Function and Transcriptome Analysis of an Oligopeptide Transporter CgOPT2 in the Rubber Anthracnose Fungus Colletotrichum Gloeosporioides

Colletotrichum gloeosporioides is a main pathogen causing rubber anthracnose, which brings huge economic loss to natural rubber industry. Oligopeptide transporter (OPT) is a kind of peptide transport protein, which usually exhibits various biological functions in fungi. In this study, an oligopeptide transporter gene CgOPT2 is identified from the rubber anthracnose fungus C. gloeosporioides as a homolog of OPT2 in Saccharomyces cerevisiae. CgOPT2 encodes a 990-amino acid protein, which has an OPT domain harboring 15 transmembrane domains. The gene knock-out mutant of CgOPT2 had reduced vegetative growth on PDA and CM media, and was more sensitive to H2O2, SDS and Congo Red than the wild-type strain. Moreover, the mutant had obviously lagged conidia germination and attenuated virulence on rubber leaves. Transcriptome analysis showed CgOPT2 could affect the expression of many genes involved in cellular transport, amino acid metabolism and signal transduction, etc. In conclusion, CgOPT2 is an important oligopeptide transporter of C. gloeosporioides, which participates in the process of vegetative growth, cell wall integrity, oxidative stress, conidia germination and pathogenicity.