Acta Entomologica Sinica ›› 2019, Vol. 62 ›› Issue (9): 1054-1064.doi: 10.16380/j.kcxb.2019.09.006

• RESEARCH PAPERS • Previous Articles     Next Articles

Effect of Sacbrood virus infection on nutritional and immune responses of Apis cerana cerana (Hymenoptera: Apidae)

ZHENG Bin-Yue, ZHAO Bi-An, JIN Xin, DUAN Xin-Le, HUANG Shao-Kang, LI Jiang-Hong   

  1. (College of Bee Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China)
  • Online:2019-09-20 Published:2019-09-03

Abstract: 【Aim】 Sacbrood virus (SBV), is a pathogen seriously threatening the health and colony number of the Eastern honey bee, Apis cerana cerana. But its lethal mechanism is not clear so far. The aim of the study is to uncover the effect of SBV on nutrition and immunity in A. cerana cerana in different developmental stages. 【Methods】 The 2-day-old larvae and newly emerged adults of A. cerana cerana were fed with SBV, and the number of daily dead larvae or adults were recorded to determine the effect of SBV on the survival of larvae and adults, respectively. Moreover, the expression levels of SBV RNA, nutrient metabolism-related genes including ilp1, ilp2, hex110, hex70b, hex70c and vg, innate virus immunity genes including rel, toll, apidaecin, abaecin, defensin, hymenoptaecin, jra, key and state92e, apoptosis genes including atg7 and LOC100577876, and anti-RNA virus genes including dis3 and dicer in 4-day-old larvae, prepupae, and 10- and 20-day-old adults of A. cerana cerana were determined by qPCR, respectively. 【Results】 SBV significantly decreased the survival rate of A. cerana cerana larvae, but had no effect on the survival of adults. The expression levels of SBV RNA in 4-day-old larvae and prepupae were significantly higher than those in 10- and 20-dayold adults of A. cerana cerana. SBV significantly decreased the expression levels of the nutrient metabolism-related genes ilp1, ilp2, hex110, hex70b and hex70c in larvae, and vg and hex110 in adults, but significantly increased the expression levels of the innate virus immunity genes rel, toll, apidaecin, abaecin, defensin, hymenoptaecin and jra in 4-day-old larvae, and key and state92e in adults, and also the expression levels of the apoptosis genes atg7 and LOC100577876 in prepupae of A. cerana cerana. 【Conclusion】 SBV has higher infection level in larvae and prepupae of A. cerana cerana than in adults, with higher virility to larvae than to adults. SBV decreases the nutrient metabolism of A. cerana cerana. Infected honeybees try to cope with the virus infection through increasing the immunity level. The increasing of apoptosis level in the prepupa might be related with the larval death and abnormal prepupal development.

Key words: Apis cerana cerana, Sacbrood virus, nutrition, immunity, life span