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61.
Cloning and identification of the promoter of the tobacco Sar8.2b gene,a gene involved in systemic acquired resistance 总被引:4,自引:0,他引:4
Expression of the Sar8.2 gene family is induced by salicylic acid (SA) in tobacco during induction of systemic acquired resistance. Expression of Sar8.2b, one member of this 12-member family, was detected as early as 12 h after treatment with SA and was maximal 36 h after SA treatment. In NahG transgenic tobacco plants, benzothiadiazole and dichloroisonicotinic acid induced expression of Sar8.2b but SA did not, suggesting that expression of the Sar8.2b gene is SA-dependent. Several putative cis-acting elements were found in the Sar8.2b gene promoter region, including an as-1 element and GT-1 and Dof binding sequences. We constructed a series of progressive deletion mutations in the Sar8.2b promoter region linked to the β-glucuronidase (GUS) coding region and analyzed GUS activities by stable expression in transformants of Arabidopsis thaliana. Deletions between −728 and −927 bp or between −351 and −197 bp of the promoter region resulted in a significant reduction in GUS activity induced by SA treatment as shown in stable transformants of A. thaliana. The −197 bp fragment of the promoter region was found to confer a relatively low level of GUS activity induced by SA treatment in stable expression of transformants in A. thaliana. The results suggest that 927 bp of the Sar8.2b gene promoter confers full promoter activity and that cis-acting elements required for high-level SA-inducible expression of the Sar8.2b gene may exist within the regions −728 to −927 bp and −197 to −351 bp. 相似文献
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High intensity and blue light regulated expression of chimeric chalcone synthase genes in transgenic Arabidopsis thaliana plants 总被引:10,自引:0,他引:10
Rhonda L. Feinbaum Gisela Storz Frederick M. Ausubel 《Molecular & general genetics : MGG》1991,226(3):449-456
Summary To establish a genetic system for dissection of light-mediated signal transduction in plants, we analyzed the light wavelengths and promoter sequences responsible for the light-induced expression of the Arabidopsis thaliana chalcone synthase (CHS) promoter fused to the -glucuronidase (GUS) marker gene. Transgenic A. thaliana lines carrying 1975, 523, 186, and 17 by of the CHS promoter fused to the GUS gene were generated, and the expression of these chimeric genes was monitored in response to high intensity light in mature plants and to different wavelengths of light in seedlings. Fusion constructs containing 1975 and 523 by of CHS promoter sequence behaved identically to the endogenous CHS gene under all conditions. Expression of these constructs was induced specifically in response to high intensity white light and blue light. The response to blue light was seen in the presence of the Pfr form of phytochrome. Fusion constructs containing 186 by of promoter sequence showed reduced basal levels of expression and only weak stimulation by blue light but were induced significantly by high intensity white light. These analyses showed that the expression of the A. thaliana CHS gene is responsive to a specific blue light receptor and that sequences between — 523 and — 186 by are required for optimal basal and blue light-induced expression of this gene. The experiments lay the foundation for a simple genetic screen for light response mutants. 相似文献
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Promoters play key roles in conferring temporal, spatial, chemical, developmental, or environmental regulation of gene expression.
Promoters that are subject to specific regulations are useful for manipulating foreign gene expression in plant cells, tissues,
or organs with desirable patterns and under controlled conditions, and have been important for both basic research and applications
in agriculture biotechnology. Recent advances in genomics technologies have greatly facilitated identification and study of
promoters in a genome scale with high efficiency. Previously we have generated a large T-DNA tagged rice mutant library (TRIM),
in which the T-DNA was designed with a gene/promoter trap system, by placing a promoter-less GUS gene next to the right border of T-DNA. GUS activity screens of this library offer in situ and in planta identifications
and analyses of promoter activities in their native configurations in the rice genome. In the present study, we systematically
performed GUS activity screens of the rice mutant library for genes/promoters constitutively, differentially, or specifically
active in vegetative and reproductive tissues. More than 8,200 lines have been screened, and 11% and 22% of them displayed
GUS staining in vegetative tissues and in flowers, respectively. Among the vegetative tissue active promoters, the ratio of
leaf active versus root active is about 1.6. Interestingly, all the flower active promoters are anther active, but with varied
activities in different flower tissues. To identify tissue specific ABA/stress up-regulated promoters, we compared microarray
data of ABA/stress induced genes with those of tissue-specific expression determined by promoter trap GUS staining. Following
this approach, we showed that the peroxidase 1 gene promoter was ABA up-regulated by 4 fold within 1 day of exposure to ABA and its expression is lateral root specific.
We suggest that this be an easy bioinformatics approach in identifying tissue/cell type specific promoters that are up-regulated
by hormones or other factors.
Su-May Yu and Swee-Suak Ko equally contributed to this work. 相似文献
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为研究玉米(Zeamays L.)19kD醇溶贮藏蛋白(zein)基因启动子种子特异性表达的控制区段,将全长694bp的启动子进行5’端缺失,共得到6个缺失突变体,长度分别为488bp、378bp、302bp、152bp、124bp和85bp。将6个片段分别与报告基因gus连接构建成表达载体pDGB系列,经土壤农杆菌(Agrobacterium)介导转化,引入烟草。GUS活性检测证明,488bp启动子片段能促使gus基因在种子中特异表达。378bp、302bp、152bp和124bp片段启动子引导的gus基因在烟草根、叶柄、种子中均可表达。 相似文献