O_3浓度升高和UV-B辐射增强对大豆叶片叶绿素含量和活性氧代谢的影响

Effects of elevated O_3 concentration and UV-B radiation on the chlorophyll content and active oxygen metabolism of soybean leaves.

以大豆栽培品种铁丰29为试验材料,利用开顶式气室研究O_3浓度升高和UV-B辐射增强复合胁迫对大豆叶片叶绿素(Chl)含量、膜脂过氧化程度、活性氧产生速率、抗氧化酶活性和籽粒产量的影响.结果表明:在大豆整个生育期内,与对照相比,O_3和UV-B单一胁迫及其复合胁迫下的大豆叶片Chl(a+b)、Chl a和Chl b含量均呈下降趋势;相对电导率、丙二醛含量增大,活性氧产生速率和H_2O_2含量增加,超氧化物歧化酶、过氧化物酶和过氧化氢酶活性下降,产量降低.O_2和UV-B复合胁迫加剧了大豆叶片膜脂过氧化程度,促进大豆体内活性氧自由基的产生,使大豆抗氧化能力减弱,叶绿素含量降低,对大豆表现为协同效应.O_3胁迫对大豆叶片的影响与复合胁迫更相近,其原因可能是在复合胁迫中臭氧起主要作用.

Taking the soybean （Glycine max） cuhivar Tiefeng 29 as test material, and by using open-top chamber, this paper studied the effects of elevated 03 concentration and UV-B radiation on the leaf chlorophyll content, lipid peroxidation, reactive oxygen species （ROS） production rate, anti-oxidation enzymes activities, and the grain yield. During the growth period of soybean, as com- pared with the control, the leaf Chl a, Chl b and Chl（a＋b） contents under the stresses of 03 and UV-B had a decreasing trend, the relative electrical conductivity, malondialdehyde content, super- oxide anion （O2 - ） production rate, and hydrogen peroxide （H2 O2 ） content increased, and the ac- tivities of superoxide dismutase, peroxidase and catalase as well as the grain yield decreased. 03 ＋ UV stress aggravated the leaf membrane lipid peroxidation, promoted the ROS production, and de- creased the plant antioxidant capacity and leaf chlorophyll content. The negative effects of 03 stress on soybean leaves were more close to the impacts of 03 ＋UV stress, suggesting that O3might play an important role in the combined stress.