Coffee Leaf Rust
Coffee (Coffea arabica) is the most important agricultural commodity in the world. It has an estimated retail value of 70 billion US dollars, and its production supports more than 100 million people worldwide, primarily small shareholder farmers in developing countries. Today, coffee production is threatened by fungal diseases, the most important of which is caused by the coffee leaf rust (CLR) fungus, Hemileia vastatrix Berk. & Broome (Basidiomycota, Pucciniales). Today CLR has successfully invaded nearly every coffee growing region of the world.
Most rust fungi require two unrelated host plants in order to complete their life cycle, where sexual recombination via fertilization occurs on one host, termed an “aecial” host, and the asexual repetitive portion of the life cycle occurs on a different host, termed the “telial” host. It remains unknown whether an aecial host exists for H. vastatrix, or if the fungus has adapted to complete the sexual cycle on its telial host, or even if the fungus undergoes sexual reproduction at all. Work in our lab is attempting to elucidate the entire life cycle of the coffee leaf rust pathogen, and to understand how epidemics of CLR arise.
Coffea arabica leaves infected with uredinia
Anatomy of H. vastatrix
Coffee Rust Is Going to Ruin Your Morning
Read about some of our work in The Atlantic by clicking the above link.
Bekele KB, Senbeta GA, Garedew W, Caixeta ET, Ramírez-Camejo LA, Aime MC. 2022. Genetic diversity and population structure of Hemileia vastatrix from Ethiopian Arabica coffee. Archives of Phytopathology and Plant Protection 13: 1483-1503. doi: 10.1080/03235408.2021.1983385
Posada, F, Aime MC, Peterson SW, Rehner SA, Vega FE. 2007. Inoculation of coffee plants with the fungal entomopathogen Beauveria bassiana (Ascomycota: Hypocreales). Mycological Research 111:749–758. doi: 10.1016/j.mycres.2007.03.006
Ramírez-Camejo LA, Eamvijarn A, Díaz-Valderrama JR, Karlsen-Ayala E, Koch RA, Johnson E, Pruvot-Woehl S, Meija LC, Montagnon C, Maldonado-Fuentes C, Aime MC. 2022. Global analysis of Hemileia vastatrix populations shows clonal reproduction for the coffee leaf rust pathogen throughout most of its range. Phytopathology 112: 643-652. doi: 10.1094/PHYTO-06-21-0255-R
Ramírez-Camejo, Keith LM, Matsumoto T, Sugiyama L, Fukada M, Brann M, Moffitt A, Liu JRA, Aime MC. 2022. Coffee leaf rust (Hemileia vastatrix) from the recent invasion into Hawaii shares a genotypic relationship with Latin-American populations. Journal of Fungi 8:189. doi: 10.3390/jof8020189
Rhiney K, Guido Z, Knudson C, Avelino J, Bacon CM, Leclerc G, Aime MC, Bebber DP. 2021. Epidemics and the future of coffee production. Proceedings of the National Academy of Sciences, USA 118 (27): e2023212118. doi: 10.1073/pnas.2023212118
Vega FE, Simpkins A, Aime MC, Posada F, Peterson SW, Rehner SA, Infante F, Castillo A, Arnold AE. 2010. Fungal endophyte diversity in coffee plants from Colombia, Hawai’i, Mexico and Puerto Rico. Fungal Diversity 3:122–138. doi: 10.1016/j.funeco.2009.07.002
Vega FE, Posada F, Aime MC, Peterson SW, Rehner SA. 2008. Fungal endophytes in green coffee seeds. Mycosystema 27:75–84.