灌浆前期高温对小麦籽粒氮代谢关键酶活性的影响

为探讨花后高温胁迫对小麦籽粒氮代谢及蛋白质合成的影响机制,以黄淮地区高产小麦品种郑麦366为材料,利用人工气候室模拟花后高温的方式,在盆栽条件下研究了灌浆前期短暂高温对小麦强势粒和弱势粒谷丙转氨酶(GPT)、谷草转氨酶(GOT)活性的影响.结果表明,灌浆前期高温显著提高了籽粒蛋白质含量,降低了籽粒蛋白质积累量和氮代谢关键酶GPT、GOT活性,其中强势粒GPT活性受高温胁迫的影响较大.小麦籽粒蛋白质含量与GPT和GOT活性均呈负相关,但相关性在不同时期间、强势粒与弱势粒间有差异,强势粒GPT活性与蛋白质含量的关系更密切.

Effects of Heat shock on Activities of Key Enzymes Involving in Nitrogen Metabolism in Wheat Grains at Early Stage of Grain Filling

Effects of heat shock in early stage of grain filling on activities of key enzymes related to nitrogen metabolism in superior and inferior grains of wheat was evaluated by using the climate controlled greenhouse. The results showed that heat treatment significantly increased the protein content, but decreased the activities of GPT and GOT. Furthermore, the activities of GPT in superior grains were more sensitive to heat stress. Correlated analysis indicated that significant negative correlations existed between protein concentration and transaminase activities in both superior and inferior grains, although the values were much different among grain filling stages and between different grain positions. Further more , GPT activity in superior grains was more closely associated with the protein concentration than in inferior grains and than GOT in any grains. This study was helpful to understanding the physiological mechanisms of N metabolisms and quality changes in wheat grains when heat stress occurred.