外源钙对高铜环境下玉米苗期生理特性的影响

Effect of exogenous Ca^2+ on the physiological characteristics of the maize seedlings under high Cu^2+ environment

为探索预防玉米幼苗遭受Cu^2+毒害的缓解途径,本文以糯玉米为材料,采用沙培法研究了10 mmol·L^-1和20 mmol·L^-1Ca^2+对Cu^2+(1 mmol·L^-1)胁迫下玉米幼苗相关生理指标的影响。结果表明:1)在高铜环境下,玉米叶片叶绿素a含量、叶绿素b含量、总叶绿素含量、可溶性蛋白含量以及POD活性下降;而叶绿素a/b、类胡萝卜素含量、脯氨酸含量、可溶性糖含量、SOD活性以及MDA含量上升;2)高铜环境下施加10 mmol·L^-1和20 mmol·L^-1的外源Ca2后,叶绿素a含量、脯氨酸含量、可溶性糖含量、POD活性呈上升趋势;叶绿素b含量、总叶绿素含量、类胡萝卜素含量、可溶性蛋白含量、SOD活性先升高而后下降;叶绿素a/b、MDA含量先下降再上升。综合可知,高铜环境下适量的外源钙抑制光合色素含量的降低和MDA含量的增加,促进渗透调节物质的积累和保护酶活性的增强。

To explore the way of relieving Cu2+stress on maize seedlings,using the waxy corn as the testing material,by method of sand culture,the effect of the Ca2+(10 mmol·L^-1 and 20 mmol·L^-1)on the physiological indicators of the maize seedlings under Cu^2+(1 mmol·L^-1)stress were studied.The results showed as follows:1)Under high Cu^2+environment,the chlorophyll content,the soluble proteins content and the POD activity decreased significantly,but chla/b,the carotenoid content,soluble sugars content,proline content,the MDA content and the SOD activity increased significantly.2)Added exogenous Ca^2+(10 mmol·L^-1 and 20 mmol·L^-1)under the high Cu^2+environment,the chla content,the soluble sugars and proline content,the POD activity increased.the chlb and total chl content,the carotenoid content,the soluble proteins content and the SOD activity firstly increased then decreased;chla/b and the MDA content firstly decreased then increased.In summary,under high Cu^2+environment,appropriate amount of exogenous Ca^2+ can inhibit decreasing of photosynthetic pigment content and increasing of MDA content,promote accumulation of osmotic adjustment substances and increasing of protective activity.