• The Plant Pathology Journal
• /
• 제29권2호
• /
• pp.209-220
• /
• 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.

• Journal of Plant Biotechnology
• /
• 제39권4호
• /
• pp.273-280
• /
• 2012

Differences of gene expression between red flash peach cultivar and white flash peach cultivar were investigated by Nest-generation sequencing (NGS). EST from the red flash peach cultivar and white flash peach cultivar were selected for nucleotide sequence determination and homology searches. The levels of transcripts coding for proteins involved in pathogenesis related proteins, temperature stress, ethylene signal pathway were significantly higher in white flash peach cultivar than in red flash peach cultivar. On the other hand, the up-regulation of proteins involved in anthocyanin and flavonol biosynthesis and protein degradation and sorbitol metabolism were observed in red flash peach cultivar. Chalcone synthase was preferentially expressed in the red flesh peach cultivar, agreeing with the accumulation of anthocyanin and expression of other previously identified genes for anthocyanin biosynthesis. Anthocyanin pathway related genes CHS, F3H, DFR, LDOX, UFGT differentially expressed between red flash peach cultivar and white flash peach cultivar. These results suggest that red flash peach cultivar and white flash peach cultivar have different anthocyanin biosynthesis regulatory mechanisms.

• The Plant Pathology Journal
• /
• 제33권4호
• /
• pp.402-409
• /
• 2017

Cyclic dipeptides (CDPs) are one of the simplest compounds produced by living organisms. Plant-growth promoting rhizobacteria (PGPRs) also produce CDPs that can induce disease resistance. Bacillus vallismortis strain BS07 producing various CDPs has been evaluated as a potential biocontrol agent against multiple plant pathogens in chili pepper. However, plant signal pathway triggered by CDPs has not been fully elucidated yet. Here we introduce four CDPs, cyclo(Gly-L-Pro) previously identified from Aspergillus sp., and cyclo(L-Ala-L-Ile), cyclo(L-Ala-L-Leu), and cyclo(L-Leu-L-Pro) identified from B. vallismortis BS07, which induce disease resistance in Arabidopsis against Pseudomonas syringae infection. The CDPs do not directly inhibit fungal and oomycete growth in vitro. These CDPs require PHYTOALEXIN DEFICIENT4, SALICYLIC ACID INDUCTION DEFICIENT2, and NONEXPRESSOR OF PATHOGENESIS-RELATED PROTEINS1 important for salicylic acid-dependent defense to induce resistance. On the other hand, regulators involved in jasmonate-dependent event, such as ETHYLENE RECEPTOR1, JASMONATE RESPONSE1, and JASMONATE INSENSITIVE1, are necessary to the CDP-induced resistance. Furthermore, treatment of these CDPs primes Arabidopsis plants to rapidly express PATHOGENESIS-RELATED PROTEIN4 at early infection phase. Taken together, we propose that these CDPs from PGPR strains accelerate activation of jasmonate-related signaling pathway during infection.

• Journal of Plant Biotechnology
• /
• 제2권2호
• /
• pp.61-71
• /
• 2000

By screening a cDNA library of auxin-treated mung bean (Vigna radiata L.) hypocotyls, we have isolated two full-length cDNA clones, pVR-ACS6 and pVR-ACS7, for 1-aminocyclopropane-1-carboxylate (ACC) synthase, the rate-limiting enzyme in the ethylene biosynthetic pathway. While PVR-ACS6 corresponds to the previously identified PCR fragment pMBA1, pVR-ACS7 is a new cDNA clone. A comparison of deduced amino acid sequences among auxin-induced ACC synthases reveal that these enzymes share a high degree of homology (65-75%) to VR-ACS6 and VR-ACS7 polypeptides, but only about 50% to VR-ACS1 polypeptide. ACS6 and ACS7 are specifically induced by auxin, while ACS1 is induced by cycloheximide, and to lesser extent by excision and auxin treatment. Results from nuclear run-on transcription assay and RNA gel blot studies revealed that all three genes were transcriptionally active displaying unique patterns of induction by IAA and various hormones in etiolated hypocotyls. Particularly, 24-epibrassinolide (BR), an active brassinosteroid, specifically enhanced the expression of VR-ACS7 by distinct temporal induction mechanism compared to that of IAA. In addition, BR synergistically increased the IAA-induced VR-ACS6 and VR-ACS7 transcript levels, while it effectively abolished both the IAA- and kinetin-induced accumulation of VR-ACS1 mRNA. In light-grown plants, VR-ACS1 was induced by IAA in roots, whereas W-ACS6 in epicotyls. IAA- and BR-treatments were not able to increase the VR-ACS7 transcript in the light-grown tissues. These results indicate that the expression of ACC synthase multigene family is regulated by complex hormonal and developmental networks in a gene- and tissue-specific manner in mung bean plants. The VR-ACS7 gene was isolated, and chimeric fusion between the 2.4 kb 5'-upstream region and the $\beta$-glucuronidase (GUS) reporter gene was constructed and introduced into Nicotiana tobacum. Analysis of transgenic tobacco plants revealed the VR-ACS7 promoter-driven GUS activity at a highly localized region of the hypocotyl-root junction of control seedlings, while a marked induction of GUS activity was detected only in the hypocotyl region of the IAA-treated transgenic seedlings where rapid cell elongation occurs. Although there was a modest synergistic effect of BR on the IAA-induced GUS activity, BR alone failed to increase the GUS activity, suggesting that induction of VR-ACS7 occurs via separate signaling pathways in response to IAA and BR.

• Korean Chemical Engineering Research
• /
• 제49권5호
• /
• pp.510-515
• /
• 2011

염화탄화수소의 고온열분해 반응에서 생성물 반응경로 특성을 파악하기 위해 $H_2$ 반응분위기에서 1,1-dichloroethylene($CH_2CCl_2$) 열분해반응 실험을 수행하였다. 열분해반응 실험은 등온관형반응기를 이용하여 반응온도 $650{\sim}900^{\circ}C$, 반응시간 0.3~2.0초에서 진행하였으며, 반응물 mole 분율은 전체 실험에서 $CH_2CCl_2:H_2$ = 4:96 일정하게 유지하였다. 반응물 $CH_2CCl_2$가 완전분해온도는(분해율 99% 이상) $825^{\circ}C$(반응시간 1초 기준)였으며, $H_2$ 반응분위기에서 $CH_2CCl_2$ 주요 분해반응경로는 H원자 추출 및 첨가교체치환 연쇄반응으로 파악되었다. $CH_2CCl_2$가 46% 분해되는 $700^{\circ}C$에서 1차 생성물로 $CH_2CHCl$가 28%로 가장 높은 농도로 검출되었다. $775^{\circ}C$ 이상에서는 탈염소화된 $C_2H_4$가 2차 생성물로 가장 많이 생성되었으며, 반응온도가 증가할수록 염소 원자수가 작은 화합물이 생성되었으며 이들 화합물은 열화학적으로 안정된 물질이다. $825^{\circ}C$ 이상의 고온반응영역에서 탈염소반응의 부산물인 HCl과 $C_2H_4$, $C_2H_6$, $CH_4$ $C_2H_2$ 등과 같은 열화학적으로 안정된 탄화수소가 주요생성물로 검출되었다. 본 연구에서 고찰된 반응계에서 분해와 생성물분포 특성을 고려하고 열화학이론 및 반응속도론을 기초로 주요 반응경로를 제시하였다.

• BMB Reports
• /
• 제36권5호
• /
• pp.433-441
• /
• 2003

A cDNA clone for a salicylic acid-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene, designated Br-sil1 (for $\underline{B}$rassica $\underline{r}$apa $\underline{s}$alicylate-$\underline{i}$nduced $\underline{l}$lipase-like 1 gene), encodes a putative lipase that has the family II lipase motif GDSxxDxG around the active site serine. A database search showed that plant genomes have a large number of genes that contain the family II lipase motif. The lipase-like proteins include a myrosinase-associated protein, an anther-specific proline-rich protein APG, a pollen coat protein EXL, and an early nodule-specific protein. The Br-sil1 gene is strongly induced by salicylic acid and a non-host pathogen, Pseudomonas syringae pv. tomato, that elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with BTH, methyl jasmonate, or ethephon showed that the Br-sil1 gene expression is induced by BTH, but not by methyl jasmonate or ethylene. This indicates that the cabbage gene is activated via a salicylic acid-dependent signaling pathway. An examination of the tissue-specific expression revealed that the induction of the Br-sil1 gene expression by BTH occurs in leaves and stems, but not in roots and flowers. Without the BTH treatment, however, the Br-sil1 gene is not expressed in any of the tissues that were examined.

• BMB Reports
• /
• 제37권3호
• /
• pp.343-350
• /
• 2004

A cDNA clone for a salicylic acid-induced gene in Chinese cabbage (Brassica rapa subsp. pekinensis) was isolated and characterized. The cabbage gene encoding a protein of 392 amino acids contained a tandem array of two thiJ-like sequences. ThiJ is a thiamin biosynthesis enzyme that catalyzes the phosphorylation of hydroxymethylpyrimidine (HMP) to HMP monophosphate. Although the cabbage gene shows a similarity to bacterial thiJ genes, it also shares a similarity with the human DJ-1, a multifunctional protein that is involved in transcription regulation, male fertility, and parkinsonism. The cabbage thiJ-like gene is strongly induced by salicylic acid and a nonhost pathogen, Pseudomonas syringae pv. tomato, which elicits a hypersensitive response in Chinese cabbage. Treatment of the cabbage leaves with BTH, methyl jasmonate, or ethephon showed that the cabbage thiJ-like gene expression is also strongly induced by BTH, but not by methyl jasmonate or ethylene. This indicates that the cabbage gene is activated via a salicylic acid-dependent signaling pathway. Examination of the tissue-specific expression revealed that the induction of the cabbage gene expression by BTH occurs in the leaf, stem, and floral tissues but not in the root.

• The Plant Pathology Journal
• /
• 제23권2호
• /
• pp.76-89
• /
• 2007

CaCDPK4, a full-length cDNA clone encoding Capsicum annuum calcium-dependent protein kinase 4, was isolated from chili pepper (Capsicum annuum L.). Deduced amino acid sequence of CaCDPK4 shares the highest homology with tobacco NpCDPK8 and chickpea CaCDPK2 with 79% identity. Genomic blot analyses revealed that CaCDPK4 is present as a single copy in pepper genome, but it belongs to a multigene family. CaCDPK4 was highly induced when pepper plants were inoculated with an incompatible bacterial pathogen. Induced levels of CaCDPK4 transcripts were also detected in pepper leaves by the treatment of ethephon, an ethylene-inducing agent, and high-salt stress condition. The bacterial-expressed GST-CaCDPK4 protein showed to retain the autophosphorylation activity in vitro. GUS expression driven by CaCDPK4 promoter was examined in transgenic Arabidopsis containing transcriptional fusion of CaCDPK4 promoter. GUS expression under CaCDPK4 promoter was strong in the root and veins of the seedlings. GW (-1965) and D3 (-1377) promoters conferred on GUS expression in response to inoculation of an incompatible bacterial pathogen, but D4-GUS (-913) and DS-GUS (-833) did not. Taken together, our results suggest that CaCDPK4 can be implicated on signal transduction pathway of defense response against an incompatible bacterial pathogen in pepper.

• Journal of Microbiology and Biotechnology
• /
• 제30권2호
• /
• pp.271-278
• /
• 2020

Glycerol dehydrogenase (GlyDH) catalyzes the oxidation of glycerol to dihydroxyacetone (DHA), which is the first step in the glycerol metabolism pathway. GlyDH has attracted great interest for its potential industrial applications, since DHA is a precursor for the synthesis of many commercially valuable chemicals and various drugs. In this study, GlyDH from Klebsiella pneumoniae (KpGlyDH) was overexpressed in E. coli and purified to homogeneity for biochemical and molecular characterization. KpGlyDH exhibits an exclusive preference for NAD⁺ over NADP⁺. The enzymatic activity of KpGlyDH is maximal at pH 8.6 and pH 10.0. Of the three common polyol substrates, KpGlyDH showed the highest k_cat/K_m value for glycerol, which is three times higher than for racemic 2,3-butanediol and 32 times higher than for ethylene glycol. The k_cat value for glycerol oxidation is notably high at 87.1 ± 11.3 sec^-1. KpGlyDH was shown to exist in an equilibrium between two different oligomeric states, octamer and hexadecamer, by size-exclusion chromatography analysis. KpGlyDH is structurally thermostable, with a T_m of 83.4℃, in thermal denaturation experiment using circular dichroism spectroscopy. The biochemical and biophysical characteristics of KpGlyDH revealed in this study should provide the basis for future research on its glycerol metabolism and possible use in industrial applications.

• Journal of Electrochemical Science and Technology
• /
• 제11권2호
• /
• pp.148-154
• /
• 2020

Highly ordered mesoporous manganese oxide films were electrodeposited onto indium tin oxide coated (ITO) glass using sodium dodecyl sulfate (SDS) and ethylene glycol (EG) which were used as a templating agent and stabilizer for the formation of micelle, respectively. The manganese oxide films synthesized with surfactant templating exhibited a highly mesoporous structure with a long-range order, which was confirmed by SAXRD and TEM analysis. The unique porous structure offers a more favorable diffusion pathway for electrolyte transportation and excellent ionic conductivity. Among the synthesized samples, Mn₂O₃-SDS+EG exhibited the best electrochemical performance for a supercapacitor in the wide range of scan rate, which was attributed to the well-developed mesoporous structure. The Mn₂O₃ prepared with SDS and EG displayed an outstanding capacitance of 72.04 F g^-1, which outperform non-porous Mn₂O₃ (32.13 F g^-1) at a scan rate of 10 mV s^-1.