Project description:Background: The soil environment is responsible for sustaining most terrestrial plant life on earth, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere and how it responds to agricultural management such as crop rotations and soil tillage will be vital for improving global food production. Methods: The rhizosphere soils of wheat and chickpea growing under + and - decaying root were collected for metagenomics sequencing. A gene catalogue was established by de novo assembling metagenomic sequencing. Genes abundance was compared between bulk soil and rhizosphere soils under different treatments. Conclusions: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the microbiome from decaying root in determining the metagenome of developing root systems, which is fundamental to plant growth, since roots preferentially inhabit previous root channels. Modifications in root microbial function through soil management, can ultimately govern plant health, productivity and food security.
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.
Project description:In this study, we aim to present a global view of transcriptome dynamics during various abiotic stresses in chickpea. We generated about 252 million high-quality reads from eight libraries (control, desiccation, salinity and cold stress samples for roots and shoots) using Illumina high-throughput sequencing GAII platform. We mapped the reads to the desi chickpea genome for estimation of their transcript abundance in different tissue samples. The transcriptome dynamics was studied by differential gene expression analyses between stress treatment and control sample.
Project description:Alternaria brassicae is a necrotrophic fungal pathogen which infects brassica crops and lead to huge loss in crop production. There is a need to exploit the novel resistance mechanism against A. brassicae. Under field condition, chickpea is the potential nonhost plant for A. brassicae. At molecular level, it is not known how the NHR in chickpea operates against A. brassicae. In present study, we did the transcriptomic analysis in chickpea plants exposed to nonhost pathogen, A. brassicae by using microarray. Chickpea plants were spray inoculated with the spore suspension of A. brassicae. The leaf samples were harvested after 24 hpi and 48 hpi from pathogen treated plants and from the mock-treated control plants. The Transcriptome analysis were done from the leaf samples obtained at both the time-points by microarray using Agilent ChickpeaGXP_8X60K chip. Our result suggested the robust transcriptional reprogramming leading to defense response against A. brassicae.
Project description:Purpose: To identify Fusarium wilt and salt-responsive miRNAs at genome wide level in Chickpea. Results: A total of 12,135,571 unique reads were obtained. In addition to 122 conserved miRNAs belonging to 25 different families, 59 novel miRNAs along with their star sequences were identified. Four legume specific miRNAs, miR5213, miR5232, miR2111 and miR2118 were found in all the libraries. The Poly (A) tailing assay based qRT-PCR was used to validate eleven conserved and five novel miRNAs. miR530 was highly up regulated in response to fungal infection and targets zinc knuckle and microtubule-associated proteins. Many miRNAs responded in a similar fashion under both biotic and abiotic stresses indicating a cross talk between the pathways involved in regulating these stresses. The potential target genes for the conserved and novel miRNAs were predicted based on sequence homology. miR166 targets a HD-ZIPIII transcription factor and was validated by 5’ RLM-RACE. Conclusions: The present study has led to identification of several conserved and novel miRNAs in chickpea associated with gene regulation in reference to wilt and salt stress conditions. This study will help in better understanding of how chickpea functions in response to stresses. Total three small RNA libraries from chickpea were prepared and sequenced independently [Control (C), Wilt stress (WS), Salt stress (SS)] on Illumina GAIIx.
Project description:Background The combination of high-throughput transcript profiling and next-generation sequencing technologies is a prerequisite for genome-wide comprehensive transcriptome analysis. Our recent innovation of deepSuperSAGE is based on an advanced SuperSAGE protocol and its combination with massively parallel pyrosequencing on RocheM-bM-^@M-^Ys 454 sequencing platform. As a demonstration of the power of this combination, we have chosen the salt stress transcriptomes of roots and nodules of the third most important legume crop chickpea (Cicer arietinum L.). While our report is more technology-oriented, it nevertheless addresses a major world-wide problem for crops generally: high salinity. Together with low temperatures and water stress, high salinity is responsible for crop losses of millions of tons of various legume (and other) crops. Continuously deteriorating environmental conditions will combine with salinity stress to further compromise crop yields. As a good example for such stress-exposed crop plants, we started to characterize salt stress responses of chickpeas on the transcriptome level. Results We used deepSuperSAGE to detect early global transcriptome changes in salt-stressed chickpea. The salt stress responses of 86,919 transcripts representing 17,918 unique 26bp deepSuperSAGE tags (UniTags) from roots of the salt-tolerant variety INRAT-93 two hours after treatment with 25 mM NaCl were characterized. Additionally, the expression of 57,281 transcripts representing 13,115 UniTags was monitored in nodules of the same plants. From a total of 144,200 analyzed 26bp tags in roots and nodules together, 21,401 unique transcripts were identified. Of these, only 363 and 106 specific transcripts, respectively, were commonly up- or down-regulated (>3.0-fold) under salt stress in both organs, witnessing a differential organ-specific response to stress. Profiting from recent pioneer works on massive cDNA sequencing in chickpea, more than 9,400 UniTags were able to be linked to UniProt entries. Additionally, gene ontology (GO) categories over-representation analysis enabled to filter out enriched biological processes among the differentially expressed UniTags. Subsequently, the gathered information was further cross-checked with stress-related pathways. From several filtered pathways, here we focus exemplarily on transcripts associated with the generation and scavenging of reactive oxygen species (ROS), as well as on transcripts involved in Na+ homeostasis. Although both processes are already very well characterized in other plants, the information generated in the present work is of high value. Information on expression profiles and sequence similarity for several hundreds of transcripts of potential interest is now available. Conclusions This report demonstrates, that the combination of the high-throughput transcriptome profiling technology SuperSAGE with one of the next-generation sequencing platforms allows deep insights into the first molecular reactions of a plant exposed to salinity. Cross validation with recent reports enriched the information about the salt stress dynamics of more than 9,000 chickpea ESTs, and enlarged their pool of alternative transcripts isoforms. As an example for the high resolution of the employed technology that we coin deepSuperSAGE, we demonstrate that ROS-scavenging and -generating pathways undergo strong global transcriptome changes in chickpea roots and nodules already 2 hours after onset of moderate salt stress (25mM NaCl). Additionally, a set of more than 15 candidate transcripts are proposed to be potential components of the salt overly sensitive (SOS) pathway in chickpea. Newly identified transcript isoforms are potential targets for breeding novel cultivars with high salinity tolerance. We demonstrate that these targets can be integrated into breeding schemes by micro-arrays and RT-PCR assays downstream of the generation of 26bp tags by SuperSAGE. SuperSAGE libraries from chickpea roots and nodules were constructed starting from hydro aeroponics-generated material. Control and stressed plants were grown in parallel Sequencing Instrument: First gerenration 454-Machine Place of sequencing: 454 Life Sciences, Branford, CT, USA