Trade-Off Relation between Fungicide Sensitivity and Melanin Biosynthesis in Plant Pathogenic Fungi

Ken Harata; Hiroyuki Daimon; Tetsuro Okuno

doi:10.1016/j.isci.2020.101660

Trade-Off Relation between Fungicide Sensitivity and Melanin Biosynthesis in Plant Pathogenic Fungi

iScience. 2020 Oct 8;23(11):101660. doi: 10.1016/j.isci.2020.101660. eCollection 2020 Nov 20.

Authors

Ken Harata¹, Hiroyuki Daimon², Tetsuro Okuno¹

Affiliations

¹ Department of Plant Life Science, Ryukoku University, Seta, Shiga 520-2194, Japan.
² Graduate School of Agriculture, Ryukoku University, Seta, Shiga 520-2194, Japan.

Abstract

Circumventing the emergence of fungicide-resistant strains is a crucial issue for robust disease management in agriculture. The agricultural fungicide ferimzone has been used for the control of rice diseases including rice blast. The emergence of ferimzone-resistant strains in rice fields has not been reported. Here, we identified the copper transport CoICT1 gene as the ferimzone sensitivity gene in Colletotrichum orbiculare and the rice blast fungus Magnaporthe oryzae. Genetic and cytological analyses showed that functional defects in the copper transport pathways, consisting of CoIct1 and P-type ATPase CoCcc2, led to the low sensitivity to ferimzone and the pathogenicity defect due to attenuated melanization in the appressorium. Importantly, the presence of CuSO₄ induced high sensitivity to ferimzone even in the coict1 mutant. Our study shows that there is a trade-off relation between the sensitivity to ferimzone and fungal pathogenicity.

Keywords: Agricultural Science; Genetics; Mycology.