| Tomato origins from tropic and subtropical, it is sensitive to temperature. Low temperaturecan delay its growth and development. At the same time that low temperature and weak light arethe most obstacle factors to attain steady produce and high produce in the winter-sping ingreenhouse. Our study deeply focused on effect of chemical signal substance induct to enhanceplants tolerance to stress. We can provided a solid basis for application of chemical substance toenhance plants tolerance to stress."Dongnong 708" was selected for material. Though spraying different concentrationsABA,SA, CaCl2 were used for exogenous substances, tomato seedlings were induced, and treatedby low temperature. Physiological indexes were collected to assay with related to cell membranesystems. At the same time that study on the ultrastructure of tomato seedling.Through thesestudies, we drew some conclusions.Compare to CK, we found those tomato which were sprayed ABA,CaCl2,SA showedbetter.The number and progression of sprayed tomato seedlings which were threatening by lowtemperature were lower than CK.Sprayed reduced damage of tomato seedling and decreased thepermeability of cell membrane, the content of nucleic acid and dissolve protein.It was alsodecreased the surface electrical potential of chloroplast membrane, catabaticate change ofpermeability of chloroplast and kept concentration of ion balance of chloroplast membrane. Theactivity of Ca2+-ATPaseand Mg2+-ATPase of chloroplast membrane and thylakoid membranewere kept higher levels by sprayed.The result demonstrated that 1200 mg·L-1 CaCl2 was better than other treatmenta whichwere sprayed Ca2+ from 600 mg·L-1 to 1400 mg·L-1.The 1200 mg·L-1 CaCl2 treatments couldkeep cell membrane systems better, decrease relative conductance, alleviate membrane lipidperoxidation and also increase content of chloroplast and Pro.The 1200 mg·L-1 CaCl-2 treatments was better to restore,and effectively alleviate colddamage to cell membrane systems.Cellular ultrastructure suffered to damage under lowtemperature intimidation.Cell membrane system suffered to dedtroy, chloroplast and mitochendria swelled and distorted,inside structure suffered to destroy until disorganization anddisappearance. |
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