG, GO and KEGG databases. There were 459 and 801 genes showing differentially expressed between vegetable pea and grain pea at early and late seed maturation phases, respectively. Sugar and starch metabolism related genes were dramatically activated during pea seed development. The up-regulated of starch biosynthesis genes could explain the increment of starch content in grain pea then vegetable pea; while up-regulation of sugar metabolism related genes in vegetable pea then grain pea should participate in sugar accumulation and associated with the increase in sweetness of vegetable pea then grain pea. Furthermore, transcription factors were implicated in the seed development regulation in grain pea and vegetable pea. Thus, our results constitute a foundation in support of future efforts for understanding the underlying mechanism that control pea seed development and also serve as a valuable resource for improved pea breeding.
Project description:The economic importance of wheat and its contribution to human and livestock diets has been already demonstrated. However, wheat production is impacted by pests that induce yield reductions. Among these pests, wheat curl mite (WCM, Aceria tosichella Keifer) impacts wheat all around the world. WCM are tiny pests that feed within the whorl of developing leaves and prevent the leaves from unfurling by causing leaves curling. The curling of the leaves provides a protective niche for the WCM. Additionally, WCM are also the vector of serious viruses in wheat. Little is known regarding the impact of the WCM on wheat transcriptome, and to date, only one article has been published describing the wheat transcriptomic changes after 1 day of WCM feeding. To better understand the wheat transcriptome variation after long-term feeding by WCM (10 days post infestation (dpi)), we used an RNA-seq approach. We collected leaves uninfested and infested with WCR from two wheat cultivars: Byrd (WCM resistant) and Settler CL (WCM susceptible) at 10 dpi. Our transcriptomic analysis revealed the common and specific transcriptomic variations in WCM resistant and susceptible wheat cultivars, chromosome specific location of the differentially expressed genes, and also identified the gene functions and pathways involved in WCM resistance. Collectively, our study provides important insights on wheat defense mechanisms against WCM after long-term feeding.
Project description:Purpose: Identify differentially expressed genes between 5 pea aphid morphs Methods: Collected whole bodies of 30 adult aphids of each of the five pea morphs and three clones (total of 15 samples)
Project description:In angiosperms, the mature seed consists of an embryo (E), a seed coat (SC), and, in many cases, an endosperm. In contrast to knowledge about embryo and endosperm, we have relatively little knowledge of SC, especially at the genomics level. In this study, we analyzed the gene expression during seed development using the panel of cultivated and wild pea genotypes. We report the comprehensive gene expression changes related both to development as well as domestication status. Analysis of seed developmental stages revealed extensive modification of gene expression between wild pea progenitor and cultivated pea crop. A significant difference in gene expression dynamics appeared between early and late developmental stages D1, D2, and D3, D4, D5 in wild pea genotypes, where the expression was increased 3-5-fold and 5-10-fold, respectively. Our work extends knowledge about the role of the seed coat during pea seed development. We described gene expression dynamic resulting in specific metabolic profiles providing new insight into pea domestication.
Project description:Rhizobium leguminosarum biovar viciae strain Rlv3841 was grown for 7 days in the rhizosphere of either 7 day old pea, alfalfa or sugarbeet before being harvested.