Effects of External Potassium (K) Supply on Drought Tolerances of Two Contrasting Winter Wheat Cultivars

Abstract

BackgroundDrought is a common stress limiting crops growth and productivities worldwide. Water deficit may increase cellular membrane permeability, resulting in K outflow. Internal K starvation may disorder plant metabolism and limit plant growth. However, it is seldom reported about the effects of external K on drought tolerance of contrasting wheat cultivars.Methodology/Principal FindingsA hydroponics experiment was carried out in a non-controlled greenhouse. Seedlings of drought-tolerant SN16 and intolerant JM22 were simultaneously treated by five levels of K2CO3 (0, 2.5, 5, 7.5, 10 mM) and two levels of PEG6000 (0, 20%) for 7 days. External K2CO3 significantly increased shoot K+ content, water potential, chlorophyll content as well as gas exchange, but decreased electrolyte leakage (EL) and MDA content in both cultivars under PEG6000 stress. Antioxidant enzymes activities were up-regulated by PEG6000 while external K2CO3 reduced those changes. Molecular basis was explained by measuring the expression levels of antioxidant enzymes related genes. Shoot and root biomass were also increased by K2CO3 supply under drought stress. Although adequate K2CO3 application enhanced plant growth for both cultivars under drought stress, SN16 was better than JM22 due to its high drought tolerance.Conclusions/SignificanceAdequate external K may effectively protect winter wheat from drought injuries. We conclude that drought-tolerant wheat combined with adequate external K supply may be a promising strategy for better growth in arid and semi-arid regions.

Effects of water and potassium stresses on potassium utilization efficiency of two cotton genotypes

“…Our research indicated that the concentrations of K + in various cotton organs under the OPT-W treatment were higher than that under the OPT-W-K treatment ( Table 2). Wei et al (2013) found that external K may increase plant drought tolerance of wheat by enhancing internal K + concentration under drought stress, which was consistent with our result. Soil moisture can also influence the uptake rate of K via affecting its mobility from the soil to the root surface.…”

Foliar Application of Potassium Sulfate Partially Alleviates Pre-anthesis Drought-induced Kernel Abortion in Maize

“…Similarly, K is essential for cell turgor maintenance via osmotic adjustment (DaCosta and Huang, 2006) and transpiration control via stomatal regulation (Jin et al, 2011) under drought stress. In a hydroponic study, external supply of K in the nutrient medium has been shown to improve drought tolerance in wheat cultivars by improving water potential, chlorophyll contents, gas exchange and an effective reactive oxygen species scavenging (Wei et al, 2013). Foliar application of K is also shown to improve maize yield under rainfed conditions (Anees et al, 2016).…”

Phytotoxicity assessment on corn stover biochar, derived from fast pyrolysis, based on seed germination, early growth, and potential plant cell damage

“…As a result, the malondialdehyde (MDA) content and the activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), were extensively applied as the sensitive biomarkers for the damnification of plants in contaminated soil or adversity stresses (Sun et al 2010;Wei et al 2013). Thus, this provides the possibility to employ the antioxidant enzymes and MDA to further investigate the potential toxicity of biochar to plants.…”