Over-expressed rice ADP-ribosylation factor 1 (RARF1) induces pathogenesis-related genes and pathogen resistance in tobacco plants

A cDNA encoding RARF1 ((r) under bar ice (A) under bar DP-(r) under bar ibosylation (f) under bar actor (1) under bar) was isolated from fungal elicitor-treated rice suspension culture cells by mRNA differential display. RARF1 transcripts accumulated in response to hydrogen peroxide (H2O2) and salicylic acid (SA) and rapidly in cells inoculated with an avirulent pathogen. Constitutively over-expressed RARF1 under the control of the cauliflower mosaic virus 35S promoter (CaMV 35S) triggered spontaneous induction of lesion mimics, induced an array of pathogenosis-related (PR) genes, reduced susceptibility to a fungal pathogen, and caused accumulation of SA. From these data, we deduced that RARF1 might be a component of various plant defence signalling pathways involved in inducing the expression of a subset of PR genes.