Expression of a higher-plant chloroplast psbD promoter in a cyanobacterium ( Synechococcus sp. strain PCC7942) reveals a conserved cis-element, designated PGT, that differentially interacts with sequence-specific binding factors during leaf development

Christopher, David A.; Shen, Yanxin; Dudley, P; Tsinoremas, Nicholas F.

doi:10.1007/s002940050465

Cited by 3 publications

(1 citation statement)

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“…and Nostoc punctiforme ). The distance‐based phylogenetic analysis of complete chloroplastic and bacterial genomes showed that the chloroplast genomes were most closely related to Cyanobacteria (Chu et al , 2004) and chloroplast promoters were shown to initiate gene expression in Cyanobacteria (Dzelzkalns et al , 1984; Christopher et al , 1999). Consequently, homologous recombination could theoretically occur in these strains.…”

Section: Resultsmentioning

confidence: 99%

Exploration of horizontal gene transfer between transplastomic tobacco and plant-associated bacteria

Demanèche¹,

Monier²,

Dugat-Bony³

et al. 2011

FEMS Microbiology Ecology

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The likelihood of gene transfer from transgenic plants to bacteria is dependent on the transgene copy number and on the presence of homologous sequences for recombination. The large number of chloroplast genomes in a plant cell as well as the prokaryotic origin of the transgene may thus significantly increase the likelihood of gene transfer from transplastomic plants to bacteria. In order to assess the probability of such a transfer, bacterial isolates, screened for their ability to colonize decaying tobacco plant tissue and possessing DNA sequence similarity to the chloroplastic genes accD and rbcL flanking the transgene (aadA), were tested for their ability to take up extracellular DNA (broad host-range pBBR1MCS-3-derived plasmid, transplastomic plant DNA and PCR products containing the genes accD-aadA-rbcL) by natural or electrotransformation. The results showed that among the 16 bacterial isolates tested, six were able to accept foreign DNA and acquire the spectinomycin resistance conferred by the aadA gene on plasmid, but none of them managed to integrate transgenic DNA in their chromosome. Our results provide no indication that the theoretical gene transfer-enhancing properties of transplastomic plants cause horizontal gene transfer at rates above those found in other studies with nuclear transgenes.

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Section: Resultsmentioning

confidence: 99%

Exploration of horizontal gene transfer between transplastomic tobacco and plant-associated bacteria

Demanèche¹,

Monier²,

Dugat-Bony³

et al. 2011

FEMS Microbiology Ecology

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Thum

Kim

Morishige

et al. 2001

Plant Molecular Biology

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The plastid gene psbD encodes D2, a photosystem II reaction center chlorophyll-binding protein. psbD is transcribed from a conserved chloroplast promoter that is activated by blue, white, or UV-A light. In this study, various forms of the barley (Hordeum vulgare L.) chloroplast psbD-LRP were fused to the uidA reporter gene and introduced into the tobacco (Nicotiana tabacum L.) plastid genome through homologous recombination. Primer extension analysis of transcripts from the psbD-LRP-uidA construct showed that the barley psbD-LRP was activated in tobacco by blue or white light. Transcription from this construct was also regulated by circadian cycling indicating that the barley psbD-LRP could respond to light modulated regulatory pathways in tobacco. Mutation of the psbD-LRP prokaryotic -10 promoter element reduced transcription to very low levels in all light regimes. In contrast, mutation of a prokaryotic -35 promoter element had no effect on transcription from the psbD-LRP. Deletion or mutation of an upstream activating element, the AAG-box (-36 to -64), also reduced transcription from the construct to very low levels. In contrast, deletion of the upstream PGT-box (-71 to -100) did not alter promoter activation by blue light, or responsiveness to circadian cycling. These in vivo studies confirm the importance of the psbD-LRP -10 promoter element and AAG-box in light regulation and demonstrate that these elements are sufficient to mediate circadian cycling of the barley psbD promoter.

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Involvement of a Nuclear-Encoded Basic Helix-Loop-Helix Protein in Transcription of the Light-Responsive Promoter ofpsbD

et al. 2001

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In the chloroplast psbD light-responsive promoter (LRP), a highly conserved sequence exists upstream from the bacterial Ϫ10/Ϫ35 elements. Multiple sequence-specific DNA binding proteins are predicted to bind to the conserved sequence as transcription factors. Using yeast one-hybrid screening of an Arabidopsis cDNA library, a possible DNA binding protein of the psbD LRP upstream sequence was identified. The protein, designated PTF1, is a novel protein of 355 amino acids (estimated molecular weight of 39.6) that contains a basic helix-loop-helix DNA binding motif in the predicted N-terminal region of the mature protein. Transient expression assay of PTF1-GFP fusion protein showed that PTF1 was localized in chloroplasts. Using the modified DNA sequence in the one-hybrid system, the ACC repeat was shown to be essential for PTF1 binding. The rate of psbD LRP mRNA accumulation was reduced in a T-DNA-inserted Arabidopsis ptf1 mutant. Compared with wild-type plants, the mutant had pale green cotyledons and its growth was inhibited under short-day conditions. These results suggest that PTF1 is a trans-acting factor of the psbD LRP.In the early stage of light-induced chloroplast development, the transcription activity of chloroplast genes increases, leading to increased mRNA accumulation (Klein and Mullet, 1990;Rapp et al., 1992; DuBell and Mullet, 1995). Transcription rates vary among promoters, and in most cases, they reflect the amount of transcripts and the stoichiometric composition of proteins (Rapp et al., 1992). Although mRNA stability is an important regulatory factor in mature chloroplasts (Kawaguchi et al., 1992; Kim et al., 1993;Staub and Maliga, 1993;Shiina et al., 1998), the transcription rate plays a primary role in controlling gene expression in developing chloroplasts (for review, see Mullet, 1993; Mayfield et al., 1995;Stern et al., 1997).Recent studies have clarified many of the molecular mechanisms of transcriptional regulation in plastids by successive cloning of RNA polymerase core and accessory subunits for plastid transcription (for review, see Maliga, 1998; Hess and Bö rner, 1999). One is nuclear-encoded bacteriophage-type RNA polymerase (Hedtke et al., 1997), which functions in transcription from the nuclear-encoded bacteriophage-type RNA polymerase promoters that exist in most nonphotosynthetic genes (Hajdukiewicz et al., 1997; Kapoor et al., 1997). On the other hand, many plastid genes have eubacterial 70 -type promoters, which are preceded by "Ϫ10" and "Ϫ35" elements (consensus TATAAT and TTGACA, respectively; Hanley- Bowdoin and Chua, 1987; Igloi and Kö ssel, 1992). These promoters are recognized by plastid-encoded RNA polymerase (PEP), which is composed of plastid-encoded catalytic core subunits associated with nuclear-encoded subunits (for review, see Link, 1996;Maliga, 1998; and Hess and Bö rner, 1999). Many plastid-factors have been cloned in higher plants (Isono et al., 1997;Tanaka et al., 1997; Kestermann et al., 1998;Tozawa et al., 1998). As in bacterial RNA polymerase, plastid-fac...

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Expression of a higher-plant chloroplast psbD promoter in a cyanobacterium ( Synechococcus sp. strain PCC7942) reveals a conserved cis-element, designated PGT, that differentially interacts with sequence-specific binding factors during leaf development

Cited by 3 publications

References 48 publications

Exploration of horizontal gene transfer between transplastomic tobacco and plant-associated bacteria

Exploration of horizontal gene transfer between transplastomic tobacco and plant-associated bacteria

Untitled

Involvement of a Nuclear-Encoded Basic Helix-Loop-Helix Protein in Transcription of the Light-Responsive Promoter ofpsbD

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