Invertase activity in trunk tissues of Karelian birch

Abstract

We investigated two forms of Betula pendula Roth: common silver birch (B. pendula var. pendula) and Karelian birch (B. pendula var. carelica) differing in wood texture. Activity of different forms of invertase in the tissues of birch trunk was determined for the first time. In the period of active operation of cambium, all three forms of invertase (vacuolar, cytoplasmic, and apoplastic) were present in the phloem and xylem of both forms of birch. Phloem and xylem of Karelian birch were notable for a high activity of apoplastic invertase. It was assumed that reprogramming of cell differentiation in cambial zone of Karelian birch causing a more pronounced parenchymatization of conducting tissues is related to an intense hydrolysis of sucrose in the apoplast. The obtained results corroborate the opinion formed in the literature about a possible participation of invertase in the synthesis of cell wall components.