Mechanism of Salinity Stress and Its Countermeasures in Crop Plants

当盐水压力和水压力的影响与大米、氯塑料中的损害在盐水压力中更突出。一种典型的沙林压力症状是甲状腺肿的一部分。氯塑料中的损伤被盐比光线更暗，即使在黑暗中，Na和Cl浓度和Na/K比率在黑暗中是可比的或高于的。因此，盐水中的损伤被认为是由光和反应性氧物质（ROS）的影响所引起的。用收缩剂（含H_2O_2的ROS的不同清除剂）和苯并酸（OH的清除剂）对减少盐水中的氯塑料损伤有很好的效果。这就是为什么Damages被·OH和/或其precursor H_2O_2引起的原因。对水稻植物的生长抑制是由Ca^<2+>在羟基培养中产生的，但K^+在土壤培养中产生了更大的影响。特别是， KNO_3显示了对大米产量的平均影响。在拍摄期间，增长抑制和Na/K比率之间有很强的联系。因此，在射击中减少钠/钾比率的培养做法对减少盐氨酸压力是有效的。用低浓度的甲基紫罗兰（ROS生产草药）减少氯塑料中的损伤进行预处理，并增加了叶子中的收缩过氧化物酶的活动。因此，在叶子中减少H_2O_2浓度的治疗对降低盐度压力是有效的。

When the effects of salinity stress and water stress were compared in rice, damages in chloroplasts were more prominent in salinity stress. Typical symptom of salinity stress was swelling of the thylakoids. Damages in chloroplasts by salinity were severer in light than in the dark even if Na and Cl concentrations and Na/K ratio in the leaf tissues were comparable or higher in the dark. Therefore, the damages in chloroplasts induced by salinity were dependent on light and the involvement of reactive oxygen species (ROS) was suggested. Pretreatment of leaf tissues with ascorbate (versatile scavenger of ROS including H_2O_2) and benzoate (scavenger of ・OH) was effective to reduce damages in chloroplasts by salinity. It is therefore suggested that the damages were caused by ・OH and/or its precursor H_2O_2. Growth inhibition of rice plants by salinity was ameliorated by Ca^<2+> in hydroponic culture but K^+ was more effective in soil culture. Especially, KNO_3 showed ameliorative effects on the yield of rice. There was a strong correlation between growth inhibition and Na/K ratio in the shoot. Therefore, cultivation practice to reduce Na/K ratio in the shoot is effective to reduce salinity stress. Pretreatment of leaf tissues with a low concentration of methyl viologen (ROS producing herbicide) reduced damages in chloroplasts by salinity and increased the activity of ascorbate peroxidase in the leaf. Therefore, treatments to reduce H_2O_2 concentration in the leaf are effective to ameliorate salinity stress.