The Transcription Factor ERF114 Mediates PevD1-induced Arabidopsis Thaliana Resistance To Pst DC3000 And Molecular Mechanism

PevD1 is a Verticillium dahliae elicitor that can induce disease resistance in cotton and tobacco.In our previous work,Nicotiana benthamiana ERF114 have been screen out from lots of differential expression genes(DEGs)in N.benthamiana in response to PevD1.Investigation indicated that ERF114transcription was strongly induced by PevD1infiltration and Pst DC3000 infection.Loss of ERF114function showed impaired disease resistance,while overexpressing ERF114 enhanced resistance to Pst DC3000.Moreover,erf114 mutants also exhibited reduced PevD1-induced resistance,indicating that ERF114 positively modulate Arabidopsis defense response and mediated PevD1-induced disease resistance.RNA-seg analysis revealed that transcript levels of phenylalanine ammonia-lyase(PAL)and its downstream biological process components are significantly suppressed in erf114 mutants compared with Col-0.Moreover,PAL1 expression was significantly up-regulated in OE-ERF114 plants but down-regulated in erf114 mutants compared with Col-0.Electrophoretic mobility shift assay(EMSA)and chromatin immunoprecipitation(Ch IP)analyses confirmed that ERF114 directly bind the promoter of PAL1.Furthermore,ERF114 positively modulated PevD1-induced lignin and SA accumulation.The main results are as follows:1.PevD1 trigger defense response and enhance disease resistance to Pst DC3000 in Arabidopsis thalianaThe patterns of ROS burst and the expression level of defense genes PR1 and PR5 in Arabidopsis infiltrated with Pev D were observed.Our results determined that PevD1 activated the Arabidopsis immune defense response and enhanced Athaliana disease resistance.2.ERF114 expression is induced by PevD1 filtration and Pst DC3000 infection.To confirm that ERF114 responds to PevD1 and Pst DC3000 in Arabidopsis,qPCR be used to analyze gene transcript levels.The result showed that ERF114 transcript levels were dramatically higher in leaves treated with PevD1 or Pst DC3000 than in that with buffer treatment.To further understand where the ERF114 gene expression is occurred,chimeric promoter fusion with the bacterial-Glucuronidase(GUS)was constructed and introduced into Arabidopsis plants.In the Prom ERF114:GUS transgenic plant leaves treatment with PevD1 and Pst DC3000 showed dark blue compared to mock leaves,indicating the ERF114 transcript is induced by PevD1 and Pst DC3000 infectiona.3.ERF114 contributes to Arabidopsis disease resistance to Pst DC3000 and mediated PevD1-induced disease resistanceTo investigate the function of ERF114 in response to Pst DC3000 in Arabidopsis plant.Firstly ERF114 gene deletion mutants and ERF114 overexpression transgenic plants were generated,and then H₂O₂ accumulation,expression levels of defense genes and plant disease resistance were compared after Pst DC3000 treament.The results showed that ERF114 positively regulated disease resistance against Pst DC3000.PevD1-induced defense response and disease resistance to bacterial pathogen were investigated,The results indicated that ERF114 mediated PevD1 induced disease resistance against Pst DC3000.4.ERF114 binds to the promoter of PAL1 in vivo and in vitro and mediates PevD1-induced PAL1expressionRNA-seq analysis showed that the transcript levels of phenylalanine ammonia-lyase(PAL1)and its downstream biological process components are significantly suppressed in erf114 mutants compared with Col-0.To investigate whether ERF114 physically interacted with the PAL1 promoter.We employed Ch IP-qPCR and EMSA and the results showed that ERF114 binds to the promoter of PAL1 in vivo and in vitro.To further analyze whether ERF114 could activate PAL1 expression,p ER8-ERF114 estrogen inducible transgenic plants were generated and treated with estrogen in a time course(1,0.5,or 3 h)to clarify the regulatory relationship between PAL1 and ERF114.The q RT-PCR results showed that PAL1was rapidly expressed along with the ERF114 expression,demonstrated that ERF114 can activate PAL1transcription.5.ERF114 contribute to lignin and SA accumulation and mediated PevD1-induced lignin and SA production in ArabidopsisPhenylpropanoid pathway in plants synthesizes a variety of structural and defence compounds.Phenylalanine ammonia-lyase(PAL)catalyzes the first step in phenylpropanoid biosynthesis.To investigate whether ERF114 regulated SA and lignin accumulation,we compared total lignin deposition and free SA concentration in Col-0,erf114 and OE-ERF114 after PevD1 treatment.The suggested that ERF114 mediated PevD1-induced disease resistance against Pst DC3000 through activating PAL1transcript to enhance the content of lignin and SA.