Why Sequence Mycosphaerella fijiensis?

Mycosphaerella fijiensis, the causal agent of the devastating leaf streak disease (commonly called Black Sigatoka) in bananas, requires the highest annual fungicide application of all pathogens globally (more than $2.5 billion worth). This pathogen is of urgent importance, as banana production relies heavily on massive use of a fungicide that is under critical public review for human safety, biosafety, and environmental reasons.

The availability of sequence data for this fungus will have a significant impact on research programs aiming at environmentally sound strategies to control Black Sigatoka disease. For example, the International Banana Action Program is being developed with the goal to reduce pesticide inputs in banana production by 50% in 10 years. The sequencing results will be made even more valuable with the inclusion of 40,000 EST sequences from the asexual fungus Cercospora zeae-maydis, the causal agent of gray leaf spot of maize, which represents a different branch of the Mycosphaerella evolutionary tree. Gray leaf spot is the major disease of maize in the United States, Africa, and South America, and C. zeae-maydis is very closely related to other species of Cercospora that cause economically important diseases in sugar beet, soybean, tobacco, and many other crops of great importance to U.S. and global agriculture.

This sequencing project will help scientists to understand processes involved in pathogenicity and resistance and give them deep insight into comparative genomics among the great diversity of Mycosphaerella pathogens. Mycosphaerella species are genetically unrelated and have a different life history from other plant pathogens with sequenced genomes. Phylogenetic analyses show that many species in this genus originated by recent adaptive radiations onto different hosts, and additional sequence information will provide a better understanding of speciation in pathogenic fungi. The research community will disseminate and use this information to develop environmentally benign control strategies for diverse crops of global significance.

CSP project participants: Stephen B. Goodwin (proposer, USDA-ARS and Purdue Univ.) and Gert H.J. Kema (proposer, Plant Research Intl. B.V., Wageningen, The Netherlands), Larry D. Dunkle (USDA-ARS and Purdue Univ.), Alice Churchill (Cornell Univ.), Jean Carlier (CIRAD, France), Andy James (CICY, Mexico), Manoel Souza (EMBRAPA, Brazil), Pedro Crous (Fungal Biodiversity Centre, Utrecht).