不同成熟度玉米叶片抗氧化生理对高温胁迫的响应

Responses of Antioxidative Physiology to High Temperature in Different Maturity Leaves of Maize

以郑单958(ZD958)和先玉335(XY335)为试验材料,研究高温胁迫下玉米叶片膜透性、抗氧化酶活性以及渗透调节物质的动态变化。结果表明,高温胁迫下,玉米叶片相对电导率、MDA含量增加,ZD958成熟叶的增幅大于幼嫩叶,XY335成熟叶增幅小于幼嫩叶。处理早期阶段,ZD958成熟叶SOD、POD和CAT活性均增加并高于对照,后期阶段增幅放缓,甚至低于对照;幼嫩叶3种酶活性在处理前期大多与对照无明显差异,后期则明显升高。XY335成熟叶CAT活性均大于或显著大于对照,SOD和POD活性多低于或显著低于对照;幼嫩叶3种酶活性均大于或显著大于对照;可溶性蛋白含量无显著性变化。ZD958成熟叶和幼嫩叶可溶性糖含量均呈先升后降的趋势,XY335成熟叶表现为升高趋势,幼嫩叶则呈升-降-升-降的变化;脯氨酸在两个品种成熟叶中呈降-升-降的变化。

Using two maize hybrids of Zhengdan958（ZD958） and Xianyu335（XY335） to explore response of antioxidative physiology to high temperature in maize leaf during the growth progress of vegetative and reproductive. The results showed that, the relative electrical conductivity and content of MDA increased in maize leaves, the increase extent was higher in mature leaves than in young leaves of ZD958, while it was lower in mature leaves than in young leaves of XY335. while it was lower in mature leaves than in young leaves of XY335. In the early stage of treatment, the activities of SOD, POD and CAT all increased in mature leaves of ZD958, then decreased even lower than control. Contrary to the mature leaves, the three enzymes activities of the young leaves increased in the later stage of high temperature treatment. In mature leaves of XY335, the activities of SOD and POD decreased while in- creased for CAT. In the young leaves, the three enzymes activities increased or increased significantly. There were no significant changes of soluble protein. The contents of soluble sugar increased first and decreased afterwards in leaves of ZD958, increased in mature leaves and showed a change of increased-decreased-increased-decreased in young leaves of XY335. The contents of free proline present a trend of decreased-increased-decreased in mature leaves of ZD958 and XY335, and increased first and decreased afterwards in young leaves of ZD958 while increased in XY335.