• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.150-150
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• 2017

Plants suffer from various abiotic stresses among them; soil salinity is one of major adverse factor in declining agricultural productivity. So, development of salt stress tolerance crops have potential role to increase crop production. The RING finger proteins are known to play crucial roles in abiotic stress environment to plants. In this study, we identified one Salt-responsive Really${\underline{I}nteresting}$ ${\underline{n}ew}$ ${\underline{g}ene}$ (RING) E3 ubiquitin ligase gene OsSIRF1 from rice root tissues during salt stress and studied its molecular function. Expression of OsSIRF1 was induced under various abiotic stress conditions, including salt, heat, drought, and ABA. Result of an in vitro ubiquitination assay clearly showed that OsSIRF1 Possess an E3 ligase activity. Moreover, OsSIRF1 was found to be localized to the nucleus within the cell. Heterogeneous overexpression of OsSIRF1 in Arabidopsis improved seed germination and increased root length under salt and Manitol stress conditions. Taking together, these results suggested that OsSIRF1 may be associated with plant responses to abiotic stressors and positively regulates salt and osmotic stress environment.

• Animal cells and systems
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• v.2 no.2
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• pp.239-242
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• 1998

Arabidopsis trp1 mutant plants, deficient in phosphoribosyI anthranilate transferase (PAT) activity, accumulate anthranilate compounds, which render them blue fluorescence. The visible phenotype of trp1 makes the PAT gene an excellent reporter gene in the mutant. In order to develop a system for the homologous recombination using the phenotypic characteristic of trp1-100, we established optimum conditions for the isolation and regenera tion of protoplast from auxin-conditioned, trp1-100 root cultures. Trvptophan had to be supplemented in the germination medium for the efficient cell division and subsequent plant regeneration. When 10 uM tryptophan was added to the germination medium, we obtained the highest yield of protoplasts ($3{\times}10^6 cells/g$) and the best viability (92%). Thirty percent of root protoplast derived from meristematic cells underwent cell division within 5 days in callus-induction medium. Regenerated rosette leaves (2-3 mm) were transferred to rooting medium and finally acclimated to the soil for flowering.

• Journal of Environmental Science International
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• v.13 no.12
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• pp.1103-1108
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• 2004

This experiment was carried out to investigate the effects of cadmium on the growth of Arabidopsis thaliana when they were treated with different concentrations of cadmium. The growth of stem was stimulated in the concentrations up to fifty times higher than the official standard concentration of cadmium of pollutant exhaust notified by the Ministry of Environment, but it decreased in the concentration one hundred fifty times or more higher in proportion to the degree of concentration. The growth of root was similar to that of stem, except that the decrease was gradual in the concentration fifty times or more higher. The growth of leaf was almost the same as that of stem, that is, it was stimulated the increase of leaf surface area in the concentration fifty times higher, but decreased in the concentration one hundred fifty times or more higher in proportion to the degree of concentration. The fresh weights of the plants were increased in accord with the degree of growth of the stem and leaf. Concentration of cadmium accumulated in the plants was increased in proportion to the concentration of cadmium. These results show that the growth of plants was stimulated in the soil polluted by cadmium up to fifty times higher than the official standard concentration, but it was decreased in proportion to the degree of concentration in the plants grown in the presence of cadmium more than one hundred fifty times.

• Molecules and Cells
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• v.39 no.7
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• pp.524-529
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• 2016

Controlling the production of diverse cell/tissue types is essential for the development of multicellular organisms such as animals and plants. The Arabidopsis thaliana root, which contains distinct cells/tissues along longitudinal and radial axes, has served as an elegant model to investigate how genetic programs and environmental signals interact to produce different cell/tissue types. In the root, a series of asymmetric cell divisions (ACDs) give rise to three ground tissue layers at maturity (endodermis, middle cortex, and cortex). Because the middle cortex is formed by a periclinal (parallel to the axis) ACD of the endodermis around 7 to 14 days post-germination, middle cortex formation is used as a parameter to assess maturation of the root ground tissue. Molecular, genetic, and physiological studies have revealed that the control of the timing and extent of middle cortex formation during root maturation relies on the interaction of plant hormones and transcription factors. In particular, abscisic acid and gibberellin act synergistically to regulate the timing and extent of middle cortex formation, unlike their typical antagonism. The SHORT-ROOT, SCARECROW, SCARECROW-LIKE 3, and DELLA transcription factors, all of which belong to the plant-specific GRAS family, play key roles in the regulation of middle cortex formation. Recently, two additional transcription factors, SEUSS and GA- AND ABA-RESPONSIVE ZINC FINGER, have also been characterized during ground tissue maturation. In this review, we provide a detailed account of the regulatory networks that control the timing and extent of middle cortex formation during post-embryonic root development.

• Molecules and Cells
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• v.21 no.1
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• pp.141-146
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• 2006

We previously showed that NtCDPK1, a tobacco calcium-dependent protein kinase, interacts with and phosphorylates the Rpn3 regulatory subunit of the 26S proteasome, and that both NtCDPK1 and Rpn3 are mainly expressed in rapidly proliferating tissues, including shoot and root meristem. In this study, we examined NtCDPK1 expression in roots using GUS expression in transgenic Arabidopsis plants, and investigated its function in root development by generating transgenic tobacco plants carrying a sense NtCDPK1 transgene. GUS activity was first detected in roots two days after sowing. In later stages, strong GUS expression was detected in the root meristem and elongation zone, as well as the initiation sites and branch points of lateral roots. Transgenic tobacco plants in which NtCDPK1 expression was suppressed were smaller, and their root development was abnormal, with reduced lateral root formation and less elongation. These results suggest that NtCDPK1 plays a role in a signaling pathway regulating root development in tobacco.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.415-421
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• 2000

The disaccharide trehalose ($\alpha$-D-glucopyranosyl-$\alpha$-D-glucopyranoside) is found in variety of organ-isms that are able to withstand almost complete desiccation. In order to identify the function of trehalose in plants, we isolated Arabidopsis trehalase (AtTRE) gene that encodes the enzyme able to hydrolyze trehalose to glucose, and trehalose-6-phosphate synthase isolog, TPS3 gene by RT-PCR. The AtTRE had the substrate specificity to hydrolyze only trehalose, and a broad pH range of enzyme activity. The AtTRE promoter/GUS reporter gene was expressed in cotyledons, mature leaf tissues including guard cells, and developing siliques. The GUS expression driven by AtTPS3 promoter was significant in root tissues, and the level of GUS activity was much higher than that of the pBll 21 control seedlings. The knockout of AtTPS3 gene in Arabidopsis resulted in the retarded root development, whereas the overexpression of AtTPS3 increased the root elongation in the presence of sucrose in MS medium. Possible functions of AtTRE and AtTPS3 in plant will be discussed. In addition, ectopic expression of yeast TPS1 driven by the inducible promoters in tobacco and potato conferred the plants on the drought and freezing tolerances.

• The Plant Pathology Journal
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• v.29 no.2
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• pp.209-220
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• 2013

Root colonization by Pseudomonas chlororaphis O6 induces systemic drought tolerance in Arabidopsis thaliana. Microarray analysis was performed using the 22,800-gene Affymetrix GeneChips to identify differentially-expressed genes from plants colonized with or without P. chlororaphis O6 under drought stressed conditions or normal growth conditions. Root colonization in plants grown under regular irrigation condition increased transcript accumulation from genes associated with defense, response to reactive oxygen species, and auxin- and jasmonic acid-responsive genes, but decreased transcription factors associated with ethylene and abscisic acid signaling. The cluster of genes involved in plant disease resistance were up-regulated, but the set of drought signaling response genes were down-regulated in the P. chlororaphis O6-colonized under drought stress plants compared to those of the drought stressed plants without bacterial treatment. Transcripts of the jasmonic acid-marker genes, VSP1 and pdf-1.2, the salicylic acid regulated gene, PR-1, and the ethylene-response gene, HEL, also were up-regulated in plants colonized by P. chlororaphis O6, but differed in their responsiveness to drought stress. These data show how gene expression in plants lacking adequate water can be remarkably influenced by microbial colonization leading to plant protection, and the activation of the plant defense signal pathway induced by root colonization of P. chlororaphis O6 might be a key element for induced systemic tolerance by microbes.

• Molecules and Cells
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• v.23 no.1
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• pp.115-121
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• 2007

Root nodule formation is controlled by plant hormones such as auxin. Auxin-repressed protein (ARP) genes have been identified in various plant species but their functions are not clear. We have isolated a full-length cDNA clone (EuNOD-ARP1) showing high sequence homology to previously identified ARP genes from root nodules of Elaeagnus umbellata. Genomic Southern hybridization showed that there are at least four ARP-related genes in the genome of E. umbellata. The cDNA clone encodes a polypeptide of 120 amino acid residues with no signal peptide or organelle-targeting signals, indicating that it is a cytosolic protein. Its cytosolic location was confirmed using Arabidopsis protoplasts expressing a EuNOD-ARP1:smGFP fusion protein. Northern hybridization showed that EuNOD-ARP1 expression was higher in root nodules than in leaves or uninoculated roots. Unlike the ARP genes of strawberry and black locust, which are negatively regulated by exogenous auxin, EuNOD-ARP1 expression is induced by auxin in leaf tissue of E. umbellata. In situ hybridization revealed that EuNOD-ARP1 is mainly expressed in the fixation zone of root nodules.

• Plant Biotechnology Reports
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• v.5 no.1
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• pp.45-51
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• 2011

A low acid phosphatase 3 (lap3) mutant was identified and characterized from an Arabidopsis activation-tagged (Weigel) population. The roots of the lap3 plants showed lower acid phosphatase (APase) activity compared to wild-type ones under low-Pi conditions ($10{\mu}M\;Pi$). Plasmid rescue experiments revealed that the activation-tagging vector was inserted into the intergenic region between At4g31540 and At4g31550 in the Arabidopsis genome. The genotypic segregation of the lap3 mutation was tightly linked with the phenotypic segregation of root APase activity in the prgeny of lap3. The transcript level of the At4g31520 (SDA1: SEVERE DEPOLYMERIZATION OF ACTIN 1), located 7.4 kb from the CaMV 35S enhancers in the lap3 mutant, was significantly reduced compared to that in the wild type. It was speculated that cellular actin polymerization may be involved in Pi acquisition in higher plants.

• Journal of Plant Biotechnology
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• v.43 no.1
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• pp.30-36
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• 2016

Brassinosteroids (BRs) are essential plant steroid hormones required for cell elongation, plant growth, development and abiotic and biotic stress tolerance. BRs are recognized by BRI1 receptor kinase that is localized in the plasma membrane, and the BRI1 protein will eventually autophosphorylate in the intracellular domain and transphosphorylate BAK1, which is a co-receptor in Arabidopsis thaliana. However, little is known of the role OsBRI1 receptor kinase plays in Oryza sativa, monocotyledonous plants, compared to that in Arabidopsis thaliana, dicotyledonous plants. As such, we have studied OsBRI1 receptor kinase in vitro and in vivo with recombinant protein and transgenic plants, whose phenotypes were also investigated. A OsBRI1 cytoplasmic domain (CD) recombinant protein was induced in BL21 (DE3) E.coli cells with IPTG, and purified to obtain OsBRI1 recombinant protein. Based on Western blot analysis with phospho-specific pTyr and pThr antibodies, OsBRI1 recombinant protein and OsBRI1-Flag protein were phosphorylated on Threonine residue(s), however, not on Tyrosine residue(s), both in vitro and in vivo. This is particularly intriguing as AtBRI1 protein was phosphorylated on both Ser/Thr and Tyr residues. Also, the OsBRI1 full-length gene was expressed in, and rescued, bri1-5 mutants, such as is seen in normal wild-type plants where AtBRI1-Flag rescues bri1-5 mutant plants. Root growth in seedlings decreased in Ws2, AtBRI1, and 3 independent OsBRI1 transgenic seedlings and had an almost complete lack of response to brassinolide in the bri1-5 mutant. In conclusion, OsBRI1, an orthologous gene of AtBRI1, can mediate normal BR signaling for plant growth and development in Arabidopsis thaliana.