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Identification and Characterization of NPR1 and PR1 Homologs in Cymbidium orchids in Response to Multiple Hormones, Salinity and Viral Stresses. Int J Mol Sci 2020; 21:ijms21061977. [PMID: 32183174 PMCID: PMC7139473 DOI: 10.3390/ijms21061977] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 02/23/2020] [Accepted: 03/12/2020] [Indexed: 12/23/2022] Open
Abstract
The plant nonexpressor of pathogenesis-related 1 (NPR1) and pathogenesis-associated 1 (PR1) genes play fundamental roles in plant immunity response, as well as abiotic-stress tolerance. Nevertheless, comprehensive identification and characterization of NPR1 and PR1 homologs has not been conducted to date in Cymbidium orchids, a valuable industrial crop cultivated as ornamental and medicinal plants worldwide. Herein, three NPR1-like (referred to as CsNPR1-1, CsNPR1-2, and CsNPR1-3) and two PR1-like (CsPR1-1 and CsPR1-2) genes were genome-widely identified from Cymbidium orchids. Sequence and phylogenetic analysis revealed that CsNPR1-1 and CsNPR1-2 were grouped closest to NPR1 homologs in Zea mays (sharing 81.98% identity) and Phalaenopsis (64.14%), while CsNPR1-3 was classified into a distinct group with Oryza sativaNPR 3 (57.72%). CsPR1-1 and CsPR1-2 were both grouped closest to Phalaenopsis PR1 and other monocot plants. Expression profiling showed that CsNPR1 and CsPR1 were highly expressed in stem/pseudobulb and/or flower. Salicylic acid (SA) and hydrogen peroxide (H2O2) significantly up-regulated expressions of CsNPR1-2, CsPR1-1 and CsPR1-2, while CsNPR1-3, CsPR1-1 and CsPR1-2 were significantly up-regulated by abscisic acid (ABA) or salinity (NaCl) stress. In vitro transcripts of entire Cymbidium mosaic virus (CymMV) genomic RNA were successfully transfected into Cymbidium protoplasts, and the CymMV infection up-regulated the expression of CsNPR1-2, CsPR1-1 and CsPR1-2. Additionally, these genes were transiently expressed in Cymbidium protoplasts for subcellular localization analysis, and the presence of SA led to the nuclear translocation of the CsNPR1-2 protein, and the transient expression of CsNPR1-2 greatly enhanced the expression of CsPR1-1 and CsPR1-2. Collectively, the CsNPR1-2-mediated signaling pathway is SA-dependent, and confers to the defense against CymMV infection in Cymbidium orchids.
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Wang YY, Tsay YF. Arabidopsis nitrate transporter NRT1.9 is important in phloem nitrate transport. THE PLANT CELL 2011; 23:1945-57. [PMID: 21571952 PMCID: PMC3123939 DOI: 10.1105/tpc.111.083618] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 04/08/2011] [Accepted: 04/22/2011] [Indexed: 05/18/2023]
Abstract
This study of the Arabidopsis thaliana nitrate transporter NRT1.9 reveals an important function for a NRT1 family member in phloem nitrate transport. Functional analysis in Xenopus laevis oocytes showed that NRT1.9 is a low-affinity nitrate transporter. Green fluorescent protein and β-glucuronidase reporter analyses indicated that NRT1.9 is a plasma membrane transporter expressed in the companion cells of root phloem. In nrt1.9 mutants, nitrate content in root phloem exudates was decreased, and downward nitrate transport was reduced, suggesting that NRT1.9 may facilitate loading of nitrate into the root phloem and enhance downward nitrate transport in roots. Under high nitrate conditions, the nrt1.9 mutant showed enhanced root-to-shoot nitrate transport and plant growth. We conclude that phloem nitrate transport is facilitated by expression of NRT1.9 in root companion cells. In addition, enhanced root-to-shoot xylem transport of nitrate in nrt1.9 mutants points to a negative correlation between xylem and phloem nitrate transport.
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Affiliation(s)
- Ya-Yun Wang
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Yi-Fang Tsay
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei 112, Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
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Wang DH, Li F, Duan QH, Han T, Xu ZH, Bai SN. Ethylene perception is involved in female cucumber flower development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 61:862-72. [PMID: 20030751 DOI: 10.1111/j.1365-313x.2009.04114.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
It is well established that ethylene promotes female flower development in cucumber. However, little is known about how the gaseous hormone selectively affects female flowers, and what mechanism it uses. Previously, we found organ-specific DNA damage in the primordial anther of female cucumber flowers. This finding led to a hypothesis that ethylene might promote female flower development via the organ-specific induction of DNA damage in primordial anthers. In this study, we tested this hypothesis first by demonstrating ethylene induction of DNA damage via the ethylene signaling pathway using cucumber protoplasts. Then, using representative component genes of the ethylene signaling pathway as probes, we found that one of the ethylene receptors, CsETR1, was temporally and spatially downregulated in the stamens of stage-6 female cucumber flowers, especially along with the increase of the nodes. Furthermore, by constructing transgenic Arabidopsis plants with organ-specific expression of antisense CsETR1 under the control of an AP3 promoter to downregulate ETR1 expression in the stamens, we generated Arabidopsis 'female flowers', in which the abnormal stamens mimic those of female cucumber flowers. Our data suggest that ethylene perception is involved in the arrest of stamen development in female cucumber flowers through the induction of DNA damage. This opens up a novel perspective and approach to solve the half-century-long puzzle of how gaseous ethylene selectively promotes female flowers in the monoecious cucumber plant.
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Affiliation(s)
- Dong-Hui Wang
- PKU-Yale Joint Research Center of Agricultural and Plant Molecular Biology, National Key Laboratory of Protein Engineering and Plant Gene Engineering, College of Life Sciences, Peking University, Beijing, 100871, China
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Almagro A, Lin SH, Tsay YF. Characterization of the Arabidopsis nitrate transporter NRT1.6 reveals a role of nitrate in early embryo development. THE PLANT CELL 2008; 20:3289-99. [PMID: 19050168 PMCID: PMC2630450 DOI: 10.1105/tpc.107.056788] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 11/05/2008] [Accepted: 11/12/2008] [Indexed: 05/18/2023]
Abstract
This study of the Arabidopsis thaliana nitrate transporter NRT1.6 indicated that nitrate is important for early embryo development. Functional analysis of cDNA-injected Xenopus laevis oocytes showed that NRT1.6 is a low-affinity nitrate transporter and does not transport dipeptides. RT-PCR, in situ hybridization, and beta-glucuronidase reporter gene analysis showed that expression of NRT1.6 is only detectable in reproductive tissue (the vascular tissue of the silique and funiculus) and that expression increases immediately after pollination, suggesting that NRT1.6 is involved in delivering nitrate from maternal tissue to the developing embryo. In nrt1.6 mutants, the amount of nitrate accumulated in mature seeds was reduced and the seed abortion rate increased. In the mutants, abnormalities (i.e., excessive cell division and loss of turgidity), were found mainly in the suspensor cells at the one- or two-cell stages of embryo development. The phenotype of the nrt1.6 mutants revealed a novel role of nitrate in early embryo development. Interestingly, the seed abortion rate of the mutant was reduced when grown under N-deficient conditions, suggesting that nitrate requirements in early embryo development can be modulated in response to external nitrogen changes.
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Affiliation(s)
- Anabel Almagro
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
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Voelker C, Schmidt D, Mueller-Roeber B, Czempinski K. Members of the Arabidopsis AtTPK/KCO family form homomeric vacuolar channels in planta. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 48:296-306. [PMID: 16984403 DOI: 10.1111/j.1365-313x.2006.02868.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The Arabidopsis thaliana K+ channel family of AtTPK/KCO proteins consists of six members including a 'single-pore' (Kir-type) and five 'tandem-pore' channels. AtTPK4 is currently the only ion channel of this family for which a function has been demonstrated in planta. The protein is located at the plasma membrane forming a voltage-independent K+ channel that is blocked by extracellular calcium ions. In contrast, AtTPK1 is a tonoplast-localized protein, that establishes a K+-selective, voltage-independent ion channel activated by cytosolic calcium when expressed in a heterologous system, i.e. yeast. Here, we provide evidence that other AtTPK/KCO channel subunits, i.e. AtTPK2, AtTPK3, AtTPK5 and AtKCO3, are also targeted to the vacuolar membrane, opening the possibility that they interact at the target membrane to form heteromeric ion channels. However, when testing the cellular expression patterns of AtTPK/KCO genes we observed distinct expression domains that overlap in only a few tissues of the Arabidopsis plant, making it unlikely that different channel subunits interact to form heteromeric channels. This conclusion was substantiated by in planta expression of combinations of selected tonoplast AtTPK/KCO proteins. Fluorescence resonance energy transfer assays indicate that protein interaction occurs between identical channel subunits (most efficiently between AtTPK1 or AtKCO3) but not between different channel subunits. The finding could be confirmed by bimolecular fluorescence complementation assays. We conclude that tonoplast-located AtTPK/KCO subunits form homomeric ion channels in vivo.
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Affiliation(s)
- Camilla Voelker
- Universität Potsdam, Institut für Biochemie und Biologie, Karl-Liebknecht-Str. 24-25, Haus 20, D-14476 Golm, Germany
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Yang X, Li T, Yang J, He Z, Lu L, Meng F. Zinc compartmentation in root, transport into xylem, and absorption into leaf cells in the hyperaccumulating species of Sedum alfredii Hance. PLANTA 2006; 224:185-95. [PMID: 16362325 DOI: 10.1007/s00425-005-0194-8] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Accepted: 11/14/2005] [Indexed: 05/05/2023]
Abstract
Sedum alfredii Hance can accumulate Zn in shoots over 2%. Leaf and stem Zn concentrations of the hyperaccumulating ecotype (HE) were 24- and 28-fold higher, respectively, than those of the nonhyperaccumulating ecotype (NHE), whereas 1.4-fold more Zn was accumulated in the roots of the NHE. Approximately 2.7-fold more Zn was stored in the root vacuoles of the NHE, and thus became unavailable for loading into the xylem and subsequent translocation to shoot. Long-term efflux of absorbed 65Zn indicated that 65Zn activity was 6.8-fold higher in shoots but 3.7-fold lower in roots of the HE. At lower Zn levels (10 and 100 microM), there were no significant differences in 65Zn uptake by leaf sections and intact leaf protoplasts between the two ecotypes except that 1.5-fold more 65Zn was accumulated in leaf sections of the HE than in those of the NHE after exposure to 100 microM for 48 h. At 1,000 microM Zn, however, approximately 2.1-fold more Zn was taken up by the HE leaf sections and 1.5-fold more 65Zn taken up by the HE protoplasts as compared to the NHE at exposure times >16 h and >10 min, respectively. Treatments with carbonyl cyanide m-chlorophenylhydrazone (CCCP) or ruptured protoplasts strongly inhibited 65Zn uptake into leaf protoplasts for both ecotypes. Citric acid and Val concentrations in leaves and stems significantly increased for the HE, but decreased or had minimal changes for the NHE in response to raised Zn levels. These results indicate that altered Zn transport across tonoplast in the root and stimulated Zn uptake in the leaf cells are the major mechanisms involved in the strong Zn hyperaccumulation observed in S. alfredii H.
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Affiliation(s)
- Xiaoe Yang
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Natural Resources and Environmental Sciences, Zhejiang University, Huajianchi Campus, 310029 Hangzhou, China.
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Choi SK, Palukaitis P, Min BE, Lee MY, Choi JK, Ryu KH. Cucumber mosaic virus 2a polymerase and 3a movement proteins independently affect both virus movement and the timing of symptom development in zucchini squash. J Gen Virol 2005; 86:1213-1222. [PMID: 15784915 DOI: 10.1099/vir.0.80744-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The basis for differences in the timing of systemic symptom elicitation in zucchini squash between a pepper strain of Cucumber mosaic virus (Pf-CMV) and a cucurbit strain (Fny-CMV) was analysed. The difference in timing of appearance of systemic symptoms was shown to map to both RNA 2 and RNA 3 of Pf-CMV, with pseudorecombinant viruses containing either RNA 2 or RNA 3 from Pf-CMV showing an intermediate rate of systemic symptom development compared with those containing both or neither Pf-CMV RNAs. Symptom phenotype was shown to map to two single-nucleotide changes, both in codons for Ile at aa 267 and 168 (in Fny-CMV RNAs 2 and 3, respectively) to Thr (in Pf-CMV RNAs 2 and 3). The differential rate of symptom development was shown to be due to differences in the rates of cell-to-cell movement in the inoculated cotyledons, as well as differences in the rate of egress of the virus from the inoculated leaves. These data indicate that both the CMV 3a movement protein and the CMV 2a polymerase protein affect the rate of movement of CMV in zucchini squash and that these two proteins function independently of each other in their interactions with the host, facilitating virus movement.
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Affiliation(s)
- Seung Kook Choi
- Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, Korea
| | | | - Byoung Eun Min
- Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, Korea
| | - Mi Yeon Lee
- Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, Korea
| | - Jang Kyung Choi
- Division of Biological Environment, Kangwon National University, Chuncheon 200-701, Korea
| | - Ki Hyun Ryu
- Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul 139-774, Korea
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Mayers CN, Lee KC, Moore CA, Wong SM, Carr JP. Salicylic acid-induced resistance to Cucumber mosaic virus in squash and Arabidopsis thaliana: contrasting mechanisms of induction and antiviral action. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2005; 18:428-34. [PMID: 15915641 DOI: 10.1094/mpmi-18-0428] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Salicylic acid (SA)-induced resistance to Cucumber mosaic virus (CMV) in tobacco (Nicotiana tabacum) results from inhibition of systemic virus movement and is induced via a signal transduction pathway that also can be triggered by antimycin A, an inducer of the mitochondrial enzyme alternative oxidase (AOX). In Arabidopsis thaliana, inhibition of CMV systemic movement also is induced by SA and antimycin A. These results indicate that the mechanisms underlying induced resistance to CMV in tobacco and A. thaliana are very similar. In contrast to the situation in tobacco and A. thaliana, in squash (Cucurbita pepo), SA-induced resistance to CMV results from inhibited virus accumulation in directly inoculated tissue, most likely through inhibition of cell-to-cell movement. Furthermore, neither of the AOX inducers antimycin A or KCN induced resistance to CMV in squash. Additionally, AOX inhibitors that compromise SA-induced resistance to CMV in tobacco did not inhibit SA-induced resistance to the virus in squash. The results show that different host species may use significantly different approaches to resist infection by the same virus. These findings also imply that caution is required when attempting to apply findings on plant-virus interactions from model systems to a wider range of host species.
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Affiliation(s)
- Carl N Mayers
- Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
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Kaplan IB, Lee KC, Canto T, Wong SM, Palukaitis P. Host-specific encapsidation of a defective RNA 3 of Cucumber mosaic virus. J Gen Virol 2004; 85:3757-3763. [PMID: 15557249 DOI: 10.1099/vir.0.80345-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Defective (D) RNAs were generated in tobacco upon passage of two isolates of Cucumber mosaic virus (CMV) initially derived from RNA transcripts of cDNA clones. In both cases, the D RNA was derived by a single in-frame deletion of either 339 or 411 nt within the 3a gene of Fny-CMV RNA 3 or M-CMV RNA 3, respectively. The generation of D RNAs was rare and occurred with two CMV isolates, the virions of which were known to differ in physico-chemical properties. The Fny-CMV D RNA 3, designated D RNA 3-1, was maintained by passage together with Fny-CMV in tobacco, but was lost by passage in squash. D RNA 3-1 accumulated in the inoculated squash cotyledons but not in upper, systemically infected leaves. Virions purified from infected squash cotyledons or leaf mesophyll protoplasts did not contain D RNA 3-1. Therefore, the failure of D RNA 3-1 to accumulate in squash leaves systemically infected by CMV was due to a lack of encapsidation of the D RNA 3-1 and movement out of the inoculated leaves.
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Affiliation(s)
- Igor B Kaplan
- Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA
| | - Kian-Chung Lee
- Department of Biological Sciences, The National University of Singapore, Kent Ridge, Singapore 117543, Singapore
| | - Tomas Canto
- Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK
| | - Sek-Man Wong
- Department of Biological Sciences, The National University of Singapore, Kent Ridge, Singapore 117543, Singapore
- Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA
| | - Peter Palukaitis
- Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK
- Department of Plant Pathology, Cornell University, Ithaca, NY 14853, USA
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Choi SK, Choi JK, Ryu KH. Involvement of RNA2 for systemic infection of Cucumber mosaic virus isolated from lily on zucchini squash. Virus Res 2003; 97:1-6. [PMID: 14550582 DOI: 10.1016/s0168-1702(03)00215-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A lily strain of Cucumber mosaic virus (LK-CMV) was not able to systemically infect zucchini squash (Cucurbita pepo), while Fny strain of CMV (Fny-CMV) caused systemic mosaic and stunting symptom at 4 days post-inoculation on the same host species. The pathogenicity of LK-CMV in zucchini squash was investigated by reassortments of genomic RNAs of LK-CMV and Fny-CMV for infection, as well as by pseudorecombinants generated from biologically active transcripts of cDNA clones of LK-CMV and Fny-CMV, respectively. The assessments of pathogenicity for LK-CMV indicated that RNA2 of LK-CMV was responsible for systemic infection in zucchini squash. In the protoplast of zucchini squash, the RNA accumulations of all constructed pseudorecombinants were indistinguishable and LK-CMV replication was slightly lower than that of Fny-CMV, suggesting that the inability of LK-CMV to infect squash plants was responsible for the poor efficiency of virus movement, rather than the reduction of replication function.
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Affiliation(s)
- Seung Kook Choi
- Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX 77843, USA
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