一个杨树第V类几丁质酶基因的克隆及表达分析  

Molecular Cloning and Expression Analysis of a Class V Chitinase Gene from Populus

作　　者：江聪[1] 宋佳亮[1] 黄瑞芳[1] 黄敏仁[1] 徐立安[1] 

机构地区：[1]南京林业大学,江苏省杨树种质创新与品种改良重点实验室,南京210037

出　　处：《分子植物育种》2013年第2期225-231,共7页Molecular Plant Breeding

基　　金：国家重点基础研究发展计划(2009CB119100);国家林业局林业公益性行业科研专项(200904048);国家自然科学基金(31170620)共同资助

摘　　要：几丁质酶是一种重要的糖苷酶，在植物抗生物及非生物胁迫的过程中发挥了重要的作用。根据序列差异及所含结构域的不同，杨树中的几丁质酶可以分为5类。其中关于第V类几丁质酶的研究最少。本研究在加拿大杨中克隆到了一个第V类几丁质酶基因PcCHl3。序列分析的结果显示，该基因eDNA全长1303bp，含完整的开放阅读框，可编码366个氨基酸。预测蛋白质分子质量为39．53kD。理论等电点（pI）为5．49。PcCHl3与苦瓜、烟草、梨的第V类几丁质酶在系统进化树上同属一个分支。对PcCHl3在逆境胁迫及病原真菌诱导下的表达模式进行分析后发现，该基因可以被杨树病原真菌杨生褐盘二孢菌强烈诱导（可达对照的83倍），在干旱胁迫及盐胁迫的条件下表达量也出现了较大的上调（为对照的4～5倍）。研究结果为杨树几丁质酶功能的系统进化及林木抗性育种研究建立了一定基础。As one of the most important Glycoside hydrolases, Chitinases are involved in multiple stress responses. Based on amino acid sequence similarities, all plant chitinases can be divided into 5 classes. Among them, class V was relative less studied yet. A class V chtinase gene from Populus was cloned to uncover its potential roles. We named this gene PcCHI3. The full-length cDNA of this gene is 1 303 bp. It encodes 366 amino acid residues with a molecular mass around 39.53 kD and a theoretical isoelectric point （pI） of 5.49. Phylogenetic analysis showed that PcCHI3 belonged to a clade with other class V chtinase genes from Momordica charantia, Nicotiana tabacum and pyrus pyrifolia. Analysis on the expression patterns of PcCHI3 revealed that not only fungal pathogen infection, but also drought and salt stresses could induce strong accumulation of this gene. It provides evidence that PcCHI3 play a crucial role in resistance against both biotic and abiotic stresses. This study will shed some light on further investigation ofPopulus chitinse genes and lay a base for the stress resistance breeding of woody trees.

关 键 词：杨树 第Ⅴ类几丁质酶 表达分析 抗逆育种 

分 类 号：S792.11[农业科学—林木遗传育种]