College of Life Sciences, Gannan Normal University, Ganzhou, Jiangxi, China.
National Navel Orange Engineering Research Center, Ganzhou, Jiangxi, China.
Insect Sci. 2021 Jun;28(3):718-734. doi: 10.1111/1744-7917.12819. Epub 2020 Jul 22.
The Asian citrus psyllid, Diaphorina citri is the principal vector of huanglongbing, which transmits Candidatus Liberibacter asiaticus. Trehalase is a key enzyme involved in trehalose hydrolysis and plays an important role in insect growth and development. The specific functions of this enzyme in D. citri have not been determined. In this study, three trehalase genes (DcTre1-1, DcTre1-2, and DcTre2) were identified based on the D. citri genome database. Bioinformatic analysis showed that DcTre1-1 and DcTre1-2 are related to soluble trehalase, whereas DcTre2 is associated with membrane-bound trehalase. Spatiotemporal expression analysis indicated that DcTre1-1 and DcTre1-2 had the highest expression levels in the head and wing, respectively, and DcTre2 had high expression levels in the fat body. Furthermore, DcTre1-1 and DcTre1-2 expression levels were induced by 20-hydroxyecdysone and juvenile hormone Ⅲ, but DcTre2 was unaffected. The expression levels of DcTre1-1, DcTre1-2, and DcTre2 were significantly upregulated, which resulted in high mortality after treatment with validamycin. Trehalase activities and glucose contents were downregulated, but the trehalose content increased after treatment with validamycin. In addition, the expression levels of chitin metabolism-related genes significantly decreased at 24 and 48 h after treatment with validamycin. Furthermore, silencing of DcTre1-1, DcTre1-2, and DcTre2 reduced the expression levels of chitin metabolism-related genes and led to a malformed phenotype of D. citri. These results indicate that D. citri trehalase plays an essential role in regulating chitin metabolism and provides a new target for control of D. citri.
柑橘木虱是黄龙病的主要传播媒介，它传播亚洲韧皮杆菌。海藻糖酶是参与海藻糖水解的关键酶，在昆虫的生长和发育中起着重要作用。该酶在柑橘木虱中的具体功能尚未确定。本研究基于柑橘木虱基因组数据库，鉴定了三个海藻糖酶基因（DcTre1-1、DcTre1-2 和 DcTre2）。生物信息学分析表明，DcTre1-1 和 DcTre1-2 与可溶性海藻糖酶有关，而 DcTre2 与膜结合型海藻糖酶有关。时空表达分析表明，DcTre1-1 和 DcTre1-2 在头部和翅膀中的表达水平最高，而 DcTre2 在脂肪体中表达水平较高。此外，DcTre1-1 和 DcTre1-2 的表达水平受 20-羟基蜕皮酮和保幼激素 Ⅲ诱导，但 DcTre2 不受影响。DcTre1-1、DcTre1-2 和 DcTre2 的表达水平显著上调，导致处理井冈霉素后死亡率升高。海藻糖酶活性和葡萄糖含量下降，但处理井冈霉素后海藻糖含量增加。此外，处理井冈霉素后 24 和 48 小时，几丁质代谢相关基因的表达水平显著下降。此外，沉默 DcTre1-1、DcTre1-2 和 DcTre2 降低了几丁质代谢相关基因的表达水平，并导致柑橘木虱出现畸形表型。这些结果表明，柑橘木虱海藻糖酶在调节几丁质代谢中起着重要作用，为柑橘木虱的防治提供了新的靶标。
