Jung Ho Won, Lim Chae Woo, Lee Sung Chul, Choi Hyong Woo, Hwang Cheol Ho, Hwang Byung Kook
Laboratory of Molecular Plant Pathology, College of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul, 136-713, South Korea.
Planta. 2008 Jan;227(2):409-25. doi: 10.1007/s00425-007-0628-6. Epub 2007 Sep 27.
A Capsicum annuum hypersensitive induced reaction protein1 (CaHIR1) was recently proposed as a positive regulator of hypersensitive cell death in plants. Overexpression of CaHIR1 in transgenic Arabidopsis plants conferred enhanced resistance against the hemi-biotrophic Pseudomonas syringae pv. tomato (Pst) and the biotrophic Hyaloperonospora parasitica. Infection by avirulent Pseudomonas strains carrying avrRpm1 or avrRpt2 caused enhanced resistance responses in transgenic plants, suggesting that CaHIR1 is involved in basal disease resistance in a race-nonspecific manner. H. parasitica exhibited low levels of asexual sporulation on CaHIR1 seedlings. In contrast, transgenic plants were susceptible not only to the necrotrophic fungal pathogen Botrytis cinerea but were also sensitive to osmotic stress caused by high salinity and drought. To identify proteins whose expression was altered by CaHIR1 overexpression in Arabidopsis leaves, a quantitative comparative proteome analysis using two-dimensional gel electrophoresis coupled with mass spectrometry was performed. Of about 400 soluble proteins, 11 proteins involved in several metabolic pathways were up- or down-regulated by CaHIR1 overexpression. Genes encoding glycine decarboxylase (At2g35370) and an unidentified protein (At2g03440), which were strongly upregulated in CaHIR1-overexpressing Arabidopsis, were also differentially induced at the transcriptional level by Pst infection. Arabidopsis carbonic anhydrase (At3g01500), highly similar to tobacco salicylic acid-binding protein 3, was up-regulated by CaHIR1 overexpression. The activity of an anti-oxidant enzyme, cooper/zinc superoxide dismutase (At2g28190), was also attenuated in transgenic Arabidopsis by CaHIR1 overexpression. Together, these results suggest that CaHIR1 overexpression in Arabidopsis mediates plant responses to biotrophic, hemi-biotrophic and necrotrophic pathogens, as well as to osmotic stress in different ways.
辣椒过敏诱导反应蛋白1（CaHIR1）最近被认为是植物过敏细胞死亡的正调控因子。在转基因拟南芥植物中过表达CaHIR1可增强对半活体营养型丁香假单胞菌番茄致病变种（Pst）和活体营养型寄生霜霉的抗性。携带无毒基因avrRpm1或avrRpt2的无毒假单胞菌菌株感染可使转基因植物中的抗性反应增强，这表明CaHIR1以非小种特异性方式参与基础抗病性。寄生霜霉在CaHIR1幼苗上的无性孢子形成水平较低。相反，转基因植物不仅对坏死营养型真菌病原体灰葡萄孢敏感，而且对高盐度和干旱引起的渗透胁迫也敏感。为了鉴定拟南芥叶片中因CaHIR1过表达而改变表达的蛋白质，进行了使用二维凝胶电泳结合质谱的定量比较蛋白质组分析。在约400种可溶性蛋白质中，参与几种代谢途径的11种蛋白质因CaHIR1过表达而被上调或下调。在过表达CaHIR1的拟南芥中强烈上调的编码甘氨酸脱羧酶（At2g35370）和一种未知蛋白质（At2g03440）的基因，在转录水平上也受到Pst感染的差异诱导。与烟草水杨酸结合蛋白3高度相似的拟南芥碳酸酐酶（At3g01500）因CaHIR1过表达而上调。抗氧化酶铜/锌超氧化物歧化酶（At2g28190）的活性在转基因拟南芥中也因CaHIR1过表达而减弱。总之，这些结果表明拟南芥中CaHIR1的过表达以不同方式介导植物对活体营养型、半活体营养型和坏死营养型病原体以及渗透胁迫的反应。
