Dysfunctional Pro1 leads to female sterility in rice blast fungi

Momotaka Uchida; Takahiro Konishi; Ayaka Fujigasaki; Kohtetsu Kita; Tsutomu Arie; Tohru Teraoka; Yasukazu Kanda; Masaki Mori; Takayuki Arazoe; Takashi Kamakura

doi:10.1016/j.isci.2023.107020

Dysfunctional Pro1 leads to female sterility in rice blast fungi

iScience. 2023 Jun 14;26(7):107020. doi: 10.1016/j.isci.2023.107020. eCollection 2023 Jul 21.

Affiliations

¹ Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
² United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology (TUAT), 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-0054, Japan.
³ Division of Plant Molecular Regulation Research, Institute of Agrobiological Sciences, NARO (NIAS), 2-1-2 Kan-nondai, Tsukuba, Ibaraki 305-8602, Japan.

Abstract

Although sexual reproduction is widespread in eukaryotes, some fungal species can only reproduce asexually. In the rice blast fungus Pyricularia (Magnaporthe) oryzae, several isolates from the region of origin retain mating ability, but most isolates are female sterile. Therefore, female fertility may have been lost during its spread from the origin. Here, we show that functional mutations of Pro1, a global transcriptional regulator of mating-related genes in filamentous fungi, is one cause of loss of female fertility in this fungus. We identified the mutation of Pro1 by backcrossing analysis between female-fertile and female-sterile isolates. The dysfunctional Pro1 did not affect the infection processes but conidial release was increased. Furthermore, various mutations in Pro1 were detected in geographically distant P. oryzae, including pandemic isolates of wheat blast fungus. These results provide the first evidence that loss of female fertility may be advantageous to the life cycle of some plant pathogenic fungi.

Keywords: Evolutionary biology; Microbiology; Plant pathology.