论文部分内容阅读
为了解共生菌对黑豆蚜蛋白质、氨基酸代谢的影响 ,用利福平处理黑豆蚜以除去其细胞内共生细菌 ,产生脱共生蚜虫。结果表明 ,被脱去共生菌的蚜虫与未经抗生素处理的正常蚜虫相比 ,7日龄时 ,脱共生蚜虫每毫克鲜重的总蛋白含量降低了 2 9% ,每毫克鲜重的游离氨基酸含量提高了 17%。对黑豆蚜取食的蚕豆苗韧皮部组织中必需氨基酸所占的比例进行分析后发现 ,蚕豆苗韧皮部组织中的必需氨基酸含量仅占 2 0 % ,而有共生菌的黑豆蚜组织中必需氨基酸已达到 4 4% ,脱共生后降低到 37% ,这些结果证明了黑豆蚜的胞内共生菌为其寄主提供了部分必需氨基酸。通过对游离氨基酸组成的分析发现 ,在测定的 17种氨基酸中 ,必需氨基酸中的苏氨酸在共生蚜虫中所占的比例为 2 1 6 % ,在脱共生蚜虫中仅为 16 7%。同样 ,非必需氨基酸中的酪氨酸和丝氨酸 ,在共生蚜虫中分别占总游离氨基酸的 8 9%和 5 6 % ,而在脱共生蚜虫中却分别升高到 2 1 1%和 13 6 %。这些结果表明 ,各种氨基酸比例的失调 ,造成了脱共生蚜虫蛋白质合成受阻和部分游离氨基酸的积累 ,并因此导致蚜虫发育和繁殖的失调。
In order to understand the impact of commensal bacteria on protein and amino acid metabolism of black bean aphid, the black bean aphid was treated with rifampin to remove its intracellular symbiotic bacteria and produce symbiotic aphids. The results showed that compared with normal aphids without antibiotic treatment, the total protein content per mg fresh weight of symbiotic aphids decreased by 29% compared with the normal aphids without antibiotic treatment. The free amino acids per mg fresh weight Content increased by 17%. The ratio of essential amino acids in the phloem tissues of Vicia faba fed on Aphis gossypii was analyzed. It was found that the essential amino acids in the phloem tissues of Vicia faba only accounted for 20%, while the essential amino acids in the tissues of Synechocystis aphids had reached 4 4%, reduced to 37% after de-symbionts. These results demonstrate that intracellular symbionts of the black bean aphid provide some essential amino acids to their hosts. Analysis of free amino acid composition found that among the 17 amino acids tested, the percentage of threonine in essential amino acids in symbiotic aphids was 21.6%, and in the symbiotic aphids only 16.7%. Similarly, tyrosine and serine in nonessential amino acids accounted for 89% and 56% of the total free amino acids respectively in symbiotic aphids but increased to 21.1% and 13.6% in the symbiotic aphids, respectively . These results indicate that the imbalance of various amino acid ratios results in the obstruction of the symbiotic aphid protein synthesis and the accumulation of some of the free amino acids, and thus the deregulation of aphid development and reproduction.