Abstract: The Hypersensitive Response (HR) is one of the most efficient and common disease resistance mechanisms in plant. Cloning signaling genes is very important to elucidate the resistance mechanisms. A gene in tomato with homology to several resistance proteins involved in HR in plant, was indentified and designated as RGL (Resistance Gene Like). RGL protein was used as bait to screen interacting protein (s) from tomato cDNA library through yeast two-hybrid system. Two interacting proteins designated as RGLIP-1 and RGLIP-2 (RGL Interacting Protein) respectively were found. RGLIP-1 is a protein of 291 amino acids with significant homology to thylakoid lumen protein. RGLIP-2 is a protein of 248 amino acids with significant homology to transducin protein. Virus-Induced Gene Silencing (VIGS) of the two genes resulted in a partial and
complete suppression of Avr4-induced HR, indicating that both genes are involved in hypersensitive response.

Key words: Tomato, Cladosporium fulvum, Hypersensitive response, Yeast two-hybrid system, Virus-induced gene silencing