A Phytochrome B-PIF4-MYC2/MYC4 module inhibits secondary cell wall thickening in response to shaded light  

作　　者：Fang Luo Qian Zhang Hu Xin Hongtao Liu Hongquan Yang Monika SDoblin Antony Bacic Laigeng Li 

机构地区：[1]National Key Laboratory of Plant Molecular Genetics,CAS Center for Excellence in Molecular Plant Sciences,Chinese Academy of Sciences,Shanghai 200032,China [2]University of the Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory of Biodiversity Conservation in Southwest,State Forestry Administration,Southwest Forestry University,Kunming 650224,China [4]College of Life and Environmental Sciences,Shanghai Normal University,Shanghai 200234,China [5]La Trobe Institute for Agriculture and Food,School of Agriculture,Biomedicine and Environment,Department of Animal,Plant and Soil Sciences,AgriBio,La Trobe University,Bundoora,VIC 3086,Australia [6]Sino-Australia Plant Cell Wall Research Centre,State Key Laboratory of Subtropical Silviculture,School of Forestry and Biotechnology,Zhejiang A&F University,Hangzhou 311300,China

出　　处：《Plant Communications》2022年第6期43-55,共13页植物通讯（英文）

基　　金：supported by the National Natural Science Foundation of China(grant no.32130072,31630014);the Chinese Academy of Sciences(grant no.XDB27020104).

摘　　要：Secondary cell walls(SCWs)in stem cells provide mechanical strength and structural support for growth.SCW thickening varies under different light conditions.Our previous study revealed that blue light enhances SCW thickening through the redundant function of MYC2 and MYC4 directed by CRYPTOCHROME1(CRY1)signaling in fiber cells of the Arabidopsis inflorescence stem.In this study,we find that the Arabidopsis PHYTOCHROME B mutant phyB displays thinner SCWs in stem fibers,but thicker SCWs are deposited in the PHYTOCHROME INTERACTING FACTOR(PIF)quadruple mutant pif1pif3pif4pif5(pifq).The shaded light condition with a low ratio of red to far-red light inhibits stem SCW thickening.PIF4 interacts with MYC2 and MYC4 to affect their localization in nuclei,and this interaction results in inhibition of the MYCs’transactivation activity on the NST1 promoter.Genetic evidence shows that regulation of SCW thickening by PIFs is dependent on MYC2/MYC4 function.Together,the results of this study reveal a PHYB-PIF4-MYC2/MYC4 module that inhibits SCW thickening in fiber cells of the Arabidopsis stem.

关 键 词：far-red light fiber cell MYC2 secondary cell wall XYLEM 

分 类 号：Q943.2[生物学—植物学]