Physiological and Biochemical Responses of Chinese Cabbage to La and Zn Stresses

[Objective] The aim of this study was to explore the physiological and biochemical responses of Chinese cabbage to La and Zn. [Method] The effects of La and Zn on seed germination and seedling growth were explored by tissue culture method. [Result] La and Zn had little effects on seed germination rate, but significantly inhibited the growth of root and seedling, decreased their fresh weight at higher concentration; the inhibition of La proved higher on Chinese cabbage. The contents of chlorophyll and soluble protein increased at lower concentrations of La and Zn, but decreased at higher concentrations. With increasing doses of La and Zn, the activities of CAT and POD rose gradually, while SOD activity decreased at lower doses and increased at higher doses. Both of La and Zn would promote Of. producing and MDA accumulation. [Conclusion] In higher concentration, La was more poisonous than Zn. It is clear that the poisonous mechanism of La is similar to that of Zn. Hence, La is possibly a kind of new pollutant.

Physiological and Biochemical Response of Artificial Wetland Plant under Electric Field

By measuring wetland plants chlorophyll content,malondialdehyde(MDA) content and superoxide dismutase(SOD) enzyme activity,the changes of wetland plant physiological characeristics under different power strength were studied,and the mechanism of electric field on plant physiological characteristics was analyzed to provide a theoretical basis for the pollutant removal ability strengthening of artificial wetland under electricfield.The results showed that compared with the control plants,low-intensity-voltage(1 V and 3 V) had no significant effect on the normal physiological and biochemical indexes of the plants,and the growth trend was better than the control group;with the voltage increasing,plant chlorophyll content,MDA content and SOD activity were greatly affected,indicating that plants were under strong oxidative stress,and the growth was damaged.Therefore,a suitable electric field could enhance the sewage treatment effect of constructed wetland.

Effects of 2,5-Norbornadiene （NBD） on Physiological and Biochemical Responses of Fresh-cut Winter Squash

Ethylene is one of the most important plant hormones that regulate physiological responses, maturity and senescence of postharvest fruits and vegetables. The determination of its role in the wound-healing response of fruits and vegetables is helpful in understanding the wound responses. 2,5-Norbornadiene （NBD）, inhibitor ethylene binding were used to determine the effect of ethylene action on wound-induced response of fresh-cut winter squash, a kind of vegetables known to produce ethylene markedly after cutting. The effect of NBD on the physiological and biochemical changes of fresh-cut winter squash was investigated in this experiment. The results showed that NBD had great effects on physio-biochemical metabolism of fresh-cut winter squash. Ethylene production was inhibited significantly by NBD. NBD also had an inhibition effect on polyphenol oxidase （PPO）, peroxidase （POD） and phenylalanine ammonia lyase （PAL） activity. The effect of NBD on lipoxygenase （LOX） activity and superoxide dismutase （SOD） was not obvious. NBD treated sample showed a more rapid increase in catalase （CAT） activity, which may help in healing the damage of the tissue. These information are important in understanding the fundamental biology of wound response and in the development of new technology to hasten wound-healing and, thereby, to minimize costly wound-related problems in fresh-cut industry.