Tomato （Lycopslcon esculentum Mill.） plants grown in a greenhouse were irradiated with two different levels of UV-B, namely 8.82 （T1） and 12.6 kJ/m^2 per day （T2）. Ethylene production, 1-aminocyclopropane-1-carb...Tomato （Lycopslcon esculentum Mill.） plants grown in a greenhouse were irradiated with two different levels of UV-B, namely 8.82 （T1） and 12.6 kJ/m^2 per day （T2）. Ethylene production, 1-aminocyclopropane-1-carboxylate （ACC） content, 1-（malonylamino） cyclopvopane-1-carboxylic acid （MACC） content, gene expression of ACC aynthase （EC 4.4.1.14）, and ACC oxidase activity in tomato leaves were determined. The results Indicated that ACC content, the activity of ACC synthase and ACC oxidase, and ethylene production Increased continuously under low doses of UV-B radiation, whereas at high doses of radiation these parameters Increased during the first 12 d and then started to decrease. The MACC content increased continuously over 18 d under both doses of UV-B irradiation. The changes in ACC content, ACC synthaae activity, ACC oxidase activity, the transcriptional level of the ACC synthase gene, and ethylene production were consistent with each other, suggesting that ACC synthase was the key enzyme in ethylene biosynthesis and that ethylene production in tomato leaf tissues under UV-B radiation could be regulated by the expression of the ACC synthase gene. The results also indicate that the change in ethylene metabolism may be an adaptive mechanism to enhanced UV-B radiation.展开更多
Objective： Endothelial nitric oxide synthase （eNOS） and nitric oxide （NO） have been implicated in protection against myocardial ischemia injury. This study was designed to explore a new method of therapy for myoc...Objective： Endothelial nitric oxide synthase （eNOS） and nitric oxide （NO） have been implicated in protection against myocardial ischemia injury. This study was designed to explore a new method of therapy for myocardial injury by eNOS gene transfection. Methods： A rat model of myocardial infarction （MI） was established by left anterior descending （LAD） coronary artery ligation, eNOS gene in an adenovirus vector was delivered locally into the rat heart and hemodynamic parameters were examined after 3 weeks, Matrix metalloproteinase-2 and 9 （MMP-2, MMP-9） mRNA were measured by reverse transcription polymerase chain reaction （RT-PCR）, and the protein levels of eNOS, caspase-3, and transforming grouth factor 131 （TGF-131） were determined by western blot assay. Results： eNOS gene transfer significantly reduced cardiomyocyte apoptosis and improved cardiac function. In addition, eNOS significantly reduced the mRNA levels of MMP-2 and MMP-9. In the eNOS gene transfected group, the activation of caspase-3 and TGF-β1 were decreased. However, the protection was reversed by administration of the NOS inhibitor, N（o））-nitro-l-arginine methyl ester （L-NAME）. Conclusion： These results demonstrate that the eNOS provides cardiac protection after myocardial infarction injury through inhibition of cardiac apoptosis and collagen deposition, and suppression of TGF-β1.展开更多
基金Supported by the National Natural Science Foundation of China （30170038, 90302010）, ＂Hundred talents＂ project of the Chinese Academy of Sciences, Gansu Key Technologies R＆D Program （GS022-A41-045）, and Gansu Agricultural Bio-technology Research ＆ Development Project. Acknowledgements The authors thank Dr Akira Nakatsuka （Laboratory of Postharvest Agriculture, Faculty of Agriculture, 0kayama University, 0kayama, Japan） for providing the ACC synthase clone.
文摘Tomato （Lycopslcon esculentum Mill.） plants grown in a greenhouse were irradiated with two different levels of UV-B, namely 8.82 （T1） and 12.6 kJ/m^2 per day （T2）. Ethylene production, 1-aminocyclopropane-1-carboxylate （ACC） content, 1-（malonylamino） cyclopvopane-1-carboxylic acid （MACC） content, gene expression of ACC aynthase （EC 4.4.1.14）, and ACC oxidase activity in tomato leaves were determined. The results Indicated that ACC content, the activity of ACC synthase and ACC oxidase, and ethylene production Increased continuously under low doses of UV-B radiation, whereas at high doses of radiation these parameters Increased during the first 12 d and then started to decrease. The MACC content increased continuously over 18 d under both doses of UV-B irradiation. The changes in ACC content, ACC synthaae activity, ACC oxidase activity, the transcriptional level of the ACC synthase gene, and ethylene production were consistent with each other, suggesting that ACC synthase was the key enzyme in ethylene biosynthesis and that ethylene production in tomato leaf tissues under UV-B radiation could be regulated by the expression of the ACC synthase gene. The results also indicate that the change in ethylene metabolism may be an adaptive mechanism to enhanced UV-B radiation.
文摘Objective： Endothelial nitric oxide synthase （eNOS） and nitric oxide （NO） have been implicated in protection against myocardial ischemia injury. This study was designed to explore a new method of therapy for myocardial injury by eNOS gene transfection. Methods： A rat model of myocardial infarction （MI） was established by left anterior descending （LAD） coronary artery ligation, eNOS gene in an adenovirus vector was delivered locally into the rat heart and hemodynamic parameters were examined after 3 weeks, Matrix metalloproteinase-2 and 9 （MMP-2, MMP-9） mRNA were measured by reverse transcription polymerase chain reaction （RT-PCR）, and the protein levels of eNOS, caspase-3, and transforming grouth factor 131 （TGF-131） were determined by western blot assay. Results： eNOS gene transfer significantly reduced cardiomyocyte apoptosis and improved cardiac function. In addition, eNOS significantly reduced the mRNA levels of MMP-2 and MMP-9. In the eNOS gene transfected group, the activation of caspase-3 and TGF-β1 were decreased. However, the protection was reversed by administration of the NOS inhibitor, N（o））-nitro-l-arginine methyl ester （L-NAME）. Conclusion： These results demonstrate that the eNOS provides cardiac protection after myocardial infarction injury through inhibition of cardiac apoptosis and collagen deposition, and suppression of TGF-β1.
