PDF(Pubmed)
Abstract：
Tetranychus truncatus (Acari: Tetranychidae) has caused serious economic losses on some crops (soybean, corn, and cotton) in China, and has developed resistance to most acaricides. Our laboratory study found that T. truncatus was resistant to pyridaben and also adapted to high temperature (34-40 °C). High temperature stress may cause arthropods to produce a large amount of reactive oxygen species (ROS), causing oxidative damage. Antioxidant enzymes, as the main antioxidants, can reduce the damage caused by excessive ROS in arthropods. In order to study the adaptation mechanism of the pyridaben-resistant strain of T. truncatus to high temperature and the role of antioxidant enzyme genes under high temperature stress, four antioxidant enzyme genes, TtSOD, TtPOD3, TtPOD4, and TtGSTs2, were screened according to the transcriptome sequencing data of pyridaben-susceptible and -resistant strains in T. truncatus. Firstly, the phylogeny and structure analyses of these four genes were carried out. Then, real-time quantitative PCR (RT-qPCR) technology was used to analyze the gene expression patterns of antioxidant enzymes in two strains of T. truncatus at three different high temperature ranges (34 °C, 38 °C, and 42 °C). The results showed that the expression levels of four antioxidant enzyme genes of two strains of T. truncatus were induced by high temperature stress, and the expression levels of antioxidant enzyme genes were significantly different in each development state. The gene expression of antioxidant enzyme genes in resistant strains at the adult stage was significantly higher than that in susceptible strains. After the TtSOD and TtPOD4 genes of adult mites of the resistant strain were silenced by RNA interference (RNAi) technology, the mortality rate of mites with TtPOD4 gene silencing reached 41.11% after 96 h at 34 °C, which was significantly higher than that of the control and TtSOD gene silencing. It has been confirmed that the TtPOD4 gene plays a key role in the adaptation of pyridaben-resistant strain of T. truncatus to high temperature. It lays a theoretical foundation for revealing the thermal adaptation mechanism of T. truncatus.
摘要：
Tetranychustruncatus（Acari：Tetranychidae）对某些作物造成了严重的经济损失（大豆，玉米,和棉花)在中国，并对大多数杀螨剂产生了抗性。我们的实验室研究发现T.truncatus对吡啶甲酸具有抗性，并且也适应高温（34-40°C）。高温胁迫可使节肢动物产生大量的活性氧(ROS),造成氧化损伤。抗氧化酶，作为主要的抗氧化剂，可以减少节肢动物中过量ROS造成的损害。为了研究高温胁迫下T.truncatus耐吡啶酯菌株对高温的适应机制和抗氧化酶基因的作用，四个抗氧化酶基因，TtSOD,TtPOD3、TtPOD4和TtGSTs2是根据T.truncatus中吡啶甲酸敏感和耐药菌株的转录组测序数据进行筛选的。首先,对这四个基因进行了系统发育和结构分析。然后，实时定量PCR（RT-qPCR）技术用于分析三种不同高温范围（34°C，38°C,和42°C)。结果表明,高温胁迫对两株截短毛虫4种抗氧化酶基因的表达水平,抗氧化酶基因的表达水平在各发育状态下差异显著。成年期抗性菌株抗氧化酶基因的基因表达显著高于易感菌株。用RNA干扰(RNAi)技术将抗性品系成虫的TtSOD和TtPOD4基因沉默后,在34°C下96小时后，TtPOD4基因沉默的螨虫死亡率达到41.11％，显著高于对照和TtSOD基因沉默。已经证实，TtPOD4基因在干T.truncatus的吡啶类抗性菌株对高温的适应中起着关键作用。为揭示T.truncatus的热适应机制奠定了理论基础。
