干旱胁迫下细胞分裂素对匍匐翦股颖抗氧化生理的影响

Impact of Cytokinin on the Antioxidative Physiology of Creeping Bentgrass under Drought Stress

为探索干旱胁迫下细胞分裂素对匍匐翦股颖(Agrostis stolonifera)活性氧水平变化及生理应答的影响,试验设计2种水分条件:干旱胁迫和充分浇水;3种浓度细胞分裂素类物质(TZR)处理:0,10,100μM。研究匍匐翦股颖叶片相对含水量、活性氧水平(O_2^-和H_2O_2)以及超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)活性和丙二醛(MDA)含量的变化。结果表明:与对照相比,在2种水分条件下,2种浓度的TZR均能显著降低匍匐翦股颖的O-2产生速率、H_2O_2含量和MDA含量(P<0.05),显著提高4种抗氧化酶的活性(P<0.05);同时干旱条件下,TZR对提高匍匐翦股颖叶片相对含水量效果明显,表明TZR能够增强匍匐翦股颖的耐旱性;在干旱胁迫后期,高浓度(100μM)TZR处理的匍匐翦股颖各项指标均表现出显著的优势(P<0.05),表明高浓度TZR对匍匐翦股颖抵御干旱胁迫的作用更大。

In this experiment,the effect of cytokinin on Creeping bentgrass（Agrostis stolonifera）oxidizeresistant physiology by spraying different concentrations of exogenous cytokinin was studied.Treatments included two moisture conditions：well-watered and drought stress;and 3concentrations of cytokinin：0,10 and 100μM.Leaf relative water contents,levels of reactive oxygen species（O_2^-and H_2O_2）,superoxide dismutase（SOD）,catalase（CAT）,peroxidase（POD）and ascorbate perxidase（APX）activities,and malondialdehyde（MDA）contents were determined.The results indicated that cytokinin reduced the generation rate of O_2^- and H_2O_2,MDA contents of creeping bentgrass compared to control under both water regimes（P0.05）; and increased the antioxidant enzymes activities and leaf relative water contents of the bentgrass under drought stress（P0.05）.These results indicated that cytokinin improved the drought tolerance of creeping bentgrass.In the late stages of drought stress,the indicators of creeping bentgrass with high concentration（100μM）cytokinin treatment showed significant advantages（P0.05）.These results indicated that the high concentration of cytokinin had a better promotion to creeping bentgrass under drought stress.