Project description:In present study we compared transcriptional response to salinity stress between susceptible CO 12 and tolerant genotype trichy 1 of finger millet. We found out that several functional group of genes like transporters, transcription factors, genes involved in cell signalling, osmotic homeostasis, compatible solutes biosynthesis were upregulated more in tolerant genotype as compared to susceptible genotype in response to salinity stress. Salnity inhibited photosynthetic capacity and photosynthesis related genes more in susceptible genotype as compared to tolerant genotype. Identified genes are excellent targets for further functional studies in order to understand more specific molecular mechanisms of salt tolerance in two genotypes of finger millet and can be further used for developing salinity tolerant crops through genetic engineering.
Project description:Foxtail millet (Setaria italica L. P. Beauv) has been considered as a tractable model crop in recent years due to its short growing cycle, lower repetitive DNA, inbreeding nature, small diploid genome, and outstanding abiotic stress-tolerance characteristics. With modern agriculture often facing various adversities, it’s urgent to dissect the mechanisms of how foxtail millet responds and adapts to drought and stress on the proteomic-level.
Project description:Rhizosphere is a complex system of interactions between plant roots, bacteria, fungi and animals, where the release of plant root exudates stimulates bacterial density and diversity. However, the majority of the bacteria in soil results to be unculturable but active. The aim of the present work was to characterize the microbial community associated to the root of V. vinifera cv. Pinot Noir not only under a taxonomic perspective, but also under a functional point of view, using a metaproteome approach. Our results underlined the difference between the metagenomic and metaproteomic approach and the large potentiality of proteomics in describing the environmental bacterial community and its activity. In fact, by this approach, that allows to investigate the mechanisms occurring in the rhizosphere, we showed that bacteria belonging to Streptomyces, Bacillus and Pseudomonas genera are the most active in protein expression. In the rhizosphere, the identified genera were involved mainly in phosphorus and nitrogen soil metabolism.
Project description:Improved understanding of bacterial-fungal interactions in the rhizosphere should assist in the successful application of bacteria as biological control agents against fungal pathogens of plants, providing alternatives to chemicals in sustainable agriculture. To understand the functional response of the fungal phytopathogen Rhizoctonia solani to different bacteria and to elucidate whether the molecular mechanisms that the fungus exploits involve general stress or more specific responses, we performed a global transcriptome profiling of R. solani Rhs1AP anastomosis group 3 (AG-3) during interaction with the S4 and AS13 species of Serratia using RNA-seq. Transcriptome analysis revealed that approximately 10% of the fungal transcriptome was differentially expressed during challenge with Serratia. The numbers of S4- and AS13-specific differentially expressed genes (DEG) were 866 and 292 respectively, while there were 1035 common DEGs in the two treatment groups. Four hundred and sixty and 242 genes respectively had fold values exceeding 8x and for further analyses this cut-off value was used. Functional classification of DEGs revealed a general shift in fungal gene expression in which genes related to xenobiotic degradation, toxin and antioxidant production, energy, carbohydrate and lipid metabolism and hyphal rearrangements were subjected to transcriptional regulation. In conclusion, it was found out that most genes were regulated in the same way in the presence of both bacterial isolates, but there were also some strain-specific responses. The findings in this study will be beneficial for further research on biological control and in depth exploration of bacterial-fungal interactions in the rhizosphere.
Project description:<p>Biological nitrogen fixation by free-living bacteria and rhizobial symbiosis with legumes plays a key role in sustainable crop production. Here, we study how different crop combinations influence the interaction between peanut plants and their rhizosphere microbiota via metabolite deposition and functional responses of free-living and symbiotic nitrogen-fixing bacteria. Based on a long-term (8 year) diversified cropping field experiment, we find that peanut co-cultured with maize and oilseed rape lead to specific changes in peanut rhizosphere metabolite profiles and bacterial functions and nodulation. Flavonoids and coumarins accumulate due to the activation of phenylpropanoid biosynthesis pathways in peanuts. These changes enhance the growth and nitrogen fixation activity of free-living bacterial isolates, and root nodulation by symbiotic Bradyrhizobium isolates. Peanut plant root metabolites interact with Bradyrhizobium isolates contributing to initiate nodulation. Our findings demonstrate that tailored intercropping could be used to improve soil nitrogen availability through changes in the rhizosphere microbiome and its functions.</p>
Project description:Elevated atmospheric CO2 can influence the structure and function of rhizosphere microorganisms by altering root growth and the quality and quantity of compounds released into the rhizosphere via root exudation. In these studies we investigated the transcriptional responses of Bradyrhizobium japonicum cells growing in the rhizosphere of soybean plants exposed to elevated atmospheric CO2. The results of microarray analyses indicated that atmospheric elevated CO2 concentration indirectly influences on expression of large number of Bradyrhizobium genes through soybean roots. In addition, genes involved in C1 metabolism, denitrification and FixK2-associated genes, including those involved in nitrogen fixation, microanaerobic respiration, respiratory nitrite reductase, and heme biosynthesis, were significantly up-regulated under conditions of elevated CO2 in the rhizosphere, relative to plants and bacteria grown under ambient CO2 growth conditions. The expression profile of genes involved in lipochitinoligosaccharide Nod factor biosynthesis and negative transcriptional regulators of nodulation genes, nolA and nodD2, were also influenced by plant growth under conditions of elevated CO2. Taken together, results of these studies indicate that growth of soybeans under conditions of elevated atmospheric CO2 influences gene expressions in B. japonicum in the soybean rhizosphere, resulting in changes to carbon/nitrogen metabolism, respiration, and nodulation efficiency.
Project description:Pearl millet is a major cereal crop that feeds more than 90 million people worldwide in arid and semi-arid regions. The stalk phenotypes of Poaceous grasses are critical for their productivity and stress tolerance, however, the molecular mechanisms governing stalk development in pearl millet remained to be deciphered. In this study, we spatiotemporally measured 19 transcriptomes for stalk internodes of four different early developmental stages. Data analysis of the transcriptomes defined 4 developmental zones on the stalks and identified 12 specific gene sets with specific expression patterns across the zones. Using weighted gene co-expression network analysis (WGCNA), we found that 2 co-expression modules together with candidate genes were involved in stalk elongation and thickening of pearl millet. Among the elongation-related candidate genes, we established by SELEX that a MYB-family transcription factor PMF7G02448 can bind to the promoters of three cell wall synthases genes (CesAs). In summary, these findings provide insights into stalk development and offer potential targets for future genetic improvement of pearl millet.
Project description:Microbial communities in the rhizosphere make significant contributions to crop health and nutrient cycling. However, their ability to perform important biogeochemical processes remains uncharacterized. Important functional genes, which characterize the rhizosphere microbial community, were identified to understand metabolic capabilities in the maize rhizosphere using GeoChip 3.0-based functional gene array method.