PEG模拟干旱处理条件下两种蚕豆的抗旱性研究

Study on Drought Resistance of Two Vicia faba L. Under PEG Simulated Drought Conditions

[目的]研究聚乙二醇(PEG)模拟干旱处理条件下2种蚕豆的抗旱性。[方法]以黄壤蚕豆(YV)和红壤蚕豆(RV)为材料,在水培条件下用PEG模拟干旱胁迫环境进行处理,并分析叶片的生理特性和质膜H+-ATPase活性的变化。[结果]在2%、5%、10%PEG处理条件下,随处理浓度和时间的增加,2种蚕豆植株失水率上升,叶片蒸腾速率降低,气孔传导率下降。在相同处理条件下,YV叶片蒸腾速率和气孔传导率下降幅度大于RV,植株失水率小于RV。在相同浓度PEG处理条件下,YV叶片可溶性糖、可溶性蛋白和脯氨酸含量比RV低,但RV叶片MDA含量比YV高,细胞膜可能会遭受更大的伤害。在抗氧化酶体系中,干旱胁迫下,YV叶片SOD、POD活性比RV高,YV叶片中SOD催化超氧自由基生产H2O2的能力强,所以干旱胁迫下YV叶片质膜H+-ATPase磷酸化水平及其与14-3-3蛋白的互作受到的抑制作用比RV强。同时YV叶片质膜H+-ATPase和H+-泵活性均比RV低,YV叶片气孔开度小于RV,导致其叶片蒸腾速率和气孔传导率较低,这是YV耐旱性比RV强的一个重要机制。[结论]该研究为植物响应干旱胁迫的机制研究奠定了基础。

[ Objective ] The paper was to study the drought resistance of two kinds of Viciafaba L. under polyethylene glycol （PEG） simula- ted drought conditions. [ Method] Using a red soil V. faba （RV） cuhivar and a yellow soil V. faba （YV） as materials, changes in physiologi- cal characteristics and activity of plasma membrane （PM） H ＋ - ATPase were analyzed in the two cultivars treated with PEG simulation drought stress under hydroponic conditions. [ Result] In the 2%, 5% and 10% PEG processing conditions, with the increase of PEG concentration and treatment time, the water loss rate of the two V. fabaplants increased and the leaf transpiration rate and stomatal conductance rate de- creased. Under the same treatment conditions, leaf transpiration rate and stomatal conductance rate of YV declined more than those of RV, while the water loss rate was less than that of RV. In the same PEG treatment conditions, the soluble sugar, soluble protein and proline content in leaves of YV were lower than those of RV, but the content of MDA in leaves of RV was higher than that of YV, indicating to lower cell membrane might suffer more damage. In the antioxidant enzyme system, the activities of SOD and POD in the leaves of YV were higher than that of RV under drought stress conditions and the ability of SOD to catalyze superoxide free radical to product H202 in the leaves of YV was strong, so the inhibition of YV in the PM H ＋ - ATPase phosphorylation level of leaves and its interaction with 14 - 3 - 3 protein were stronger than those of RV under drought stress conditions. At the same time, the activities of PM H ＋ - ATPase and H ＋ - pump in the leaves of YV Were lower than those of RV, and the stomata aperture in the leaves of YV was less than that of RV, leading to lower leaf transpiration rate and stomatal conductance rate, which was an important mechanism of the stronger drought tolerance in YV than that in RV. [ Conclusion ] The study laid a foundation for research on the mechanism of plant response to drought stress.