Premium
P opulus endo‐beta‐mannanase P tr MAN 6 plays a role in coordinating cell wall remodeling with suppression of secondary wall thickening through generation of oligosaccharide signals
Author(s) -
Zhao Yunjun,
Song Dongliang,
Sun Jiayan,
Li Laigeng
Publication year - 2013
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12137
Subject(s) - cell wall , polysaccharide , thickening , xylem , chemistry , oligosaccharide , secondary cell wall , microbiology and biotechnology , downregulation and upregulation , gene knockdown , mannan , cell , biochemistry , gene , biology , botany , polymer science
Summary Endo‐1,4‐β‐mannanase is known to able to hydrolyze mannan‐type polysaccharides in cell wall remodeling, but its function in regulating wall thickening has been little studied. Here we show that a P opulus endo‐1,4‐β‐mannanase gene, named P tr MAN 6 , suppresses cell wall thickening during xylem differentiation. P tr MAN 6 is expressed specifically in xylem tissue and its encoded protein localizes to developing vessel cells. Overexpression of P tr MAN 6 enhanced wall loosening as well as suppressed secondary wall thickening, whilst knockdown of its expression promoted secondary wall thickening. Transcriptional analysis revealed that P tr MAN 6 overexpression downregulated the transcriptional program of secondary cell wall thickening, whilst P tr MAN 6 knockdown upregulated transcriptional activities toward secondary wall formation. Activity of P tr MAN 6 hydrolysis resulted in the generation of oligosaccharide compounds from cell wall polysaccharides. Application of the oligosaccharides resulted in cellular and transcriptional changes that were similar to those found in P tr MAN 6 overexpressed transgenic plants. Overall, our results demonstrated that P tr MAN 6 plays a role in hydrolysis of mannan‐type wall polysaccharides to produce oligosaccharides that may serve as signaling molecules to suppress cell wall thickening during wood xylem cell differentiation.