PtrCel9A6, an Endo-l,4-β-Glucanase, Is Required for Cell Wall Formation during Xylem Differentiation in Populus  

作　　者：Liangliang Yu Jiayan Sun Laigeng Li 

机构地区：[1]National Key Laboratory of Plant Molecular Genetics/CAS Key Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai [2]Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China

出　　处：《Molecular Plant》2013年第6期1904-1917,共14页分子植物（英文版）

基　　金：the National Key Basic Research Program of China，the National Natural Science Foundation of China，Shanghai Science and Technology Commission (11XD1405900) to L.L

摘　　要：ABSTRACT Endo-l,4-β-glucanases （EGases） are involved in many aspects of plant growth. Our previous study found that an EGase, PtrCel9A6, is specifically expressed in differentiating xylem cells during Populus secondary growth. In this study, the xylem-specific PtrCel9A6 was characterized for its role in xylem differentiation. The EGase is localized on the plasma membrane with catalytic domain toward the outside cell wall, hydrolyzing amorphous cellulose. Suppression of PtrCel9A6 expression caused secondary cell wall defects in xylem cells and significant cellulose reduction in Populus. Heterologous expression of PtrCelgA6 in Arabidopsis enhanced plant growth as well as increased fiber cell length. In addition, introduction of PtrCel9A6 into Arabidopsis resulted in male sterility due to defects in anther dehiscence. Together, these results demonstrate that PtrCel9A6 plays a critical role in remodeling the 1,4-β-glucan chains in the wall matrix and is required for cell wall thickening during Populus xylem differentiation.ABSTRACT Endo-l,4-β-glucanases （EGases） are involved in many aspects of plant growth. Our previous study found that an EGase, PtrCel9A6, is specifically expressed in differentiating xylem cells during Populus secondary growth. In this study, the xylem-specific PtrCel9A6 was characterized for its role in xylem differentiation. The EGase is localized on the plasma membrane with catalytic domain toward the outside cell wall, hydrolyzing amorphous cellulose. Suppression of PtrCel9A6 expression caused secondary cell wall defects in xylem cells and significant cellulose reduction in Populus. Heterologous expression of PtrCelgA6 in Arabidopsis enhanced plant growth as well as increased fiber cell length. In addition, introduction of PtrCel9A6 into Arabidopsis resulted in male sterility due to defects in anther dehiscence. Together, these results demonstrate that PtrCel9A6 plays a critical role in remodeling the 1,4-β-glucan chains in the wall matrix and is required for cell wall thickening during Populus xylem differentiation.

关 键 词：endo-l 4-β-glucanase cell wall cellulose synthesis cell wall thickening Populus. 

分 类 号：Q942[生物学—植物学] TS262.5[轻工技术与工程—发酵工程]