Effects of ectopic expression of fungal alpha glucuronidase in hybrid aspen.

Saprophytic and pathogenic microbes living on lignocellulose developed specific ways of decomposing it. The repertoire of microbial enzymes has been greatly explored for enzymatic lignocellulose digestion in vitro. Such enzymes, generally not found among native plant enzymes, have been successfully used in different crops for post-synthetic modification of cell wall. Hydrolyzing the bond between glucuronic acid and xylan is considered a strategy to improve the conversion of plant biomass to sugars for bioenergy. This bond is thought to mediate the formation of lignin-carbohydrate complexes (LCCs) in woody species, a crucial factor of lignocellulose recalcitrance. When we expressed fungal alpha glucuronidase form Aspergillus niger in hybrid aspen, involved in the hydrolysis of alpha-glucuronic acid side chain of xylan, we observed altered profile of wood associated lipid compounds. The plants grew normally and did not show any untargeted effects, due the activity of the enzyme in transgenic plants.