Isolation and Identification of miRNAs in Jatropha curcas

licenses/by-nc-nd/3.0/). Reproduction is permitted for personal, noncommercial use, provided that the article is in whole, unmodified, and properly cited. Received: 2011.10.19; Accepted: 2012.02.20; Published: 2012.02.28 MicroRNAs (miRNAs) are small noncoding RNAs that play crucial regulatory roles by tar-geting mRNAs for silencing. To identify miRNAs in Jatropha curcas L, a bioenergy crop, cDNA clones from two small RNA libraries of leaves and seeds were sequenced and analyzed using bioinformatic tools. Fifty-two putative miRNAs were found from the two libraries, among them six were identical to known miRNAs and 46 were novel. Differential expression pat-terns of 15 miRNAs in root, stem, leave, fruit and seed were detected using quantitative re-al-time PCR. Ten miRNAs were highly expressed in fruit or seed, implying that they may be involved in seed development or fatty acids synthesis in seed. Moreover, 28 targets of the isolated miRNAs were predicted from a jatropha cDNA library database. The miRNA target genes were predicted to encode a broad range of proteins. Sixteen targets had clear BLASTX hits to the Uniprot database and were associated with genes belonging to the three major gene ontology categories of biological process, cellular component, and molecular function