Acta Entomologica Sinica ›› 2019, Vol. 62 ›› Issue (11): 1250-1259.doi: 10.16380/j.kcxb.2019.11.002

• RESEARCH PAPERS • Previous Articles     Next Articles

Effects of heavy metal cadmium on the trehalose metabolism in Aedes albopictus (Diptera: Culicidae) larvae

YU Ling-Yuan, WEI Ying, CHEN Xu-Min, DING Yan-Juan, HU Yao-Wen, TANG Bin, WANG Shi-Gui   

  1. (College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, China)
  • Online:2019-11-20 Published:2019-11-05

Abstract: 【Aim】 This study aims to understand the toxic effects of cadmium on Aedes albopictus and its adaptation to the extreme environment, and to reveal the possible effects of heavy metal stress on the occurrence of mosquitoes and disease transmission, so as to provide reference for the control of hygienic pests. 【Methods】 The late 3rd instar to early 4th instar larvae of A. albopictus with the same growth status in 320 mL disposable cups were acutely exposed to 200 mL prepared 50, 100, 200, 300, and 400 mg/L Cd2+ solution, respectively, for 12 h, and the larvae cultured in double distilled water were used as the control. The contents of trehalose, sucrose and total glycogen, and the activities of soluble trehalase (TRE1) and membrane-bound trehalase (TRE2) in the larvae at 12 h post treatment were determined by biochemical methods, and the relative expression levels of trehalose-6-phosphate synthase gene (TPS), TRE1 and TRE2 in these larvae were detected by qRT-PCR. 【Results】 The results showed that the trehalose content in A. albopictus larvae exposed to 200 and 300 mg/L Cd2+ solution for 12 h increased significantly, while the glucose content in larvae exposed to high concentrations of Cd2+ solution (300 and 400 mg/L) decreased significantly, as compared with the control. The acute treatment of different Cd2+ concentrations had no effect on the total glycogen content. The activities of TRE1 and TRE2 in larvae exposed to high concentrations of Cd2+ (300 and 400 mg/L) decreased significantly as compared with those in the control group. The relative expression level of TPS was the highest in the 300 mg/L Cd2+ treated group. The relative expression levels of TRE1 and TRE2 in larvae exposed to high concentrations of Cd2+ solution (300 and 400 mg/L) decreased significantly as compared with those in the control group. 【Conclusion】 The acute stress of Cd2+ up-regulates the expression of TPS gene in A. albopictus larvae when the Cd2+ concentration is lower than the LC50 value (217 mg/L), while the relative expression level of TRE gene and the TRE activity decrease,  thereby promoting the conversion of glucose to trehalose and resisting the Cd2+ stress by the production of trehalose. These results indicate that trehalose may play a role in heavy metal stress in A. albopictus larvae, which can improve the resistance to Cd2+ stress by trehalose synthesis.

Key words: Aedes albopictus, heavy metal, cadmium stress, trehalose, trehalose metabolism