Effects of high temperature stress on plasma membrane permeability and chloroplast structure of Huperzia serrata / 中草药

ABSTRACT

Objective: Huperzia serrata, whose growth is limited by high temperature, is a rare medicinal plant with the treatment function for Alzheimer's disease (AD). To research the effect of high temperature on the structure and function of cell membrane and chloroplast, and to provide the evidence for production practices. Methods: H. serrata was processed at 25, 30, 35, and 40°C, respectively, then the content changes of malondial dehyde (MDA) and conductivity rate, and the content changes of total chlorophyll, chlorophyll a, chlorophyll b, and chlorophyll a/b values were measured. The changes of the chloroplast ultra microstructure were observed under the transmission electron microscope (TEM). Results: The changes of MDA and conductivity rate in the process at 35 and 40°C were significantly higher than those of the control group; After processed at 40°C for 4 d, the total chlorophyll was decreased significantly, and became the lowest on the day 6, just was 58% compared to the control group; the change trends to the contents of chlorophyll a, chlorophyll b, and total chlorophyll were similar; TEM observation revealed that after processed at 35°C for 4 d, the chloroplast structure appeared deformation, and after processed at 40°C for 4 d, the chloroplast structure subjected obvious destruction capsule fuzzy, fracture in different degrees, thylakoid in disorder, matrix lamellar irregular, and so on. Conclusion: According to the changes of physiological index, ultramicroscopic structure, and external morphology of chloroplast, the suitable temperature for H. serrata is 25-30°C, 40°C is the limited temperature, causing death after 4 d stress, and 35°C has obvious impact on the growth, long-time stress in 35°C could also cause plant deaths.