Abstract
The loss of chlorophyll from plants is induced by transition of the season, senescence, fruit maturation or sufferance from environmental stress . The chlorophyll degradation is two pathway including pheophorbide a oxygenase pathway and peroxidase pathway . Pheophorbide a oxygenase pathway is popular in most plants and algae . The programmed cell death and the degradation of chlorophyll is intermix ; The degradation of chlorophyll is according to pheophorbide a oxygenase pathway and peroxidase pathway . The pheophorbide a oxygenase pathway is mainly discovered in the programmed cell death of senescence ; the peroxidase pathway is mainly discovered in necrosis and the programmed cell death of hypersensitive response induced from phage and environmental stress . The different programmed cell death has different morphological characters . In this study, we want to study the programmed cell death of heat-treated chlorella after incubated in light condition . We discovery the degradation of chlorophyll is according to the peroxidase pathway by HPLC . We discovery the morphological characters by TEM and nuclear florescence staining (DAPI and Acrindine orange) is similar as morphological characters of the programmed cell death induced hypersensitive response . The chloroplast cooperate with mitochondria in the programmed cell death of heat – treaed chlorella .