Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

CBF/DREB (C-repeat binding factor/dehydration responsive element binding factor) family of transcription factors in plants is reported to be associated with regulation of gene expression under stress conditions. Here, we report the functional characterization of a DREB transcription factor, DREB1B gene from rice (Oryza sativa ssp. indica). The OsDREB1B gene was differentially regulated at the transcriptional level by osmotic stress, oxidative stress, salicylic acid, ABA, and cold. A 745 bp promoter region of OsDREB1B cDNA was fused to the beta-glucuronidase (GUS) gene and introduced via Agrobacterium tumifaciens into the genome of Arabidopsis. Histochemical analysis of GUS expression in T(2) transgenic Arabidopsis plants indicated that OsDREB1B shows stress-specific induction pattern in response to a variety of stresses like mannitol, NaCl, PEG, methyl viologen, cold, ABA, and salicylic acid. Leaf-order-dependent induction pattern of the promoter was observed in response to both cold and ABA stresses. Further, OsDREB1B cDNA was introduced into tobacco plants under the control of CaMV35S promoter to investigate the role of DREB1B product in plant stress response. Transgenic tobacco plants have shown improved seed germination, root growth, membrane stability, and 2, 2-diphenyl-1-pycrilhydrazil hydrate (DPPH) free radical scavenging activity under inhibitory concentrations of mannitol. Importantly, transgenic plants accumulated higher fresh weight under long-term osmotic stress, and also have shown retention of more water than the wild type during drought stress. Overexpression of OsDREB1B in tobacco also improved the oxidative and freezing stress tolerance of transgenic plants. In addition, tobacco plants constitutively expressing OsDREB1B have shown decreased sensitivity to tobacco streak virus infection. Constitutive expression of OsDREB1B in tobacco also induced the expression of PR genes in transgenic plants. The data obtained provide strong in vivo evidence that OsDREB1B is involved in both abiotic and biotic stress responses, and confers broad-spectrum stress tolerance to transgenic plants.
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PMID:Rice DREB1B promoter shows distinct stress-specific responses, and the overexpression of cDNA in tobacco confers improved abiotic and biotic stress tolerance. 1875 79

We had previously identified the MYBC1 gene, which encodes a single-repeat R3-MYB protein, as a putative osmotic responding gene; however, no R3-MYB transcription factor has been reported to regulate osmotic stress tolerance. Thus, we sought to elucidate the function of MYBC1 in response to osmotic stresses. Real-time RT-PCR analysis indicated that MYBC1 expression responded to cold, dehydration, salinity and exogenous ABA at the transcript level. mybc1 mutants exhibited an increased tolerance to freezing stress, whereas 35S::MYBC1 transgenic plants exhibited decreased cold tolerance. Transcript levels of some cold-responsive genes, including CBF/DREB genes, KIN1, ADC1, ADC2 and ZAT12, though, were not altered in the mybc1 mutants or the 35S::MYBC1 transgenic plants in response to cold stress, as compared to the wild type. Microarray analysis results that are publically available were investigated and found transcript level of MYBC1 was not altered by overexpression of CBF1, CBF2, and CBF3, suggesting that MYBC1 is not down regulated by these CBF family members. Together, these results suggested that MYBC1is capable of negatively regulating the freezing tolerance of Arabidopsis in the CBF-independent pathway. In transgenic Arabidopsis carrying an MYBC1 promoter driven beta-glucuronidase (GUS) construct, GUS activity was observed in all tissues and was relatively stronger in the vascular tissues. Fused MYBC1 and GFP protein revealed that MYBC1 was localized exclusively in the nuclear compartment.
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PMID:A single-repeat R3-MYB transcription factor MYBC1 negatively regulates freezing tolerance in Arabidopsis. 2033 73