木霉诱导新疆野苹果抗斑点落叶病及其分子机理研究

[Objective]M.sieversii is the only natural gene pool of economic fruit tree resources in China.Using Trichoderma biofertilizer to improve the M.sieversii living environment,control the number of pathogenic in their habitats,solve the problem of population degradation,and more fully preserve the M.sieversii genetic resources.[Method]Following treated with Trichoderma biofertilizer and pathogen Aalm,the M.sieversii RNA-Seq data showed the transcription factor MsERF105 induced by Trichoderma and pathogenic,heterologously transform Populus davidiana×P.alba var.pyramidalis,and identify the upstream regulatory genes and interaction proteins of MsERF105 to determine its role in the disease resistance process of M.sieversii.[Result]1)Trichoderma rossicum Tro7 and Trichoderma harzianum Tha2 were isolated from the rhizosphere of M.sieversii.The two Trichoderma strains had significant inhibitory effects on Alternaria alternata f.sp.mali(Aalm),Fusarium oxysporum(FOSC)and Cytospora mali(CMA),ranging from 34%to 58%,and could colonize the roots of M.sieversii.Trichoderma can affect the number of pathogen and soil metabolism by regulating the community structure of fungi and bacteria.2)M.sieversii RNA-Seq data showed that the differentially expressed genes were related to pathogen infection and signal transduction,and the differential expression of MsERF105 was the most significant.The heterologous expression of MsERF105 in Populus davidiana×P.alba var.pyramidalis(PdPap)showed that it could reduce the soaring reactive oxygen species caused by pathogen infection.Compared with the control,the relative lesion area of PdPap-MsERF105 was significantly smaller.Further studies showed that MsERF105 could activate the expression of defense genes,such as PR1s and PD Fs,which shows that MsERF105 activates the internal defense response system of M.sieversii.3)The promoter region of MsERF105 gene was analyzed and found to contain five cis-acting motifs related to disease resistance.WRKY33 and WRKY40 transcription factor can bind motif WBOXATNPR1,and signal transduction response regulator STRR and GT1 transcription factor can bind motif GT1CONSENSUS in the promoter region to regulate the expression of MsERF105 transcription factor.Yeast two hybrid showed that MsERF105 transcription factor may interact with tRNA methyltransferase MsTRMT,far upstream element binding protein MsFUBP2 or disease resistance protein MsDRP,further regulate the expression of disease resistance genes together.In addition,we also found the small heat shock protein MsHSP17.8 is the molecular chaperone of MsERF105 transcription factor.Finally,we obtained MsERF105 transcription factor can regulate the expression of disease resistance genes and defense response genes by binding to GCCBOX,CCAATBOX and ERS(GCGT),then activate the resistance of M.sieversii to Aalm.[Conclusion]The MsERF105 transcription factor of M.sieversii is a key gene in the disease resistance system,which can regulate the expression of disease resistance genes and defense response genes,activate the resistance of M.sieversii to the pathogen Aal,and provide a theoretical basis for the repair of fungal disease induced degradation of M.sieversii species by Trichoderma.