Agronomic and Proteomic Assessment of Salt Stress Responses in <i>Pennisetum glaucum</i> (Pearl Millet) Genotypes

Abstract

Salinity is one of the environmental stresses that alter protein expression. To evaluate that, two ICRISAT Pennisetum glaucum (pearl millet) genotypes (IP 19586 and IP 22269) were subjected to 0.3 dSm-1 and 10 dSm-1 salinities. The agronomic parameters and ion content were assessed to find the tolerance level of the genotype to salinity. Differential expression of proteins on salt stress in both genotypes were analyzed by 2-dimensional gel electrophoresis. MALDI–MS/MS-TOF-TOF analysis helped in ascertain the amino acid sequences and the MASCOT search suggested the biological process of the predicted proteins. IP 22269 exclude the accumulation of toxic level of sodium in leaf. Based on physiological responses, IP 22269 was proposed to be salt-sensitive, and IP 19586 salt-tolerant genotypes. 67 proteins were responsive either less or more abundant to salinity. As per findings, the proteins responsive to salt stress are granule-bound starch synthase 1, alpha-amylase, Meiotic recombination protein SPO11, flavonoid 3'- monooxygenase, ethylene receptor 4, protein transcription initiation factor Y 11g, and auxin-responsive protein IAA16. Further, based on the STRING analysis these proteins form a protein-protein interaction network with 171 proteins. This research elucidates few salt stress tolerance traits and network between the salt stress-responsive mechanisms in pearl millet.