Submitted on January 18, 2007
Revised on August 1, 2007
Accepted on August 7, 2007
Comparative proteomic analysis of differentially expressed proteins in chickpea extracellular matrix during dehydration stress
Deepti Bhushan, Aarti Pandey, Mani Kant Choudhary, Asis Datta, Subhra Chakraborty, and Niranjan Chakraborty
National Centre for Plant Genome Research, New Delhi, Delhi 110067
Corresponding Author: nchakraborty{at}hotmail.com
Water-deficit or dehydration is the most crucial environmental factor that limits crop productivity and influences geographical distribution of many crop plants. It is suggested that dehydration responsive changes in expression of proteins may lead to cellular adaptation against water-deficit conditions. Most of the earlier understanding of dehydration responsive cellular adaptation has evolved from transcriptome analyses. By contrast, comparative analysis of dehydration responsive proteins (DRPs), particularly proteins in the subcellular fraction, is limiting. In plants, cell wall or extracellular matrix (ECM) serves as the repository for most of the components of cell signaling process and acts as front-line defense. Thus, we have initiated a proteomic approach to identify dehydration responsive ECM proteins in a food legume, chickpea. Several commercial chickpea varieties were screened for the status of dehydration tolerance using different physiological and biochemical indexes. Dehydration responsive temporal changes of ECM proteins in JG-62, a relatively tolerant variety, revealed 186 proteins with variance at 95% significance level statistically. The comparative proteomic analysis led to the identification of 134 differentially expressed proteins that include predicted and novel DRPs. This study, for the first time, demonstrates that over a hundred ECM proteins, presumably involved in a variety of cellular functions viz., cell wall modification, signal transduction, metabolism, and cell defense and rescue, impinge on the molecular mechanism of dehydration tolerance in plants.