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Exogenous abscisic acid improves grain filling capacity under heat stress by enhancing antioxidative defense capability in rice

Authors :
Xiaolong Liu
Xin Zhong
Jingpeng Liao
Ping Ji
Jinshuo Yang
Zhiruo Cao
Ximiao Duan
Junru Xiong
Ying Wang
Chen Xu
Hongtao Yang
Bo Peng
Kai Jiang
Source :
BMC Plant Biology, Vol 23, Iss 1, Pp 1-18 (2023)
Publication Year :
2023
Publisher :
BMC, 2023.

Abstract

Abstract Background Heat stress is a major restrictive factor that causes yield loss in rice. We previously reported the priming effect of abscisic acid (ABA) on rice for enhanced thermotolerance at the germination, seedling and heading stages. In the present study, we aimed to understand the priming effect and mechanism of ABA on grain filling capacity in rice under heat stress. Results Rice plants were pretreated with distilled water, 50 μM ABA and 10 μM fluridone by leaf spraying at 8 d or 15 d after initial heading (AIH) stage and then were subjected to heat stress conditions of 38 °C day/30 °C night for 7 days, respectively. Exogenous ABA pretreatment significantly super-activated the ABA signaling pathway and improved the SOD, POD, CAT and APX enzyme activity levels, as well as upregulated the ROS-scavenging genes; and decreased the heat stress-induced ROS content (O2 – and H2O2) by 15.0–25.5% in rice grain under heat stress. ABA pretreatment also increased starch synthetase activities in rice grain under heat stress. Furthermore, ABA pretreatment significantly improved yield component indices and grain yield by 14.4–16.5% under heat stress. ABA pretreatment improved the milling quality and the quality of appearance and decreased the incidence of chalky kernels and chalkiness in rice grain and improved the rice grain cooking quality by improving starch content and gel consistence and decreasing the amylose percentage under heat stress. The application of paraquat caused overaccumulation of ROS, decreased starch synthetase activities and ultimately decreased starch content and grain yield. Exogenous antioxidants decreased ROS overaccumulation and increased starch content and grain yield under heat stress. Conclusion Taken together, these results suggest that exogenous ABA has a potential priming effect for enhancing rice grain filling capacity under heat stress at grain filling stage mainly by inhibiting ROS overaccumulation and improving starch synthetase activities in rice grain.

Details

Language :
English
ISSN :
14712229
Volume :
23
Issue :
1
Database :
Directory of Open Access Journals
Journal :
BMC Plant Biology
Publication Type :
Academic Journal
Accession number :
edsdoj.9955ad9b0b4458a6a3e12313e9dbbd
Document Type :
article
Full Text :
https://doi.org/10.1186/s12870-023-04638-5