The causal agent of Black leaf streak sequenced

The sequencing of the Mycosphaerella fijiensis genome was announced at the first meeting of the ProMusa Crop Protection working group.
January 2008

Weighing in at 72 Mb, the recently sequenced Mycosphaerella fijiensis genome is 80% larger than the Mycosphaerella graminicola genome, whose sequence was made public at the end of 2006, but less rich in genes. The banana pathogen has something like 1000 fewer genes than the wheat pathogen, which at last count had 11,414 genes. The difference is explained by the high number of DNA repeats in the M. fijiensis genome.

“The decision to adopt M. graminicola as a model to develop research in M. fijiensis turned out to be an excellent choice”, said Gert Kema of Plant Research International (PRI) in The Netherlands. Comparing the two genomes should not only accelerate gene discovery but also the development of environmentally-friendly strategies to control M. fijiensis in banana plantations.

The causal agent of Black leaf streak disease, better known as Black Sigatoka, is a particularly aggressive fungus that can require up to 70 applications of fungicides a year. Moreover, it is particularly adept at evolving resistance to fungicides. Resistance to strobilurins, for example, has been traced to a point mutation on the mitochondrial genome. Having also sequenced the mitochondrial genome will help in the identification of other point mutations that lead to resistance.

Initiated by PRI and Purdue University, through the Community Sequencing Program sponsored by the US Department of Energy’s Joint Genome Institute, the sequencing of M. fijiensis was done by a consortium that also includes institutes in Brazil, France and Mexico. Once the genome is annotated, in about 18 months’ time, the genomic information will be made publicly available.

The insights gained from studying the pathogen’s DNA sequence will no doubt make an important contribution to reducing pesticide use in commercial banana plantations through multi-disciplinary initiatives such as the Pesticide Reduction Plan for Banana, also spearheaded by PRI.

For more information, contact Gert Kema at This e-mail address is being protected from spambots. You need JavaScript enabled to view it