Involvement of peroxidases in structural changes of barley stem

ABSTRACT The aim of this study was to investigate anatomical characteristics of barley (Hordeum vulgare L.) internodes and to reveal the connection with activity of guaiacol-peroxidases, their isoenzyme profiles, lignin, and cellulose content. Three lower internodes were sampled at elongation stage and differed in their anatomical features by showing that lignin deposition follows developmental pattern. Epidermis and hypodermis in the first internode were characterized by continuous layer of the lignified cells while in the second and third internode thin walled parenchyma cells could be observed in the hypodermis. These observations were in accordance with increment of peroxidase activity from the first to the third internode. Two acidic and 2 basic isoforms of peroxidases were present. The third internode had higher total soluble protein content and lower dry weight as well as Klason lignin content in comparison to the first and second internode. Studying lignification process in barley stem by using anatomical and physiological approach will provide valuable information regarding developmental changes connected with lignin deposition in the stem.