Seasonal changes in antioxidant enzymes, polyphenol oxidase enzyme, flavonoids and phenolic content in three leafy liverworts

Seasonal changes in the total phenolic content, flavonoid content, specific activity of the enzyme polyphenol oxidase (PPO) and that of the antioxidative enzymes-catalase (CAT) and peroxidases (POX) were analyzed in three leafy liverworts, namely Solenostoma crenulata, Chiloscyphus gollani and Fossombronia himalayensis. In the rainy season (July–September), the plants were in their young juvenile stage and the levels of activity of antioxidative enzymes catalase (CAT) and peroxidases (POX) were observed to be the lowest. The enzymes showed maximum activity during the months January–March which constitute a dormant season for bryophytes. Activity of POX is found to be higher than that of CAT in all the three seasons. Highest content of flavonoids was observed towards the end of the growing season (January–March). Total phenolic content was found to be highest in winter season (October–December). PPO showed highest activity in the rainy season (July–September) and lowest during winter season. Activity of enzyme PPO and that of phenolic content showed inverse relationship.