Functional Analysis Of The Late Sexual Development Protein MaLsdA In Metarhizium Acridum

Fungal insecticide is a biological agent that uses entomogenous fungi to control harmful insects.It mainly uses the mutual restriction between species in nature.Compared with chemical pesticides,it has target specificity,spread among target pests,Can kill underground pests,resistance to resistance,long-lasting insecticidal,ecological balance and good environmental compatibility have become the focus of agricultural and forestry applications.Metarhizium acridum can specifically infect locusts and grasshoppers.Because of its narrow host range,environmental protection,safety,and easy mass production,it has been widely research as an important biocontrol fungus.its stress resistance,spore production and pathogenic ability have become the focus of research.LsdA(Late sexual development protein)is highly expressed in the late sexual development stage of Aspergillus nidulans.The absence ofLsdA will cause A.nidulans to produce a large number of sexual sporulation structures.Lsd A can inhibit the sexual development of A.nidulans regulated by Ve A through high concentration of salt.In this study,the late sexual development protein of M.acridum(MaLsdA)is homologous toLsdA in A.nidulans and was selected from the differential expression library of the gene related to sporulation transformation Ma Cre A.By predicting the conserved domain of MaLsdA,it was found that the late sexual development protein encoded by this gene has a signal peptide and Ferritin＿2 domain.Through homologous recombination and random insertion,the knockout and complementary strains of MaLsdA were obtained.It was found that MaLsdA affects the hyphae development of M.acridum,and the deletion of this gene will cause M.acridum to produce more hyphae;The knockout strain was make the M.acridum sporulation time on 1/4 SDAY medium be extended from 18 h to 24 h,and the microcirculation conidiation was converted to normal conidiation on SYA medium;the deletion of MaLsdA made M.acridum produces a large number of spore-forming structures,and the amount of spores is significantly reduced.At the same time,the absence of MaLsdA reduces the resistance of M.acridum to UV-B and heat resistance,oxidation resistance and hyperosmolarity,and damages the integrity of the cell wall.The results of WT and ΔMaLsdA comparative transcriptome were analyzed and found that there were 38 differentially expressed genes when cultured on SYA for 10 h,of which 30 genes were down-regulated and 8 genes were up-regulated.5 of the 30 down-regulated genes are involved in iron balance or iron transport.By measuring the intracellular iron content of WT and ΔMaLsdA,it was found that the absence of MaLsdA reduced the intracellular iron content of M.acridum.GO function analysis was performed on 38 differentially expressed genes,and it was found that the functions of a large proportion of differential genes were in metabolic process,single biological process,catalytic activity,binding ability,cell membrane and membrane components.This shows that MaLsdA may regulate the metabolic process of M.acridum by regulating the catalytic activity of some enzymes and the binding activity of transcription factors,affecting cell membrane components,and thus regulating the transformation of the sporulation mode of M.acridum.In summary,MaLsdA(late sexual development protein)plays an important role in hyphae development of M.acridum,transformation of spore production mode,resistance to abiotic stress,virulence,and iron balance.This study provides an experimental basis for exploring the function of l late sexual development protein,and lays a foundation for the study of microcirculation sporulation mechanisms and the exploration of microcycle conidiation pathways.