文献类型：期刊文献

英文题名：KNAT2/6b, a class I KNOX gene, impedes xylem differentiation by regulating NAC domain transcription factors in poplar

作者：Zhao, Yanqiu[1,2] Song, Xueqin[1,2,3] Zhou, Houjun[1,2] Wei, Kaili[1,2] Jiang, Cheng[1,2,4] Wang, Jinnan[1,2] Cao, Yuan[1] Tang, Fang[1,2,3] Zhao, Shutang[1,2,3] Lu, Meng-Zhu[1,2,3,4]

第一作者：Zhao, Yanqiu

通信作者：Lu, MZ[1];Lu, MZ[2];Lu, MZ[3];Lu, MZ[4]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China;[2]Chinese Acad Forestry, Key Lab Tree Breeding & Cultivat State Forestry A, Res Inst Forestry, Beijing 100091, Peoples R China;[3]Nanjing Forestry Univ, Coinnovat Ctr Sustainable Forestry Southern China, Nanjing 210037, Jiangsu, Peoples R China;[4]Zhejiang Agr & Forestry Univ, Hangzhou 311300, Zhejiang, Peoples R China

年份：2020

卷号：225

期号：4

起止页码：1531-1544

外文期刊名：NEW PHYTOLOGIST

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000478954100001)】；

基金：We thank Prof. Andrew Groover (University of California) for suggestions and comments. We thank Prof. Yihua Zhou (Institute of Genetics and Developmental Biology, Chinese Academy of Sciences) for cell wall composition measurement. We than Dr Yanbao Tian (Institute of Genetics and Developmental Biology, Chinese Academy of Sciences) for scanning electron microscopy observations. This work was supported by the National Key Research and Development Program of China (2016YFD0600103), the National Natural Science Foundation of China (31570676), the National Key Program on Transgenic Research of China (2018ZX08020-002), the Ten-thousand Talents Program of China for Lu and the Basic Research Fund of Research Institute of Forestry, Chinese Academy of Forestry (RIF-2013-07 and RIF-2014-08).

语种：英文

外文关键词：NAC domain; PagKNAT2; 6b; Populus; secondary wall; XND1; xylem differentiation

摘要：Wood formation is the terminal differentiation of xylem mother cells derived from cambial initials, and negative regulators play important roles in xylem differentiation. The molecular mechanism of the negative regulator of xylem differentiation PagKNAT2/6b was investigated. PagKNAT2/6b is an ortholog of Arabidopsis KNAT2 and KNAT6 that is highly expressed in phloem and xylem. Compared to nontransgenic control plants, transgenic poplar plants overexpressing PagKNAT2/6b present with altered vascular patterns, characterized by decreased secondary xylem with thin cell walls containing less cellulose, xylose and lignin. RNA sequencing analyses revealed that differentially expressed genes are enriched in xylem differentiation and secondary wall synthesis functions. Expression of NAM/ATAF/CUC (NAC) domain genes including PagSND1-A1, PagSND1-A2, PagSND1-B2 and PagVND6-C1 is downregulated by PagKNAT2/6b, while PagXND1a is directly upregulated. Accordingly, the dominant repression form of PagKNAT2/6b leads to increased xylem width per stem diameter through downregulation of PagXND1a. PagKNAT2/6b can inhibit cell differentiation and secondary wall deposition during wood formation in poplar by modulating the expression of NAC domain transcription factors. Direct activation of PagXND1a by PagKNAT2/6b is a key node in the negative regulatory network of xylem differentiation by KNOXs.