Huang Qitong, Ma Qian, Li Fangxiang, Zhu-Salzman Keyan, Cheng Weining
Key Laboratory of Plant Protection Resources & Pest Management of the Ministry of Education, College of Plant Protection, Northwest A&F University, Yangling 712100, China.
Xi'an Agricultural Technology Extension Centre, Xi'an 710061, China.
Insects. 2022 Mar 30;13(4):339. doi: 10.3390/insects13040339.
, a notorious pest of wheat worldwide, copes with temperature extremes during harsh summers and winters by entering obligatory diapause as larvae. However, the metabolic adaptive mechanism underlying this process is largely unknown. In this study, we performed a comparative metabolomics analysis on larvae at four programmed developmental stages, i.e., pre-diapause, diapause, low temperature quiescence and post-diapause development. In total, we identified 54 differential metabolites based on pairwise comparisons of the four groups. Of these metabolites, 37 decreased in response to diapause, including 4 TCA cycle intermediates (malic acid, citric acid, fumaric acid, α-ketoglutaric acid), 2 saturated fatty acids (palmitic acid, stearic acid) and most amino acids. In contrast, nine metabolites, including trehalose, glycerol, mannitol, proline, alanine, oleic acid and linoleic acid were significantly higher in both the diapause and quiescent stages than the other two stages. In addition to two of them (trehalose, proline), glutamine was also significantly highest in the cold quiescence stage. These elevated metabolites could function as cryoprotectants and/or energy reserves. These findings suggest that the reduced TCA cycle activity and elevated biosynthesis of functional metabolites are most likely responsible for maintaining low metabolic activity and cold tolerance during diapause, which is crucial for the survival and post-diapause development of this pest.
是全球小麦的一种臭名昭著的害虫，它在严酷的夏季和冬季通过以幼虫形式进入 obligatory 滞育来应对极端温度。然而，这一过程背后的代谢适应机制在很大程度上尚不清楚。在本研究中，我们对处于四个程序化发育阶段的幼虫进行了比较代谢组学分析，即滞育前、滞育、低温静止和滞育后发育阶段。总共，我们基于四组的两两比较鉴定出了54种差异代谢物。在这些代谢物中，37种因滞育而减少，包括4种三羧酸循环中间体（苹果酸、柠檬酸、富马酸、α-酮戊二酸）、2种饱和脂肪酸（棕榈酸、硬脂酸）以及大多数氨基酸。相比之下，9种代谢物，包括海藻糖、甘油、甘露醇、脯氨酸、丙氨酸、油酸和亚油酸，在滞育和静止阶段均显著高于其他两个阶段。除了其中两种（海藻糖、脯氨酸）外，谷氨酰胺在低温静止阶段也显著最高。这些升高的代谢物可作为抗冻剂和/或能量储备。这些发现表明，三羧酸循环活性的降低和功能性代谢物生物合成的增加最有可能是在滞育期间维持低代谢活性和耐寒性的原因，这对这种害虫的存活和滞育后发育至关重要。
