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J W Roenhorst - One of the best experts on this subject based on the ideXlab platform.
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dahlia latent Viroid a recombinant new species of the family pospiViroidae posing intriguing questions about its origin and classification
Journal of General Virology, 2013Co-Authors: Jacobus Th J Verhoeven, J W Roenhorst, E. T. M. Meekes, P SerraAbstract:A Viroid-like RNA has been detected in two asymptomatic dahlia accessions by return and double PAGE. It appeared smaller than Chrysanthemum Stunt Viroid and Potato spindle tuber Viroid, the two members of the genus PospiViroid, family PospiViroidae, reported in this ornamental previously. RT-PCR with primers designed for amplifying all pospiViroids produced no amplicons, but RT-PCR with random primers revealed a 342 nt RNA. The sequence of this RNA was confirmed with specific primers, which additionally revealed its presence in many dahlia cultivars. The RNA was named Dahlia latent Viroid (DLVd) because it replicates autonomously, but symptomlessly, in dahlia and shares maximum sequence identity with other Viroids of less than 56 %. Furthermore, DLVd displays characteristic features of the family PospiViroidae: a predicted rod-like secondary structure of minimum free energy with a central conserved region (CCR), and the ability to form the metastable structures hairpins I and II. Its CCR is identical to that of Hop Stunt Viroid (HSVd, genus HostuViroid). However, DLVd: (i) has the terminal conserved region present in members of the genus PospiViroid, but absent in HSVd, and (ii) lacks the terminal conserved hairpin present in HSVd. Phylogenetic reconstructions indicate that HSVd and Pepper chat fruit Viroid (genus PospiViroid) are the closest relatives of DLVd, but DLVd differs from these Viroids in its host range, restricted to dahlia so far. Therefore, while DLVd fulfils the criteria to be a novel species of the family PospiViroidae, its recombinant origin makes assignment to the genera PospiViroid or HostuViroid problematic.
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first report of solanum jasminoides infected by citrus exocortis Viroid in germany and the netherlands and tomato apical Stunt Viroid in belgium and germany
Plant Disease, 2008Co-Authors: Th J J Verhoeven, C C C Jansen, J W Roenhorst, S Steyer, N Schwind, M WasseneggerAbstract:Recent identifications of Chrysanthemum Stunt Viroid (CSVd) and Potato spindle tuber Viroid (PSTVd) in Solanum jasminoides (3,4) prompted the testing of this plant species for infections with other pospiViroids. From autumn of 2006 to spring of 2007, samples from symptomless plants of S. jasminoides were collected in Belgium (3 samples ranging from 75 to 150 plants), Germany (3 samples ranging from 1 to 200 plants), and the Netherlands (3 samples ranging from 2 to 200 plants). Samples were tested for pospiViroids by reverse transcription (RT)-PCR assays using the Pospi1-FW/RE and Vid-FW/RE (2) and PSTV-Nb-FW (5′-ggatccccggggaaacctgga-3′)/RE (5′-ggatccctgaagcgctcctcc-3′) primer sets. Each set amplifies several but not all pospiViroids. The first and last primer sets amplified PCR products from six samples. The full-length genomes of all six isolates were amplified using primer pairs CEVd-FW1/RE1 (1) and CEVd-FW2 (5′-gtgctcacctgaccctgcagg-3′)/RE2 (5′-accacaggaacctcaagaaag-3′), which are fully complementary ...
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first report of potato virus m and Chrysanthemum Stunt Viroid in solanum jasminoides
Plant Disease, 2006Co-Authors: Th J J Verhoeven, C C C Jansen, J W RoenhorstAbstract:In 2005, a plant of the ornamental crop Solanum jasminoides from the Netherlands was submitted for testing on viruses and Viroids because of its intended use for propagation. Sap from this plant was mechanically inoculated to the test plant species Chenopodium quinoa, Nicotiana benthamiana, N. hesperis-67A, and N. occidentalis-P1 (3). N. hesperis-67A showed chlorotic local lesions and rugosity followed by vein necrosis, N. occidentalis-P1 showed necrotic local lesions and systemic leaf distortion, and the two other test plant species remained symptomless. Potato virus M (PVM) was identified by double antibody sandwich enzyme-linked immunosorbent assay using leaves from S. jasminoides and N. hesperis-67A. The plant of S. jasminoides was also tested for the presence of Viroids by reverse transcriptase-polymerase chain reaction (RT-PCR) with universal pospiViroid primers Pospi1-RE/FW (2). This reaction yielded an amplicon of the expected size of 198 bp. The sequence showed 100% identity to an isolate of Chry...
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detection of Chrysanthemum Stunt Viroid and potato spindle tuber Viroid by return polyacrylamide gel electrophoresis
Eppo Bulletin, 2000Co-Authors: J W Roenhorst, R P T Butot, K A Van Der Heijden, M Hooftman, A Van ZaayenAbstract:Return-polyacrylamide gel electrophoresis (R-PAGE) is one of the methods used for the detection of Viroids, in particular Chrysanthemum Stunt Viroid (CSVd) and Potato spindle tuber Viroid (PSTVd). The method is based on temperature-related conformational changes of the circular single-stranded RNA molecule. This results in a characteristic electrophoretic behaviour, providing a clear separation between the Viroid and nucleic acids of the plant. Since the description of R-PAGE, several modifications of the procedure have been published. In addition, several molecular techniques have been applied for the detection of Viroids. However, R-PAGE is still particularly suitable for phytosanitary purposes because detection is not influenced by variations in the nucleotide sequence. This means that any PospiViroid will be detected, provided the amount is above the detection threshold. In addition, relatively large amounts of leaf material can be handled in one test. This paper presents a recently developed R-PAGE procedure, based on the use of a horizontal electrophoresis system and paper wicks as buffer reservoirs. In comparison with the existing procedures, the new procedure is easy to perform and the use of chemicals is decreased. Results of the new procedure are shown and discussed in relation to those obtained by the previous procedure.
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natural infection of petunia by Chrysanthemum Stunt Viroid
European Journal of Plant Pathology, 1998Co-Authors: J T J Verhoeven, M S J Arts, Robert A Owens, J W RoenhorstAbstract:A Viroid that behaved similar to Chrysanthemum Stunt Viroid (CSVd) during return-polyacrylamide gel electrophoresis has been detected in petunia. Subsequent transmission studies as well as reverse transcription-polymerase chain reaction and sequence analysis showed that the Viroid is indeed a strain of CSVd. As long as the Viroid is absent from plants used for vegetative propagation, it appears not to pose a serious threat to petunia cultivation.
Munetaka Hosokawa - One of the best experts on this subject based on the ideXlab platform.
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Chrysanthemum Stunt Viroid Resistance in Chrysanthemum
MDPI AG, 2018Co-Authors: Tomoyuki Nabeshima, Yosuke Matsushita, Munetaka HosokawaAbstract:Chrysanthemum Stunt Viroid (CSVd) is one of the most severe threats in Chrysanthemum morifolium production. Over the last decade, several studies have reported the natural occurrence of CSVd resistance in Chrysanthemum germplasms. Such CSVd-resistant germplasms are desirable for the stable production of Chrysanthemum plants. Current surveys include finding new resistant Chrysanthemum cultivars, breeding, and revealing resistant mechanisms. We review the progress, from discovery to current status, of CSVd-resistance studies, while introducing information on the improvement of associated inoculation and diagnostic techniques
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comparative analysis of Chrysanthemum Stunt Viroid accumulation and movement in two Chrysanthemum Chrysanthemum morifolium cultivars with differential susceptibility to the Viroid infection
Frontiers in Plant Science, 2017Co-Authors: Tomoyuki Nabeshima, Motoaki Doi, Munetaka HosokawaAbstract:Chrysanthemum Stunt Viroid (CSVd) was inoculated into two Chrysanthemum (Chrysanthemum morifolium) cultivars, the CSVd-susceptible cultivar Piato and the CSVd-resistant cultivar Mari Kazaguruma. For CSVd inoculation, grafting and Agrobacterium-mediated inoculation were used. In grafting experiments, CSVd was detectable in Mari Kazaguruma after grafting onto infected Piato, but after removal of infected rootstocks, CSVd could not be detected in the uppermost leaves. In agroinfection experiments, CSVd systemic infection was observed in Piato but not in Mari Kazaguruma. However, agro-inoculated leaves of Mari Kazaguruma accumulated circular CSVd RNA to levels equivalent to those in Piato at 7 days post-inoculation. In situ detection of CSVd in inoculated leaves revealed that CSVd was absent in phloem of Mari Kazaguruma, while CSVd strongly localized to this site in Piato. We hypothesize that CSVd resistance in Mari Kazaguruma relates not to CSVd replication but to CSVd movement in leaves.
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Agrobacterium-mediated inoculation of Chrysanthemum (Chrysanthemum morifolium) plants with Chrysanthemum Stunt Viroid.
Journal of Virological Methods, 2016Co-Authors: Tomoyuki Nabeshima, Munetaka HosokawaAbstract:Agroinfiltration was tested as a method of inoculation of Chrysanthemum plants with Chrysanthemum Stunt Viroid (CSVd). Binary vectors harboring dimeric CSVd sequences in sense and antisense orientations were constructed, and Agrobacterium transfected with these binary vectors was infiltrated into Chrysanthemum leaves. Northern blotting and reverse transcription polymerase chain reaction analysis showed that local infection was established within 7 days and systemic infection within 20 days. CSVd polarities showed no difference in infectivity. This study showed that agroinfiltration of Chrysanthemum plants is an easy, rapid, and cost-effective method for CSVd inoculation.
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digestion of Chrysanthemum Stunt Viroid by leaf extracts of capsicum chinense indicates strong rna digesting activity
Plant Cell Reports, 2016Co-Authors: Boubourakas Iraklis, Tomoyuki Nabeshima, Sota Koeda, Hiroko Kanda, Mayu Onda, Nao Ota, Munetaka HosokawaAbstract:CSVd could not infect Nicotiana benthamiana when the plants were pretreated with crude leaf extract of Capsicum chinense ‘Sy-2’. C. chinense leaves were revealed to contain strong RNA-digesting activity. Several studies have identified active antiviral and antiViroid agents in plants. Capsicum plants are known to contain antiviral agents, but the mechanism of their activity has not been determined. We aimed to elucidate the mechanism of Capsicum extract’s antiViroid activity. Chrysanthemum Stunt Viroid (CSVd) was inoculated into Nicotiana benthamiana plants before or after treating the plants with a leaf extract of Capsicum chinense ‘Sy-2’. CSVd infection was determined using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) 3 weeks after inoculation. When Capsicum extract was sprayed or painted onto N. benthamiana before inoculation, it was effective in preventing infection by CSVd. To evaluate CSVd digestion activity in leaf extracts, CSVd was mixed with leaf extracts of Mirabilis, Phytolacca, Pelargonium and Capsicum. CSVd-digesting activities were examined by quantifying undigested CSVd using qRT-PCR, and RNA gel blotting permitted visualization of the digested CSVd. Only Capsicum leaf extract digested CSVd, and in the Capsicum treatment, small digested CSVd products were detected by RNA gel blot analysis. When the digesting experiment was performed for various cultivars and species of Capsicum, only cultivars of C. chinense showed strong CSVd-digesting activity. Our observations indicated that Capsicum extract contains strong RNA-digesting activity, leading to the conclusion that this activity is the main mechanism for protection from infection by CSVd through spraying or painting before inoculation. To our knowledge, this is the first report of a strong RNA-digesting activity by a plant extract.
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evaluation of Chrysanthemum Stunt Viroid csvd infection in newly expanded leaves from csvd inoculated shoot apical meristems as a method of screening for csvd resistant Chrysanthemum cultivars
Journal of Horticultural Science & Biotechnology, 2014Co-Authors: Tomoyuki Nabeshima, Munetaka Hosokawa, S Yano, Kazushi Ohishi, Motoaki DoiAbstract:SummaryA total of 199 Chrysanthemum (Chrysanthemum × morifolium Ramat.) cultivars were used in screening for resistance to Chrysanthemum Stunt Viroid (CSVd). Plants were inoculated with CSVd by attaching leaf primordia-free, shoot apical meristems to CSVd-infected root tips of a CSVd-sensitive cultivar. CSVd titres in the first and third youngest expanded leaves were analysed after 2 months in culture, and a systematic classification into four groups was conducted. Long-term cultivation records provided by a breeding nursery confirmed our findings of those screened cultivars classified in vitro as “non-detected-type” (i.e., those expected to have a high level of resistance). In addition, of the 15 candidate cultivars selected as “non-detected-type”, four cultivars were shown to have a high level of CSVd-resistance by ex vitro grafting experiments. From the results of our in vitro and ex vitro experiments, the advantages of our newly-developed in vitro-screening system are discussed.
Mi-young Chung - One of the best experts on this subject based on the ideXlab platform.
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Elimination of Chrysanthemum Stunt Viroid and Chrysanthemum chlorotic mottle Viroid from infected Chrysanthemum by cryopreservation.
Protoplasma, 2015Co-Authors: Su Min Jeon, Aung Htay Naing, Mi-young ChungAbstract:Chrysanthemum morifolium ‘Borami’ and ‘Secret Pink’ showing symptoms of Stunt disease caused by Chrysanthemum Stunt Viroid (CSVd) and ‘Yellow Cap’ showing chlorotic mottle disease caused by Chrysanthemum chlorotic mottle Viroid (CChMVd) were confirmed to be infected by the respective Viroids by using reverse transcription polymerase chain reaction (RT-PCR). Real-time PCR results showed that the Viroid concentrations in the infected cultivars varied between the different regions of origin (Chilgok, Gumi, and Gyeongsan). We applied a cryopreservation protocol for elimination of CSVd from naturally infected ‘Borami’ collected from Gumi, showing the lowest concentration of CSVd, by varying several factors such as plant vitrification solutions (PVS2 and PVS3), duration of exposure to liquid nitrogen, shoot-tip size, and low-temperature treatment. The solution (PVS2) and low-temperature treatment were found to be critical factors determining the efficacy of Viroid elimination. We optimized the protocol by combining of all resulted optimal factors and tested the applicability of the protocol in ‘Borami’ collected from Chilgok and Gyeongsan and in ‘Secret Pink’ from Chilgok, Gumi, and Gyeongsan, which displayed different Viroid concentrations. We found that the elimination rates varied depending on the cultivar and region of origin. Similar results were observed when the protocol was applied to eliminate CChMVd from the ‘Yellow Cap’ collected from the same regions. Finally, we found that nested PCR is more reliable for Viroid detection than RT-PCR. Overall, cryopreservation can be used to eliminate Viroids from infected Chrysanthemums; however, the efficacy depends on genotype and initial Viroid concentration.
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Elimination of Chrysanthemum Stunt Viroid (CSVd) from meristem tip culture combined with prolonged cold treatment
Horticulture Environment and Biotechnology, 2013Co-Authors: Wina Dian Savitri, Su Min Jeon, Kyung Il Park, Mi-young ChungAbstract:Chrysanthemum production in Korea has recently been greatly affected by the spread of Chrysanthemum Stunt Viroid (CSVd) infection, necessitating the use of CSVd-free stocks to ensure successful Chrysanthemum cultivation. We investigated the effects of low temperature (4°C), antiviral chemicals (ribavirin and amantadine) and a combination of these treatments on CSVd elimination by meristem tip cultures using plantlets that originated from CSVd-infected Chrysanthemum ‘Ency’. Neither antiviral agents led to CSVd elimination, despite the suppression of meristem tip growth in a concentration dependent manner. However, the CSVd elimination rate increased up to 42.8% when meristem tips were excised after storage at 4°C for two months. The most effective results were obtained from a combination of low temperature for three months at 4°C followed by meristem tip culture on media containing 50 and 100 mg·L^−1 ribavirin. These results suggest that antiviral agents can also be useful for CSVd elimination if their treatment is combined with prolonged periods of low temperature. This is the first report of eradication of Viroids from spray type Chrysanthemum bred in Korea.
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Elimination of Chrysanthemum Stunt Viroid (CSVd) from an Viroidinfected Chrysanthemum through Shoot Tip Culture
Korean Society for Floricultural Science, 2012Co-Authors: Su Min Jeon, Mi-young Chung, Wina Dian Savitri, Kyeung-il Park, Chang Kil KimAbstract:As the increase of Chrysanthemum demand on Chrysanthemum increases in Korea, the production of high quality Chrysanthemum is needed. Chrysanthemum Stunt Viroid (CSVd) is one of the important Viroid, which infects Chrysanthemum and induces diseases that affects the decrease of quality and yield. To solve this problem, we used different size of meristem of Chrysanthemum ‘Ency’ for shoot tip culture and also that of combined with heat treatment at 37οC. The efficiency of CSVd elimination was influenced by the size of shoot tip. The small-sized of meristems with 1 or 2 leaf primodia were regenerated into the highest number of CSVd-free plantlets. By RT-PCR, the 214-bp band corresponding to CSVd was not detected in 22.2% of the total number of tested regenerants from shoot tips with 2 leaf primordia. While, shoot tip culture combined with heat treatment of one-month-old in vitro shoots was not effective for CSVd-elimination. The CSVd-free plants grew more vigorously than CSVd-infected plants in the greenhouse.
Yosuke Matsushita - One of the best experts on this subject based on the ideXlab platform.
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Genetic diversity and pathogenicity of potato spindle tuber Viroid and Chrysanthemum Stunt Viroid isolates in Russia
European Journal of Plant Pathology, 2021Co-Authors: Yosuke Matsushita, Hironobu Yanagisawa, Aleksandr Khiutti, Nina Mironenko, Yasuo Ohto, Olga AfanasenkoAbstract:To investigate the current status of Viroid infection in potato fields in Russia, potato spindle tuber Viroid (PSTVd) and Chrysanthemum Stunt Viroid (CSVd) were detected in potato ( Solanum tuberosum ) and S. nigrum plants growing in the Volga (V), North-Western (NW), and Far Eastern (FE) federal districts in Russia. While both PSTVd and CSVd were detected in potato samples from the V and FE regions, only CSVd was detected in potato samples from NW. CSVd was detected in S. nigrum from FE, and this was the first detection of CSVd in S. nigrum . Analysis of the complete genomes of 30 PSTVd and 10 CSVd variants revealed that 5 and 7 PSTVd variants from V and FE, respectively, and 2, 4, and 3 CSVd variants from V, NW, and FE, respectively, were new. Analysis of the infectivity of and symptoms caused by 15 Russian PSTVd isolates in tomato revealed that 14 PSTVd isolates caused intermediate or severe symptoms, and only FP14 caused mild symptoms. Our survey revealed that most of the Russian PSTVd isolates from V and FE caused intermediate symptoms in tomato, and the genome sequences were identical to that of PSTVd isolated from S. demissum. Phylogenetic analysis of nucleotide sequences of the Russian PSTVd variants showed their close relationship to previously studied PSTVd isolates, suggesting that most strains in Russia have not substantially changed genetically, but have widely spread in potato fields.
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Screening of Chrysanthemum seticuspe accessions reveals different degrees of resistance to Chrysanthemum Stunt Viroid
European Journal of Plant Pathology, 2019Co-Authors: Yosuke Matsushita, Msaaki OsakaAbstract:The Chrysanthemum Stunt Viroid (CSVd) causes severe Stunting and significant reduction in flower yield and quality of commercial Chrysanthemum ( Chrysanthemum morifolium ). The pattern of inheritance and the detailed mechanism underlying CSVd resistance remains unclear. Chrysanthemum morifolium shows unstable and variable chromosome numbers that form a hexaploid complex with aneuploidy. To overcome the issue of complex hybridity and polyploidy, a diploid wild Chrysanthemum, C. seticuspe f. boreale was used here as an alternative model to C. morifolium . We screened 20 C . seticuspe accessions for resistance to CSVd and identified one resistant accession “AET-19” showing resistance. Tissue print hybridization analysis showed that CSVd concentration decreased in the uppermost leaves of the AET-19 after the scions were cut from the infected rootstocks, suggesting the resistance seems to be ‘CSVd-disappearance type’. In situ hybridization experiments revealed that CSVd does not invade the shoot tip of AET-19 plants after graft-inoculation onto infected rootstocks. Taken together, the results highlight the usefulness of C. setiscupe as a model for analyzing the mechanism of CSVd resistance and its pattern of inheritance.
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First report of Chrysanthemum Stunt Viroid isolated from potato (Solanum tuberosum) plants in Russia
Journal of General Plant Pathology, 2019Co-Authors: Yosuke Matsushita, Hironobu Yanagisawa, Aleksandr Khiutti, Nina Mironenko, Yasuo Ohto, Olga AfanasenkoAbstract:A pospiViroid, detected from asymptomatic potato plants ( Solanum tuberosum ) from Russia, was identified as Chrysanthemum Stunt Viroid (CSVd). The genomic sequence of this potato isolate showed 100% identity with that of the Chrysanthemum isolates from Japan. The CSVd RNA transcribed from the cDNA, having the sequence of the isolate from Russia, was able to infect potato, tomato, and Chrysanthemum plants. The infected Chrysanthemum plants exhibited Stunting symptom. This is the first report of the occurrence of CSVd in Russia, its natural infection of potato plants and the potential spread of CSVd through propagation of infected potato.
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Chrysanthemum Stunt Viroid Resistance in Chrysanthemum
MDPI AG, 2018Co-Authors: Tomoyuki Nabeshima, Yosuke Matsushita, Munetaka HosokawaAbstract:Chrysanthemum Stunt Viroid (CSVd) is one of the most severe threats in Chrysanthemum morifolium production. Over the last decade, several studies have reported the natural occurrence of CSVd resistance in Chrysanthemum germplasms. Such CSVd-resistant germplasms are desirable for the stable production of Chrysanthemum plants. Current surveys include finding new resistant Chrysanthemum cultivars, breeding, and revealing resistant mechanisms. We review the progress, from discovery to current status, of CSVd-resistance studies, while introducing information on the improvement of associated inoculation and diagnostic techniques
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Effect of low temperature on the distribution of Chrysanthemum Stunt Viroid in Chrysanthemum morifolium
Phytoparasitica, 2015Co-Authors: Yosuke Matsushita, Yoshiteru ShimaAbstract:Replication and cellular movement of Viroids are dependent on host plant components. Low temperatures reduce the physiological activity of host plants and thus suppress the levels of Viroids. Chrysanthemum Stunt Viroid (CSVd) concentration was reduced in infected Chrysanthemum ( Chrysanthemum morifolium ) plants subjected to low-temperature treatment compared with untreated plants. In this study, we investigated the distribution patterns of CSVd in the developing shoot tips of CSVd-infected Chrysanthemum plants subjected to one-month, three-month, and six-month low-temperature treatment using in situ hybridization. After one month of low-temperature treatment, strong CSVd signals were detected in leaf primordia (LP) and the apical dome (AD); after three months, weak CSVd signals were detected in LP and the AD; while after six months, CSVd signals were not detected in LP or the AD, but only in tissues within the vascular bundle directly beneath Viroid-free LP and AD areas. These changes in the distribution of CSVd in shoot tips subjected to low-temperature treatment might result from a reduction in Viroid replication and/or the inhibition of Viroid intra- and intercellular movement.
Dagragnar Blystad - One of the best experts on this subject based on the ideXlab platform.
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low temperature treatment affects concentration and distribution of Chrysanthemum Stunt Viroid in argyranthemum
Frontiers in Microbiology, 2016Co-Authors: Zhibo Zhang, Yeonkyeong Lee, Jihong Liu Clarke, Qiaochun Wang, Astrid Sivertsen, Gry Skjeseth, Sissel Haugslien, Dagragnar BlystadAbstract:Chrysanthemum Stunt Viroid (CSVd) can infect Argyranthemum and cause serious economic loss. Low temperature treatment combined with meristem culture has been applied to eradicate Viroids from their hosts, but without success in eliminating CSVd from diseased Argyranthemum. The objectives of this work were to investigate 1) the effect of low temperature treatment combined with meristem culture on elimination of CSVd, 2) the effect of low temperature treatment on CSVd distribution pattern in shoot apical meristem (SAM), and 3) CSVd distribution in flowers and stems of two infected Argyranthemum cultivars. After treatment with low temperature combined with meristem tip culture, two CSVd-free plants were found in ‘Border Dark Red’, but none in ‘Yellow Empire’. With the help of in situ hybridization, we found that CSVd distribution patterns in the SAM showed no changes in diseased ‘Yellow Empire’ following 5oC treatment, compared with non-treated plants. However, the CSVd-free area in SAM was enlarged in diseased ‘Border Dark Red’ following prolonged 5oC treatment. Localization of CSVd in the flowers and stems of infected ‘Border Dark Red’ and ‘Yellow Empire’ indicated that seeds could not transmit CSVd in these two cultivars, and CSVd existed in phloem. Results obtained in the study contributed to better understanding of the distribution of CSVd in systemically infected plants and the combination of low temperature treatment and meristem tip culture for production of Viroid-free plants.
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invasion of shoot apical meristems by Chrysanthemum Stunt Viroid differs among argyranthemum cultivars
Frontiers in Plant Science, 2014Co-Authors: Zhibo Zhang, Yeonkyeong Lee, Carl Spetz, Jihong Liu Clarke, Qiaochun Wang, Dagragnar BlystadAbstract:Chrysanthemum Stunt Viroid (CSVd) is a damaging pathogen attacking Argyranthemum plants. Our study attempted to reveal distribution patterns of CSVd in shoot apical meristems (SAM) and to explore reasons for differential ability of CSVd to invade SAM of selected Argyranthemum cultivars. Symptom development was also observed on greenhouse-grown Argyranthemum plants. Viroid localization using in situ hybridization revealed that the ability of CSVd to invade SAM differed among cultivars. In diseased ‘Yellow Empire’ and ‘Butterfly’, CSVd was found in all tissues including the uppermost cell layers in the apical dome and the youngest leaf primordia 1 and 2. In diseased ‘Border Dark Red’ and ‘Border Pink’, CSVd was detected in the lower part of the apical dome and elder leaf primordia, leaving the upper part of the apical dome, and leaf primordia 1 and 2 free of Viroid. Histological observations and transmission electron microscopy showed similar developmental patterns of vascular tissues and plasmodesmata in the SAMs of ‘Yellow Empire’ and ‘Border Dark Red’, while immunolocalization studies revealed a major difference in the number of callose (β -1, 3-glucan) particles deposited at plasmodesmata in SAM. A lower number of callose particles were found deposited at plasmodesmata of SAM of ‘Yellow Empire’ than ‘Border Dark Red’. This difference is most likely responsible for the differences in ability of CSVd to invade SAM among Argyranthemum cultivars.