A General Protocol for Gene Expression Analysis in Chemically Mutant Coffee Plants in Response to Rust (Hemileia vastatrix Berk & Broome) Infection.

Coffea spp. is the source of one of the most widely consumed beverages in the world. However, the cultivation of this crop is threatened by Hemileia vastatrix Berk & Broome, a fungal disease, which reduces the productivity and can cause significant economic losses. In this protocol, coffee leaf segment derived from a chemical mutagenesis process are inoculated with uredospores of the pathogen. Subsequently, the gene expression changes are analyzed over the time (0, 5, 24, 48, and 120 h) using quantitative real-time polymerase chain reaction (RT-qPCR). The procedures and example data are presented for expression analysis in the CaWRKY1 gene. This procedure can be applied for quantitative analysis of other genes of interest to coffee breeders and scientists for elucidating the molecular mechanisms involved in the interaction between the plant and pathogen, potentially leading to the development of more efficient approaches for managing this disease.