Development of citrus plants resistant to Xanthomonas citri

• Grant number: 09/00994-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2009
• End date: November 30, 2010
• Field of knowledge: Biological Sciences - Genetics - Plant Genetics
• Principal Investigator: Celso Eduardo Benedetti
• Grantee: Maria Luiza Peixoto de Oliveira
• Host Institution: Associação Brasileira de Tecnologia de Luz Síncrotron (ABTLuS). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

The production of citrus fruits has being constantly threatened by the bacterium Xanthomonas axonopodis pv. citri (Xac), the citrus canker disease agent. This bacterium, when in contact with host plants, induces canker lesions on leaves, fruits and branches. On the other hand, when this pathogen infects a non-host plant a necrotic reaction is induced at the infection site as a hypersensitive-like reaction. The principals measures applied for control of canker are immediate destruction of infected trees and quarantine restrictions have been enforced to prevent the spread of the pathogen to new area. These measures have generated significant monetary losses. The present project proposes to develop plants of sweet orange (Citrus sinensis) resistant to Xac. Initially, two approaches will be tested: first, a pathogenicity gene of Xac, which in many Xanthomonas strains, is essential for the pathogen to cause hyperplastic cankers on citrus, will be expressed as truncated form to suppress protein function in host; the second approach, will be test the superexpression of sweet orange genes activated in defense response induced by Xanthomonas axonopodis pv. aurantifolii, pathotype C (Xaa), identified in previous work in our laboratory. (AU)