冬小麦抗氧化酶对冬季节律性日变温和非节律性变温的响应  

Responses of winter wheat antioxidant enzymes to the rhythmical and non-rhythmical changes of diurnal temperature in winter

作　　者：周瑞莲[1] 王艳杰[1] 朱露英[1] 王爱兰[1] 左进程[1] 

机构地区：[1]鲁东大学生命科学学院,山东烟台264025

出　　处：《生态学杂志》2012年第8期1968-1976,共9页Chinese Journal of Ecology

基　　金：国家重点基础研究发展计划项目(2009CB421303);国家自然科学基金项目(30972422)资助

摘　　要：通过对冬季室内和室外分别生长30d的冬小麦在节律性和非节律性融冻变温过程中抗氧化酶活力和渗透调解物含量变化的分析,揭示其在冬小麦适应日融冻胁迫中的作用。结果表明:生育期不同的室内(均温11℃,拔节期)和室外(均温1℃,分蘖静滞期)冬小麦叶片抗氧化酶和脯氨酸对日光强和温度节律变化的响应趋势是一致的,即随日出而增高,中午气温较高时最高,日落而降低;在非节律性变温处理中,室外冬小麦抗氧化酶活力和脯氨酸含量随气温上升至18℃而增高,气温迅速下降到-2.5℃而降低,经历冻-融-冻胁迫冬小麦生长良好。室内冬小麦抗氧化酶活力随气温降低到-6℃,叶片结冻,迅速下降,气温升高到18℃而增加,经历融-冻-融胁迫后植株死亡;室外冬小麦光合速率(Pn)和比室内的低,而抗氧化酶活力高于室内;冬小麦快速提高抗氧化酶活力和脯氨酸含量,抑制氧自由基积累、维护细胞水分平衡,这在适应冬季节律性融冻胁迫中起重要作用;暖冬中冬小麦较高的Pn和较低的抗氧化酶活力可能是引起冬小麦在"倒春寒"中死亡的生理原因。After 30 days growing in greenhouse and field in winter, the winter wheat （Triticum aestivum） plants were exposed to naturally rhythmical change of diurnal temperature and to extremely high or low temperature, with the dynamic changes in the leaf antioxidant enzyme activities and osmoregulation substance contents analyzed, aimed to understand the physiological mechanisms of winter wheat to adapt freeze-thaw stress. The plants from the greenhouse （average temperature 11 ℃） at jointing stage and from the field （average temperature 1 ℃） at tillering stage all had the same patterns of leaf antioxidant enzyme activities and proline content in response to naturally rhythmical diurnal temperature change, i.e., increased with sunrise, peaked at 13：00, and decreased with sunset. When the plants from the field were exposed to high temperature （18 ℃） for 2 days, the leaf antioxidant enzyme activities and proline content increased, but it was in adverse when the plants were exposed to low temperature （-2.5 ℃）. After freeze-thaw stress, the plants grew well. When the plants from the greenhouse were shortly exposed to -6 ℃, the leaves were frozen, their antioxidant enzyme activities and proline content decreased, but increased after exposure to 18 ℃. After short exposure to freeze-thaw stress, the plants from the greenhouse died. However, the plants from the field had lower net photosynthesis rate （Pn） but higher activities of antioxidant enzymes than those from the greenhouse. It was suggested that the rapid responses of the leaf antioxidant enzyme system and proline to the diurnal temperature and light intensity to scavenge oxygen free-radical and keep water balance in cell would play important role in the adaptation of winter wheat to diurnal freeze-thaw stress, and the higher Pn and lower antioxidant enzyme activities in the leaves of winter wheat growing in warming winter could be the reason why winter wheat died in late spring cold of next year.

关 键 词：冬小麦 融冻交替 日变化 抗氧化系统 渗透调节 

分 类 号：S512.11[农业科学—作物学]