Effect of desiccation on antioxidant enzymes activity of recalcitrant tea (Camellia sinensis L.) seeds

ABSTRACT:Tea (Camellia sinensis (L.) O. Kuntze) is the most popular beverage consumed by over two thirds of the world’s population. Tea seed is believed to be recalcitrant based on its sensitivity to chilling or drying stress.Desiccation interferes with metabolic processes of recalcitrant seeds causing an increase in potentially harmful reactive oxygen species (ROS) and alterations in cytosolic redox statues. It investigated changes antioxidant enzyme activity of recalcitrant seed of 5 genotypes of tea in response desiccation. Mature tea seeds were harvested from plants grown in the tea field ofFashalam tea research station in IRAN. Seed were desiccated at 15% relative humidity at 15?C at different intervals of time. Measuring total protein, and enzymes activity assay such as ascorbate peroxides (APX), superoxide dismutas (SOD), peroxidase (POD) and catalase (CAT) carried out in 5 times with prolonged desiccation in factorial completely randomized design in three replicates. Results showed that desiccation treatment dramatically increased activities of antioxidant enzymes like APX and SOD. Increased antioxidant, CAT partially assuaged desiccation damage to tea seed, resulting in improved germination rates. APX and CAT activities in tea seed embryos were slightly increased with prolonged desiccation, while SOD and POD activities decreased. It proposes that desiccation causes an over-accumulation of ROS that are not efficiently scavenged by increased levels of antioxidant enzymes. High levels of ROS alter the redox status and are detrimental to seed viability. Reducing ROS to appropriate concentrations in an efficient way to reduce desiccation damage and improve germination rates of recalcitrant seeds.