Use of a Secretion Trap Screen in Pepper Following Phytophthora capsici Infection Reveals Novel Functions of Secreted Plant Proteins in Modulating Cell Death

作者：Yeom Seon In; Baek Hyang Ku; Oh Sang Keun; Kang Won Hee; Lee Sang Jik; Lee Je Min; Seo Eunyoung; Rose Jocelyn K C; Kim Byung Dong; Choi Doil^*

来源：Molecular Plant-Microbe Interactions, 2011, 24(6): 671-684.

DOI：10.1094/MPMI-08-10-0183

In plants, the primary defense against pathogens is mostly inducible and associated with cell wall modification and defense-related gene expression, including many secreted proteins. To study the role of secreted proteins, a yeast-based signal-sequence trap screening was conducted with the RNA from Phytophthora capsici-inoculated root of Capsicum annuum 'Criollo de Morelos 334' (CM334). In total, 101 Capsicum annuum secretome (CaS) clones were isolated and identified, of which 92 were predicted to have a secretory signal sequence at their N-terminus. To identify differences in expressed CaS genes between resistant and susceptible cultivars of pepper, reverse Northern blots and real-time reverse-transcription polymerase chain reaction were performed with RNA samples isolated at different time points following P capsici inoculation. In an attempt to assign biological functions to CaS genes, we performed in planta knock-down assays using the Tobacco rattle virus-based gene-silencing method. Silencing of eight CaS genes in pepper resulted in suppression of the cell death induced by the non-host bacterial pathogen (Pseudomonas syringae pv. tomato T1). Three CaS genes induced phenotypic abnormalities in silenced plants and one, CaS259 (PR4-1), caused both cell death suppression and perturbed phenotypes. These results provide evidence that the CaS genes may play important roles in pathogen defense as well as developmental processes.

• 出版日期2011-6