Expression of drought responsive genes in pigeonpea and in silico comparison with soybean cDNA library

Pigeonpea, a drought tolerant, semi-arid pulse crop has been investigated for the expression of differentially expressed genes (DEGs) under drought stress. The cDNA library of soybean leaf tissue retrieved from the Unigene database of the NCBI, were compared for in silico expression using IDEG6 web statistical tool. A list of 52 non-redundant DEGs consisting of 11 up-regulated and 41 down-regulated was obtained. Among these, more photosynthesis and light harvesting proteins were down-regulated in drought stress conditions. Pathways were assigned based on KEGG database, revealing 32 genes involved in 17 metabolic pathways. Homologous sequences of six up-regulated genes namely, ADF3, APB, ASR, DLP, LTP1, and UGE5 were then used for quantitative reverse transcription PCR (qRT-PCR) in pigeonpea. The qRT-PCR result revealed the significant up-regulation of dehydrin-like protein (DLP) (5.02 log2 fold) and down-regulation of acid phosphatase class B family protein (APB) (9.43 log2 fold) and non-specific lipid transfer protein 1-like (LTP1) (18.81 log2 fold) in pigeonpea water-stressed leaf sample compared to well-watered leaf samples. No significant difference was observed in the stressed root compared to the stressed pigeonpea leaf sample except that APB showed an up-regulation of 11.35 log2 fold chang