Functional characterization of three recombinant chitinase-like proteins of Picea glauca

Abstract EN

North temperate tree species such as white spruce (Picea glauca [Moench] Voss) have evolved strategies to protect themselves against abiotic and biotic stresses that trees encounter during the inclement winter months.

Chitinases not only play well-documented roles in plant defense but also function during physiological and developmental preparations for overwintering, including growth cessation, cold and desiccation acclimation, and dormancy acquisition.

Transcript abundance profiling suggested roles for three white spruce chitinases during the growth-to-dormancy transition.

In silico analyses of these three sequences suggested that two of the CHITINASES under study belonged to Cluster I(Pg_GQ0183_A06 and Pg_GQ03904_P01) which was associated with both cold tolerance and antifreeze activity.

Pg_GQ0046_J03.1 belonged to cluster VI which was associated with cell wall modification.

Chitinase activity assays showed that two of three tested total soluble protein fractions were exhibiting endochitinase activity.

Taken together, our results imply that dormancy-associated chitinases act in concert to(1) confer protection against freezing injury, pests, and pathogens, (2) store nitrogen, and(3) promote cell maturation that precedes growth cessation.