Choi Du Seok, Hong Jeum Kyu, Hwang Byung Kook
Laboratory of Molecular Plant Pathology, College of Life Sciences and Biotechnology, Korea University, Anam-dong, Sungbuk-ku, Seoul, 136-713, Republic of Korea.
Department of Plant Biology and The Genome Center, College of Biological Sciences, University of California Davis, Davis, CA, 95616, USA.
Planta. 2013 Dec;238(6):1113-24. doi: 10.1007/s00425-013-1956-3. Epub 2013 Sep 11.
Osmotin or osmotin-like protein, a PR-5 family member, is differentially induced in plants by abiotic and biotic stresses. Here, we demonstrate that the pepper (Capsicum annuum) osmotin-like protein 1 gene, CaOSM1, was required for the defense and hypersensitive cell death response and oxidative burst signaling during Xanthomonas campestris pv. vesicatoria (Xcv) infection. CaOSM1 protein was localized to the plasma membrane in leaf cells of Nicotiana benthamiana. Agrobacterium-mediated transient expression of CaOSM1 in pepper distinctly induced the hypersensitive cell death response and H2O2 accumulation. Knock-down of CaOSM1 in pepper by virus-induced gene silencing increased the susceptibility to Xcv infection, which was accompanied by attenuation of the cell death response and decreased accumulation of H2O2. CaOSM1 overexpression in transgenic Arabidopsis conferred reduced susceptibility and accelerated cell death response and H2O2 accumulation to infection by Pseudomonas syringe pv. tomato and Hyaloperonospora arabidopsidis. Together, these results suggest that CaOSM1 is involved in cell death and oxidative burst responses during plant defense against microbial pathogens.
渗调蛋白或类渗调蛋白，作为病程相关蛋白5（PR - 5）家族成员之一，在植物中会因非生物胁迫和生物胁迫而受到差异诱导。在此，我们证明辣椒（Capsicum annuum）类渗调蛋白1基因CaOSM1在野油菜黄单胞菌辣椒斑点病致病变种（Xanthomonas campestris pv. vesicatoria，Xcv）侵染期间的防御反应、过敏细胞死亡反应及氧化爆发信号传导过程中发挥作用。CaOSM1蛋白定位于本氏烟草叶片细胞的质膜上。通过农杆菌介导在辣椒中瞬时表达CaOSM1可明显诱导过敏细胞死亡反应及H2O2积累。利用病毒诱导的基因沉默技术使辣椒中的CaOSM1基因表达量降低，导致其对Xcv侵染的易感性增加，同时伴随着细胞死亡反应减弱及H2O2积累减少。在转基因拟南芥中过表达CaOSM1，可使其对番茄细菌性斑点病菌（Pseudomonas syringe pv. tomato）和拟南芥霜霉病菌（Hyaloperonospora arabidopsidis）侵染的易感性降低，并加速细胞死亡反应及H2O2积累。综上所述，这些结果表明CaOSM1在植物抵御微生物病原体的过程中参与了细胞死亡及氧化爆发反应。
