Warm temperature activates the TCP15-HDA4 module to suppress shoot branching through promoting auxin biosynthesis and signaling in tomato

Xuewei Song; Yue Liu; Xiaole Meng; Shangyu Chen; Kangqi Sang; Qixiang Zheng; Yanhong Zhou; Michael Considine; Jingquan Yu; Xiaojian Xia

doi:10.1016/j.molp.2025.10.010

Warm temperature activates the TCP15-HDA4 module to suppress shoot branching through promoting auxin biosynthesis and signaling in tomato

Mol Plant. 2025 Oct 15:S1674-2052(25)00360-0. doi: 10.1016/j.molp.2025.10.010. Online ahead of print.

Authors

Affiliations

¹ Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, P.R. China.
² Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, P.R. China; Hainan Institute, Zhejiang University, Sanya 572025, P.R. China.
³ School of Molecular Science, the University of Western Australia, Perth, Western Australia 6009, Australia.
⁴ Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, P.R. China; Hainan Institute, Zhejiang University, Sanya 572025, P.R. China; Key Laboratory of Horticultural Plant Growth and Development, Agricultural Ministry of China, Hangzhou 310058, P.R. China.
⁵ Department of Horticulture, Zijingang Campus, Zhejiang University, 866 Yuhangtang Road, Hangzhou, 310058, P.R. China; Hainan Institute, Zhejiang University, Sanya 572025, P.R. China. Electronic address: xiaojianxia@zju.edu.cn.

PMID: 41103034
DOI: 10.1016/j.molp.2025.10.010

Abstract

Shoot branching, as an important agronomic trait, is controlled by environment. Epigenetic modifications play a pivotal role in governing transcriptional responses to light and temperature cues for plant growth. Nevertheless, the contribution of epigenetic modifiers in regulating shoot branching under varying temperatures remains elusive. Our study reveals that elevated temperature suppresses lateral bud outgrowth in tomato (Solanum lycopersicum), accompanied by increased levels of HISTONE DEACETYLASE 4 (HDA4). Loss of function of SlHDA4 augmented lateral bud outgrowth resulting from a reduced auxin response. Notably, increased lateral bud outgrowth observed in slhda4 mutants was insensitive to an increase in temperature but was restored by SlHDA4 overexpression. Furthermore, the histone deacetylase SlHDA4 interacts with SlTCP15 transcription factor to suppress the expression of genes encoding light receptor SlPHYB1 and auxin signaling repressor SlIAA12 by decreasing the H3K9ac levels at their promoters. In summary, the SlTCP15-SlHDA4 module participates in warm temperature regulation of lateral bud outgrowth by enhancing auxin biosynthesis and signaling in tomato.

Keywords: SlIAA12; SlPHYB1; auxin; histone acetylation; shoot branching; warm temperature.