Browse Articles

Article|08 Nov 2023|OPEN
StSN2 interacts with the brassinosteroid signaling suppressor StBIN2 to maintain tuber dormancy
Shifeng Liu1 , Chengcheng Cai1 , Luopin Li1 , He Wen1 , Jie Liu1 , Liqin Li1 , Qiang Wang1 and Xiyao Wang,1 ,
1State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
*Corresponding author. E-mail: wxyrtl@163.com

Horticulture Research 11,
Article number: uhad228 (2024)
doi: https://doi.org/10.1093/hr/uhad228
Views: 41

Received: 10 Jul 2023
Accepted: 29 Oct 2023
Published online: 08 Nov 2023

Abstract

After harvest, potato tubers undergo an important period of dormancy, which significantly impacts potato quality and seed vigor. StSN2 has been reported as a key gene for maintaining tuber dormancy; in this study, we explored the molecular mechanism by which StSN2 maintains dormancy. StBIN2 was first identified as a candidate protein that interacts with StSN2 by co-immunoprecipitation/mass spectrometry, and both qPCR and enzyme activity experiments showed that StSN2 can promote the StBIN2 expression and activity. In addition, the interaction between StSN2 and StBIN2 was verified by yeast two-hybrid, luciferase complementation experiments and co-immunoprecipitation. Bioinformatics analysis and site-directed mutagenesis confirmed the critical role of cysteine residues of StBIN2 in its binding to StSN2. Similar to that of StSN2, overexpression of StBIN2 extended the dormancy of potato tuber. Interaction between StSN2 and StBIN2 increased the activity of the StBIN2 enzyme, inhibited the expression of StBZR1, and suppressed BR signaling. On the contrary, this interaction promoted the expression of StSnRK2.2/2.3/2.4/2.6 and StABI5, key genes of ABA signaling, and the phosphorylation of StSnRK2.3, thereby promoting ABA signaling. Altogether, our results indicate that StSN2 interacts with StBIN2 through key cysteine residues and StBIN2 maintains tuber dormancy by affecting ABA and BR signaling. Findings of this research offer new insights into the molecular mechanism by which StSN2 maintains potato tuber dormancy through interaction with StSIN2 and provide guidance for potato improvement.