Withania somnifera Transcriptome or Gene expression

Withania somnifera (L.) Dunal (Family, Solanaceae), is one of the most important medicinal plants synthesizing large number of pharmacologically active secondary metabolites known as withanolides. Though the plant has been characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the genes responsible for biosynthesis of these compounds. Phytochemical profiling suggests that withanolide biosynthesis may take place differentially in leaf and root tissues as well as in different chemotypes of Withania with differences in the content and/or nature of withanolide moiety. To develop basic understanding about withanolide biosynthesis in different chemotypes, we established transcriptome sequences of leaf and root tissues of NMITLI-135 chemotype using 454 pyrosequencing. The transcriptome data obtained was of 207 and 172 MB with 708367 and 598182 ESTs in leaf and root libraries respectively. Assembly of data yielded 20135 contigs and 66176 singletons in NMITLI-135 leaf and 18413 contigs and 79737 singletons in NMITLI-135 root transcriptomes. Each transcriptome had approximately 52% large contigs with an average length of 905.5 bps. Each library was annotated using BLASTx against TAIR10, nr and tomato databases. Using established transcriptome, we have identified total 1974 and 1966 SSR markers for leaf and root, which will help in future genetic studies of this valuable medicinal plant.