文献类型：期刊文献

英文题名：The LkMTA2/LkMTB8-LkERF1-LkEXPA8 cascade regulates xylem cell expansion in larch

作者：Lyu, Zhongrui[] Xie, Yunhui[] Zhang, Kaikai[] Han, Hua[] Zhang, Shougong[] Sun, Xiaomei[1]

第一作者：Lyu, Zhongrui

通信作者：Sun, XM[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Natl Forestry & Grassland Adm, Beijing 100091, Peoples R China; Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat, Natl Forestry & Grassland Adm, Beijing 100091, Peoples R China

年份：2026

外文期刊名：NEW PHYTOLOGIST

收录：;WOS:【SCI-EXPANDED(收录号:WOS:001689601700001)】；

基金：This work was supported by the Scientific and Technological Innovation 2030 Key Project (2023ZD0405903 and 2023ZD0405904) and the National Key Research and Development Program of China (2022YFD2200103). We are grateful to Yucheng Liu and Guiyun Tao for technical assistance.

语种：英文

外文关键词：ETHYLENE RESPONSE FACTOR; EXPANSIN; Larix kaempferi; methyltransferase; N6-methyladenosine; xylem cell expansion

摘要：Cell expansion is a critical determinant of the final shape and size of wood cells. In this study, the role of N6-methyladenosine (m6A), an abundant mRNA modification, in regulating xylem cell expansion was investigated. Treatment with the m6A methylation inhibitor STM2457 triggered global m6A hypomethylation in larch and significantly enlarged the xylem cell cross-sectional area. Analysis of m6A-seq data indicated that the hypomethylated m6A peaks were primarily localized within coding sequences and correlated with decreased transcript abundance. Among these transcripts, we identified a gene associated with xylem cell expansion, ETHYLENE-RESPONSIVE FACTOR 1 (LkERF1), whose overexpression in poplar reduced the xylem cell cross-sectional area. We characterized MRNA ADENOSINE METHYLASE 2 (LkMTA2) and METHYLTRANSFERASE B8 (LkMTB8), whose overexpression in poplar resulted in a significant reduction in vessel lumen cross-sectional area. LkMTA2 and LkMTB8 form a heterodimeric complex, which enhances the mRNA stability and abundance of LkERF1 via m6A hypermethylation, while LkERF1 directly represses the expression of EXPANSIN A8 (LkEXPA8), a key regulator of cell expansion. These findings provide novel insights into the LkMTA2/LkMTB8-LkERF1-LkEXPA8 cascade in regulating xylem cell expansion and reveal a molecular link between m6A RNA modification and wood formation.