Plant Quarantine Technology Center, Animal and Plant Quarantine Agency, Gimcheon, 39660, Republic of Korea.
Sci Rep. 2022 Mar 8;12(1):4129. doi: 10.1038/s41598-022-08174-4.
The fall armyworm (FAW), Spodoptera frugiperda, is native to the tropical and subtropical areas of the American continent and is one of the world's most destructive insect pests and invaded Africa and spread to most of Asia in two years. Glycerol is generally used as a cryoprotectant for overwintering insects in cold areas. In many studies, the increase in glycerol as a main rapid cold hardening (RCH) factor and enhancing the supercooling point was revealed at low temperatures. There are two genes, including glycerol-3-phosphate dehydrogenase (GPDH) and glycerol kinase (GK), that were identified as being associated with the glycerol synthesis pathway. In this study, one GPDH and two GK sequences (GK1 and GK2) were extracted from FAW transcriptome analysis. RNA interference (RNAi) specific to GPDH or GK1 and GK2 exhibited a significant down-regulation at the mRNA level as well as a reduction in survival rate when the RNAi-treated of FAW larvae post a RCH treatment. Following a cold period, an increase in glycerol accumulation was detected utilizing high-pressure liquid chromatography and colorimetric analysis of glycerol quantity in RCH treated hemolymph of FAW larvae. This research suggests that GPDH and GK isozymes are linked to the production of a high quantity of glycerol as an RCH factor, and glycerol as main cryoprotectant plays an important role in survival throughout the cold period in this quarantine pest studied.
秋粘虫（FAW），Spodoptera frugiperda，原产于美洲大陆的热带和亚热带地区，是世界上最具破坏性的昆虫害虫之一，在两年内入侵非洲并传播到亚洲大部分地区。甘油通常被用作寒冷地区越冬昆虫的冷冻保护剂。在许多研究中，甘油作为主要的快速冷却硬化（RCH）因素的增加以及在低温下提高过冷点的作用得到了揭示。有两个基因，包括甘油-3-磷酸脱氢酶（GPDH）和甘油激酶（GK），被鉴定与甘油合成途径有关。在这项研究中，从 FAW 转录组分析中提取了一个 GPDH 和两个 GK 序列（GK1 和 GK2）。针对 GPDH 或 GK1 和 GK2 的 RNA 干扰（RNAi）在 RNAi 处理的 FAW 幼虫进行 RCH 处理后，在 mRNA 水平上表现出显著下调，并降低了存活率。经过一个寒冷期后，利用高压液相色谱法和 FAW 幼虫 RCH 处理血淋巴中甘油含量的比色分析检测到甘油积累增加。这项研究表明，GPDH 和 GK 同工酶与产生大量甘油作为 RCH 因子有关，甘油作为主要的冷冻保护剂在研究的这种检疫性害虫的整个寒冷期的生存中起着重要作用。
