Host-dependent fungus-fungus competition suppresses fungal pathogenesis in Arabidopsis thaliana [article]

Kuldanai Pathompitaknukul, Kei Hiruma, Hiroyuki Tanaka, Nanami Kawamura, Atsushi Toyoda, Takehiko Itoh, Yusuke Saijo
2020 bioRxiv   pre-print
Like animals, plants accommodate a rich diversity of microbes, typically without discernible disease symptoms. How their pathogenesis is prevented in the host remains obscure. Here, we show that the root-infecting fungus Colletotrichum fructicola of the C. gloeosporioides clade (CgE), isolated from field-grown healthy Brassicaceae plants, inhibits growth of pathogenic fungi in Arabidopsis thaliana, in a phosphate status-dependent manner. Loss of host ethylene signaling or phytoalexins,
more » ... toalexins, camalexin or indole glucosinolates, however, allows CgE to display pathogenesis, suggesting host contributions to endophytic CgE colonization and benefit. Compared to a closely-related C. gloeosporioides pathogen (CgP), CgE is characterized by genome expansion and >700 fungal genes (4.34%) specifically induced in the host roots when co-inoculated with CgP, including genes related to fungal secondary metabolism. This may underlie antimicrobial tolerance of CgE and its dominance over pathogenic fungi within the host, pointing to a role for fungus-fungus competition in asymptomatic fungal colonization in plants.
doi:10.1101/2020.05.27.117978 fatcat:f3arooroqbbxfaxme7hll5emp4