Journal Article

Lilium regale Wilson WRKY3 modulates an antimicrobial peptide gene, LrDef1, during response to Fusarium oxysporum

Chen, Hongjun, Liang, Tingting, Deng, Jie, Liu, Diqiu, Su, Linlin, Zheng, Lilei, Wang, Zie

2022

Overview

Background WRKY transcription factors (TFs) play vital roles in plant growth and development, secondary metabolite synthesis, and response to biotic and abiotic stresses. In a previous transcriptome sequencing analysis of Lilium regale Wilson, we identified multiple WRKY TFs that respond to exogenous methyl jasmonate treatment and lily Fusarium wilt ( Fusarium oxysporum ). Results In the present study, the WRKY TF LrWRKY3 was further analyzed to reveal its function in defense response to F. oxysporum . The LrWRKY3 protein was localized in the plant cell nucleus, and LrWRKY3 transgenic tobacco lines showed higher resistance to F. oxysporum compared with wild-type (WT) tobacco. In addition, some genes related to jasmonic acid (JA) biosynthesis, salicylic acid (SA) signal transduction, and disease resistance had higher transcriptional levels in the LrWRKY3 transgenic tobacco lines than in the WT. On the contrary, L. regale scales transiently expressing LrWRKY3 RNA interference fragments showed higher sensitivity to F. oxysporum infection. Moreover, a F. oxysporum -induced defensin gene, Def1 , was isolated from L. regale , and the recombinant protein LrDef1 isolated and purified from Escherichia coli possessed antifungal activity to several phytopathogens, including F. oxysporum . Furthermore, co-expression of LrWRKY3 and the LrDef1 promoter in tobacco enhanced the LrDef1 promoter-driven expression activity. Conclusions These results clearly indicate that LrWRKY3 is an important positive regulator in response to F. oxysporum infection, and one of its targets is the antimicrobial peptide gene LrDef1 .

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Agriculture / Amino acids / Antifungal activity / Antifungal agents / antifungal properties / Antiinfectives and antibacterials / Antimicrobial peptides / Biomedical and Life Sciences / Biosynthesis / Botanical research / cell nucleus / Control / Defensin / Disease resistance / E coli / Escherichia coli / Fungal diseases of plants / Fungicides / Fusarium oxysporum / Fusarium wilt / Gene expression / genes / Genetic aspects / Genetic transcription / genetically modified organisms / growth and development / Infections / Jasmonic acid / Life Sciences / Lilium regale / Localization / Metabolites / Methyl jasmonate / Physiological aspects / Plant growth / Plant immunology / plant pathogens / Plant Sciences / Proteins / recombinant proteins / RNA interference / RNA-mediated interference / Salicylic acid / secondary metabolites / Sequence analysis / Signal transduction / Tobacco / transcription (genetics) / Transcription factors / Transcriptional regulation / transcriptome / Transcriptomes / Transgenic plants / Tree Biology / Wilt / WRKY transcription factor