The genome, Martin said, shows a large number of new and expanded gene families compared with other fungi. Many of these families are involved in signaling and other processes that drive the complex transition between two distinct lifestyles of Laccaria: the benign saprotroph, able to use decaying matter of animal and bacterial origins, versus the symbiont, living in mutually profitable harmony with plant roots.
The team also discovered new classes of genes that may be candidates for the complex communication that must occur between the players in the host/plant subsoil arena during fungal development. They report that fungi play a critical role in plant nutrient use efficiency by translocating nutrients and water captured in soil pores inaccessible to roots of the host plant.
"The Laccaria genome sequence, its analysis, associated genomics, and bioinformatics tools provide an unprecedented opportunity to identify the key components of organism-environment interactions that modulate ecosystem responses to global change and increased nutrient input needed for faster growth, said Martin. "By examining and manipulating patterns of gene expression, we can identify the genetic control points that regulate plant growth and plant-mutualist response in an effort to better understand how these interactions control ecosystem function."
Mycorrhizae are critical elements of the terrestrial ecosystems, Martin said, since approximately 85 percent of all plant species, including trees, are dependent on such interactions to thrive. Mycorrhizae significantly improve photosynthetic carbon assimilation by plants.
"Host trees like Populus are able to harness this formidable web of mycorrhizal hyphae that permeates the soil and leaf litter and coax a r
|Contact: David Gilbert|
DOE/Joint Genome Institute