Abstract: To explore the effect of thrips on amino acid composition and content of alfalfa, the thrips-resistant 'Caoyuan No.4' variety and the thrips-susceptible 'Caoyuan No.2' variety were selected as research material, which were treated with and without Odontothrips loti infestation. The content of 17 amino acids and amino acid derivatives were determined by amino acid analyzer and liquid chromatography-mass spectrometry, respectively. The results showed that: there was no significant difference in the total amino acid content between thrips-resistant alfalfa and thrips-susceptible alfalfa. Thrips feeding led to a significant decrease in the total amino acid content of alfalfa leaves (P < 0.05), which mainly included aspartic acid, threonine, serine, glutamic acid and valine. Compared with thrips-sensitive materials, thrips-resistant variety had higher contents of aspartic acid, serine, glutamic acid and tyrosine, while lower contents of threonine, proline, glycine and histidine and arginine. After thrips ingestion, sulfur-containing amino acids (such as methionine, cysteine) or phenyl-ring amino acids (such as phenylacetylglycine and N-phenylacetyl-L-glutamine) increased, while amino related to glutathione metabolism pathway including reduced glutathione glycine, oxidized glutathione, S-methyl glutathione were down-regulated.

Key words: Alfalfa, Odontothrips loti, Resistance to insect, Amino acids, Amino acid derivatives

摘要： 为了探究蓟马取食对苜蓿(Medicago sativa L.)氨基酸组成及含量的影响，本研究以'草原2号’(Medicago varia Martin.'Caoyuan No.2’)感蓟马品种和'草原4号’(Medicago sativa L.'Caoyuan No.4’)抗蓟马品种为材料，分别进行牛角花齿蓟马(Odontothrips loti)接虫和不接虫处理，利用氨基酸分析仪测定苜蓿叶片中17种氨基酸含量，利用液质联用仪测定苜蓿叶片中氨基酸衍生物种类及含量。结果表明：抗蓟马苜蓿和感蓟马苜蓿氨基酸总含量无显著性差异，接种蓟马后导致苜蓿叶片氨基酸总含量(主要包括天冬氨酸、苏氨酸、丝氨酸、谷氨酸和缬氨酸)显著下降(P＜0.05)，和感蓟马材料相比，抗蓟马品种天冬氨酸、丝氨酸、谷氨酸和酪氨酸含量较高，苏氨酸、脯氨酸、甘氨酸、组氨酸和精氨酸含量较低。蓟马取食苜蓿后，苜蓿叶片蛋氨酸、半胱氨酸、苯乙酰甘氨酸和N-苯乙酰基-L-谷氨酰胺等含硫或含苯环氨基酸显著上升(P＜0.05)；谷胱甘肽还原型、氧化谷胱甘肽、S-甲基谷胱甘肽等与谷胱甘肽代谢通路相关的氨基酸及其衍生物显著下调(P＜0.05)。

关键词: 苜蓿, 牛角花齿蓟马, 抗虫性, 氨基酸, 氨基酸衍生物