Researchers annotate genome of the smallest known fungal plant pathogen

Apr 23, 2014
The fungal plant pathogen Mixia osmundea has been isolated from fronds of the fern Osmundea cinnamomea. Credit: Sturgis McKeever, Georgia Southern University, Bugwood.org CC BY-NC 3.0

Researchers sequenced and analyzed the genome of Mixia osmundea, the smallest fungal plant pathogen (13.6 million bases) to date, to provide insight into its mode of pathogenicity and reproductive biology.

Aside from learning how the reproduces, genome annotation revealed its capabilities in breaking down wall components, which is of interest to bioenergy researchers.

With a kingdom of more than a million species, fungi thrive in diverse ecological niches, play roles in plant health, and are considered to have a whole host of untapped, as-yet unknown applications. At the Department of Energy Joint Genome Institute (DOE JGI), fungal researchers are involved in several worldwide collaborations to learn more about fungi, and how they can be harnessed for roles such as improving the health of candidate biomass feedstocks for biofuels development.

As part of the work toward illuminating the fungal tree of life, a study published in the April 2014 issue of New Phytologist focused on a tiny plant pathogen called Mixia osmundea, a member of the Pucciniomycotina family that has had few species sequenced to date. Though it was first described 100 years ago, the fungus is rarely seen and has only been isolated on the fronds of two fern species in Japan, Taiwan and America. The genome was sequenced and annotated and the data have been made available on the DOE JGI's fungal portal MycoCosm.

During the team's analysis of the fungus, they identified several carbohydrate-active enzymes that indicate M. osmundea's capabilities in breaking down plant mass, as expected of the . They also found multiple copies of an enzyme that suggests the fungus is "especially efficient" at breaking down a particular compound in . However, they did not find genes that would indicate the fungus can break down xylan, or convert cellobiose into glucose. "Therefore," the team wrote, "although M. osmundae seems to possess a set of enzymes that can be used to break down cellulose, it lacks the enzyme sets necessary for depolymerizing it to simple sugars."

Explore further: How scavenging fungi became a plant's best friend

More information: Toome M et al. "Genome sequencing provides insight into the reproductive biology, nutritional mode and ploidy of the fern pathogen Mixia osmundae." New Phytol. 2014 Apr;202(2):554-64. DOI: 10.1111/nph.12653

add to favorites email to friend print save as pdf

Related Stories

Fungal genome offers clues on how leaf-cutter ants farm

Jun 13, 2013

Leaf-cutter ants are well-known examples of insects that use microbes to gain access to nutrients, farming "gardens" in which bacteria and fungi break down plant mass. In an article featured on the cover ...

Breaking biomass better

Jul 12, 2010

One of the challenges in making cellulosic biofuels commercially viable is to cost-effectively deconstruct plant material to liberate fermentable energy-rich sugars. The U.S. Department of Energy (DOE) is ...

How scavenging fungi became a plant's best friend

Nov 25, 2013

Glomeromycota is an ancient lineage of fungi that has a symbiotic relationship with roots that goes back nearly 420 million years to the earliest plants. More than two thirds of the world's plants depend ...

Formidable fungal force counters biofuel plant pathogens

May 03, 2011

Fungi play significant ecological and economic roles. They can break down organic matter, cause devastating agricultural blights, enter into symbiotic relationships to protect and nourish plants, or offer ...

Differences in the genomes of related plant pathogens

Aug 12, 2012

Many crop plants worldwide are attacked by a group of fungi that numbers more than 680 different species. After initial invasion, they first grow stealthily inside living plant cells, but then switch to a highly destructive ...

Recommended for you

The microbes make the sake brewery

Jul 24, 2014

A sake brewery has its own microbial terroir, meaning the microbial populations found on surfaces in the facility resemble those found in the product, creating the final flavor according to research published ahead of print ...

User comments : 0