RNAi-mediated suppression of the abscisic acid catabolism gene OsABA8ox1 increases abscisic acid content and tolerance to saline-alkaline stress in rice (Oryza sativa L.)

第一作者：	Liu, Xiaolong
英文第一作者：	Liu, Xiaolong
联系作者：	Liang, Zhengwei
英文联系作者：	Liang, Zhengwei
发表年度：	2022
卷：	10
摘要：	Saline-alkaline (SA) stress is characterized by high salinity and high alkalinity (high pH), which severely inhibit plant growth and cause huge losses in crop yields worldwide. Here we show that a moderate elevation of endogenous abscisic acid (ABA) levels by RNAi-mediated suppression of OsABA8oxl (OsABA8ox1-kd), a key ABA catabolic gene, significantly increased tolerance to SA stress in rice plants. We produced OsABA8ox1-kd lines in two different japonica cultivars, Dongdao 4 and Nipponbare. Compared with non-transgenic control plants (WT), the OsABA8ox1-kd seedlings accumulated 25.9%-55.7% higher levels of endogenous ABA and exhibited reduced plasmalemma injury, ROS accumulation and Na+/K+ ratio, and higher survival rates, under hydroponic alkaline conditions simulated by 10, 15, and 20 mmol L-1 of Na2CO3. In pot trials using SA field soils of different alkali levels (pH 7.59, 8.86, and 9.29), OsABA8ox1-kd plants showed markedly higher seedling survival rates and more vigorous plant growth, resulting in significantly higher yield components including panicle number (85.7%-128.6%), spikelets per panicle (36.9%-61.9%), branches (153.9%-236.7%), 1000-kernel weight (20.0%-28.6%), and percentage of filled spikelets (96.6%-1340.8%) at harvest time. Under severe SA soil conditions (pH = 9.29, EC = 834.4 mu S cm(-1)), OsABA8ox1-kd lines showed an 194.5%-1090.8% increase in grain yield per plant relative to WT plants. These results suggest that suppression of OsABA8ox1 to increase endogenous ABA levels provides a new molecular approach for improving rice yield in SA paddies. (C) 2021 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.
刊物名称：	Crop Journal
参与作者：	X. L. Liu, X. Z. Xie, C. K. Zheng, L. X. Wei, X. W. Li, Y. Y. Jin, G. H. Zhang, C. J. Jiang and Z. W. Liang