Effects of spraying foliar nitrogen on activities of key regulatory enzymes involved in protein formation in winter wheat suffered post-anthesis high temperature and waterlogging.

摘要

High temperature and waterlogging are main stress factors during late growing period of winter wheat (Triticum aestivum L.) in Yangtze Valley region of China. The effects of spraying foliar nitrogen on activities of key regulatory enzymes involved in protein formation in winter wheat suffered post-anthesis high temperature and waterlogging were studied. The results showed that both post-anthesis high temperature and post-anthesis waterlogging significantly reduced activities of nitrate reductase (NR), glutamine synthetase (GS) in flag leaf and grain and glutamic-pyruvic transaminase (GPT) in grain. High temperature increased the negative effects of waterlogging, while spraying foliar nitrogen significantly increased these enzyme activities. High temperature reduced grain yield, protein accumulation and ratio of Glu/Gli, but improved protein content and each protein ingredient. Waterlogging reduced grain yield, protein accumulation, protein content, each protein ingredient and ratio of Glu/Gli. Interaction between high temperature and waterlogging significantly affected grain yield, protein accumulation and ratio of Glu/Gli, while did not significantly affect protein content and each protein ingredient. The degree of negative effects was waterlogging + high temperature > waterlogging > high temperature. Spraying foliar nitrogen resulted in the increase of grain yield, protein accumulation, protein content, each protein ingredient and rat io of Glu/Gli. The activities of key regulatory enzymes involved in protein formation were significantly positively correlated with grain yield, protein accumulation and ratio of Glu/Gli, but did not correlate with protein content. Our results suggest that spraying foliar nitrogen was an effective way to improve protein quality of winter wheat when suffered post-anthesis high temperature and waterlogging.