Cloning and expression analysis of a dirigent protein gene from the resurrection plant Boea hygrometrica  

作　　者：Renhua Wu Lili Wang Zhi Wang Haihong Shang Xia Liu Yan Zhu Dongdong Qi Xin Deng 

机构地区：[1]Key Laboratory of Photosynthesis and Environmental Molecular Physiology,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China

出　　处：《Progress in Natural Science:Materials International》2009年第3期347-352,共6页自然科学进展·国际材料(英文版)

基　　金：supported by the National Natural Science Foundationof China (Grant No. 30400027)

摘　　要：Resurrection plants are tolerant to extreme dehydration and are useful model systems to study genes that play a role in drought tolerance. A gene fragment encoding a dirigent protein that is predicted to function in lignin biosynthesis was identified from leaves of the resurrection plant Boea hygrometrica via cDNA microarray screening. A cDNA, designated BhDIR1, containing the complete predicted open reading frame, was obtained by Y-RACE. BhDIR1 transcripts were found to be accumulated in response to changes in plant dehydration status, exogenously applied phytohormones and signaling molecules, and temperature stresses. BhDIR1 encodes a protein of 199 amino acids, which shows 20-40% similarity to dirigent proteins reported from other plants. BhDIR1 is predicted to contain a cleavable signal peptide at the N-terminal, and its plasma membrane/cell wall localization was confirmed using a GFP fusion protein assay. Consistent with this discovery, the acid-soluble lignin content decreased in dehydrated B. hygrometrica leaves. Taken together, our results indicate a protective role for a dirigent protein in response to drought stress by changing the physical characters of lignin which in turn is predicted to affect the mechanical strength and flexibility of the plant cell wall.Resurrection plants are tolerant to extreme dehydration and are useful model systems to study genes that play a role in drought tolerance. A gene fragment encoding a dirigent protein that is predicted to function in lignin biosynthesis was identified from leaves of the resurrection plant Boea hygrometrica via cDNA microarray screening. A cDNA, designated BhDIR1, containing the complete predicted open reading frame, was obtained by 50-RACE. BhDIR1 transcripts were found to be accumulated in response to changes in plant dehydration status, exogenously applied phytohormones and signaling molecules, and temperature stresses. BhDIR1 encodes a protein of 199 amino acids, which shows 20-40% similarity to dirigent proteins reported from other plants. BhDIR1 is predicted to contain a cleavable signal peptide at the N-terminal, and its plasma membrane/cell wall localization was confirmed using a GFP fusion protein assay. Consistent with this discovery, the acid-soluble lignin content decreased in dehydrated B. hygrometrica leaves. Taken together, our results indicate a protective role for a dirigent protein in response to drought stress by changing the physical characters of lignin which in turn is predicted to affect the mechanical strength and flexibility of the plant cell wall.

关 键 词：Resurrection plant Dirigent protein DROUGHT LIGNIN Cell wall 

分 类 号：Q943.2[生物学—植物学]