Abstract
Salinity is an extensive and adverse environmental stress to crop plants across the globe, and a major abiotic constraint responsible for limited crop production threatening the crop security. Soil salinization is a widespread problem across the globe, threatening the crop production and food security. Salinity impairs plant growth and development via reduction in osmotic potential, cytotoxicity due to excessive uptake of ions such as sodium (Na+) and chloride (Cl−), and nutritional imbalance. Cotton, being the most cultivated crop on saline-alkaline soils, it is of great importance to elucidate the mechanisms involved in Na2SO4 tolerance which is still lacking in upland cotton. Zhong 9835, a Na2SO4 resistant cultivar was screened for transcriptomic studies through various levels of Na2SO4 treatments, which results into identification of 3329 differentially expressed genes (DEGs) in roots, stems and leave at 300 mM Na2SO4 stress till 12 h in compared to control. According to gene functional annotation analysis, genes involved in reactive oxygen species (ROS) scavenging system including osmotic stress and ion toxicity were significantly up-regulated, especially GST (glutathione transferase). In addition, analysis for sulfur metabolism, results in to identification of two rate limiting enzymes [APR (Gh_D05G1637) and OASTL (Gh_A13G0863)] during synthesis of GSH from SO42−. Furthermore, we also observed a crosstalk of the hormones and TFs (transcription factors) enriched in hormone signal transduction pathway. Genes related to IAA exceeds the rest of hormones followed by ubiquitin related genes which are greater than TFs. The analysis of the expression profiles of diverse tissues under Na2SO4 stress and identification of relevant key hub genes in a network crosstalk will provide a strong foundation and valuable clues for genetic improvements of cotton in response to various salt stresses.
Highlights
Salinity is an extensive and adverse environmental stress to crop plants across the globe, and a major abiotic constraint responsible for limited crop production threatening the crop security
The calcium sensor SOS3 interacts and activates the serine/threonine protein kinase SOS2 with an increase in cytosolic free calcium levels, which results in the activation of the plasma membrane-localized Na+/H+ antiporter SOS1 to export the Na+ out of the cell to prevent the accumulation of toxic material[12]
The Ca2+ signaling pathway and ion transport showed the crosstalk with SOS system to enhance salt tolerance13. Ca2+ binding proteins mainly include CDPKs containing the catalytic domain of serine/threonine protein kinase, CAMs with an EF-hand unit that binds Ca2+, and CBLs (Calcineurin B-like proteins) which consist of a single CIPKs protein[14]
Summary
Salinity is an extensive and adverse environmental stress to crop plants across the globe, and a major abiotic constraint responsible for limited crop production threatening the crop security. Soil salinity is a major environmental factor which limits the growth and development of plants, resulting in decrease in crop productivity and quality[1]. To cope with the oxidative damage resulting from ROS, the enzymatic antioxidants (SOD, APX, PRX, GPX, CAT, GRX and TRX) and non-enzymatic scavengers (ASA, GSH, metabolite of proline, tocopherols, carotenoids and phenolic compounds)[21], and the hormones signaling pathway with a lot of transcription factors (TFs), such as abscisic acid (ABA) signaling p athway[22,23], developed a complex regulatory network for plant growth. Previous studies have shown that the majority of plant hormones related to salt stress are melatonin, ETH (ethylene), BR (brassinolactone), ASA (ascorbic acid), IAA/auxin and ABA (abscisic acid) 24,25 These hormones mainly increases the plant salt tolerance by scavenging active oxygen[26]. Salt stress can induce the accumulation of endogenous ABA, and induce the expression of E3 ubiquitin ligase or others transcription factors[25,27], ion transporter[22], antioxidant enzyme[28] and other salt stress-related genes to enhance plant salt tolerance[29]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
