Aspectos moleculares da interação entre Diaphorina citri e Candidatus Liberibacter asiaticus

Author(s)

Inaiara de Souza Pacheco

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2019-06-13

Examining board members

Marcos Antonio Machado; Helvecio Della Coletta Filho; Michele do Carmo de Sousa Timossi; Henrique Marques Souza; Ricardo Harakava

• Advisor: Marcos Antonio Machado

Abstract

Citrus and it¿s subproducts are one of the most important commodities of Brazil, however, since the discovery of Huanglongbing (HLB), in 2004, the sector has been suffering dramatic loses of production. The causal agents of this disease are gram-negative phloem-limited bacteria of Liberibacter genus. These bacteria spread systemically throughout the plant causing leaves and fruit abscission and promoting the plant death in a few years. Candidatus Liberibacter asiaticus (Ca. Las ) is the main causal agent of HLB in Brazil. In vitro isolation and culture of this specie have been unsuccessful so far, which difficult their study. Asian citrus psysilid, Diaphorina citri Kuwayama,, is responsible for transmission of Ca. Las . Many studies have been developed with the aim of elucidating aspects of these pathosystem, primarily on plant-pathogen interactions and plant-insect interactions. However, studies on interaction of the pathogen and its insect vector are rare and recent. Based on that, we aiming cooperate with efforts to understand the genetics and physiological mechanisms of D. citri and Ca. Las interactions. First were determined the fluctuation of energetic metabolism of D. citri were observed on four different life stages and also between Ca. Las -free and Ca. Las - infected insects. As a result, were observed that D. citri adult phase present elevated metabolic activity compared with other instars. Suppression of D. citri energetic metabolism genes were observed on Ca. Las - infected insects. Once feeding is the main vehicle of acquisition and transmission of Ca. Las by D. citri, we predict D. citri candidate effectors. Three proteins were identified as able to be secreted on D. citri saliva. The genes of those proteins are modulated by Ca. Las . RNAi-silencing of those genes promoted interference on D. citri feeding and mortality (AU)

• FAPESP's process: 15/13971-0 - Global gene expression of Candidatus Liberibacter asiaticus in different stages of development of the vector (Diaphorina citri).
• Grantee: Inaiara de Souza Pacheco
• Support Opportunities: Scholarships in Brazil - Doctorate