Scientists find toxins that increase the toxicity of Metarhizium anisopliae

Researchers from the Institute of Plant Physiology and Ecology of the Chinese Academy of Sciences (InstituteofPlantPhysiologyandEcology) and the Department of Entomology of the University of Maryland in the United States have discovered a neurotoxin that can promote the virulence of insecticides, which provides important data for the application of this insecticide and the study of the mechanism of fungal insecticides and the molecular mechanism of fungal-insect interaction. The findings are published in the journal NatureBiotechnology.

The authors are Professor RaymondJStLeger of the University of Maryland and Dr. Wang Chengshu, head of the "hundred people Plan" of the Institute of Plant Ecology. Dr. Wang Chengshu's research fields mainly include the functional study of pathogenic genes of entomopathogenic fungi, the molecular mechanism of fungus-insect interaction, the molecular mechanism of filamentous fungi degradation and senescence, and the developmental biology of Cordyceps sinensis and metabolic pathway of active components.

Insecticides are mainly used to control agricultural pests, and some of them can also be used for health and epidemic prevention and pest control of animal husbandry and industrial raw materials and products. The utility model has the advantages of long use history, large dosage, many varieties and remarkable control effect.

Metarhizium anisopliae (Metarhiziumanisopliae) is an important insect parasitic fungus, which belongs to the genus Metarhizium anisopliae. The process of its infection to the host includes adhesion, spore germination, penetration, in vivo development and death. This process is a comprehensive result of the physiological and biochemical effects of substances such as appressorium, epidermis-degrading enzymes and disruptors. Because of its wide host range, strong pathogenicity, non-toxic to human, livestock and crops, no residual poison, easy production of bacteria, long effective period and so on, it has a broad application prospect.

However, the low toxicity of this fungus affects its application in the prevention and control of diseases and insect pests. In this paper, the researchers found that an insect-specific neurotoxin (neurotoxin) from the yellow fat-tailed scorpion (Androctonusaustralis) can promote the toxicity of this fungal insecticide and explain the mechanism of this effect.

They found that the high expression of this specific neurotoxin increased the toxicity of fungi to tobaccohornworm (Manducasexta) by 22 times and to adultyellowfevermosquitoes (Aedesaegypti) by 9 times without harming the specificity of the host.

These results provide important data for understanding the action mechanism of fungal insecticides and the molecular mechanism of fungal-insect interaction.