Kolosova N, Breuil C, Bohlmann J
Michael Smith Laboratories, University of British Columbia, 312-2185 East Mall, Vancouver, British Columbia V6T 1Z4, Canada; Department of Botany, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Department of Wood Science, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada.
Phytochemistry. 2014 May;101:32-9. doi: 10.1016/j.phytochem.2014.02.006. Epub 2014 Feb 21.
Chitinases have been implicated in the defence of conifers against insects and pathogens. cDNA for six chitinases were cloned from interior spruce (Picea glauca x engelmannii) and four from lodgepole pine (Pinus contorta). The cloned interior spruce chitinases were annotated class I PgeChia1-1 and PgeChia1-2, class II PgeChia2-1, class IV PgeChia4-1, and class VII PgeChia7-1 and PgeChia7-2; lodgepole pine chitinases were annotated class I PcChia1-1, class IV PcChia4-1, and class VII PcChia7-1 and PcChia7-2. Chitinases were expressed in Escherichia coli with maltose-binding-protein tags and soluble proteins purified. Functional characterization demonstrated chitinolytic activity for the three class I chitinases PgeChia1-1, PgeChia1-2 and PcChia1-1. Transcript analysis established strong induction of most of the tested chitinases, including all three class I chitinases, in interior spruce and lodgepole pine in response to inoculation with bark beetle associated fungi (Leptographium abietinum and Grosmannia clavigera) and in interior spruce in response to weevil (Pissodes strobi) feeding. Evidence of chitinolytic activity and inducibility by fungal and insect attack support the involvement of these chitinases in conifer defense.
几丁质酶与针叶树抵御昆虫和病原体的防御机制有关。从内陆云杉（白云杉×恩氏云杉）中克隆了6种几丁质酶的cDNA，从扭叶松中克隆了4种。克隆的内陆云杉几丁质酶被注释为I类PgeChia1-1和PgeChia1-2、II类PgeChia2-1、IV类PgeChia4-1以及VII类PgeChia7-1和PgeChia7-2；扭叶松几丁质酶被注释为I类PcChia1-1、IV类PcChia4-1以及VII类PcChia7-1和PcChia7-2。几丁质酶在带有麦芽糖结合蛋白标签的大肠杆菌中表达，并纯化出可溶性蛋白。功能特性表明，三种I类几丁质酶PgeChia1-1、PgeChia1-2和PcChia1-1具有几丁质分解活性。转录分析表明，在接种与树皮甲虫相关的真菌（冷杉细孔病菌和格氏新壳梭孢）后，内陆云杉和扭叶松中大多数被测几丁质酶，包括所有三种I类几丁质酶，都有强烈的诱导表达，并且在内陆云杉中，响应象鼻虫（云杉八齿小蠹）取食也有诱导表达。几丁质分解活性以及受真菌和昆虫攻击诱导的证据支持这些几丁质酶参与针叶树防御。
