Tavakol Ershad, Jákli Bálint, Cakmak Ismail, Dittert Klaus, Senbayram Mehmet
K+S Minerals and Agriculture GmbH, Bertha-von-Suttner Str. 7, 34041 Kassel, Germany.
Land Surface-Atmosphere Interactions, Technical University of Munich, Hans-Carl-v.-Carlowitz-Platz 2, 85354 Freising, Germany.
Plants (Basel). 2021 Dec 25;11(1):55. doi: 10.3390/plants11010055.
Potassium (K) is the most abundant cation in plants, playing an important role in osmoregulation. Little is known about the effect of genotypic variation in the tolerance to osmotic stress under different K treatments in barley. In this study, we measured the interactive effects of osmotic stress and K supply on growth and stress responses of two barley cultivars ( L.) and monitored reactive oxygen species (ROS) along with enzymatic antioxidant activity and their respective gene expression level. The selected cultivars (cv. Milford and cv. Sahin-91Sahin-91) were exposed to osmotic stress (-0.7 MPa) induced by polyethylene glycol 6000 (PEG) under low (0.04 mM) and adequate (0.8 mM) K levels in the nutrient solution. Leaf samples were collected and analyzed for levels of K, ROS, kinetic activity of antioxidants enzymes and expression levels of respective genes during the stress period. The results showed that optimal K supply under osmotic stress significantly decreases ROS production and adjusts antioxidant activity, leading to the reduction of oxidative stress in the studied plants. The cultivar Milford had a lower ROS level and a better tolerance to stress compared to the cultivar Sahin-91. We conclude that optimized K supply is of great importance in mitigating ROS-related damage induced by osmotic stress, specifically in drought-sensitive barley cultivars.
钾（K）是植物中含量最丰富的阳离子，在渗透调节中起重要作用。关于不同钾处理下大麦对渗透胁迫耐受性的基因型变异影响，人们了解甚少。在本研究中，我们测定了渗透胁迫和钾供应对两个大麦品种（L.）生长和胁迫响应的交互作用，并监测了活性氧（ROS）以及酶促抗氧化活性及其各自的基因表达水平。所选品种（米尔福德品种和萨欣 - 91品种）在营养液中低（0.04 mM）和充足（0.8 mM）钾水平下，暴露于由聚乙二醇6000（PEG）诱导的渗透胁迫（-0.7 MPa）。在胁迫期间收集叶片样本，分析钾、ROS、抗氧化酶的动力学活性以及各自基因的表达水平。结果表明，渗透胁迫下最佳的钾供应显著降低ROS产生并调节抗氧化活性，从而减少所研究植物中的氧化胁迫。与萨欣 - 91品种相比，米尔福德品种的ROS水平较低且对胁迫的耐受性更好。我们得出结论，优化钾供应对于减轻渗透胁迫诱导的与ROS相关的损伤非常重要，特别是对于干旱敏感的大麦品种。
