Poster: Plant-pathogen interactions

Abs # 507: CaTin1 (Capsicum annuum TMV-induced clone 1) expression perturbation alters the plant¡¯s response to ethylene and interferes with the redox homeostasis

Presenter:	Paek, Kyung-Hee , khpaek95@korea.ac.kr
Authors	Paek, Kyung-Hee  (A)   Shin, Ryoung  (C)   An, Jong-Min  (A)   Park, Chang-Jin  (A)   Kim, Young Jin  (A)   Joo, Sunjoo  (B)   Kim, Woo Taek  (B)
Affiliations:	(A): School of Life Sciences and Biotechnology, Korea University (B): Department of Biology, Yonsei University (C): Donald Danforth Plant Science Center
Web Site:	http://biotech.korea.ac.kr/member/khpaek95

CaTin1 (Capsicum annuum TMV-induced clone 1) gene was expressed early during incompatible interaction of hot pepper plants with Tobacco mosaic virus (TMV) and Xanthomonas campestris. RNA blot analysis showed that CaTin1 gene was expressed only in root in untreated plants and induced mainly in leaf in response to ethylene, NaCl and methyl viologen but not by salicylic acid (SA) and methyl jasmonate (MeJA). The ethylene dependence of CaTin1 induction upon TMV inoculation was demonstrated by the decrease of CaTin1 expression in response to several inhibitors of ethylene biosynthesis or its action. Transgenic tobacco plants expressing CaTin1 gene in sense- or antisense-orientation showed interesting characteristics such as the accelerated growth and the enhanced resistance to biotic as well as abiotic stresses. Such characteristics appear to be caused by the elevated level of ethylene and H2O2. Moreover, in transgenic plants expressing antisense CaTin1 gene, the expression of some pathogenesis-related genes was enhanced constitutively, which may be mainly due to the increased ethylene level. The promoter of CaTin1 has four GCC-boxes, two AT-rich regions, and an elicitor-inducible W-box. The induction of the promoter activity by ethylene depends on GCC-boxes and by TMV depends on W-box. Taken together, we propose that the CaTin1 upregulation or downregulation interferes with the redox balance of plants leading to the altered response to ethylene and biotic as well as abiotic stresses.