Seasonal Changes In C6-C3 Acids And The Activity Of Different Forms Of Peroxidases During The Vegetative Growth Of Shoots Of The Apple-Tree (Malus Domestica Borkh.)

Abstract

Summary The Article Reports About Seasonal Changes In The Content Of Hydroxycinnamic Acids In Xylem, A Study Of The Different Forms Of The Total Activity Of Peroxidases (Soluble, Ionically And Covalently Bound) In Xylem And Cambium And Of The Soluble Isoperoxidase Composition In Cambium And As Well As In Xylem Of The One-Year-Old Vegetative Shoots Of The Apple-Tree In Connection With The Differentiation Of Cells And The Lignification Of Cell Walls. Phenolic Cinnamic Acids Are Present In Xylem As Free Acids And By Alkaline Hydrolysis In Ethanol Extract (“Soluble Esters”) And In The Insoluble Residue (“Insoluble Esters”). Experiments Indicate That Insoluble Esters May Be Involved More Intensively Than Free And Soluble Esters In Lignin Biosynthesis During The Differentiation Of Cells. The Degree Of The Total Activity Of All Different Forms Of Peroxidases Rises With The Differentiation Of Cells And Of Tissues, Reaching Their Maxima In Cambial Cells In August And In Xylem Cells In September, And Thereafter Their Activity Begins To Decrease. Covalently Bound Peroxidase In Cell Walls Indicates The Highest Degree Of Activity Of The Special Froms Of Peroxidases And May Be One Of The Indicators In The Process Of Lignification. Measurement Of The Activities Of The Isoenzyme Patterns Of Soluble Peroxidase Reveals That Changes Are Different In Cambium And Xylem. Changes In The Content Of Cinnamic Acids As Well As Changes In The Activity Of Peroxidases In The Vegetative Growth Of Shoots Of The Appletree Can Be Regarded As Biochemical Markers Of Differentiation And Lignification.