Jatropha 454 Transcriptome sequencing
De novo assembly and transcriptome analysis of five major tissues of Jatropha curcas L. using GS FLX Titanium Platform of 454 pyrosequencing
Jatropha curcas L. is an important non edible oilseed crop with promising future in biodiesel production. However, factors like oil quantity, quality, toxicity of seed cake, pests and diseases limit its commercial potential. Well established genetic engineering methods using cloned genes could be used to address these limitations.  Earlier we have cloned 7,009 unigenes by sequencing 12,084 ESTs from the developing seeds of J. curcas using Sanger's method. In order to expedite the process of gene discovery, we have undertaken high throughput 454 pyrosequencing of the cDNA fragments prepared from roots, mature leaves, flowers, developing seeds, and embryos of the same species. Here we report the assembly of 17,457 transcripts from 381,957 reads with an average read length of 343 bases. Average length of the assembled transcripts was 916 bp. About 30% of the assembled transcripts were longer than 1000 bases, and the size of the longest transcript was 7,173 bases. BLASTX result revealed that 2,589 of these transcripts represent full length genes. The assembled transcripts were validated by RT-PCR analysis of 28 randomly selected transcripts, and the results showed that the transcripts were correctly assembled and represent actively expressed genes. KEGG pathway mapping showed that 2,320 transcripts are related to major biochemical pathways. This included 56 genes coding for 29 enzymes and proteins involved in oil biosynthesis. This is a significant outcome of the current study because cloned genes are essential for genetic manipulation of the oil biosynthesis pathway in jatropha to make it an ideal biodiesel crop.