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Mie Kasuga

Publications and source records attributed to Mie Kasuga.

6 recordsLinked to original sources
PubMed2006

Heterologous expression of the AtDREB1A gene in chrysanthemum increases drought and salt stress tolerance.

DNA cassette containing an AtDREB1A cDNA and a nos terminator, driven by a cauliflower mosaic 35S promoter, or a stress-inducible rd29A promoter, was transformed into the ground cover chrysanthemum (Dendranthema grandiflorum) 'Fall Color' genome. Compared with wild type plants, severe growth retardation was observed in 35S:DREB1A plants, but not in rd29A:DREB1A plants. RT-PCR analysis revealed that, under stress conditions, the DREB1A gene was over-expressed constitutively in 35S:DREB1A plants, but was over-expressed inductively in rd29A:DREB1A plants. The transgenic plants exhibited tolerance to drought and salt stress, and the tolerance was significantly stronger in rd29A:DREB1A plants than in 35S:DREB1A plants. Proline content and SOD activity were increased inductively in rd29A:DREB1A plants than in 35S:DREB1A plants under stress conditions. These results indicate that heterologous AtDREB1A can confer drought and salt tolerance in transgenic chrysanthemum, and improvement of the stress tolerance may be related to enhancement of proline content and SOD activity.

Arabidopsis↗
PubMed2004

A combination of the Arabidopsis DREB1A gene and stress-inducible rd29A promoter improved drought- and low-temperature stress tolerance in tobacco by gene transfer.

The transcription factor DREB1A/CBF3 specifically interacts with the dehydration responsive element (DRE/CRT) and induces expression of genes involved in environmental stress tolerance in Arabidopsis: Overexpression of DREB1A improved drought- and low-temperature stress tolerance in tobacco. The stress-inducible rd29A promoter minimized the negative effects on the plant growth in tobacco. Furthermore, we detected overexpression of stress-inducible target genes of DREB1A in tobacco. These results indicate that a combination of the rd29A promoter and DREB1A is useful for improvement of various kinds of transgenic plants that are tolerant to environmental stress.

Acclimatization↗
PubMed2004

Identification of cold-inducible downstream genes of the Arabidopsis DREB1A/CBF3 transcriptional factor using two microarray systems.

The transcriptional factor DREB/CBF (dehydration-responsive element/C-repeat-binding) specifically interacts with the dehydration-responsive element (DRE)/C-repeat (CRT) cis-acting element (A/GCCGAC) and controls the expression of many stress-inducible genes in Arabidopsis. Transgenic plants overexpressing DREB1A showed activated expression of many stress-inducible genes and improved tolerance to not only drought, salinity, and freezing but also growth retardation. We searched for downstream genes in transgenic plants overexpressing DREB1A using the full-length cDNA microarray and Affymetrix GeneChip array. We confirmed candidate genes selected by array analyses using RNA gel blot and identified 38 genes as the DREB1A downstream genes, including 20 unreported new downstream genes. Many of the products of these genes were proteins known to function against stress and were probably responsible for the stress tolerance of the transgenic plants. The downstream genes also included genes for protein factors involved in further regulation of signal transduction and gene expression in response to stress. The identified genes were classified into direct downstream genes of DREB1A and the others based on their expression patterns in response to cold stress. We also searched for conserved sequences in the promoter regions of the direct downstream genes and found A/GCCGACNT in their promoter regions from -51 to -450 as a consensus DRE. The recombinant DREB1A protein bound to A/GCCGACNT more efficiently than to A/GCCGACNA/G/C.

Arabidopsis↗
PubMed2003

OsDREB genes in rice, Oryza sativa L., encode transcription activators that function in drought-, high-salt- and cold-responsive gene expression.

The transcription factors DREBs/CBFs specifically interact with the dehydration-responsive element/C-repeat (DRE/CRT) cis-acting element (core motif: G/ACCGAC) and control the expression of many stress-inducible genes in Arabidopsis. In rice, we isolated five cDNAs for DREB homologs: OsDREB1A, OsDREB1B, OsDREB1C, OsDREB1D, and OsDREB2A. Expression of OsDREB1A and OsDREB1B was induced by cold, whereas expression of OsDREB2A was induced by dehydration and high-salt stresses. The OsDREB1A and OsDREB2A proteins specifically bound to DRE and activated the transcription of the GUS reporter gene driven by DRE in rice protoplasts. Over-expression of OsDREB1A in transgenic Arabidopsis induced over-expression of target stress-inducible genes of Arabidopsis DREB1A resulting in plants with higher tolerance to drought, high-salt, and freezing stresses. This indicated that OsDREB1A has functional similarity to DREB1A. However, in microarray and RNA blot analyses, some stress-inducible target genes of the DREB1A proteins that have only ACCGAC as DRE were not over-expressed in the OsDREB1A transgenic Arabidopsis. The OsDREB1A protein bound to GCCGAC more preferentially than to ACCGAC whereas the DREB1A proteins bound to both GCCGAC and ACCGAC efficiently. The structures of DREB1-type ERF/AP2 domains in monocots are closely related to each other as compared with that in the dicots. OsDREB1A is potentially useful for producing transgenic monocots that are tolerant to drought, high-salt, and/or cold stresses.

Adaptation, Physiological↗
PubMed2002

Important roles of drought- and cold-inducible genes for galactinol synthase in stress tolerance in Arabidopsis thaliana.

Raffinose family oligosaccharides (RFO) accumulating during seed development are thought to play a role in the desiccation tolerance of seeds. However, the functions of RFO in desiccation tolerance have not been elucidated. Here we examine the functions of RFO in Arabidopsis thaliana plants under drought- and cold-stress conditions, based on the analyses of function and expression of genes involved in RFO biosynthesis. Sugar analysis showed that drought-, high salinity- and cold-treated Arabidopsis plants accumulate a large amount of raffinose and galactinol, but not stachyose. Raffinose and galactinol were not detected in unstressed plants. This suggests that raffinose and galactinol are involved in tolerance to drought, high salinity and cold stresses. Galactinol synthase (GolS) catalyses the first step in the biosynthesis of RFO from UDP-galactose. We identified three stress-responsive GolS genes (AtGolS1, 2 and 3) among seven Arabidopsis GolS genes. AtGolS1 and 2 were induced by drought and high-salinity stresses, but not by cold stress. By contrast, AtGolS3 was induced by cold stress but not by drought or salt stress. All the GST fusion proteins of GST-AtGolS1, 2 and 3 expressed in Escherichia coli had galactinol synthase activities. Overexpression of AtGolS2 in transgenic Arabidopsis caused an increase in endogenous galactinol and raffinose, and showed reduced transpiration from leaves to improve drought tolerance. These results show that stress-inducible galactinol synthase plays a key role in the accumulation of galactinol and raffinose under abiotic stress conditions, and that galactinol and raffinose may function as osmoprotectants in drought-stress tolerance of plants.

Acclimatization↗