English
Unraveling the Secretion Mechanism of Cytoplasmic Effector in Rice Blast Fungus, Magnaporthe oryzae
Eunbin Choi1, Heeryoung Ahn1, Song Hee Lee1,2, Jin Young Kim1 and Junhyun Jeon1,2*
1Department of Biotechnology, College of Life and Applied Sciences, Yeungnam University, Gyeongsan, Gyeongbuk, Republic of Korea.
2Plant Immunity Research Center, Seoul National University, Seoul, Republic of Korea.
*Email: jjeon@yu.ac.kr
Success infection and host plant colonization relies on secretion of a set of effectors. The rice blast fungus has been found to utilize two distinct secretion mechanisms. Apoplastic effectors are secreted via conventional secretory pathway, whereas cytoplasmic effectors are secreted from blast interfacial complex (BIC) via ER to Golgi-independent pathway. This cytoplasmic effector secretion pathway remains elusive. In this study, we aim to study the cytoplasmic effectors secretion mechanism based on the use of cytoplasmic effector, Avr-Pita in rice blast fungus, Magnaporthe oryzae. The genome of M. oryzae strain CP987 lacks Avr-Pita, allowing it to cause disease in rice variety Yashiro-mochi (Yamo), which contains the Pita, R gene counterpart to Avr-Pita. We introduced Avr-Pita into CP987, resulting in the fungus avirulent to Yamo. To identify the genes involved in the secretion of cytoplasmic effectors, we generated random insertional mutants using Agrobacterium tumefaciens-mediated transformation (ATMT). To date, we have screened over 2,000 mutants and selected transformants that regain pathogenicity on Yamo. Through inverse PCR, we identified a hypothetical gene (MGG_04851) disrupted by T-DNA insertion in one transformants. This gene is located approximately 400bp away from the putative phospholipid-transporting ATPase 1 (MGG_04852). Given their proximity, we generated deletion mutants for each gene. Furthermore, we will assess their expression levels and investigate whether there is any correlation to cytoplasmic effector secretion. The resulting mutants would be valuable resource for uncovering important yet obscure pathogenesis mechanism.
