Rust plant pathogens make up a large fungal group which cannot survive on their own so they use crops as hosts, leading to reduced yields and potentially hindering efforts to grow biomass for fuel. To learn more about these, a 2006 Community Sequencing Program project generated the 101-million base pair genome of the poplar leaf rust fungus Melampsoralarici-populina, the first tree pathogen sequenced.
Original confocal microscopy image of infected leaves from poplar cv.
(Image by StéphaneHacquard, INRA Nancy)
The fungal project complements work as poplar leaf rust outbreaks weaken poplar trees, a candidate bioenergy feedstock whose genome sequence was published by the DOE JGI in 2007.
Published the week of May 2, 2011 in the early edition of the Proceedings of the National Academy of Sciences, an international team of researchers that included DOE JGI Fungal Genome Program head Igor Grigoriev compared the genomes of poplar leaf rust and wheat stem rust fungi in order to develop biocontrol methods. The latter fungus was sequenced by the Broad Institute.
In combination with the genome sequence of Populus, published in 2006, researchers will be able to compare and dissect the molecular interactions that lead to symbiotic versus pathogenic responses in the host plant. Tuskan who lead the team that published the Populus genome remarked that “There may be a fine distinction at the moment of initial communication between host and symbiont and host and pathogen that allow the biochemical resistance machinery of the host to reject or welcome a fungal associate.”