• Title/Summary/Keyword: abscisic acid

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Cloning and Expression Analysis of a Grape asr gene, VlASR Containing a Promoter Region. (포도 VIASR 유전자 프로모터의 분리 및 발현 분석)

  • Kihl, Joon-Yeong;Pyee, Jae-Ho
    • Journal of Life Science
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    • v.17 no.8 s.88
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    • pp.1157-1165
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    • 2007
  • VvMSA, a grapevine ASR which is highly inducible by sugar and abscisic acid signals was previously shown to be a transcription factor for a hexose transporter gene VvHT1. We isolated a cDNA clone, VlASR which is regulated temporally during the grape berry development by ACP RT-PCR (annealing control primer reverse transcriptase-polymerase chain reaction) and it proved identical to VvMSA. RT-PCR and real-time PCR analyses revealed that the VlASR gene was expressed in berries at fruit set and that its expression increased as berries aged but decreased at the late ripening stage. In order to understand the regulatory mechanism of the asr gene, a genomic fragment was cloned from grapevine. The genomic DNA was 1375 bp long and a sugar box (sucrose box 3 and sucrose responsive element 1) was identified in the 611 bp upstream region of the open reading frame. Analysis of the VlASR promoter::reporter gene fusion demonstrated that this promoter was expressed in transgenic Arabidopsis even without sucrose treatment. This result suggests that the ASR/VvHT1-mediated sugar/ABA signaling, previously reported in grapevine, may not function in Arabidopsis which has no ASR homologue.

Inhibitory Effects of ABA and $Ca^{2+}$ on Dark Respiration in Protoplasts Isolated from the Basal Intercalary Meristematic Tissues of Oat Leaves (귀리잎의 기저부 절간분열조직에서 분이한 원형질체의 암호흡 활성에 미치는 ABA와 $Ca^{2+}$의 억제효과)

  • 홍영남
    • Journal of Plant Biology
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    • v.38 no.2
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    • pp.195-201
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    • 1995
  • The present study was made of the effects of abscisic acid(ABA) and calcium ions on dark respiration in protoplasts isolated from the basal intercalary meristematic tissues of oat (Avena sativa L.) seedlings. The influences of calcium channel blockers diitiazem(DTZ), verapamil(VPM), and $LaCl_2$ and the calmodulin antagonist trifluoperazine(TFP) on protoplast respiration activities were also investigated in order to evaluate the possible involvement of calcium channels and calmodulin during the dark respiration. The ABA only caused an 21% inhibition of protoplast respiration at $10^{-6}\;M$, but the extent of inhibition was very low by calcium treatments in the absence of ABA. In the presence of $10^{-6}\;M$ ABA, however, this inhibition of respiration increased by the increment of calcium ions concentrations. Treatments of DTZ and VPM were all found to restore the calcium-dependent inhibition of protoplast respiration by ABA and it was the same in thc $LaCl_2$ treatment except at $10^{-4}\;M$. At concentration from $10^{-6}\;M\;to\;10^{-4}\;M$, TFP also restored an inhibition of respiration. These results support the possibility that ABA increases plasmalemma permeability to calcium ions which might then bind to calmodulin to regulate oat protoplast dark respiration.ration.

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Physiochemical Mechanism of Allelopathic Inhibition by Water Soluble Extracts from Sicklepod(Cassia tora L.) Seeds (결명자(決明子)의 수용성(水溶性) 추출물(抽出物)의 타감성(他感性) 저해(沮害) 작용(作用)에 대한 생리화학적(生理化學的) 기작(機作))

  • Lim, Sun-Uk;Moon, Kyung-Whan
    • Korean Journal of Soil Science and Fertilizer
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    • v.26 no.3
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    • pp.189-196
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    • 1993
  • Allelopathic inhibition by substance(s) originated from sicklepod(Cassia tora L.) seed on germination of other plant seeds, was confirmed and used to elucidate general mechanism of allelopathy which was occurred widly in natural and/or agricultural ecosystems. The mechanism was deduced from changes in water contents, ${\alpha}$-amylase activities, protease activities, concentrations of abscisic acid and total phenolic compounds during germination of rice and radish seeds treated with water-soluble extracts of sicklepod seeds. The results obtained were summarized as follows. 1. The % germinations of radish, rice, lettuce, barley seeds were decreased by substances originated from crushed sicklepod seeds. 2. By the treatment of water-soluble extracts of sicklepod seeds, the inhibition of germination of radish seeds was occured with the sequential phenomena of increase of protease activity(synthesis), decrease of water content and increase of total phenolic compounds content. 3. In rice, the inhibition of seed germination by the water-slouble extracts of sicklepod seeds was related to increase of abscisic acid concentration and then decrease of ${\alpha}$-amylase activity(synthesis).

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Induction of antioxygenic enzymes as defense systems in plant cells against low temperature stress : (II) $Mn^{+2}-induced$ SOD activation and enhancement of cold tolerance in rice seedlings (식물의 냉해에 대한 생체방어기구로서 항산소성 효소의 유도 : (II) $Mn^{+2}$이온에 의한 세포내 SOD의 활성화와 벼 유묘의 내냉성 향상)

  • Hahn, Chang-Kyun;Kim, Jong-Pyung;Jung, Jin
    • Applied Biological Chemistry
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    • v.34 no.2
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    • pp.168-173
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    • 1991
  • The uptake of $Mn^{+2}$, a metal cofactor Mn-SOD, by rice seedings resulted in not only a substantial increase in SOD activity in leaf tissues of the plants, but also a significant enhancement of their cold tolerance : the relative extent of the cold tolerance appeared to accord with relative level of the SOD activity. In contrast, $Fe^{+3},\;Cu^{+2}$ and $Zn^{+2}$, which are the cofactors of Fe-SOD and Cu/Zn-SOD, were found to be ineffective for increasing the SOD activity as well as for improving the chilling-resistant capacity of the plants. The results suggest that Mn-SOD, which is most likely induced by its substrate(superoxide) and activated by the presence of $Mn^{+2}$a at high level, is the enzyme acting as an active component of the defense system against low temperature stress in rice plants. In addition, the application of abscisic acid which has been know to protect to some extent certain plants from chilling injury brought about an increase in SOD activity in rice tissues, providing another affirmative information for the crucial role of SOD under the circumstance of cold stress in plants.

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Somatic Embryo Germination and the Related Biochemical Changes of Liriodendron tulipifera by Bioreactor Immersion Time (생물반응기 내 침지시간에 따른 백합나무 체세포배 발아 및 생화학적 변화)

  • An, Chan-Hoon;Yi, Jae-Seon;Kim, Yong-Wook;Moon, Heung-Kyu
    • Journal of Korean Society of Forest Science
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    • v.99 no.3
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    • pp.423-431
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    • 2010
  • To determine physical and physiological factors for Liriodendron tulipifera L. somatic embryo germination, temporary immersion bioreactor (TIB) system was investigated. It was designed to immerse liquid media with plantlets so that it was able to adjust the immersion time. Immersion of 120 minutes every 4 hours and 60 minutes every 4 hours was found to be effective in germination (91.64%, 85.67%, respectively). However, hyperhydricity of the plantlets was higher in short immersion time (15 minutes every 6 hours) and long immersion time (120 minutes every 4 hours) (51.61%, 34.28%, respectively). Immersion of 60 minutes every 4 hours showed the lowest hyperhydric plantlets, and also it showed the lowest activities of abscisic acid (ABA), superoxide dismutase (SOD), and catalase. The overall results implied that immersion time of media affected germination and growth of somatic embryo, and it was able to make use of germination and growth of L. tulipifera somatic embryos.

Alteration of Endogenous Growth Substances in Cold-moist Stratified Seeds of Ginkgo biloba L. (냉습적(冷濕積)에 따른 은행나무종자내(種子內) 생장조정물질(生長調整物質)의 변화(變化))

  • Lee, Kyong Jae;Yim, Kyong Bin
    • Journal of Korean Society of Forest Science
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    • v.38 no.1
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    • pp.1-12
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    • 1978
  • This study has intended to disclose the change of some chemical compositions of Ginkgo seeds which were acquired the treatment of cold-moist-stratification after collection. As check sample, the room-stored seeds were used. With the reasons that when the seeds not stratified were sown the delay of field germination has usually been resulted, the effectiveness of stratificaation in respect to alteration of chemical composition is to be investigated. The increase and decrease of growth promoting and inhibiting substances were investigated by means of chromatography method followed by rice seedling test or wheat coleoptile straight-growth test. The results obtained are summarized as follows; 1. In the untreated seeds, the zone of growth inhibitors on paper chromatograph were observed without regard to the tissue differences, embryo, endosperm and seedcoat. 2. Due to stratification, the amount of inhibitor has decreased in the embryo and seed coat, but growth promoters was decreased as compared with the check materials 3. The indications of results appear that each portion of the embryo, endosperm, and seedcoats of Ginkgo biloba L. contains the growth in hibitor taking part in germination dormancy. 4. It was presumed that hastening germination was influenced by decreasing of inhibitors in the embryo and seed coats rather than by increasing of promoters. 5. Gibberellin was detected at Rf 0.26 under the UV-lamp and the abscisic acid was detected at Rf 0.62, Rf 0.70, and Rf 0.78 and showed purple, gray, blue fluorescence respectively under the UV-lamp.

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Molecular Characterization of a Transient Expression Gene Encoding for 1-Aminocyclopropane-1-carboxylate Synthase in Cotton (Gossypium hirsutum L.)

  • Wang, Xia;Zhang, Ying;Zhang, Jiedao;Cheng, Cheng;Guo, Xingqi
    • BMB Reports
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    • v.40 no.5
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    • pp.791-800
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    • 2007
  • Ethylene performs an important function in plant growth and development. 1-aminocyclopropane-1-carboxylate (ACC) synthase (ACS), the key enzyme involved in ethylene biosynthesis, has been the focus of most ethylene studies. Here, a cotton ACS gene referred to as Gossypium hirsutum ACS1 (GhACS1), was isolated. The full-length cDNA of GhACS1 encodes for a 476-amino acid protein which harbors seven conserved regions, 11 invariant amino acid residues, and the PLP binding active site, all of which characterize ACC synthases. Alignment analysis showed that GhACS1 shared a high degree of identity with other known ACC synthases from different species. Two introns were detected in the genomic DNA sequence, and the results of Southern blot analysis suggested that there might be a multi-gene family encoding for ACC synthase in cotton. From the phylogenetic tree constructed with 24 different kinds of ACC synthases, we determined that GhACS1 falls into group II, and was closely associated with the wound-inducible ACS of citrus. The analysis of the 5' flanking region of GhACS1 revealed a group of putative cis-acting elements. The results of expression analysis showed that GhACS1 displayed its transient expression nature after wounding, abscisic acid (ABA), and $CuCl_2$ treatments. These results indicate that GhACS1, which was transiently expressed in response to certain stimuli, may be involved in the production of ethylene for the transmission of stress signals.

Isolation and characterization of LHT-type plant amino acid transporter gene from Panax ginseng Meyer

  • Zhang, Ru;Zhu, Jie;Cao, Hong-Zhe;Xie, Xiao-Lei;Huang, Jing-Jia;Chen, Xiang-Hui;Luo, Zhi-Yong
    • Journal of Ginseng Research
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    • v.37 no.3
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    • pp.361-370
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    • 2013
  • A lysine histidine transporter (LHT) cDNA was isolated and characterized from the roots of Panax ginseng, designated PgLHT. The cDNA is 1,865 bp with an open reading frame that codes for a protein with 449 amino acids and a calculated molecular mass of 50.6 kDa with a predicted isoelectric point of 8.87. Hydropathy analysis shows that PgLHT is an integral membrane protein with 9 putative membrane-spanning domains. Multiple sequence alignments show that PgLHT shares a high homology with other plant LHTs. The expression profile of the gene was investigated by real-time quantitative polymerase chain reaction during various chemical treatments. PgLHT was up-regulated in the presence of abscisic acid, salicylic acid, methyl jasmonate, NaCl, and amino acids. To further explore the function of PgLHT gene, full-length cDNA of PgLHT was introduced into P. ginseng by Agrobacterium rhizogenes A4. The overexpression of PgLHT in the hairy roots led to an obviously increase of biomass compared to the controls, and after addition of the amino acids, the overexpressed-PgLHT hairy roots grew more rapidly than untreated controls during early stage of the culture cycle. The results suggested that the PgLHT isolated from ginseng might have role in the environmental stresses and growth response.

Characterization of dihydroflavonol 4-reductase cDNA in tea [Camellia sinensis (L.) O. Kuntze]

  • Singh, Kashmir;Kumar, Sanjay;Yadav, Sudesh Kumar;Ahuja, Paramvir Singh
    • Plant Biotechnology Reports
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    • v.3 no.1
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    • pp.95-101
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    • 2009
  • Tea leaves are major source of catechins—antioxidant flavonoids. Dihydroflavonol 4-reductase (DFR, EC 1.1.1.219) is one of the important enzymes that catalyzes the reduction of dihydroflavonols to leucoanthocyanins, a key ''late'' step in the biosynthesis of catechins. This manuscript reports characterization of DFR from tea (CsDFR) that comprised 1,413 bp full-length cDNA with ORF of 1,044 bp (115-1,158) and encoding a protein of 347 amino acids. Sequence comparison of CsDFR with earlier reported DFR sequences in a database indicated conservation of 69-87% among amino acid residues. In silico analysis revealed CsDFR to be a membrane-localized protein with a domain (between 16 and 218 amino acids) resembling the NAD-dependent epimerase/dehydratase family. The theoretical molecular weight and isoelectric point of the deduced amino sequence of CsDFR were 38.67 kDa and 6.22, respectively. Upon expression of CsDFR in E. coli, recombinant protein was found to be functional and showed specific activity of 42.85 nmol $min^{-1}$ mg $protein^{-1}$. Expression of CsDFR was maximum in younger rather than older leaves. Expression was down-regulated in response to drought stress and abscisic acid, unaffected by gibberellic acid treatment, but up-regulated in response to wounding, with concomitant modulation of catechins content. This is the first report of functionality of recombinant CsDFR and its expression in tea.

The Role of Adenylyl Sulfate Reductase to Abiotic Stress in Tomato

  • Seong, Eun-Soo;Lee, Ji-Yeon;Yu, Chang-Yeon;Yang, Deok-Chun;Eom, Seok-Hyun;Cho, Dong-Ha
    • Journal of Plant Biotechnology
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    • v.34 no.3
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    • pp.173-180
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    • 2007
  • The full-length cDNA of LeAPR1 encoded a protein of 461 amino acid residues, which contained homology with phosphoadenosine phosphosulphate reductase (PAPS reductase) in N-terminal and an adenylylsulfate reductase in N-term and C-terminal. Analysis of the deduced amino acid sequence of LeAPR1 revealed that it shares high sequence identity with potato StAPR (96% identity)(Gene bank accession no. CDC44841). We found that multiple copies of LeAPR1 gene are present in the tomato genome through southern blot using genomic DNA was digested with 3 different restriction enzymes. The expression of LeAPR1 was also examined in various organs and its expression was also detected at high levels in roots and stems. Only high amounts of LeAPR1 transcripts were detected at high transcripts in the leaves at time 0, and then reduced as the plant stressed by the NaCl and abscisic acid (ABA). After 24h treatment of NaCl and ABA were showed increasing patterns of LeAPR1 gene. Time course of LeAPR1 gene expression was examined under oxidative stresses from metyl viologen (MV) and hydrogen peroxide ($H_2O_2$). In the presence of 10 mM $H_2O_2$ and $50\;{\mu}M$ MV, the levels of LeAPR1 transcript in leaves decreased after 1 h, and then increased strongly, peaked at 24 h. Our results indicated that LeAPR1 may play a role function of circadian regulation involved in abiotic stresses signaling pathways.