Response of spikelet water status to high temperature and its relationship with heat tolerance in rice  

作　　者：Wencheng Wang Kehui Cui Qiuqian Hu Chao Wu Guohui Li Jianliang Huang Shaobing Peng 

机构地区：[1]National Key Laboratory of Crop Genetic Improvement,MOA Key Laboratory of Crop Ecophysiology and Farming System in the Middle Reaches of the Yangtze River,College of Plant Science and Technology,Huazhong Agricultural University,Wuhan 430070,Hubei,China [2]Hubei Collaborative Innovation for Grain Industry,Yangtze University,Jingzhou 434023,Hubei,China [3]Guangxi Key Laboratory of Functional Phytochemicals Research and Utilization,Guangxi Institute of Botany,the Chinese Academy of Sciences,Guilin 541006,Guangxi,China [4]College of Agronomy,Yangzhou University,Yangzhou 221116,Jiangsu,China

出　　处：《The Crop Journal》2021年第6期1344-1356,共13页作物学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (31871541)。

摘　　要：In rice, high-temperature stress(HT) during flowering results in decreased grain yield via a reduction in spikelet fertility;however, the effect of plant water status on spikelet fertility under HT remains unknown. To investigate the relationship between spikelet water status and spikelet fertility under HT, two experiments were performed under temperature-controlled conditions using four genotypes with varying tolerance to HT. Rice plants were exposed to HT for seven consecutive days during the flowering stage under three soil water treatments(soil water potential 0, -20, and -40 kPa), as well as under hydroponic conditions in a separate experiment. HT significantly decreased spikelet fertility, pollen fertility, and anther dehiscence under each of the three water treatments. HT significantly increased the spikelet transpiration rate, and this change was accompanied by a significant decrease in the internal temperature of the spikelets. HT decreased pollen grain diameter in heat-sensitive genotypes. HT had varying effects on the water potential of panicles and anthers but increased anther soluble-sugar concentration. Different aquaporin genes showed different expression profiles under HT, and the expression levels of PIPs for plasma membrane intrinsic proteins and TIPs for tonoplast intrinsic proteins increased in anthers but decreased in glumes.Correlation analyses showed that anther dehiscence and pollen(spikelet) fertility were tightly associated with anther water status, and the expression levels of almost all anther aquaporin genes were significantly correlated with anther dehiscence under HT. In summary, an increased spikelet transpiration rate and decreased internal spikelet temperature were associated with alleviation of the effects of HT in rice genotypes with varying degrees of heat tolerance, and the response of spikelet water status to HT, involving increased total expression of aquaporins and soluble sugar content, thereby improved pollen fertility,anther dehiscence, and spikelet fertility, especial

关 键 词：AQUAPORINS Heat stress Rice(Oryza sativa L.) Spikelet fertility Spikelet water status 

分 类 号：S511[农业科学—作物学]