Understanding the role of mycorrhizal fungi in decomposition of plant necromass
Florian Barbi, PhD
(Institue of Microbiology, Czech Academy of Science)
Link to the seminar: meet.google.com/fsu-cwmi-rkm
The decomposition of plant necromass is an essential process for the nutrient cycles. Fungi occupy a central role in plant organic matter decomposition, especially in forest ecosystems. Further, this process is generally associated to saprotrophic fungi - free living organisms - that depend essentially of their decomposition capacities to obtain nutrients, in particular carbon found under the form of glucose through the decomposition of hemi/cellulose. At the contrary, biotroph organisms, like mycorrhizal fungi, obtain glucose from their living host. In return, in this mutual association, mycorrhizal fungi provide nutrients such as nitrogen and phosphorus to their host.
Lignin is one of the main components of the plant organic matter and it protects hydrolysable molecules such as cellulose and hemicellulose. Moreover, this phenolic compound is particularly recalcitrant to decomposition and oxidative reactions are needed for its degradation. Oxidative capacity is consequently a keystone function for plant necromass decomposition.
Saprotroph have the genetic machinery to produce enzymes that efficiently decompose plant organic matter, but it has been observed that some mycorrhizal fungi may have this potential as well, especially an efficient oxidative capacity.
According to this we can question the importance of mycorrhizal fungi in decomposition of plant necromass. Are they decomposer in disguise? Partial saprotroph? Specialist of a specific part of the decomposition?
In this talk, we will explore these questions and see what kind of answers we can bring by using a recent molecular approach – metatranscriptomic – for environmental microbiology.