Cloning And Functional Characterization Of LrABCF1 From Lilium Regale

ATP-binding cassette(ABC)transporter family is a kind of membrane translocation protein.It is related to plant ion transport,lipid transport,foreign transport transshipment,and secondary metabolites in diverse biological processes.ABC transporters family can be divided into two types,total transporters and half transporters.This study selected and investigated a class of ABC transporter F subfamily-GCN(general control non-derepressible).LrABCF1,which is belonged to GCN type,was identified from Cucumber mosaic virus(CMV)-induced cDNA library of L.regale.LrABCF1 overexpression conferred reduced susceptibility to CMV,Tobacco rattle virus(TRV),and Botrytis cinerea infection in transgenic petunia plants.The expression level of LrABCF1 in L.regale?L.leucanthum?L.lancifolium?L.brownii?L.pumilum?L.duchartrei?L.leichtlinii?L.dauricum?L.davidii?L.sulphureum after inoculation with CMV and Lily mottle virus(LMoV)were tested then found that LrABCF1 was up-regulated.Its maximum induction was observed in L.regale rather than other 9 wild Lilium species.Stress-related hormone salicylic acid(SA)and ethylene(ET),as well as the treatment of abiotic stresses,including cold,high salinity,and wounding,increased the transcript abundances of LrABCF1.Through the RACE method,we cloned the L.regale LrABCF1 full-length gene sequence.The complete LrABCF1 cDNA had a total 2,087 bp length containing a predicted 1,779 bp open reading frame(ORF),which encodes a protein of 592 amino acids.Amino acid alignment and phylogenetic tree analysis showed that LrABCF1 shared high similarity with OsABCF1 in rice and AtGCN1 in Arabidopsis.LrABCF1 overexpression conferred a decreased speed of plant growth in transgenic petunia plants,accompanying by elevated transcripts of PhGCN2 and a few defense-related genes in SA-signaling pathway.Taken together,our results indicate that LrABCF1 probably plays an essential role in lily plant resistance to viral and fungal pathogens.