Both TATA box and upstream regions are required for the nopaline synthase promoter activity in transformed tobacco cells

We studied cis regulatory elements controlling the light-dependent organ-speciflc expression of Arabidopsis thaliana chlorophyll a/b binding protein gene (cab)) by stably transforming tobacco plants using a tumor-inducing (Ti) plasmid vector system. The results from the 5' and internal deletion analyses indicate that there are at least three cis-acting elements that are involved in the light-dependent developmental expression of cab) gene. Two such elements are located at the immediate upstream regulatory region and the other element is located at the further upstream region. The 1120-base-pair (bp) DNA fragment containing the immediate and far upstream region can confer light-inducible organ specificity on the truncated nds promoter. However, deletion of the 39-bp DNA fragment at the immediate uplstream regulatory region from this hybrid promoter resulted in a nonfunctional promoter, revealing that the 39-bp region is important for the cab promoter specificity. Further analyses of this region suggest that a potential Z-DNA-forming sequence (ATACGTGT) is involved in light-dependent developmental expression of the cab) gene. Two additional Z-DNA-forming sequences (ACA-CATAT) that are inverted repeats of this sequence are also found in the upstream region where the additional regulatory elements are expected.Expression ofmany photosynthetic genes is highly specific to green tissues (1, 2) and the primary regulation of these genes occurs at the transcriptional level (3-7). Studies with ribulose-1,5-bisphosphate carboxylase/oxygenase (rbcS) gene indicate that several hundred base pairs ofthe DNA sequence preceding the coding region carry cis-acting elements, which are necessary for promoter regulation (8). In pea rbcS-3A gene this region is composed of multiple regulatory elements. Within the upstream enhancer region two light-responsive elements (box II and III) and their homologous sequences have been identified, with which trans-acting factors interact (9, 10). It has been suggested that positive and negative regulatory elements are involved in the control of the rbcS gene expression (9,11).Few studies have been made to define the cis regulatory elements involved in organ-specific expression of other photosynthetic genes. Expression of chlorophyll a/b binding protein (cab) gene, which is another family of photosynthetic genes, is also specific to green tissues. However, the expression pattern of the cab gene in plants is different from that of the rbcS under certain physiological conditions. For example, responses to light quality and diurnal rhythm are different between these two genes (2, 12). Sequence comparison of rbcS and cab upstream regions reveals no obvious homology, indicating that the expression of these two genes may be mediated by different regulatory mechanisms. Studies on wheat and pea cab genes indicate that an -250-base-pair (bp)

Section: Resultsmentioning

confidence: 99%

Identification of upstream regulatory elements involved in the developmental expression of the Arabidopsis thaliana cab1 gene.

1988

“…A 923-bp Taq 1/Sca I fragment carrying the proteinase inhibitor 11 5' control region was ligated with a truncated nopaline synthase (nos) promoter -101 (17) that was followed by the coding region of the CAT gene and the terminator of the transcript 6b gene (17). The 600 bp of stuffer sequence isolated from pUC plasmid was inserted between the proteinase inhibitor II and nos promoter to facilitate generation of deletion mutants.…”

Section: Methodsmentioning

confidence: 99%

Wound-inducible nuclear protein binds DNA fragments that regulate a proteinase inhibitor II gene from potato.

Palm

Costa

et al. 1990

“…In retransformation experiments, a fusion between domains of R and C1 (CRC) encoding the protein functions necessary to activate anthocyanin accumulation (28,29) was used as a marker to score transgenic calli, and the bar gene (30) was used for bialaphos selection. Promoters driving expression of visible marker genes included a doubleenhanced cauliflower mosaic virus (CaMV) 35S promoter (31), the nopaline synthase (Nos) promoter (32), and the maize ubiquitin (Ubi) promoter (33). Downstream 3Ј regions used in expression cassettes included those from a proteinase inhibitor (pinII; ref.…”

mentioning

confidence: 99%

Stimulation of the cell cycle and maize transformation by disruption of the plant retinoblastoma pathway

Gordon‐Kamm

Dilkes

Lowe

et al. 2002

The genome of the Mastreviruses encodes a replication-associated protein (RepA) that interacts with members of the plant retinoblastoma-related protein family, which are putative cell cycle regulators. Expression of ZmRb1, a maize retinoblastoma-related gene, and RepA inhibited and stimulated, respectively, cell division in tobacco cell cultures. The effect of RepA was mitigated by over-expression of ZmRb1. RepA increased transformation frequency and callus growth rate of high type II maize germplasm. RepA-containing transgenic maize calli remained embryogenic, were readily regenerable, and produced fertile plants that transmitted transgene expression in a Mendelian fashion. In high type II, transformation frequency increased with the strength of the promoter driving RepA expression. When a construct in which RepA was expressed behind its native LIR promoter was used, primary transformation frequencies did not improve for two elite Pioneer maize inbreds. However, when LIR:RepA-containing transgenic embryos were used in subsequent rounds of transformation, frequencies were higher in the RepA؉ embryos. These data demonstrate that RepA can stimulate cell division and callus growth in culture, and improve maize transformation.