Functional Analysis Of Constitutively Photomorphogenesis Signalosome SsCSN5 Gene In Sclerotinia Sclerotiorum

Sclerotinia sclerotiorum(Lib.)de Bary is a typical plant necrotrophic fungus that can infect plants on a large scale with its unique infection structure.Among them,sclerotinia is one of the common diseases caused by Sclerotinia sclerotiorum.The wide host range,strong transmission,and strong environmental adaptability of Sclerotinia sclerotiorum have greatly increased the difficulty of preventing and controlling sclerotinia.Therefore,clarifying the pathogenic molecular mechanism of Sclerotinia sclerotiorum can help to explore potential drug targets and provide new strategies for the prevention and control of sclerotinia.Ss Fkh1 and Ss Fox E3 are transcription factors that regulate the formation of sclerotium,the developent of infection cushions and pathogenicity of Sclerotinia sclerotiorum.In order to further clarify their roles in the growth and development of Sclerotinia sclerotiorum,Ss Fkh1 and Ss Fox E3 were used as bait proteins to screen the Sclerotinia sclerotiorum c DNA library using yeast two-hybrid technology.The candidate interacting proteins were subjected to bioinformatics analysis and it was found that Ss CSN5 interacts with both.Ss CSN5 is homologous to the yeast COP9 signalosome(Constitutively Photomorphogenesis 9 Signalosome,CSN)subunit CSN5.CSN5 has a metal ion zinc binding site and a complete catalytic active site.It relies on the Jab1/MPN functional domain as a catalytic center and is the core subunit of the COP9 signalosome.It mediates the interaction between other subunits of the COP9 signalosome and target proteins,and plays an important role in the form of small complexes in organisms.Therefore,clarifying the role of Ss CSN5 in the growth and development of Sclerotinia sclerotiorum,obtaining Sclerotinia sclerotiorum Ss CSN5 gene knockout mutants and gene complementation strains by gene knock-out technology,can clarify its main biological functions.The main research results are as follows:(1)By using yeast two-hybrid technology to screen the Sclerotinia sclerotiorum c DNA library,proteins that may interact with Ss Fkh1 and Ss Fox E3 were screened respectively,and their homologous proteins were found to interact with both.(2)The Ss CSN5 gene of Sclerotinia sclerotiorum participates in regulating hyphal growth and sclerotium development of Sclerotinia sclerotiorum.The hyphal growth rate of Ss CSN5 gene knockout mutant mutant was significantly slowed down,the dry weight of sc-leotium was significantly reduced,and the number of sclerotium was significantly reduced.(3)In terms of stress tolerance of Sclerotinia sclerotiorum,Ss CSN5 positively regulates cell wall stress tolerance,oxygen stress tolerance and osmotic stress tolerance.(4)Pathogenicity analysis showed that the Ss CSN5 gene has an important impact on the pathogenicity of Sclerotinia sclerotiorum,and the pathogenicity of Ss CSN5 gene knockout mutant was significantly weakened.In summary,the Ss CSN5 gene plays an important role in the growth and development and abiotic stress response of Sclerotinia sclerotiorum,and participates in regulating the pathogenic process of Sclerotinia sclerotiorum.The preliminary study on the function of the Sclerotinia sclerotiorum Ss CSN5 gene helps to further clarify its signaling pathway involved in Sclerotinia sclerotiorum and provides new drug targets for comprehensive prevention and co-ntrol of diseases caused by this fungus.