Liao Chunli, Yang Yi, Fan Xingzhao, Du Jiangnan, Zhu Jing, Sang Mingbo, Li Bingbing
College of Life Science and Engineering, Henan University of Urban Construction, Pingdingshan, 467036 Henan China.
Center of Healthy Food Engineering and Technology of Henan, Henan University of Urban Construction, Pingdingshan, 467036 Henan China.
3 Biotech. 2021 Feb;11(2):101. doi: 10.1007/s13205-021-02662-6. Epub 2021 Jan 28.
Entomopathogenic bacteria have great potential in insect control in the agricultural production because they produce a large variety of protein toxins that can kill their hosts by damaging the insect midgut. However, the mechanisms on how these toxins or specific insecticidal proteins act on insects are very diverse and elusive. Here we select larvae as the host to explore the effects of insecticidal proteins on the activities of three protective enzymes (SOD, POD, and CAT) and on the morphology of the midgut tissues. As a result, the activities of the three enzymes consistently increased and then decreased when the host was injected with the insecticidal proteins from the entomopathogenic bacterium . Moreover, the microscopy analysis showed that tissues, cells, and organelles of the host midgut are all diseased after uptake of the insecticidal proteins. Remarkably, the protein toxins contributed to the deformation of the midgut, blackening of the midgut surface, dissolution of cell membrane, shrinkage of cell nucleus, and chromatin condensation. Our findings will advance the explanation of pathogenesis caused by the insecticidal proteins.
昆虫病原细菌在农业生产的害虫防治中具有巨大潜力，因为它们能产生多种蛋白质毒素，这些毒素可通过损害昆虫中肠来杀死宿主。然而，这些毒素或特定杀虫蛋白作用于昆虫的机制非常多样且难以捉摸。在此，我们选择幼虫作为宿主，以探究杀虫蛋白对三种保护酶（超氧化物歧化酶、过氧化物酶和过氧化氢酶）活性以及中肠组织形态的影响。结果显示，当宿主注射来自昆虫病原细菌的杀虫蛋白后，这三种酶的活性先持续升高然后降低。此外，显微镜分析表明，宿主中肠的组织、细胞和细胞器在摄取杀虫蛋白后均出现病变。值得注意的是，蛋白质毒素导致了中肠变形、中肠表面变黑、细胞膜溶解、细胞核收缩以及染色质凝聚。我们的研究结果将推动对杀虫蛋白致病机制的解释。
