[생명공학연구소] 2020학년도 제 1 차 세미나 개최

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교수님들과 교직원 여러분의 많은 참여 부탁드립니다

주제  :: I dentification and molecular evolutionary analysis of fungal effector proteins

연사  :: 김기태 박사

(Post-doc, Plant Immunity Research Center, Seoul National University, Seoul, Korea)    

일시  :: 2020년 7월 15일 (수) 16:00

장소  :: 생명응용과학대학 제 1 실험동 333 호

Abstract

The recent advancement of sequencing technology has enabled comprehensive molecular evolution and comparative genomics research on Kingdom fungi. In the field of plant pathology, pathogenomics has revealed a plethora of factors in fungal pathogens pertinent to pathogenicity. The most versatile group of pathogenic factors at the frontline of plant-pathogen interaction is effectors, which are transferred from a fungus to its host plant to manipulate host metabolism and physiology. Understanding plant pathogen effectors can be instrumental to the discovery of related interactors in plants, providing valuable information for resistant crop and development of sustainable plant disease control strategies. Therefore, a pipeline has been established to predict effector proteins from fungal genomes, and evolutionary analysis of effector genes was conducted to understand the evolutionary trajectory of fungal pathogenicity. Fungi secrete various proteins to interact with surrounding organisms. These proteins constitute the secretome and contain a variety of enzymes, including effectors. Through the pipeline, I identified the contents in the secretome and found that the proportion of catabolic enzymes to whole-genome was dependent on the host association of fungi, but effectors were in higher proportions as the host association increased. The proportion of effector repertoire depending on the fungal lifestyles may be due to coevolution with hosts. On the other hand, I analyzed the mechanism of host specialization using the genome of  Magnaporthe oryzae , which can infect various Poaceae crops and weeds. The effectors were identified from the rice pathotype  M. oryzae  using the effector prediction pipeline, and its homologous effectors were identified from the genomes of different pathotype strains. As a result, the greater the evolutionary distance from the rice pathotype strain, the number of homologous effectors was decreased, and the structural variation was increased. These variations seem to be caused by transposable elements and attributed to the selection pressure exerted by the different host plants on the strains. This study established an effector mining pipeline that can be used continuously with newly released fungal genomes and will provide a foundation for the molecular genetics study of effector genes. Further, the evolutionary study of the effector genes possessed by different pathotypes of  M. oryzae  strains suggests the possibility of understanding host specialization and the evolutionary direction of pathogens. Taken together, these results will provide new insights into understanding the plant-microbe interactions.

Keywords : fungi, pathogenomics, secretome, effector, host association, Magnaporthe oryzae , pathotype, host specialization