The Variation Of Cell Structure And Some Physiological And Biochemical Indexes In Aging Of Michelia Macclurei Dandy

In this paper, changes of physiology and biochemical and cell structure in the petal during development and aging process of Michelia macclurei were studied by using Gas Chromatography-Mass Spectrometer(GC-MS),(High Performance Liquid Chromato-graphy)HPLC,Optical Microscope(OM), Scanning Electric Microscope(SEM), Transmission Electron Microscopy (TEM) and other technique. The results were showed as below:(1)relationship between hormone changes and petal senescenceIn the early stage of development, contents of IAA, GA, Zt that regulated the development of petal were high while the content of ABA was low; Content of Aging hormones changed in the development of petal, content of IAA decreased while GA and ZT increased. Content of ETH increased and petals fell off with the senesce of cell aggravated. It was indicated that ETH would be the accelerator of petal senescence other than inducer.(2)relationship between changes in antioxidant system and petal senescenceAntioxidant system in the early petal development played a significant role in renovating of intracellular free radicals, protecting cell membrane lipid peroxidation. But with the reduced capacity of synthesizing enzymes and Vc and other substances of cells, the capacity of the antioxidant system declined, which induce programmed cell death. So, the declined of capacity of antioxidant system promoted the aging, but it was not the induction factor of the cell senescence.(3)relationship between changes of inclusions of cells and petal senescenceCellular inclusion accumulated during the development of cell aging, which reflected the process of cell senescence, the contents of MDA and proline were the important indexes of cell aging. The consumption of phenol and other substances reduced the ability of protection cellular damage. Increase of superoxide anion and the content of hydrogen peroxide caused serious damage to the cell membrane stability and imbalance of metabolism and increased petal senescence.(4)relationship between changes of aromatic substance and petal senescenceAromatic substances in petals during the development process were complex, 37 species of chemical components were identified and most of them increased firstly and then decreased. In this paper, the types and relative content of the aromatic substance at the fourth period were the highest reflected the stage from buds to flower buds were fully grown is mainly synthesized and accumulated precursor of aromatic substances. And then aroma began to distribute with cell senescence of petals.(5) relationship between changes of constructure of cells and petal senescence Starch complexes on parenchyma cells were discovered by HistochemicalStaining. In the progress of the petal development, the size was bigger and bigger and the amount was more and more. The number of starch complexes, mitochondria, lysosomes increased during stageâ…¡t oâ…¡by using TEM. Aroma substance transformed from starch complexes whose number gradually indrease was distributed. The epidermal cells of petals collapsed, intercellular space cracked, mitochondria, lysosomes and other organelles disintegrated in various degrees. Petals stripped off with the deformation of cell wall. The trend of cell structure changes of petals during development was basically the same as Programmed cell death.We can conclude from the research above that the change of the perianth cells structure and the physiological and biochemical change have a close relationship with the aging process of the cells.