Effects Of Copper Stress On The Character Of Physiology And Biochemistry And Ultrastructure In Chinese Cabbage

As a member of Cruciferae Brassica ,Chinese cabbage (Brassica campestris L. ) is a one or two years herbage plant. Along with the frequently use of bactericide and a great deal of contamination, more and more Copper was inpoured into the entironment.It is resulted in the pollution of soil and worse vegetable.Copper pollution has been a problem of cosmopolitan.The thesis studied the photosynthesis,isoenzyme,ultrastructure and the damnification of DNA of Shanghaiqing and Wuyueman,which were planted in hydrponic solution added different quantity of Copper.The main conclusions of investigation were as follow:1．The Copper stress had obviously toxic effects on Shanghaiqing and Wuyueman.It restrained the growth of Shanghaiqing and Wuyueman.Along with the increasing of Copper concentration and the time of disposal, both Shanghaiqing and Wuyueman's laminae became etiolation,the roots lost water,root and stem became black.At last the plant wilted and went to death.Shanghaiqing was more sensitive to Copper stress concluding from the appearing time and degree of symptom.The roots were affected more than the overground part when exposed to the same ion concentration and same time of exposure.2．The Copper stress restained the photosynthesis of Chinese cabbage.It induced to the drop of photosynthesis pigments'content,the fell of photosynthesis's intension and Hill reaction activity.The activity of ATPase presented increase first and reduce afterwards along with the treating concentration.3．Studied the change of Chinese cabbage's isoenzyme(POD and SOD) under Copper stress for the first time.The result indicated that the difference between the normal and low concentration was unconspicuous.But the enzymatic activity increased and new enzymatic cingulums brought when in the high concentration.It showed that the enzyme(POD and SOD) of Chinese cabbage changed in order to the environment variation.4．The ultrastructure changes of mesophyll cells in Shanghaiqing and Wuyueman occurred during suffering from Copper stress,were abserved using transmission electron microscopy.The result showed that both two varieties under the normal condition,various organelles were morphologically integrated, when under Copper stress,the number of chloroplasts was reduced with increasing external copper concentration.When the concentration was from 10 mg·L^-1 to 20 mg·L^-1 , the chloroplast structure of Wuyueman was injured slightly. However, under high Copper concentration(40,50 mg·L^-1 ),disruption of chloroplast membrane disrupted; some cristae of mitochondria decreased and appearance of certain crystal structure were observed in some mitochondria.With a increase of Copper concentration,the ultrasturctural damage on the Shanghaiqing mesophyll cells unceasing aggravated;the cell wall and cytoplast was separated while in high Copper stress,the chloroplast membrane was almost disorganized, some cristae of mitochondria was chaos.5．The test maked clear that the DNA content of both Shanghaiqing and Wuyueman was descended,and the descend extent of Shanghaiqing was larger than Wuyueman.At the same time ,the test indicated that 10 to 50 mg·L^-1 concentration parted the DNA chain all.Shanghaiqing reached the highest of the hyperchromicity of DNA earlier than Wuyueman.It showed that Shanghaiqing was more sensitive to Copper stress.6．From the results hereinbefore,we transpired that compare to Wuyueman, Shanghaiqing was more sensitive to Copper stress.