Effects Of Apoplastic In The Tender Stems And Photosynthesis In The Leaves Of Populus Under Osmotic Stress By Microdialysis

The conventional animal physiologyexperiment instruments-microdialysis was used into biochemical research of plant physiology, which could be realized the real-time, on-line, non-destructive research in the relationship between various bio-material changes of apoplast of tender stems of poplar and stress physiology. According the application of microdialysis in Schefflera early, we achieved a series of experience. Then microdialysis was applied to the poplar. The methods of detection of trace four kinds of endogenous hormones、ions and proline were determined and applied to the research of physiological and biochemical in poplar under the stress of salt and drought.First of all, the method of getting the pure apoplasy sap with microdialysis was established. By direct experiment, external hormone, ion concentration, and indirect experimental malate dehydrogenase assay activity to determine the microdialysis dialysis after 120min is pure apoplast sap.Secondly, the quantitative identification method of four kinds of endogenous hormones, ions and proline were achieved. Endogenous hormones were detected by HPLC, four hormones detection wavelength are:GA3 203nm,6-BA 273nm, IAA 214nm, ABA 263nm, retention time is GA3 7.036min,6-BA 7.626min, IAA 9.287min, ABA 11.003min. Th recovery rate of four kinds of hormone is more than 93%, which proved that the measuring precision is high. Proline also were detected by HPLC, detection wavelength:254nm, the retention time is 20min. Ions in microdialysis are detected by atomic absorption spectrophotometer (graphite furnace).The recovery rate of proline and ions is more than 95%, which conclued that the measuring precision is high too.Finally, the microdialysis method was applied to the study of stress physiological biochemical research in tender stem of poplar, at the same time, using Li-6400 portable photosynthesis system to detect chlorophyll fluorescence and gas exchange parameters, combined with the changes of the material in the apoplast of poplar and achieved initial results in research of stress physiology. The result showed that under high concentration salt stress for fifteenth days, ABA of Populus×wutunensis accumulation is controlled 1.3 times, and Populus×euramericana accumulation is controlled 1.8 times, under the same stress conditions Populus×euramericana need to accumulate more ABA to resist stress environment; Fv/Fm and ETR value of Populus xeuramericana were significantly lower than those of Populus xwutunensis and optical system absolutely spoiled seriously; The coefficient balance of anti-salt stress of Populus xeuramericana is significantly larger than the Populus xwutunensis, which showed in high concentrations of salt stress hormones coordinations between each other of Populus xeuramericana declined, and growth inhibition by stress greater than Populus×wutunensis. Therefore we concluded that salt tolerance of Populus xwutunensis is strong than Populus xeuramericana. The endogenous hormone metabolism of plants adapt to arid environment under drought stress. The study shows that, during drought stress of three kinds of poplar, GA3,6-BA,3-IAA and ABA in tender stem changed in the dynamic regularity, which could conclude tha the apoplast is involved in physiological and biochemical response of poplar to drought stress. At the same time, the research varied concention of free proline accumulated in apoplast of poplar. We concluded that only different stages, including the initial accumulation of proline content, medium the proline accumulation and maintenance period proline accumulation all should be considered to analysis, which could be more fully express the relationship between proline accumulation and plant resistance.