Table_4_Performance and Transcriptional Response of the Green Peach Aphid Myzus persicae to the Restriction of Dietary Amino Acids.XLSX

Free amino acids in the phloem sap are the dominant nitrogen source for aphids, but their availability is usually poor. Although some studies have explored the effect of dietary amino acid restriction on aphid performance, little is known about the molecular basis of these effects. Here, we examined the performance and transcriptome of the green peach aphid, Myzus persicae, fed a standard diet (Control diet) or a diet containing 50% of the total amino acids of the Control diet (Half diet). Aphid weight and fecundity were significantly reduced in the Half diet group. Transcriptomic analysis showed that a total of 1460 genes were differentially expressed between the groups were fed on the two diets, which many of them were associated with nutrient and energy metabolism. When feeding on the Half diet, aphids upregulated genes associated with the amino acid biosynthetic pathway (predominantly amino acid biosynthesis genes and some amino acid transporter genes) as well as the cysteine and serine protease genes. Furthermore, these aphids displayed increased expression of genes associated with glycolysis, which could generate intermediates for de novo amino acid biosynthesis. Consistent with this, elevated glucose levels were observed in aphids in the Half diet group. Additionally, the expression levels of several genes associated with hormonal signaling pathway were altered. Several genes related to juvenile hormone and insulin-like peptide (ILP) signaling were downregulated, including Krüppel homolog 1 (Kr-h1) and insulin-like peptide 5 (Ilp5), respectively. In contrast, several genes related to ecdysone signaling were upregulated including broad-complex core protein (Br-c) and shade (Shd). Despite their poor performances, M. persicae adapted to dietary restriction of amino acids, through upregulation of genes involved in amino acid biosynthesis, glycolysis, and protein degradation, as well as by altering the expression level of genes involved in hormone signaling pathways.

韧皮部汁液中的游离氨基酸是蚜虫的主要氮源，但其可获得性普遍较差。尽管已有部分研究探讨了日粮氨基酸限制对蚜虫适合度的影响，但对于这些效应背后的分子机制仍缺乏深入了解。本研究以桃蚜（Myzus persicae）为研究对象，分别为其饲喂标准日粮（对照组日粮）以及仅含对照组50%总氨基酸的日粮（半量日粮），并分析了蚜虫的生长表现与转录组特征。半量日粮组的蚜虫体重与繁殖力均显著下降。转录组分析显示，饲喂两种日粮的蚜虫组间共有1460个差异表达基因，其中多数与营养及能量代谢过程相关。当饲喂半量日粮时，桃蚜会上调氨基酸生物合成通路相关基因的表达，其中主要包括氨基酸合成基因与部分氨基酸转运蛋白基因，同时还会上调半胱氨酸蛋白酶和丝氨酸蛋白酶基因的表达。此外，该组蚜虫的糖酵解相关基因表达量上调，而糖酵解过程可产生从头合成氨基酸所需的中间代谢产物。与此一致，半量日粮组蚜虫体内的葡萄糖水平显著升高。此外，多项与激素信号通路相关的基因表达水平亦发生显著改变。与保幼激素及类胰岛素肽（insulin-like peptide, ILP）信号通路相关的多个基因表达量下调，分别包括Krüppel同源框1（Krüppel homolog 1, Kr-h1）与类胰岛素肽5（insulin-like peptide 5, Ilp5）。与之相反，多项与蜕皮激素信号通路相关的基因表达量上调，包括broad-complex核心蛋白（broad-complex core protein, Br-c）与Shade（Shd）。尽管生长表现受损，但桃蚜（Myzus persicae, M. persicae）可通过上调氨基酸生物合成、糖酵解及蛋白质降解相关基因的表达，并调控激素信号通路相关基因的表达水平，从而适应日粮氨基酸限制环境。