Proteome responses of pearl millet genotypes under salinity

Abstract

Soil salinity is a major problem worldwide, and plants counteract the salt-stress with various cellular strategies. A vast advancement has been achieved for elucidation of abiotic stress-tolerance mechanisms using high-throughput methods of proteomics. In the present study, two pearl millet genotypes with contrasting salt-stress tolerance were selected on the basis of our previous study for large-scale screening of 33 pearl millet accessions, showing differences in their morpho-physiological parameters and stress-related gene expression under salinity. They were subjected to comparative whole proteome analysis after treatment with 150 mm NaCl. We have observed 295 and 315 protein spots on Sypro-Ruby stained 2-DE gels for the tolerant (Tol) and sensitive (Sen) accessions, respectively, in the range of 12-200 kDa MW and 4-7 pI. Data obtained for differential protein expression indicated that maximum proteins exhibited reduced expression in the sensitive accession, while most of them were highly upregulated salt-induced proteins in the tolerant accession. The present study provided a possible insight into the regulatory mechanism of salinity-stress tolerance at whole proteome level. The tolerant genotype of pearl millet can be used as a potential source of novel candidate genes responsible for imparting salinity-stress tolerance. It can further be exploited to develop salt-tolerant crop plants through biotechnological interventions.