›› 2009, Vol. 52 ›› Issue (2): 133-139.

• RESEARCH PAPERS • Previous Articles     Next Articles

Activities of four sugar metabolic enzymes in Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae) larvae at different diapause stages

  

  • Online:2009-03-18 Published:2009-02-20

Abstract:

In order to reveal the accumulation mechanism of trehalose, a main chemical substance to maintain diapause of Sitodiplosis mosellana (Gehin), we measured the activities of four sugar metabolic enzymes including glycogen phosphorylase (Gpase), hexokinase (HK), phosphofructokinase (PFK) and aldolase (ALD) in pre-diapause, diapause and post-diapause larvae of S. mosellana by using testing kits. The results indicated that activities of these sugar metabolic enzymes were obviously different at various diapause stages of S. mosellana larvae. Gpase activity was increased significantly, while activities of glycolysis enzymes (HK, ALK and PFK) were decreased significantly after entering diapause. Gpase activity was decreased, while activities of glycolysis enzymes were increased after diapause termination. Activities of four enzymes were all related with developmental status of diapause larvae during diapause. Gpase and PFK were also influenced by environmental temperature, namely, activities of Gpase and PFK were higher in summer and winter than those in spring and autumn. At the same diapause stage, activities of HK, PFK and ALK of non-cocooned larvae were higher than those of cocooned larvae. On the contrary, Gpase activity of non-cocooned larvae was lower than that of cocooned larvae. No obvious difference in four metabolic enzyme activities was found between the 1st and 2nd year diapause larvae.

Key words: Sitodiplosis mosellana, diapause, trehalose, sugar metabolic enzymes, enzyme activity