AUTHOR=Kim Ki-Tae , Ko Jaeho , Song Hyeunjeong , Choi Gobong , Kim Hyunbin , Jeon Jongbum , Cheong Kyeongchae , Kang Seogchan , Lee Yong-Hwan 

TITLE=Evolution of the Genes Encoding Effector Candidates Within Multiple Pathotypes of Magnaporthe oryzae

JOURNAL=Frontiers in Microbiology

VOLUME=10

YEAR=2019

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2019.02575

DOI=10.3389/fmicb.2019.02575

ISSN=1664-302X

ABSTRACT=<p><italic>Magnaporthe oryzae</italic> infects rice, wheat, and many grass species in the Poaceae family by secreting protein effectors. Here, we analyzed the distribution, sequence variation, and genomic context of effector candidate (<italic>EFC</italic>) genes in 31 isolates that represent five pathotypes of <italic>M. oryzae</italic>, three isolates of <italic>M. grisea</italic>, a sister species of <italic>M. oryzae</italic>, and one strain each for eight species in the family Magnaporthaceae to investigate how the host range expansion of <italic>M. oryzae</italic> has likely affected the evolution of effectors. We used the <italic>EFC</italic> genes of <italic>M. oryzae</italic> strain 70-15, whose genome has served as a reference for many comparative genomics analyses, to identify their homologs in these strains. We also analyzed the previously characterized avirulence (<italic>AVR</italic>) genes and single-copy orthologous (<italic>SCO</italic>) genes in these strains, which showed that the <italic>EFC</italic> and <italic>AVR</italic> genes evolved faster than the <italic>SCO</italic> genes. The <italic>EFC</italic> and <italic>AVR</italic> repertoires among <italic>M. oryzae</italic> pathotypes varied widely probably because adaptation to individual hosts exerted different types of selection pressure. Repetitive DNA elements appeared to have caused the variation of some <italic>EFC</italic> genes. Lastly, we analyzed expression patterns of the <italic>AVR</italic> and <italic>EFC</italic> genes to test the hypothesis that such genes are preferentially expressed during host infection. This comprehensive dataset serves as a foundation for future studies on the genetic basis of the evolution and host specialization in <italic>M. oryzae</italic>.</p>