类黄酮在草甘膦诱导的苦荞膜脂过氧化中的作用

研究了草甘膦对苦荞类黄酮次生代谢的影响及类黄酮与草甘膦作用下膜脂过氧化伤害的关系，以探讨植物类黄酮代谢的意义及在草甘膦伤害中的作用机制。结果表明，分别用浓度为0．1、0．3、1mmoL／L的草甘膦处理苦荞幼苗，苦荞类黄酮代谢受到明显抑制，处理3天时类黄酮含量比对照分别下降58．1％、65．8％和76．5％。草甘膦处理导致苦荞膜脂过氧化加剧，0．1mmoL／L草甘膦处理使苦荞相对电导率增加275．4％、丙二醛（MDA）含量增加134．1％、超氧自由基O2^-产生速率增加121．7％，且随草甘膦浓度升高而增加幅度加大，说明草甘膦伤害与膜脂过氧化程度有关。0．3mmoL／L草甘膦处理后再用0．1mmoL／L类黄酮物质芦丁处理，电解质外渗下降34．2％，MDA含量下降51．1％，O2^-产生下降33．9％，明显减轻了草甘膦的伤害，这说明草甘膦作用下类黄酮含量的下降与草甘膦对苦荞组织伤害有一定的关系。

The role of flavonoid in glyphosate-induced membrane lipid peroxidation in Fagopyrum tataricum

The role of flavonoids metabolism in glyphosate phytotoxicity were studied through the effects of glyphosate on secondary metabolism of flavonoids and the relationship between flavonoids and the phytotoxicity of glyphosate. The seedlings of Fagopyrum tataricum were treated with 0.1mmol/L, 0.3mmol/L and 1.0mmol/L of glyphosate, respectively. The result showed that the flavonoids metabolism in F.tataricum seedling was inhibited obviously. The flavonoid contents in seedlings were 58.1%, 65.8% and 76.5% lower than that of the control after 3d. The treatment of glyphosate enhanced membrane lipid peroxidation which gradually increased following the increase of glyphosate concentration. When F.tataricum seedlings were treated with 0.1mmol/L of glyphosate, the relative electrical conductivity, malondialdehyde (MDA) content and O-_2.yield were 275.4%, 134.1% and 121.7% higher than that of control, showing that the injury of glyphosate happened upon membrane lipid peroxidation process. Treatment with 0.1 mmol/L rutin as a flavonoids matter after 0.3mmol/L glyphosate treatment caused the decrease of glyphosate injury obviously. The electrolyte leakage, MDA content and O-_2.yield in F.tataricum seedlings decreased by 34.2%, 51.1% and 33.9% respectively. The decrease in flavonoids contents may relate to tissue injury of F.tataricum by glyphosate.