Phosphorylation of LTF1, an MYB Transcription Factor in Populus, Acts as a Sensory Switch Regulating Lignin Biosynthesis in Wood Cells  

作　　者：Jinshan Gui Laifu Luo Yu Zhong Jiayan Sun Toshiaki Umezawa Laigeng Li 

机构地区：[1]National Key Laboratory of Plant Molecular Genetics and CAS Center for Excellence in Molecular Plant Sciences,Shanghai Institute of Plant Physiology and Ecology,Chinese Academy of Sciences,Shanghai 200032,China [2]University of the Chinese Academy of Sciences,Beijing 100049,China [3]School of Life Science,Lanzhou University,Lanzhou 730000,China [4]Research Institute for Sustainable Humanosphere,Kyoto University,Uji,Kyoto 611-0011,Japan

出　　处：《Molecular Plant》2019年第10期1325-1337,共13页分子植物（英文版）

基　　金：the Chinese Ministry of Science and Technology(grant no.2016YFD0600104);the National Natural Science Foundation of China(grant nos.31630014 and 31401301);the Chinese Ministry of Agriculture(grant no.2018ZX08020002);the Youth Innovation Promotion Association CAS(grant no.2017318);the Chinese Academy of Sciences(grant no.XDB27020104);the SANOFI-SIBS Scholarship Program,and the Shanghai Key Laboratory of Bio-Energy Crops.

摘　　要：Lignin is specifically deposited in plant secondary cell walls,and initiation of lignin biosynthesis is regulated by a variety of developmental and environmental signals.However,the mechanisms governing the regulation of lignin biosynthesis remain to be elucidated.In this study,we identified a lignin biosynthesis-associated transcription factor(LTF)from Populus,LTF1,which binds the promoter of a key lignin biosynthetic gene encoding 4-coumarate-CoA ligase(4CL).We showed that LTF1 in its unphosphorylated state functions as a regulator restraining lignin biosynthesis.When LTF1 becomes phosphorylated by PdMPK6 in response to external stimuli such as wounding,it undergoes degradation through a proteasome pathway,resulting in activation of lignification.Expression of a phosphorylation-null mutant version of LTF1 led to stable protein accumulation and persistent attenuation of lignification in wood cells.Taken together,our study reveals a mechanism whereby LTF1 phosphorylation acts as a sensory switch to regulate lignin biosynthesis in response to environmental stimuli.The discovery of novel modulators and mechanisms modifying lignin biosynthesis has important implications for improving the utilization of cell-wall biomass.

关 键 词：LIGNIN POPULUS secondary XYLEM cell wall 

分 类 号：TS7[轻工技术与工程—制浆造纸工程]