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Zhang Z, Huang J, Gao Y, Liu Y, Li J, Zhou X, Yao C, Wang Z, Sun Z, Zhang Y. Suppressed ABA signal transduction in the spike promotes sucrose use in the stem and reduces grain number in wheat under water stress. J Exp Bot 2020; 71:7241-7256. [PMID: 32822501 PMCID: PMC7906786 DOI: 10.1093/jxb/eraa380] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 08/17/2020] [Indexed: 05/06/2023]
Abstract
Water stress is a primary trigger for reducing grain number per spike in wheat during the reproductive period. However, under stress conditions, the responses of plant organs and the interactions between them at the molecular and physiological levels remain unclear. In this study, when water stress occurred at the young microspore stage, RNA-seq data indicated that the spike had 970 differentially expressed genes, while the stem, comprising the two internodes below the spike (TIS), had 382. Abscisic acid (ABA) signal transduction genes were down-regulated by water stress in both these tissues, although to a greater extent in the TIS than in the spike. A reduction in sucrose was observed, and was accompanied by increases in cell wall invertase (CWIN) and sucrose:sucrose 1-fructosyl-transferase (1-SST) activities. Hexose and fructan were increased in the TIS but decreased in the spike. ABA was increased in the spike and TIS, and showed significant positive correlation with CWIN and 1-SST activities in the TIS. Overall, our results suggest that water stress induces the conversion of sucrose to hexose by CWIN, and to fructan by 1-SST, due to increased down-regulation of ABA signal transduction related-genes in the TIS; this leads to deficient sucrose supply to the spike and a decrease in grain number.
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Affiliation(s)
- Zhen Zhang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Jing Huang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Yanmei Gao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Yang Liu
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Jinpeng Li
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Xiaonan Zhou
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Chunsheng Yao
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
| | - Zhimin Wang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
- Engineering Technology Research Center for Agriculture in Low Plain Areas, Heibei Province, China
| | - Zhencai Sun
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
- Engineering Technology Research Center for Agriculture in Low Plain Areas, Heibei Province, China
| | - Yinghua Zhang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing, China
- Engineering Technology Research Center for Agriculture in Low Plain Areas, Heibei Province, China
- Correspondence:
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