A common plant cell-wall protein HyPRP1 has dual roles as a positive regulator of cell death and a negative regulator of basal defense against pathogens

作者：Yeom Seon In; Seo Eunyoung; Oh Sang Keun; Kim Ki Woo; Choi Doil^*

来源：Plant Journal, 2012, 69(5): 755-768.

DOI：10.1111/j.1365-313X.2011.04828.x

• cell death
• basal disease resistance
• hybrid proline-rich protein (HyPRP)
• eight-cysteine motif (8CM)
• Capsicum annuum
• Nicotiana benthamiana

Although hybrid proline-rich proteins (HyPRPs) are ubiquitous in plants, little is known about their roles other than as cell-wall structural proteins. We identified the gene HyPRP1 in Capsicum annuum and Nicotiana benthamiana, which encodes a protein containing proline-rich domain and eight-cysteine motif (8CM) that is constitutively expressed in various organs, mostly in the root, but is down-regulated upon inoculation with either incompatible or compatible pathogens. Ectopic expression of HyPRP1 in plants accelerated cell death, showing developmental abnormality with down-regulation of ROS-scavenging genes, and enhanced pathogen susceptibility suppressing expression of defense-related genes. Conversely, silencing of HyPRP1 suppressed pathogen-induced cell death, but enhanced disease resistance, with up-regulation of defense-related genes and inhibition of in planta growth of bacterial pathogens independently of signal molecule-mediated pathways. Furthermore, the secreted 8CM was sufficient for these HyPRP1 functions. Together, our results suggest that a common plant cell-wall structural protein, HyPRP1, performs distinct dual roles in positive regulation of cell death and negative regulation of basal defense against pathogen.

• 出版日期2012-3