Evaluation of proteome complexes normalizing osmoregulation in salt stressed Luffa acutangula (L.) Roxb.

Abstract

Modern-day agriculture is facing the challenge of sustaining global food security. However, the rapid increase in salinity stress among arable areas poses a major threat to crop health and yield. Salinity stress is one of the most common and rapidly spreading stress that has a detrimental effect on the productivity of edible plant family i.e. Cucurbitaceae. The present study endeavors to evaluate the Osmoregulators (anti-oxidants and proteins), that supports the growth of two varieties of Luffa acutangula (L.) Roxb. under salt stress. The 2-3 weeks old saplings were exposed to salt stress (up to 200 mM NaCl) for one week. Post-treatment the osmoregulatory metabolites like Trehalose, Proline & enzymic anti-oxidants like peroxidase (POD), Superoxide dismutase (SOD) and proteins using LC-MS/MS were analyzed. In both the varieties, Trehalose increased with increasing salt concentration, while the level of Proline increased in Variety 1 and decreased in Variety 2. With increasing salt concentrations, the POD activity decreased in both varieties whereas that of SOD levels increased in Variety 2 and decreased in Variety 1. The protein identified by LC-MS/MS and functional annotation analysis employing Uniport database & BlastP algorithm, aided in the detection of differentially expressed proteins in response to salt stress. This was followed by metabolic interaction annotation enrichment analysis by FunRich 3.0 tool, enabling characterization of proteins to be involved in the Calvin cycle, amino acids biosynthesis, carbohydrate and energy metabolism, ROS defence, hormonal biosynthesis and signal transduction. The augmentation of the metabolic activities of the Calvin cycle, biosynthesis of amino acids, carotenoids and peroxisomes, glycolytic pathway and the tricarboxylic acid cycle will conceivably influence the photosynthetic capacity in L. acutangula varieties under salt stress. The upsurge of key enzymes involved in these above described biological processes possibly appears to play an important role in the enhancement of salt tolerance.