Expression of Genes Involved in Anthracnose Resistance in Chili (Capsicum baccatum) 'PBC80'-Derived Recombinant Inbred Lines

Wassana Kethom; Paul W J Taylor; Orarat Mongkolporn

doi:10.3390/pathogens12111306

Expression of Genes Involved in Anthracnose Resistance in Chili (Capsicum baccatum) 'PBC80'-Derived Recombinant Inbred Lines

Pathogens. 2023 Nov 1;12(11):1306. doi: 10.3390/pathogens12111306.

Authors

Wassana Kethom¹, Paul W J Taylor², Orarat Mongkolporn¹

Affiliations

¹ Department of Horticulture, Faculty of Agriculture at Kamphaeng Saen, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand.
² Faculty of Science, The University of Melbourne, Parkville, VIC 3010, Australia.

Abstract

Chili anthracnose has long been a threat to chili production worldwide. Capsicum baccatum 'PBC80' has been identified as a source of resistance to anthracnose. Recently, a QTL for ripe fruit resistance from 'PBC80'-derived RILs was located on chromosome 4 (123 Mb) and contained over 80 defense-related genes. To identify the genes most related to anthracnose resistance, a fine map of the QTL region was developed using single-marker analysis. Nine genes were selected from the new QTL (1.12 Mb) to study their expression after being challenged with Colletotrichum scovillei 'MJ5' in two different RIL genotypes (Resistance/Resistance or R/R and Susceptible/Susceptible or S/S) at 0, 6 and 12 h. Of the nine genes, LYM2, CQW23_09597, CLF, NFXL1, and PR-14 were significantly up-regulated, compared to the control, in the R/R genotype. ERF was up-regulated in both chili genotypes. However, the expression was relatively and constantly low in the S/S genotype. Most up-regulated genes reached the highest peak (2.3-4.5 fold) at 6 h, except for ERF, which had the highest peak at 12 h (6.4 fold). The earliest and highest expressed gene was a pathogen receptor, LYM2.

Keywords: Colletotrichum scovillei; defense-related genes; hypersensitive reaction; microinjection; qRT-PCR; wounded inoculation.

Grants and funding

This research was funded by the Office of the Ministry of Higher Education, Science, Research and Innovation; and the Thailand Science Research and Innovation through the Kasetsart University Reinventing University Program 2021 (Grant ID: RUP2.2/Con-CASAF PD01).