Expression of small heat shock proteins in compatible and incompatible plant-pathogen interactions.

GAROFALO CG; GARAVAGLIA BS; DUNGER G; GOTTIG N; ORELLANO EG; OTTADO J

Rosario, Argentina

Congreso; VII Simposio Nacional de Biotecnología REDBIO-Argentina, II Congreso Internacional-REDBIO-Argentina; 2009

REDBIO

Plant resistance is mediated by R proteins that recognize specific effector molecules of the pathogen which induces the hypersensitive response (HR) characterized by a program cell death at the initial site of infection. Plant small heat shock proteins (sHsp) are produced under different stress conditions and at certain developmental stages. Recent studies suggest that these proteins might play a role in compatible and incompatible plantpathogen interaction. The phytopathogen bacteria Xanthomonas axonopodis pv. citri (Xac), responsible of the citrus canker disease, and Xanthomonas campestris pv. vesicatoria (Xcv), causative agent of bacterial spot disease in Capsicum sp., are able to induce HR in nonhost plants (incompatible non-host interaction). In this work we analyzed the expression of sHsp in orange and pepper plants subjected to thermal stress and in the interaction with Xac and Xcv. For the temperature experiments, oranges and pepper plants grown at 25ºC were subjected to thermal stress at 37ºC. By electrophoresis in denaturing polyacrylamide gels, we observed that the sHsp were induced at 30 minutes of the thermal stress in both plants. For the interaction experiments plants were infiltrated with 107 UFC/ml of Xac or Xcv. In orange plants the sHsp were induced 24 hours post inoculation in the compatible interaction with Xac and 2 hours post inoculation in the incompatible interaction with Xcv. Similar results were obtained for pepper plants; however the induction of sHsp was earlier than in orange. These results suggest that orange and pepper sHsp are induced during heat shock treatment and in plant-pathogen interactions.