The DUF579 proteins GhIRX15s regulate cotton fiber development by interacting with proteins involved in xylan synthesis  

作　　者：Mengyun Li Feng Chen Jingwen Luo Yanan Gao Jinglong Cai Wei Zeng Monika S.Doblin Gengqing Huang Wenliang Xu 

机构地区：[1]Hubei Key Laboratory of Genetic Regulation and Integrative Biology,School of Life Sciences,Central China Normal University,Wuhan 430079,Hubei,China [2]Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation,School of Life Sciences,Taizhou University,Taizhou 318000,Zhejiang,China [3]La Trobe Institute for Sustainable Agriculture&Food,School of Agriculture,Biomedicine and Environment,La Trobe University,Bundoora,VIC 3086,Australia

出　　处：《The Crop Journal》2024年第4期1112-1125,共14页作物学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(31970516 and 32372104);the Foundation of Hubei Hongshan Laboratory(2021hszd014).

摘　　要：Cotton provides the most abundant natural fiber for the textile industry.The mature cotton fiber largely consists of secondary cell walls with the highest proportion of cellulose and a small amount of hemicellulose and lignin.To dissect the roles of hemicellulosic polysaccharides during fiber development,four IRREGULAR XYLEM 15(IRX15)genes,GhIRX15-1/-2/-3/-4,were functionally characterized in cotton.These genes encode DUF579 domain-containing proteins,which are homologs of AtIRX15 involved in xylan biosynthesis.The four GhIRX15 genes were predominantly expressed during fiber secondary wall thickening,and the encoded proteins were localized to the Golgi apparatus.Each GhIRX15 gene could restore the xylan deficient phenotype in the Arabidopsis irx15irx15l double mutant.Silencing of GhIRX15s in cotton resulted in shorter mature fibers with a thinner cell wall and reduced cellulose content as compared to the wild type.Intriguingly,GhIRX15-2 and GhIRX15-4 formed homodimers and heterodimers.In addition,the GhIRX15s showed physical interaction with glycosyltransferases GhGT43C,GhGT47A and GhGT47B,which are responsible for synthesis of the xylan backbone and reducing end sequence.Moreover,the GhIRX15s can form heterocomplexes with enzymes involved in xylan modification and side chain synthesis,such as GhGUX1/2,GhGXM1/2 and GhTBL1.These findings suggest that GhIRX15s participate in fiber xylan biosynthesis and modulate fiber development via forming large multiprotein complexes.

关 键 词：Cotton fiber Xylan biosynthesis GhIRX15s Protein-protein interaction Protein complexes 

分 类 号：S562[农业科学—作物学]