%A Liu Xiaolong, Ji Ping, Yang Hongtao, Ding Yongdian, Fu Jialing, Liang Jiangxia, Yu Congcong %T Priming Effect of Abscisic Acid on High Temperature Stress During Rice Heading-flowering Stage %0 Journal Article %D 2022 %J Chinese Bulletin of Botany %R 10.11983/CBB22022 %P 596-610 %V 57 %N 5 %U {https://www.chinbullbotany.com/CN/abstract/article_82358.shtml} %8 2022-09-01 %X

To understand the priming effect of abscisic acid (ABA) on high temperature stress during rice heading-flowering stage, Huanghuazhan, a main rice variety in Jiangxi province, was used as experimental material. Six kinds of solutions were arranged to spray on rice at the booting stage, including distilled water, ABA solution (10, 50 and 100 µmol∙L-1), fluridone (FLU) and proanthocyanidins (PC), then the rice plants were moved to control (CK) and high temperature stress (HS) conditions for 8 d. The effects of ABA by spraying at booting stage were measured by the accumulation of reactive oxygen species (ROS), antioxidant defense capacity, yield components and the expression levels of related genes. The results showed that significant negative correlations were detected between the panicle length, panicle weight, percentage of filled spikelets, 1 000-kernel weight, grain yield and contents of superoxide anion and hydrogen peroxide respectively. Spraying ABA solution significantly upregulated the expression of ABA-responsive and antioxidant defense genes, and decreased contents of ROS by 8.24%-31.35% under high temperature stress. The panicle length, panicle weight, percentage of filled spikelets and 1 000-kernel weight were significantly increased by spraying ABA solution, as well as the expression levels of yield related genes. The grain yield was increased by 12.73%-20.77% by spraying ABA solution under high temperature stress. The application of the ABA biosynthesis inhibitor, FLU, inhibited the ABA biosynthesis and leaded to excessive accumulation of ROS and yield loss under high temperature stress. While application of the antioxidant PC inhibited the excessive accumulation of ROS and improved grain yield under high temperature stress. These results suggested that spraying ABA solution at booting stage enhanced tolerance to high temperature stress in rice at heading-flowering stage by upregulating not only ABA signaling pathway, but also antioxidant defense activity and yield related genes, so as to further improve grain yield under high temperature stress.