Abstract

TFIIIA is a zinc-finger transcription factor that is involved in post-transcriptional regulation during development. Here, theBcTFIIIAgene was isolated from pak choi. Sequence analysis showed thatBcTFIIIAencodes 383 amino acids (aa) with an open reading frame (ORF) of 1152 base pairs (bp). We investigated the subcellular location of BcTFIIIA and found the localized protein in the nucleus.BcTFIIIAwas suppressed when the pak choi was infected by the turnip mosaic virus (TuMV). TheBcTFIIIAmRNA expression level in a resistant variety was higher than that in a sensitive variety, as determined by qRT-PCR analysis. Yeast two hybrid (Y2H) assay and bimolecular fluorescence complementation (BiFC) suggested that BcTFIIIA interacts with TuMV CP and VPg in vivo, respectively, and in vitro. A virus-induced gene silencing (VIGS) experiment showed that the silencing ofBcTFIIIAgene expression in pak choi promoted the accumulation of TuMV. These results suggest that BcTFIIIA negatively regulates viral infection through the interaction with TuMV CP and VPg.Keywords:BcTFIIIA;turnip mosaic virus;disease resistance;pak choi