Auxin dependent changes in peroxidase and polyphenol oxidase activities accompanying cell differentiation in protonema of wild strain and auxin mutants of Funaria hygrometrica

摘要

Transition from chloronema to caulonema state of moss protonema in Funaria hygrometrica is under the metabolic control of endogenous auxins and can further be enhanced by exogenous auxins in culture. The parallel increase in browning of the cell walls in caulonema cells seems to have a correlation with spatial distribution of peroxidase (PO) and polyphenol oxidase (PPO) activities between cytoplasm and cell wall. Auxin-stimulated caulonema differentiation was accompanied with relative lowering of PO activity in the wall/particulate fraction. In contrast to very high PO activity in particulate fraction of moss protonema (as compared to the soluble fraction), polyphenol oxidase (PPO) activity showed more or less uniform distribution. PO and PPO activities in the wild type were compared with the activities in two auxin mutants. The observed increase in total PPO activity as a result of auxin treatment was in congruence with the morphogenetic responses of the respective strains.