J Integr Plant Biol. ›› 2023, Vol. 65 ›› Issue (8): 1859-1873.DOI: 10.1111/jipb.13489

• Abiotic Stress Responses • Previous Articles     Next Articles

The basic helix-loop-helix transcription factor gene, OsbHLH38, plays a key role in controlling rice salt tolerance

Fengping Du1,2, Yinxiao Wang1, Juan Wang1, Yingbo Li1, Yue Zhang1, Xiuqin Zhao1, Jianlong Xu1, Zhikang Li1,3, Tianyong Zhao2*, Wensheng Wang1,3,4* and Binying Fu1*   

  1. 1. Institute of Crop Sciences/State Key Laboratory of Crop Gene Resources and Breeding, Chinese Academy of Agricultural Sciences, Beijing 100081, China;
    2. State Key Laboratory of Crop Stress Biology for Arid Areas, College of Life Sciences, Northwest A&F University, Yangling 712100, China;
    3. Anhui Agricultural University, Hefei 230036, China;
    4. Hainan Yazhou Bay Seed Lab/National Nanfan Research Institute (Sanya), Chinese Academy of Agricultural Sciences, Sanya 572024, China
    *Correspondences: Tianyong Zhao (tzzhao2@nwafu.edu.cn); Wensheng Wang (wangwensheng02@caas.cn); Binying Fu (fubinying@caas.cn, Dr. Fu is responsible for the distributions of the material associated with this article)
  • Received:2022-11-22 Accepted:2023-03-27 Online:2023-03-29 Published:2023-08-01

Abstract: The plant hormone abscisic acid (ABA) is crucial for plant seed germination and abiotic stress tolerance. However, the association between ABA sensitivity and plant abiotic stress tolerance remains largely unknown. In this study, 436 rice accessions were assessed for their sensitivity to ABA during seed germination. The considerable diversity in ABA sensitivity among rice germplasm accessions was primarily reflected by the differentiation between the Xian (indica) and Geng (japonica) subspecies and between the upland-Geng and lowland-Geng ecotypes. The upland-Geng accessions were most sensitive to ABA. Genome-wide association analyses identified four major quantitative trait loci containing 21 candidate genes associated with ABA sensitivity of which a basic helix-loop-helix transcription factor gene, OsbHLH38, was the most important for ABA sensitivity. Comprehensive functional analyses using knockout and overexpression transgenic lines revealed that OsbHLH38 expression was responsive to multiple abiotic stresses. Overexpression of OsbHLH38 increased seedling salt tolerance, while knockout of OsbHLH38 increased sensitivity to salt stress. A salt-responsive transcription factor, OsDREB2A, interacted with OsbHLH38 and was directly regulated by OsbHLH38. Moreover, OsbHLH38 affected rice abiotic stress tolerance by mediating the expression of a large set of transporter genes of phytohormones, transcription factor genes, and many downstream genes with diverse functions, including photosynthesis, redox homeostasis, and abiotic stress responsiveness. These results demonstrated that OsbHLH38 is a key regulator in plant abiotic stress tolerance.

Key words: abscisic acid, genome-wide association analysis, rice, salt tolerance, seed germination

Editorial Office, Journal of Integrative Plant Biology, Institute of Botany, CAS
No. 20 Nanxincun, Xiangshan, Beijing 100093, China
Tel: +86 10 6283 6133 Fax: +86 10 8259 2636 E-mail: jipb@ibcas.ac.cn
Copyright © 2022 by the Institute of Botany, the Chinese Academy of Sciences
Online ISSN: 1744-7909 Print ISSN: 1672-9072 CN: 11-5067/Q