《植物生理学报》 2015, 51(7): 1061-1066

拟南芥果胶甲酯化酶基因PME17在抵御丁香假单胞杆菌番茄致病变种DC3000株中的功能

张倩, 鲍依群, 谭小云^*

南京农业大学生命科学学院, 南京210095

通信作者：谭小云；E-mail: tanxiaoyun@njau.edu.cn；Tel: 025-84395044

摘　要：

细胞壁是植物抵御病原菌入侵的第一道屏障, 果胶是细胞壁初生壁的主要组分。果胶甲酯化酶(PME)是修饰果胶的主要酶之一, 它在合成细胞壁、调节其弹性和通透性等过程中发挥重要作用。拟南芥基因表达数据库显示, PME17等多个果胶甲酯化酶基因在病原菌侵染情况下强烈表达。本文研究了PME17的组织表达及其在丁香假单胞杆菌番茄致病变种DC3000株(Pst DC3000)侵染过程中的功能。结果表明, 在未受Pst DC3000侵染的条件下, PME17基因在主根、根毛、子叶、叶毛、花粉等部位表达; 在受Pst DC3000感染时, PME17表达显著增强。和野生型相比, pme17突变体对Pst DC3000侵染更加敏感, 说明拟南芥PME17基因的表达受Pst DC3000的诱导, 并在防御Pst DC3000侵染中起积极作用。

关键词：植物抗病; 细胞壁; 果胶甲酯化酶; 丁香假单胞杆菌番茄致病变种DC3000株

收稿：2015-01-04   修定：2015-07-06

资助：国家自然科学基金(31200236)和中国博士后科学基金面上资助(2013M541683)。

Functional Analysis of Arabidopsis thaliana Pectin Methylesterase Gene PME17 in Immunity against Pseudomonas syringae pv. tomato DC3000

ZHANG Qian, BAO Yi-Qun, TAN Xiao-Yun^*

College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China

Corresponding author: TAN Xiao-Yun; E-mail: tanxiaoyun@njau.edu.cn; Tel: 025-84395044

Abstract:

In plants, cell walls act as structural barriers against pathogen entry. Pectin, a major component of plant cell wall, is critical for cell wall integrity. Pectin methylesterases (PMEs), which deesterify newly synthesized pectins, is important for cell wall rigidity and elasticity. In Arabidopsis thaliana, published microarray data indicated that expression of some pectin methylesterase genes (include PME17 gene) was up-regulated during infection with various pathogens, suggesting that PMEs play important roles during pathogens infection. In this study, we investigated expression pattern of PME17 gene and its function during infection by Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). We found that in normal conditions, PME17 gene was highly expressed in root hairs, trichomes, and floral organs. Its expression level was obviously up-regulated under infection of pathogen Pst DC3000. Furthermore, compared to wild type plants, pme17-2 mutant was more sensitive to Pst DC3000 infection, indicating that PME17 gene plays a positive role in immunity against Pst DC3000 infection.

Key words: plant immunity; cell wall; pectin methylesterase; Pseudomonas syringae pv. tomato DC3000