A novel transcription factor involved in plant defense endowed with protein phosphatase activity

Open Access
Publisher Website
Google Scholar
Abstract
In plants, expression of a disease‐resistance character following perception of a pathogen involves massive deployment of transcription‐dependent defenses. Thus, if rapid and effective defense responses have to be achieved, it is crucial that the pathogenic signal is transduced and amplified through pre‐existing signaling pathways. Reversible phosphorylation of specific transcription factors, by a concerted action of protein kinases and phosphatases, may represent a mechanism for rapid and flexible regulation of selective gene expression by environmental stimuli. Here we identified a novel DNA‐binding protein from tobacco plants, designated DBP1, with protein phosphatase activity, which binds in a sequence‐specific manner to a cis ‐ acting element of a defense‐related gene and participates in its transcriptional regulation. This finding helps delineate a terminal event in a signaling pathway for the selective activation of early transcription‐dependent defense responses in plants, and suggests that stimulus‐dependent reversible phosphorylation of regulatory proteins may occur directly in a transcription protein–DNA complex.