辣椒根系分泌的潜力化感物质对生菜幼苗抗氧化代谢的影响

Effect of Root Exudated Potential Allelochemicals in Hot Pepper(Capsicum annumm L.) on Antioxidative Metabolism for Lettuce(Lactuca sativa L.)

以盆栽辣椒为试验材料,采用树脂吸附萃取和气质联用仪测定辣椒根系分泌物,分析、确定其中的疑似化感物质。分别使用6种(0、2、4、8、12、16μg·mL-1)不同浓度的外源潜力化感物质处理生菜种子,通过种子发芽、幼苗生长分析其潜力化感作用,并研究其对生菜幼苗抗氧化代谢的影响。结果表明,2,6-二叔丁基苯酚(2,6-DTBP)、邻苯二甲酸二异丁酯(DIBP)和邻苯二甲酸二丁酯(DBP)为辣椒根系分泌的潜力化感物质,随三种潜力化感物质浓度的增加,生菜幼苗的谷胱甘肽(GSH)含量降低,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)、多酚氧化酶(PPO)和抗坏血酸氧化酶(APX)活性先增加后降低。2,6-DTBP、DIBP和DBP化感抑制作用的低限浓度分别为4、8、8μg·mL-1,三者通过降低GSH含量而损伤生菜幼苗的抗氧化代谢系统。

In this paper, potted hot pepper （Capsicum annumm L.） was selected as the experiment materials, and resin adsorption extraction with gas chromatography-mass spectrometry （GC-MS） was used to determine root exudates of hot pepper to analyze potential aUelochemicals. Six different concentration of exogenous suspected allelochemicals （0, 2, 4, 8, 12, 16 pg.mL1） were applied to lettuce seed. Seed germination and seedling growth of lettuce were used to analyze allelopathy and effect on antioxidative metabolism of lettuce seedling. The results showed that 2,6-di-tertbutylphenol （2,6-DTBP）, diisobutyl phthalate （DIBP） and dibutyl phthalate （DBP） were potential allelochemicals of root exudates in hot pepper, The content of glutathione （GSH） increased, and superoxide dismutase （SOD）, catalase （CAT）, peroxidase （POD）, polyphenol oxidase （PPO） and ascorbate peroxidase （APX） activity increased first, then decreased with increasing concentration of potential allelochemicals. Low limit concentration of allelopathic inhibition were 4, 8, and 8 μg·mL-1 for 2, 6-DTBP, DIBP and DBP, respectively, three potential allelochemicals damaged antioxidative metabolism system of lettuce seedling by decreasing the content of GSH.