Salt-stress-responsive chloroplast proteins in Brassica juncea genotypes with contrasting salt tolerance and their quantitative PCR analysis

Abstract

Brassica juncea is mainly cultivated in the arid and semi-arid regions of India where its production is significantly affected by soil salinity. Adequate knowledge of the mechanisms underlying the salt tolerance at sub-cellular levels must aid in developing the salt-tolerant plants. A proper functioning of chloroplasts under salinity conditions is highly desirable to maintain crop productivity. The adaptive molecular mechanisms offered by plants at the chloroplast level to cope with salinity stress must be a prime target in developing the salt-tolerant plants. In the present study, we have analyzed differential expression of chloroplast proteins in two Brassica juncea genotypes, Pusa Agrani (salt-sensitive) and CS-54 (salt-tolerant), under the effect of sodium chloride. The chloroplast proteins were isolated and resolved using 2DE, which facilitated identification and quantification of 12 proteins that differed in expression in the salt-tolerant and salt-sensitive genotypes. The identified proteins were related to a variety of chloroplast-associated molecular processes, including oxygen-evolving process, PS I and PS II functioning, Calvin cycle and redox homeostasis. Expression analysis of genes encoding differentially expressed proteins through real time PCR supported our findings with proteomic analysis. The study indicates that modulating the expression of chloroplast proteins associated with stabilization of photosystems and oxidative defence plays imperative roles in adaptation to salt stress.

Na2CO3-Responsive Photosynthetic and ROS Scavenging Mechanisms in Chloroplasts of Alkaligrass Revealed by Phosphoproteomics

“…Similarly, Lhcb1 and Lhcb2 increased in abundances by salt in salt-tolerant plants ( e.g.,K. candel , moss ( Physcomitrella patens )), B. juncea , soybean ( Glycine max ), and sugar beet [17,34,35,40,41]. Furthermore, Lhcb3 phosphorylation also increased in alkaligrass (Table 1).…”

Salicylic acid alleviates salinity-caused damage to foliar functions, plant growth and antioxidant system in Ethiopian mustard (Brassica carinata A. Br.)

“…The present study indicates that the salinity-induced loss of the growth and biomass of B. carinata is relatively stronger in cultivar Merawi than in Adet. The saline environment in the soil influences water imbibition by roots due to low osmotic potential of the substrate, besides hampering the phenomena of photosynthesis, protein synthesis, nutrient homeostasis, compatible solutes accumulation and the antioxidant defense mechanisms [5,8,25,53]. The salinity-caused decline in growth and biomass of B. carinata cultivars might be due to reduced leaf area, imbalance in plant water status and low production of photoassimilates [3][4][5]54].…”

“…Plants have exhibited an array of enzymatic and nonenzymatic defense mechanisms to protect cells from oxidative damage [22][23][24][25]. Plant growth regulators such as auxins, brassinosteroid, jasmonates and strigolactones play a vital role in connection with the signaling network and the developmental and adaptive phenomena in plants growing under stress [3,26,27].…”

Zinc application mitigates the adverse effects of NaCl stress on mustard [Brassica juncea (L.) Czern & Coss] through modulating compatible organic solutes, antioxidant enzymes, and flavonoid content

“…Zinc application considerably reduces the salinity-caused damage because of its positive effects on the uptake and partitioning of important mineral elements (Weisany et al 2011(Weisany et al , 2014. It improves plant growth by increasing the natural auxin (indole acetic acid) production and, consequently, activating the cell division and enlargement (Ali and Mahmoud 2013), maintaining membrane structural integrity (Weisany et al 2014), accumulating phospholipids (Jiang et al 2014), improving protein synthesis (Ebrahimian and Bybordi 2011), scavenging free oxygen radicals (Jiang et al 2014), mediating nutrient translocation from developing cells (Jiang et al 2014), and restricting excessive Na + and Cl − uptake (Weisany et al 2011;Siddiqui et al 2015;Yousuf et al 2016aYousuf et al , 2016b.…”