›› 2013, Vol. 56 ›› Issue (8): 934-944.

• SHORT COMMUNICATIONS • Previous Articles     Next Articles

Pathological changes in larval midgut tissues of the cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae), after feeding Cry2Ab

GAO Zhen, LIANG Ge-Mei*, WEI Ji-Zhen, ZHANG Li-Li   

  1. (State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China)  
  • Online:2013-08-20 Published:2013-08-20

Abstract: In order to ascertain the action mechanism of the insecticidal protein Cry2Ab, the pathological changes in the larval midgut of the cotton bollworm, Helicoverpa armigera (Hübner), fed on an artificial diet containing Cry2Ab protein (8 μg/g) were observed using transmission electron microscope, and the changes induced by Cry1Ac (0.97 μg/g) and the normal diet were also investigated. The results showed that the midgut cells and organelles both exhibited obvious pathological changes after H. armigera larvae fed on the artificial diet containing Cry2Ab. The main changes include that: the lumen of the goblet cells became swollen or elongated, some columnar cells were extruded by the goblet cells, microvilli dropped off, cell nuclei shrank, the membrane of plasma and nuclear were blurred, chromatin cohered, mitochondria was stretched and deformed, and the endoplasmic reticulum swelled and broken. The pathological changes became more obvious with extension of feeding time. The pathological changes of larval midgut cells in H. armigera caused by Cry2Ab were slower than those caused by Cry1Ac. These results may provide the theoretical basis for better using Cry2Ab as important insecticidal protein in transgenic cotton in the future.

Key words: Helicoverpa armigera, insecticidal protein, Cry2Ab, Cry1Ac, midgut tissues, pathological changes