水分胁迫下夏玉米根叶保护酶活性变化及其对膜脂过氧化作用的影响

 利用防雨旱棚，研究了水分胁迫下夏玉米根叶保护酶系活性变化及其对膜脂过氧化作用的影响。结果表明：在水分胁迫下，玉米根系、叶片保护酶系SOD、CAT、POD活性均在生长发育前中期显著升高而后期下降，根系SOD、CAT和POD活性小于叶片。膜脂过氧化产物MDA含量随水分胁迫程度加剧而增加，且根系MDA含量小于叶片MDA含量。研究还表明，在水分胁迫下，玉米根系保护酶活性及膜脂过氧化作用对水分胁迫的反应和叶片保护酶活性及膜脂过氧化作用对水分胁迫的反应呈正相关关系，且绝大多数的相关系数达显著或极显著水平。此外，叶片与根系中可溶性蛋白质含量降低。水分胁迫导致夏玉米果穗性状恶化，经济产量大幅下降。造成减产的主要原因是每穗粒数的减少和百粒重的下降。

Effects of Water Stress on the Protective Enzyme Activities and Lipid Peroxidation in Roots and Leaves of Summer Maize

Using water proof installations, a systematic study was conducted determine the effects of water stress on the protective enzyme activities and lipid peroxidation were determined. The results showed that: Under water stress, the activities of superoxide dismutase(SOD), catalase(CTA),and peoxidase(POD) in leaves and roots increased sharply at prophase and metaphase growth stages such as male tetrad stage, while declined at the evening developmental stages such as milky stage.The protective enzyme activities in root are lower than that in leaves. The content of malondialdehyde (MDA) increased following the stronger water stress, and also the content of MDA in roots was lower than that in leaves. The protective enzyme activities and lipid peroxidation in root were positively related to that in leaf, and furthermore the most of correlated coefficients showed the significant difference. In addition, the soluble protein in roots and leaves decreased. The ear characteristics were deteriorated and the economic yields of maize decreased significantly under water stress. The main factors that caused reduction of yields were the decrease of ear kernel number and 100-kernel weight.