Identification of three kinds of mutually related composite elements conferring S phase‐specific transcriptional activation

Abstract

Summary Conservation of the Oct motif (CGCGGATC) is a remarkable feature of plant histone gene promoters. Many of the Oct motifs are paired with a distinct motif, Hex, TCA or CCAAT‐box, constituting the type I element (CCACGTCANCGATCCGCG), type II element (TCACGCGGATC) and type III element (GATCCGCG‐N14‐ACCAATCA). To clarify the roles of these Oct‐containing composite elements (OCEs) in cell cycle‐dependent and tissue‐specific expression, we performed gain‐of‐function experiments with transgenic tobacco cell lines and plants harboring a derivative of the 35S core promoter/β‐glucuronidase fusion gene in which three or four copies of an OCE had been placed upstream. Although their activities were slightly different, results showed that each of the three types of OCEs could confer the ability to direct S phase‐specific expression on a heterologous promoter. In transgenic plants, the type I and III elements exhibited a similar activity, directing expression in meristematic tissues, whereas the activity of the type II element appeared to be restricted to young cotyledons and maturating guard cells. Mutational analyses demonstrated that the co‐operation of Oct with another module (Hex, TCA or CCAAT‐box) was absolutely required for both temporal and spatial regulation. Thus, OCEs play a pivotal role in regulation of the expression of plant histone genes.

Transcriptional Dynamics Driving MAMP-Triggered Immunity and Pathogen Effector-Mediated Immunosuppression in Arabidopsis Leaves Following Infection with Pseudomonas syringae pv tomato DC3000

“…MEME analysis (Bailey et al, 2006) revealed that promoter sequences of five of these eight genes contained a paired Oct-TCA motif in close proximity to the transcriptional start site. This motif, originally identified in tobacco histone genes, has been shown to confer S phasespecific transcriptional activation (Taoka et al, 1999). These data suggest that effectors either directly bind to Oct-TCA and neighboring motifs or recruit/maintain transcriptional repressors on the promoters of these histones.…”

“…The DC3000-DC3000hrpA-comparison ( Figure 6C) highlights clusters that have combinatorial overrepresented motifs: WRKY (Eulgem et al, 1999), tll (Noyes et al, 2008b), and exd (Noyes et al, 2008a) motifs in cluster 11; and NF-Y (Mantovani, 1998) and two histone OCTAMER (Taoka et al, 1999) motifs in cluster 5 revealing a set of motifs that appear to recruit TFs that are central to ETS. Thus, both our targeted analysis of effector-suppressed genes and untargeted global motif analysis suggest effectors specifically target a subset of genes with OCT motifs.…”

Highly specific targeted mutagenesis in plants using Staphylococcus aureus Cas9

“…Petit Havana SR-1) was transformed via Agrobacterium-mediated transformation as described previously38. Transgenic tobacco plants were regenerated from leaf disks on medium containing 50 mg/L kanamycin (Wako Pure Chemicals, Japan) and 25 mg/L meropenem.…”

Transcriptional Control of the Plant Cell Cycle

“…These are at present only defined by the cisregulatory elements identified in promoters of some periodically expressed genes and not yet conclusively by the cognate proteins that bind these elements. These are: (i) expression of histone genes in S-phase depends on octamer (OCT) and hexamer (HEX) motifs (Chaubet et al 1996;Taoka et al 1999;Minami et al 2000); (ii) the promoters of many genes that are up-regulated at G1/S or in S-phase contain motifs known to bind E2F/DP factors (RamirezParra et al 2003;Vandepoele et al 2005); and (iii) expression of some genes at G2/M depends on MSA elements, to which a class of transcription factors with three repeats of the canonical Myb-type DNA binding motif bind (3RMybs) (Ito et al 1998(Ito et al , 2001). However, with the exception of the latter class of Mybtype transcription factors (Ito et al 2001;Haga et al 2007), far too little is known about the transcription factors that comprise the regulatory network responsible for cell cycle phase-specific gene expression in plants.…”