Differential growth and yield responses of salt-tolerant and susceptible rice cultivars to individual (Na+ and Cl−) and additive stress effects of NaCl

Abstract

Negative impacts exerted by sodium (Na ? ) and chloride (Cl -) ions individually as well their possible additive effects (under NaCl) were evaluated on growth and yield reductions in rice, besides investigating whether salt-tolerant genotypes respond differentially than their sensitive counterparts. Though both Na ? and Cl -ions get accumulated in plant tissues under NaCl stress, most research has historically been aimed to decipher harmful effects induced by Na ? ions. Accordingly, physiological and molecular mechanisms involved in Cl -toxicity are not clearly understood in crop plants. To address these issues, 65-day-old plants of two rice cultivars, Panvel-3 (tolerant) and Sahyadri-3 (sensitive) were subjected to Cl -, Na ? and NaCl (each with 100 mM concentration and electrical conductivity of &10 dS m -1 ) stress using soil-based systems. Stress conditions were maintained till harvesting of mature (128-day-old) plants. All three treatments induced substantial antagonistic effects on growth, dry mass, yield components (number of grains per panicle, length, width, thickness and weight of grain, along with the percentage of grains filled) and overall crop yield, with greater impacts under NaCl than its constituent ions. Salinity treatments caused an imbalance in reducing sugars, protein, starch and proline contents, with the greatest magnitude under NaCl.A negative correlation between Cl -/Na ? accumulation and crop yield was witnessed, with higher severity on the sensitive cultivar. The overall magnitude of toxicity was observed highest in NaCl followed by Na ? and Cl -, respectively, suggesting additive effects of constituent ions under NaCl. Both cultivars responded similarly; however, the tolerant cultivar, unlike the sensitive one, kept Na ? :K ? ratio \1.0 and accumulated proline in response to salinity treatments used in this study.

Upregulation of antioxidant and glyoxalase systems mitigates NaCl stress inBrassica junceaby supplementation of zinc and calcium

“…Earlier, Arshi et al (2010) also observed a significant reduction in Na/K in salt-stressed Glycine max as a result of Ca supplementation and it has been suggested that calcium and potassium show much similarity in behavior during the selective transport of ions across the membranes (Boursier and Läuchli 1990). Decreases in yield attributes by NaCl stress in the present study corroborates with the findings of Kumar and Khare (2016) in rice. Size of grain and its shape is very important as it determines its quality.…”

“…Salinity stress decreases the yield and yield components in rice seedlings (Mohammadi et al 2013). Kumar and Khare (2016) also reported reduced grain yield and quality of yield in rice seedlings under NaCl stress. Accumulation of Na + has been reported to hamper many important biological functions such as photosynthesis, respiration, and uptake of nutrients (Ahmad et al 2015, Ahmad et al 2016b, Ahanger and Agarwal 2017.…”

Effect of Enterobacter sp. CS2 and EDTA on the Phytoremediation of Ni-contaminated Soil by Impatiens balsamina

“…High proline contents represent Ni stress in plants growing in contaminated media [44]. The susceptible cultivars show less proline contents as compared to resistant ones when subjected to the same level of abiotic stress [45]. The increased proline contents improve plant resistance against heavy metal stress [46].…”

Varietal differences in physiological and biochemical responses to salinity stress in six finger millet plants

“…The resistance and response of plants to a salt stress varies according to its species or varieties or genotypes or variety and environment which could be attributed to the biological dissimilarities between the species or varieties or genotypes, plant growth, and composition and concentration of the salt stress conditions (Bertazzini et al, 2018; Filichkin et al, 2018; Shabala et al, 2013). Many reports have shown that short term salinity stress significantly affects the germination rate, seedling and root growth as well as ion composition, levels of relative water content, photosynthetic pigments, proline content, level of membrane lipid peroxidation as well as the amounts of reducing sugars and total protein (Dugasa et al, 2019; Sarabi et al, 2017; Kumar and Khare, 2016). These physiological and biochemical indices multivariate cluster analysis been used for classification of salt-sensitive and salt-tolerant varieties so that they can further be used in plant breeding programmes.…”

“…The crop is well adapted to heat, drought and poor soil stress in marginal and degraded soils. Further, its cereals have comparatively better antioxidant and nutraceutical properties and superb storage qualities which lack in other cereals (Kumar et al, 2016). All these attributes make finger millet one of the important and promising plant genetics resources for agriculture, and food and nutritional security and alleviation of poverty of poor farmers who live in arid, infertile and marginal lands.…”