Molecular characterization and evaluation for Candidatus Liberibacter asiaticus resistance in transgenic plants of Citrus sinensis (L.) Osbeck expressing attA or D4E1 gene

• Grant number: 12/21734-0
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): May 01, 2013
• Effective date (End): April 30, 2017
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal researcher: Adriana Pinheiro Martinelli
• Grantee: Eveline Carla da Rocha Tavano
• Home Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

The Huanglongbing (HLB) associated to Candidatus Liberibacter spp., which colonizes the phloem, is considered one of the most serious diseases of citrus. One of the strategies to control this disease consists to produce transgenic plants expressing genes encoding antibacterial peptides under the control of phloem-specific promoters. Recently, transgenic plants were obtained from Citrus sinensis cv. 'Hamlin', 'Valencia' and 'Pera', containing genes encoding antibacterial peptides attacin A or D4E1 driven by phoem-specific promoters (AtSuc2, AtPP2 or CsPP2) or driven by constitutive promoter CaMV35S (D4E1). Part of the plants obtained was analyzed by Southern blot and RT-qPCR for molecular characterization. The objective of this project is to continue the molecular characterization and to evaluate the resistance level to HLB of acclimatized transgenic plants. Plants with positive results for the Southern blot and RT-qPCR analyzes will be selected for propagation and inoculation with Candidatus Liberibacter asiaticus through infected psyllids. The resistance evaluation to HLB will be performed by visual observation of symptoms and molecular analysis for detection and quantification of bacteria by quantitative PCR.