Comparative genomics to decipher host adaptation of the fungal pathogen Austropuccinia psidii to its plant host species in the Myrtaceae family

• Grant number: 22/11900-1
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• Start date: March 01, 2023
• End date: June 30, 2023
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Nelson Sidnei Massola Júnior
• Grantee: Thaís Regina Boufleur
• Supervisor: Benjamin Schwessinger
• Host Institution: Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: Australian National University (ANU), Australia
• Associated to the scholarship: 21/01606-6 - Identification of genetic pathogenicity mechanisms of Austropuccinia psidii to the Myrtaceae family, BP.PD

Abstract

Myrtle rust, caused by Austropuccinia psidii, is responsible for significant economic, environmental, and social impacts. A. psidii is an obligate biotroph that has its asexual dikaryotic stage associated with epidemic outbreaks around the world. Brazil is the center of origin of A. psidii, and currently, myrtle rust has a wide host range, associated with more than 480 species in the Myrtaceae family. Thus far, four main genetic groups of the pathogen, with specialization to different hosts and/or geographic regions have been reported worldwide: two biotypes with a strong relationship with different hosts in Brazil; a polyphagous biotype restricted to South Africa, and a polyphagous pandemic biotype, widely spread around the globe. To clarify knowledge gaps around the pathogenicity and evolution of rust fungi, both haplotypes are needed. Recent advances in genome sequencing technologies and bioinformatic tools allowed the assembly of both haplotypes of A. psidii genome, revealing high heterozygosity between the haploid genomes. Comparative genomics between different strains of A. psidii will facilitate our understanding of the genetic relationship and evolution of the different biotypes. This is important to better decipher host adaptation processes to different species in the Myrtaceae family. Moreover, this proposal aims to provide insights into the genetic relationships and evolutionary history of the pathogen, which is key to preventing new incursions of the pathogen around the world. (AU)