Early responses of Eucalyptus grandis during rust infection

• Ano de defesa: 2020
• Autor(a) principal: Sekiya, Alline
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Austropuccinia psidii; Fisiologia vegetal; Metabolômica; Metabolomics; Plant physiology; Proteômica; Proteomics
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/11/11137/tde-30042020-170013/

Eucalyptus grandis (E. grandis) is the main tree species used to produce paper and pulp in Brazil, which is the second-largest global producer. Rust disease is among the most harmful conditions affecting Eucalyptus plantations, and it is caused by the biotrophic fungus Austropuccinia psidii (A. psidii), which can interfere with annual tree development and lead to productivity losses. In this context, we aimed to study the molecular events involved in the early response of E. grandis to rust infection. To accomplish these aims, contrasting plant genotypes derived from a half-sibling progeny of E. grandis were either inoculated with A. psidii or subjected to control conditions to evaluate their physiological, metabolomic and proteomic responses 24 hours after inoculation (hai). Our results showed that responses of the genotypes against A. psidii diverged at 12 hai, when the rust-resistant genotype detected the fungus and initiated both oxidative burst and flavonoid production as an effective defense against the pathogen. Simultaneously, the immune system of the rustsusceptible genotype was unable to induce the production of ROS (reactive oxygen species) and hypersensitive response was suppressed. Thus, our findings enabled us to understand some of the key molecular mechanisms that underly the interactions between E. grandis and A. psidii, identify key molecules for further study of the disease pathology, and important features for enhancing molecular breeding efforts.