Ameliorative Effects of Silicon against Salt Stress in Gossypium hirsutum L.

Abstract

Silicon (Si) could alleviate the adverse effect of salinity in many crops, but the effect in cotton remains unclear. In this study, we evaluated the role of Si in regulating the salt stress tolerance of cotton by analyzing the induced morpho-physiological changes. A hydroponic experiment was conducted by using contrasting salt-tolerant cotton genotypes (sensitive Z0102; tolerant Z9807) and four treatments (CK, control; CKSi, 0.4 mM Si; NaCl, 150 mM NaCl; NaClSi, 150 mM NaCl+0.4 mM Si). The results showed that Si significantly enhanced the net photosynthesis rate and improved the growth of cotton seedling under salt stress in both salt-sensitive and salt-tolerant genotypes. Exogenous Si significantly reduced the accumulation of reactive oxygen species (ROS) and decreased the malondialdehyde (MDA) content in salt-stressed cotton. In addition, the application of Si up-regulated the expression of CAT1, SODCC and POD, and significantly enhanced the antioxidant enzymatic activities, such as catalase (CAT) and peroxidase (POD), of the salt-stressed cotton seedlings. Further, Si addition protected the integrity of the chloroplast ultrastructure, including key enzymes in photosynthesis such as ferredoxin-NADP reeducates (FNR), ATP synthase (Mg2+Ca2+-ATPase) and ribulose-1, 5-bisphosphate carboxylase/oxygenase (RubisCO), and the structure and function of the photosynthetic apparatus PSII from salt stress. Moreover, Si significantly increased the effective stomatal density and stomatal aperture in the salt-stressed cotton seedlings. Taken together, Si could likely ameliorate adverse effects of salt stress on cotton by improving the ROS scavenging ability and photosynthetic capacity.

B. subtilisCNBG‐PGPR‐1 induces methionine to regulate ethylene pathway and ROS scavenging for improving salt tolerance of tomato

“…Salt stress causes ion toxicity and osmotic stress, which can lead to the accumulation of high levels of ROS, resulting in ROS toxicity (Li et al., 2018, 2022; Zhou et al., 2017). The GO enrichment analysis above has shown that CNBG‐PGPR‐1 may enhance the antioxidant capacity of plants (Figure 4c,d).…”

“…Regarding tomato roots, CNBG‐PGPR‐1‐inoculated tomatoes had lower H 2 O 2 content under both nonsalt and salt conditions, with reductions of 38.93% and 37.40%, respectively, compared to the control. Malondialdehyde (MDA) is the final decomposition product of membrane lipid peroxidation, and its content can reflect the degree of plant oxidative injury (Li et al., 2022). Similarly, the MDA content also increased when subjected to salt stress.…”

Genotypic variation in carbon and nitrogen metabolism in the cotton subtending leaves and seed cotton yield under various nitrogen levels

“…To calculate MDA content, about 0.5 g of leaf sample was used following the standard protocol 24,53 . Similarly, 0.5 g leaf sample was used to determine the enzymes related to the antioxidant system using 5 mL of 50 mmol L −1 phosphate buffer solution.…”

“…To calculate MDA content, about 0.5 g of leaf sample was used following the standard protocol. 24,53 Similarly, 0.5 g leaf sample was used to determine the enzymes related to the antioxidant system using 5 mL of 50 mmol L −1 phosphate buffer solution. The superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities were measured according to the published protocols.…”

Phosphorus Availability Affects the Photosynthesis and Antioxidant System of Contrasting Low-P-Tolerant Cotton Genotypes

“…Photosynthesis is an essential process that generates energy to support plant growth. Components participating in photosynthetic machinery, such as photosynthetic pigments, photosystems, electron-transport systems, gas-exchange processes, and enzymes involved in carbon metabolism, are important for photosynthetic efficiency [6,7]. Photosynthesis commonly declines under P deficiency, since P is involved in several cellular processes, including energy conservation, metabolic regulation, and signal transduction [8].…”