| The enhanced UV-B radiation reaching to the earth surface resulted from depletion of the ozone layer in the stratosphere, and causes damage to the growing development and physiobiochemical processes of plants. In order to find a new methods which can prevent the harm of UV-B radiation from the plants, First, under regular paraffin method and the fluorescence microscope,the anthraquinone with the character of giving off fluorescence was distributed in the epidermal and the vascular bundle. Then the methods of plant chemistry and the technology of TLC and HPLC were used to distill and detect the anthraquinones of aloe leaf. in this paper, we used corn, wheat, spinach and asparagu splettuce as the research objects to determine the growth and development, physiology and biochemistry of plants, while acquireing natural light and artificial enhanced ultraviolet radiation(with a UV-B radiation light exposure of wavelength of 280～320nm). Besides the enhanced artificial UV-B radiation, the corn, wheat, spinach and asparagu splettuce was given to apply a certain dilution of the concentration of aloe anthraquinones, The effects of Aloe's anthraquinones components on the plants were investigated, and explored a new ways to defense the harm of UV-B radiation to plants .The results showed that:1.Under conditions of enhanced UV-B radiation and was given to apply a certain dilution of the concentration of aloe anthraquinones, the corn, wheat, spinach and asparagu splettuce was showing tight and symmetrical arranged cells, the leafs structure in assimilation cell was intact, the large phloem parenchymatous cells of vascular bundie canbe seen clearly, The same situation to the plants with natural light. but under conditions of enhanced UV-Bradiation and was not given to apply the aloe anthraquinones, the corn, wheat, spinach and asparagu splettuce was showing thinner assimilation tissue, depauperate vascular bundie,the large phloem parenchymatos cells sink, the growth was limited. The results showed that, the corn, wheat, spinach and asparagu splettuce was hurt by the UV-B radiation , and enhanced UV-B irradiation didn't destroy the structure of the plant with spraying anthraquinones.2.Determination of biochemical indicators of physiological results showed that under conditions of enhanced UV-B radiation, the chlorophyll contents of the corn, wheat, spinach and asparagu splettuce had a significantly decrease,However the REC, the MDA content, the net rate of O2- generation, the activity of SOD and POD kept at quite a high level with the CK, and the biochemical indicators of physiological of the spinach changed significantly most. Under conditions of enhanced UV-B radiation and was given to apply a certain dilution of the concentration of aloe anthraquinones , the chlorophyll contents of the corn,wheat,spinach and asparagu splettuce kept at quite a high level, but the REC,the MDA content,the net rate of O2- generation,the activity of SOD and POD had a significantly decrease, The growth of the plant are close to normal level . Results indicate that the enhanced UV-B radiation will harm the growing development of plants, and the spinach was hurt badly. Dicotyledons are more sensitive to enhanced UV-B radiation than monocotyledons, the C3 plant are more sensitive to enhanced UV-B radiation than the C4 plant, The aloe anthraquinones can prevent the harm of UV-B radiation from the plants, and the protection of dicotyledons by the aloe anthraquinones is most obviously. |
