Treatment with 24-epibrassinolide mitigates NaCl-induced toxicity by enhancing carbohydrate metabolism, osmolyte accumulation, and antioxidant activity in Pisum sativum

Abstract

A pot culture study was performed to evaluate the differences between salt-stressed pea (Pisum sativum L.) plants of tolerant (Climax and Samarina Zard) and sensitive (Ambassidar and PF-400) genotypes, and to determine whether treatment with 24-epibrassinolide (EBL) could enhance the accumulation of osmolytes and antioxidant activity and thereby induce tolerance in saltstressed plants. Three-week-old seedlings were subjected to +NaCl (5 dS m -1 ) and -NaCl conditions (0 dS m -1 ). After 4 days of salt stress, the plants were sprayed with Milli-Q water or EBL (0.125 mg L -1 ). The plants were sampled at 32 days after sowing and at the final maturity stage. Half-strength Hoagland solution was used as the nutrient medium. Both the tolerant and sensitive plants subjected to saline condition showed decreases in germination percentage, embryo axis length, plant fresh/dry biomass, leaf area, chlorophyll content, relative water content (RWC), photosynthesis, rubisco content, rubisco activity, stomatal conductance, number of stomata, stomatal size, number of epidermal cells, and yield attributes and increases in lipid peroxidation, total phenolics content, proline content, glycine betaine content, total amino acids content, total soluble sugars content, sucrose content, sucrose phosphate synthase activity, sucrose synthase activity, and activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase, ascorbate peroxidase, and guaiacol peroxidase). Salt stress had a less deleterious effect on Climax and Samarina Zard than on Ambassidar and PF-400. The foliar application of EBL mitigated the deleterious effects of NaCl by improving growth, productivity, and gas exchange attributes and by further enhancing the concentrations of the above osmolytes and antioxidants, particularly in the tolerant genotypes. The enhanced concentrations of osmolytes and antioxidants may have induced salt tolerance in the plants subjected to saline conditions, resulting in improved growth, gas exchange attributes, and yield.

Regulation of Growth and Physiological traits of Cucumber (Cucumis sativus L.) through various levels of 28-Homobrassinolide under salt stress conditions

“…NaCl. The increase in the weight of cucumber plants foliar-sprayed with BRs may be due to the positive effect on accumulation of various osmolytes (Zeng et al 2010;Shahid et al 2014), cell division, and cell enlargement (Hu et al 2000). Brassinoids control a wide range of biological activities that enhance the stress tolerance of plants and cell elongation and genetically enhancing BR biosynthesis (Divi and Krishna 2009) regulates growth, biomass, and metabolism (Yuan et al 2012).…”

The Mitigation Effects of Exogenous Hydrogen Peroxide when Alleviating Seed Germination and Seedling Growth Inhibition on Salinity-Induced Stress in Barley

“…Therefore, the delay in growth of barley can be explained by the suppression of germination under salt stress. Various plant growth regulators and osmoprotectans are used to alleviate the detrimental effects of salt stress on plants [35][36][37]. They act by either increasing nutrient intake and transfer, or protecting osmotic balance [36].…”

Exogenous Brassinolide Alleviates Salt Stress in Malus hupehensis Rehd. by Regulating the Transcription of NHX-Type Na+(K+)/H+ Antiporters

“…Reactive oxygen species (ROS) induced by salt stress is alleviated by antioxidant systems, including antioxidants and antioxidant enzymes (Tofighi et al, 2017;Wu et al, 2017). The accumulation of osmolytes, such as sorbitol, proline, and lycine, is critical to osmotic balance (Shahid et al, 2014;Yusuf et al, 2017). Maintaining homeostasis of Na + and K + in cells by activating Na + and K + transporters is vital for plant salt stress tolerance (Azhar et al, 2017).…”