• Journal of Applied Biological Chemistry
• /
• v.43 no.1
• /
• pp.12-17
• /
• 2000

To understand the signal transduction pathway that leads to the activation of the wound-inducible proteinase inhibitor II (pin2) promoter. $F_2$ progenies of wound (-) mutant crossed with wild-type Arabidopsis plants were biochemically and genetically characterized. Wound (-) mutant was derived from transgenic Arabidopsis plants containing bacterial cytosine deaminase gene under the control of pin2 promoter. The cytosine deaminase assays indicated that wound (-) mutant is a dominant inhibitor of wound-inducibility as only 3 of the $20F_2$ progenies showed cytosine deaminase (CDase) activity, To construct a structural map of the wound (-) mutant chromosomal regions, cleaved, amplified polymorphic sequences (CAPS) markers that cover all Chromosomes were used. Chromosomal regions covered by three different CAPS markers could be candidates for further fine mapping of the location of the wound (-) mutation. g4026, RGA1 and ASA1 located at 84.9 on recombinant inbred (RI) map of chromosome I, at 1.75 on RI map of chromosome II, and 18.35 on RI map of chromosome V, respectively.

• BMB Reports
• /
• v.32 no.1
• /
• pp.6-11
• /
• 1999

To understand the function of phospholipids and their fatty acid composition on the morphological changes in the amp 1-4 mutant of Arabidopsis, the mutant was compared to the wild-type Arabidopsis by TLC, HPTLC, phosphorous assay, HPLC, and GC. In the mutant, phosphatidylethanolamine (PE) was increased 5-fold and phosphatidylglycerol (PG) was decreased 1.2-fold (nmol phosphorous/g tissue). Inositol phospholipids showed a generally increased trend ranging from 1.4-to 3.0-fold (nmol inositol/g tissue). When fatty acid composition of the mutant was compared to the wild-type, linoleic (18:2) and linolenic (18:3) acids of phosphatidylcholine (PC) and PG were decreased but palmitoleic acid (16:1) and oleic acid (18:1) of PC was increased 2.5- and 2.1-fold (mol%), respectively. In galactolipids, myristic acid (14:0) of monogalactosyl-diacylglycerol (MGDG) were increased 5.8-fold (mol%). Among the inositol phospholipids, lysophosphatidylinositol (L-PI) and phosphatidylinositol 4,5-bisphosphate ($PIP_2$) showed 4-and 1.9-fold (mol%) increase of 16:1, respectively. These results suggest that the increase of PE, the decrease of PG, the increase of inositol phospholipids, and the altered fatty acid composition are related to the phenotypic changes affecting the morphological features, and might cause different physiological changes in the amp 1-4 mutant compared to wild-type Arabidopsis.

• Molecules and Cells
• /
• v.19 no.1
• /
• pp.81-87
• /
• 2005

Phytochelatins play an important role in heavy metal detoxification in plants as well as in other organisms. The Arabidopsis thaliana mutant cad1-3 does not produce detectable levels of phytochelatins in response to cadmium stress. The hypersensitivity of cad1-3 to cadmium stress is attributed to a mutation in the phytochelatin synthase 1 (AtPCS1) gene. However, A. thaliana also contains a functional phytochelatin synthase 2 (AtPCS2). In this study, we investigated why the cad1-3 mutant is hypersensitive to cadmium stress despite the presence of AtPCS2. Northern and Western blot analyses showed that expression of AtPCS2 is weak compared to AtPCS1 in both roots and shoots of transgenic Arabidopsis. The lower level of AtPCS2 expression was confirmed by RT-PCR analysis of wild type Arabidopsis. Moreover, no tissue-specific expression of AtPCS2 was observed. Even when AtPCS2 was under the control of the AtPCS1 promoter or of the cauliflower mosaic virus 35S promoter (CaMV 35S) it was not capable of fully complementing the cad1-3 mutant for cadmium resistance.

• BMB Reports
• /
• v.41 no.1
• /
• pp.79-85
• /
• 2008

The source of nitric oxide (NO) in plants is unclear and it has been reported NO can be produced by nitric oxide synthase (NOS) like enzymes and by nitrate reductase (NR). Here we used wild-type, Atnos1 mutant and nia1, nia2 NR-deficient mutant plants of Arabidopsis thaliana to investigate the potential source of NO production in response to Verticillium dahliae toxins (VD-toxins). The results revealed that NO production is much higher in wild-type and Atnos1 mutant than in nia1, nia2 NR-deficient mutants. The NR inhibitor had a significant effect on VD-toxins-induced NO production; whereas NOS inhibitor had a slight effect. NR activity was significantly implicated in NO production. The results indicated that as NO was induced in response to VD-toxins in Arabidopsis, the major source was the NR pathway. The production of NOS-system appeared to be secondary.

• Journal of Applied Biological Chemistry
• /
• v.48 no.4
• /
• pp.183-186
• /
• 2005

Arabidopsis AHL gene encodes a 3'(2')-phosphoadenosine 5'-phosphate (PAP)-specific phosphatase that plays a role in the sulfate activation pathway. We complemented E. coli cysQ mutant defective in cysteine biosynthesis with the AHL gene. AHL cDNA was cloned into the prokaryotic expression vector pKK388-1 and transformed into the bacterial mutant. Since cysQ mutant is a leaky cysteine auxotroph only under aerobic conditions, the bacteria were grown in liquid media with vigorous shaking to provide more aeration. In cysteine-free medium, cysQ mutant and the mutant harboring empty vector did not grow well, whereas cells harboring AHL cDNA exhibited significantly improved growth with doubling time of approximately 3 h. cysQ is known to encode a 3'(2'),5'-diphosphonucleoside 3'(2')-phosphohydrolase (DPNPase). However, our data suggest that cysQ protein has PAP-specific phosphatase activity in addition to DPNPase activity. Microbial complementation procedure described in this paper is useful for structure-activity studies of PAP-specific phosphatases identified from microbes and plants.

• Molecules and Cells
• /
• v.25 no.1
• /
• pp.70-77
• /
• 2008

Proteome analysis was performed to identify proteins differentially expressed in an Arabidopsis mutant, ntm1-D. In this mutant the NAC transcription factor NTM1 is constitutively expressed and the resultant phenotypic changes include dwarfism, serrated leaves, and altered floral structures, probably due to reduced cell division. Marked elevation of proteins mediating environmental stress responses, including annexin, vegetative storage proteins, beta-glucosidase homolog 1, and glutathione transferases was observed. Overexpression of annexin was confirmed by RT-PCR and Western blotting. These observations suggest that the reduced growth observed in the ntm1-D mutant is caused by enhancement of its stress responses, possibly resulting in a cost in fitness.

• Molecules and Cells
• /
• v.23 no.2
• /
• pp.154-160
• /
• 2007

An Arabidopsis hy4 mutant that is specifically impaired in its ability to undergo blue light dependent photomorphogenesis was used to identify cryptochrome 1 signaling-related components. Proteomic analysis revealed about 205 differentially expressed protein spots in the blue light-irradiated hy4 mutant compared to the wild-type. The proteins corresponding to 28 up-regulated and 33 down-regulated spots were identified. Obvious morphological changes in the hy4 mutant were closely related to the expression of various transcription factors. Our findings suggest that blue light signals may be involved in many cellular processes including disease resistance and stress responses.

• Interdisciplinary Bio Central
• /
• v.3 no.1
• /
• pp.2.1-2.4
• /
• 2011

Arabidopsis is well-known to the world's plant research community as a model plant. Many significant resources and innovative research tools, as well as large bodies of genomic information, have been created and shared by the research community, partly explaining why so many researchers use this small plant for their research. The genome sequence of Arabidopsis was fully characterized by the end of the $20^{th}$ century. Soon afterwards, the Arabidopsis research community began a 10-year international project on the functional genomics of the species. In 2001, at the beginning of the project, the RIKEN BioResource Center (BRC) started its Arabidopsis resource project. The following year, the National BioResource Project was launched, funded by the Japanese government, and the RIKEN BRC was chosen as a core facility for Arabidopsis resource. Seeds of RIKEN Arabidopsis transposon-tagged mutant lines, activation-tagged lines, full-length cDNA over-expresser lines, and natural accessions, as well as RIKEN Arabidopsis full-length cDNA clones and T87 cells, are preserved at RIKEN BRC and distributed around the world. The major resources provided to the research community have been full-length cDNA clones and insertion mutants that are suitable for use in reverse-genetics studies. This paper provides an overview of the Arabidopsis resources made available by RIKEN BRC and examples of research that has been done by users and developers of these resources.

• Journal of Life Science
• /
• v.12 no.6
• /
• pp.715-720
• /
• 2002

A mutant Arabidopsis thaliana which is very sensitive to Ultraviolet-B(UV-B) radiation has been isolated by ethylmethane sulfonate(EMS) mutagenesis. Genetic cross proved the UV-sensitive gene(uvs) to segregate as a single Mendelian locus. For mapping of uvs, we crossed Arabidopsis thaliana Lansberg with uvs plant(Columbia), and made F2 plants by F1 selfcross. We designed 10 kinds of CAPS marker primers. Each primers amplifies a single mapped DNA sequence from uvs and Lansberg erecta ecotyres. Also identified was at least one restriction endonuclase for each of these PCR product that generates ecotype-specific digestion pattern. We got crossing over value of UB-sensitivity and each CAPS marker which located on different chromosome arm. The value of crossing over showed that uvs was linked to LFY3 which was on chromosome 5.

• Molecules and Cells
• /
• v.23 no.3
• /
• pp.405-409
• /
• 2007

A putative type-I chalcone isomerase (CHI) cDNA clone EuNOD-CHI was previously isolated from the root nodule of Elaeagnus umbellata [Kim et al. (2003)]. To see if it encodes a functional CHI, we ectopically overexpressed it in the Arabidopsis (Arabidopsis thaliana) transparent testa 5 (tt5) mutant, which is defective in naringenin production and has yellow seeds due to proanthocyanidin deficiency. Ectopic overexpression of EuNOD-CHI resulted in recovery of normal seed coat color. Naringenin produced by CHI from naringenin chalcone was detected in the transgenic lines like in the wild-type, whereas it was absent from the tt5 mutant. We conclude that EuNOD-CHI encodes a functional type-I CHI. In situ hybridization revealed that EuNOD-CHI expression is localized to the infected cells of the fixation zone in root nodules.