Transposon mutagenesis of ACC deamination gene alters the proteomic analysis of wheat plant under non-saline and saline stress

Abstract

The development of high-throughput techniques with evolving bioinformatics tools has elucidated the adaptation mechanism of plant to certain environmental stress like salinity. The characterization of proteins is critical for plant stress responses and it provides the comprehensive information about the cellular and biochemical pathway involved in various stress mitigation. In the present work, we provide the information about the alteration in wheat proteomic profile in response to plant growth-promoting rhizobacterial (PGPR)-inoculation under abiotic stress like salinity. PGPR facilitate the plant growth and enhance their induced systemic tolerance (ISR) under various stress conditions. The present study was aimed to generate the AcdS− mutant of Enterobacter cloacae SBP-8 which differs in its ability to breakdown the stress ethylene precursor ‘ACC’ (1-aminocyclopropane-1-carboxylic acid). The proteomic profile of wheat (Triticum aestivum L.) plant was investigated under non-saline and high salinity stress (200 mM NaCl) following wild type and its mutant inculcation. A total of four treatments were taken to monitor the differential expression of proteins in the wheat seedlings exposed to high salt stress for 15 days. The major changes concerned the proteins involved in metabolism, ion-transport, photosynthesis, defense and stress responses. The observed changes at the proteomic level in each treatment can be related to effects of salt and bacterial inoculation. The identified proteins were further classified into cellular, biological and molecular function. Bacterial inoculation significantly enhanced the expression of Thioredoxin and Ninja family proteins in addition to Heat shock proteins (Hsp70, Hsp 90), which play a major role in defense against abiotic stress. Taken together, the observed results suggest that bacterial inoculation alleviated the salinity-induced damages by improving the metabolism, photosynthesis and defense-related proteins.