Project description:MicroRNAs or miRNAs are endogenously encoded small RNAs that play a key role in diverse plant biological processes. Jatropha curcas L. has received much attention as a potential oilseed crop for the production of renewable oil. Here, a sRNA library from mature seeds and three mRNA libraries, from three different stages of seed development, were generated by deep sequencing in order to identify and characterize miRNAs and pre-miRNAs of J. curcas. Computation analysis allowed the identification of 180 conserved miRNAs and 41 precursors (pre-miRNAs), as well as 16 novel pre-miRNAs. The predicted miRNA target genes are involved in a broad range of physiological functions, including cellular structure, nuclear function, translation, transport, hormone synthesis, defense and also lipid metabolism. Some of pre-miRNA and miRNA targets have different abundance among the three stages of seed development. A search for sequences that produce siRNA was performed indicating that J. curcas siRNAs play a role in nuclear functions, transport, catalytic process and diseases resistance. This study presents the first large scale identification of J. curcas miRNAs and their targets in mature seeds based on deep sequencing and contributes to understand the function of these miRNAs. microRNA identification in a mature seed library of Jatropha curcas by deep sequencing (Illumina HiSeq2000).
Project description:Jatropha is known for its ability to grow in marginal lands and drought prone areas receiving limited amounts of rainfall. Accordingly, gene discovery in Jatropha will be useful for providing a source of genetic information for the improvement of drought tolerance in crops. In this study, a Jatropha oligomicroarray was developed to evaluate the gene expression profile of Jatropha plants during drought stress response and recovery from stress. When the gene expression patterns were compared between those differentially expressed during exposure to drought stress and re-watering, it was possible to identify 333 genes that are involved in the response to dehydration, while 592 genes were found to be significant during recovery, and 375 genes are associated in both dehydration and recovery. Furthermore, representative genes from the three gene categories were compared to those found in other plant species and a basic understanding on how Jatropha copes with drought and its mechanism for survival in dry conditions is discussed. Taken together, the oligomicroarray that we developed in this study is a useful tool for analyzing expression profiles of Jatropha genes to better understand molecular mechanism underlying drought stress responses as well as other aspects of molecular studies in Jatropha.
Project description:MicroRNAs or miRNAs are endogenously encoded small RNAs that play a key role in diverse plant biological processes. Jatropha curcas L. has received much attention as a potential oilseed crop for the production of renewable oil. Here, a sRNA library from mature seeds and three mRNA libraries, from three different stages of seed development, were generated by deep sequencing in order to identify and characterize miRNAs and pre-miRNAs of J. curcas. Computation analysis allowed the identification of 180 conserved miRNAs and 41 precursors (pre-miRNAs), as well as 16 novel pre-miRNAs. The predicted miRNA target genes are involved in a broad range of physiological functions, including cellular structure, nuclear function, translation, transport, hormone synthesis, defense and also lipid metabolism. Some of pre-miRNA and miRNA targets have different abundance among the three stages of seed development. A search for sequences that produce siRNA was performed indicating that J. curcas siRNAs play a role in nuclear functions, transport, catalytic process and diseases resistance. This study presents the first large scale identification of J. curcas miRNAs and their targets in mature seeds based on deep sequencing and contributes to understand the function of these miRNAs.
Project description:Jatropha curcas, a tropical shrub, is an attractive biofuel crop, which produces seeds with a high content of oil and protein. Most J. curcas accessions contain a range of toxins and anti-nutritional compounds, which are unfavorable for human consumption and animal feed. With the goal of better understanding the development of its seeds and to improve Jatropha`s agronomic performance, a two-step approach was performed: 1) generation of the entire transcriptome of six different developmental stages of J. curcas seeds using 454-Roche sequencing of a cDNA library, 2) comparison of transcriptional expression levels in six different developmental stages of seeds using a custom Agilent 8x60K oligonucleotide gene expression microarray. A total of 793,875 high quality reads with an average length of 358 bp were generated and assembled into 19,841 unique full-length contigs, of which 13,705 could be annotated with GO terms. Microarray data analysis identified a total of 9,111 contigs which were differentially expressed between the six developmental stages (based on P-value of < 1e-8). The microarray-based differential expression results were validated for 192 putative genes using high-throughput quantitative real-time PCR. Results from Gene Ontology (GO) and pathway enrichment analysis showed that the upstream biosynthesis pathways were relatively active among differentially expressed sequences (DESs) during seed development, such as starch and sucrose metabolism, glycolysis/gluconeogenesis, glycerophospholipid metabolism, amino sugar and nucleotide sugar metabolism. Further, DESs related to hormone and seed development, flavonoid biosynthesis-related pathways were over-represented. A pairwise comparison was used to discover particular seed maturation dependent patterns of gene expression. Genes related to fatty acid biosynthesis were over represented in early stage, while flavonoid biosynthesis in the late stage. The data provide a useful resources and references for the seed transcriptome of J. curcas and other related species with oil producing seeds. The identified transcripts related to seed development provide a starting point for further investigation into the molecular mechanisms underlying this process.