Potassium‐induced decrease in cytosolic Na⁺ alleviates deleterious effects of salt stress on wheat (Triticum aestivum L.)

Abstract

Accumulation of NaCl in soil causes osmotic stress in plants, and sodium (Na + ) and chloride (Cl À ) cause ion toxicity, but also reduce the potassium (K + ) uptake by plant roots and stimulate the K + efflux through the cell membrane. Thus, decreased K + /Na + ratio in plant tissue lead us to hypothesise that elevated levels of K + in nutrient medium enhance this ratio in plant tissue and cytosol to improve enzyme activation, osmoregulation and charge balance.• In this study, wheat was cultivated at different concentrations of K + (2.2, 4.4 or 8.8 mM) with or without salinity (1, 60 or 120 mM NaCl) and the effects on growth, root and shoot Na + and K + distribution and grain yield were determined. Also, the cytosolic Na + concentration was investigated, as well as photosynthesis rate and water potential.• Salinity reduced fresh weight of both shoots and roots and dry weight of roots. The grain yield was significantly reduced under Na + stress and improved with elevated K + fertilisation. Elevated K + level during cultivation prevented the accumulation of Na + into the cytosol of both shoot and root protoplasts. Wheat growth at vegetative stage was transiently reduced at the highest K + concentration, perhaps due to plants' efforts to overcome a high solute concentration in the plant tissue, nevertheless grain yield was increased at both K + levels.• In conclusion, a moderately elevated K + application to wheat seedlings reduces tissue as well as cytosolic Na + concentration and enhances wheat growth and grain yield by mitigating the deleterious effects of Na + toxicity.Plant Biology 21 (2019) 825-831

Involvement of l-Cysteine Desulfhydrase and Hydrogen Sulfide in Glutathione-Induced Tolerance to Salinity by Accelerating Ascorbate-Glutathione Cycle and Glyoxalase System in Capsicum

“…Salinized soil and saltwater are the main reasons for the reduced production of most crops [ 4 , 5 ]. Salt stress causes a buildup of sodium (Na + ) and chloride (Cl − ), which causes osmotic and ionic stresses in plants [ 6 , 7 ]. This leads to detrimental effects on both metabolic and biochemical events in plants, and thus causes the inhibition of plant growth and development [ 8 ].…”

Thiourea and hydrogen peroxide priming improved K+ retention and source-sink relationship for mitigating salt stress in rice

“…The Na + dependent inhibition of photosynthesis has been reported in various crops like rice 54 , barley 55 and wheat 56 . The lower Na + accumulation as observed in our study could have facilitated the improved photosynthesis (Table 1B) and overall plant growth and vigor.…”

Green leaf volatile (Z)‐3‐hexeny‐1‐yl acetate reduces salt stress in peanut by affecting photosynthesis and cellular redox homeostasis

“…Glycophyte plants are usually salt‐sensitive and the ratio of K + :Na + is reduced under salt stress (Hauser and Horie , Kronzucker and Britto , Zhu et al ). At the whole‐plant level, the higher ratio of K + :Na + in cytosols could help to enhance the osmotic adjustment ability and maintain a higher cell turgor pressure to combat salt stress (Munns and Tester , Garma et al , Hanin et al , Gul et al ). In accordance with these reports, the present results reveal that exogenous application of Z‐3‐HAC resulted in a significantly higher ratio of K + :Na + in the shoots and roots of both peanut genotypes under salinity conditions (Fig.…”

“…During the course of evolution, plants have developed sophisticated mechanisms to cope with salt stress. A growing body of literature indicates that low‐molecular‐weight substances and phytohormones, such as hydrogen peroxide (H 2 O 2 ; Li et al , Niu et al ), nitric oxide (Zhu et al , Ahmad et al ), melatonin (Arora and Bhatla , Chen et al ), silicon (Zhu et al ), potassium (K + ions; Chakraborty et al , Gul et al ) and jasmonic acid (JA; Qiu et al , Shahzad et al ), are crucial regulators in combating salt stress. These substances could alleviate salt stress by osmotic adjustment, balancing K + :Na + ratios, enhancing the photochemical efficiency of the photosystems and antioxidant systems.…”