scholarly journals Multiple Resistance Traits Control Plum pox virus Infection in Arabidopsis thaliana

2006 ◽  
Vol 19 (5) ◽  
pp. 541-549 ◽  
Author(s):  
V. Decroocq ◽  
O. Sicard ◽  
J. M. Alamillo ◽  
M. Lansac ◽  
J. P. Eyquard ◽  
...  
Keyword(s):  
Recessive Gene ◽  
Systemic Infection ◽  
Chromosome 1 ◽  
Plum Pox Virus ◽  
Local Infection ◽  
Lettuce Mosaic Virus ◽  
Long Distance ◽  
Resistance Pathway ◽  
Long Distance Movement ◽  
First Time

Twelve Arabidopsis accessions were challenged with Plum pox potyvirus (PPV) isolates representative of the four PPV strains. Each accession supported local and systemic infection by at least some of the PPV isolates, but high variability was observed in the behavior of the five PPV isolates or the 12 Arabidopsis accessions. Resistance to local infection or long-distance movement occurred in about 40% of all the accession-isolate combinations analyzed. Except for Nd-1, all accessions showed resistance to local infection by PPV-SoC; in the Landsberg erecta (Ler) accession, this resistance was compromised by sgt1 and rar1 mutations, suggesting that it could be controlled by an R gene-mediated resistance pathway. While most of the susceptible accessions were symptomless, PPV induced severe symptoms on inflorescences in C24, Ler, and Bay-0 as early as 15 days after inoculation. Genetic analyses indicated that these interaction phenotypes are controlled by different genetic systems. The restriction of long-distance movement of PPV-El Amar and of another member of genus Potyvirus, Lettuce mosaic virus, in Col-0 requires the RTM genes, indicating for the first time that the RTM system may provide a broad range, potyvirus-specific protection against systemic infection. The restriction to PPVPS long-distance movement in Cvi-1 is controlled by a single recessive gene, designated rpv1, which was mapped to chromosome 1. The nuclear inclusion polymerase b-capsid protein region of the viral genome appears to be responsible for the ability of PPV-R to overcome rpv1-mediated resistance.

scholarly journals The Determinant of Potyvirus Ability to Overcome the RTM Resistance of Arabidopsis thaliana Maps to the N-Terminal Region of the Coat Protein

2009 ◽  
Vol 22 (10) ◽  
pp. 1302-1311 ◽  
Author(s):  
V. Decroocq ◽  
B. Salvador ◽  
O. Sicard ◽  
M. Glasa ◽  
P. Cosson ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Coat Protein ◽  
Biological Properties ◽  
Terminal Region ◽  
Plum Pox Virus ◽  
Lettuce Mosaic Virus ◽  
Long Distance ◽  
Resistance Breaking ◽  
Viral Determinant ◽  
Long Distance Movement

In Arabidopsis thaliana Columbia (Col-0) plants, the restriction of Tobacco etch virus (TEV) long-distance movement involves at least three dominant RTM (restricted TEV movement) genes named RTM1, RTM2, and RTM3. Previous work has established that, while the RTM-mediated resistance is also effective against other potyviruses, such as Plum pox virus (PPV) and Lettuce mosaic virus (LMV), some isolates of these viruses are able to overcome the RTM mechanism. In order to identify the viral determinant of this RTM-resistance breaking, the biological properties of recombinants between PPV-R, which systemically infects Col-0, and PPV-PSes, restricted by the RTM resistance, were evaluated. Recombinants that contain the PPV-R coat protein (CP) sequence in an RTM-restricted background are able to systemically infect Col-0. The use of recombinants carrying chimeric CP genes indicated that one or more PPV resistance-breaking determinants map to the 5′ half of the CP gene. In the case of LMV, sequencing of independent RTM-breaking variants recovered after serial passages of the LMV AF199 isolate on Col-0 plants revealed, in each case, amino acid changes in the CP N-terminal region, close to the DAG motif. Taken together, these findings demonstrate that the potyvirus CP N-terminal region determines the outcome of the interaction with the RTM-mediated resistance.

scholarly journals Maize resistance to Sugarcane mosaic virus

2017 ◽  
Vol 38 (SI 2 - 6th Conf EFPP 2002) ◽  
pp. 542-544
Author(s):  
R. Pokorný ◽  
M. Porubová
Keyword(s):  
Mosaic Virus ◽  
Systemic Infection ◽  
Sugarcane Mosaic Virus ◽  
Resistant Line ◽  
Mechanisms Of Resistance ◽  
Long Distance ◽  
Maize Hybrids ◽  
Resistant Lines ◽  
Maize Resistance ◽  
Long Distance Movement

Under greenhouse conditions 12 maize hybrids derived from crosses of four resistant lines with several lines of different level of susceptibility were evaluated for resistance to Czech isolate of Sugarcane mosaic virus (SCMV). These hybrids were not fully resistant to isolate of SCMV, but the symptoms on their newly growing leaves usually developed 1 to 3 weeks later in comparison with particular susceptible line, the course of infection was significantly slower and rate of infection lower. As for mechanisms of resistance, the presence of SCMV was detected by ELISA in inoculated leaves both of resistant and susceptible lines, but virus was detected 7 days later in resistant line. Systemic infection developed only in susceptible lines. These results indicate restriction of viral long distance movement in the resistant line.

scholarly journals Potyviral 6K2 Protein Long-Distance Movement and Symptom-Induction Functions Are Independent and Host-Specific

2004 ◽  
Vol 17 (5) ◽  
pp. 502-510 ◽  
Author(s):  
Carl Spetz ◽  
Jari P. T. Valkonen
Keyword(s):  
Spontaneous Mutation ◽  
Systemic Infection ◽  
Wild Type ◽  
Virus Propagation ◽  
Long Distance ◽  
Potato Virus A ◽  
Viral Mutant ◽  
Membrane Bound ◽  
Long Distance Movement

Deletion of various portions, or insertion of six histidine residues (6×His) into various positions of the membrane-bound 6K2 protein (53 amino acids) of Potato virus A (PVA, genus Potyvirus), inhibited systemic infection in Nicotiana tabacum and N. benthamiana plants. However, a spontaneous mutation (Gly2Cys) that occurred in 6K2 adjacent to the 6×His insert placed between Ser1 and Gly2 enabled systemic infection in a single N. benthamiana plant. No symptoms were observed, but virus titers were similar to the symptom-inducing wild-type (wt) PVA. N. tabacum plants were not systemically infected, albeit virus propagation was observed in inoculated protoplasts. The 6×His/Gly2Cys mutant was reconstructed in vitro and serially propagated by mechanical inoculation in N. benthamiana. Following the third passage, a novel viral mutant appeared, lacking the last four His residues of the insert, as well as the Gly2 and Thr3 of 6K2. It infected N. tabacum plants systemically, and in the systemically infected N. benthamiana leaves, vein chlorosis and mild yellowing symptoms were observed, typical of wt PVA infection. The mutant virus accumulated to titers similar to wt PVA in both hosts. These results show that the PVA 6K2 protein affects viral long-distance movement and symptom induction independently and in a host-specific manner.

scholarly journals The Rate of Cell-to-Cell Movement in Squash of Cucumber Mosaic Virus Is Affected by Sequences of the Capsid Protein

1999 ◽  
Vol 12 (7) ◽  
pp. 628-632 ◽  
Author(s):  
Sek-Man Wong ◽  
Sharon Swee-Chin Thio ◽  
Michael H. Shintaku ◽  
Peter Palukaitis
Keyword(s):  
Amino Acids ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Capsid Protein ◽  
Cell Movement ◽  
Systemic Infection ◽  
Long Distance ◽  
Local Movement ◽  
Long Distance Movement

The M strain of cucumber mosaic virus (CMV) does not infect squash plants systemically and moves very slowly in inoculated cotyledons. Systemic infection and an increase in the rate of local movement were observed when amino acids 129 or 214 of the M-CMV capsid protein (CP) were altered to those present in the Fny strain of CMV. While the opposite alterations to the CP of Fny-CMV inhibited systemic infection of squash, they did not show the same effects on the rates of both cell-to-cell and long-distance movement. However, the ability of CMV to infect squash systemically was affected by the rate of cell-to-cell movement.

scholarly journals Long-Distance Movement, Virulence, and RNA Silencing Suppression Controlled by a Single Protein in Hordei- and Potyviruses: Complementary Functions between Virus Families

2002 ◽  
Vol 76 (24) ◽  
pp. 12981-12991 ◽  
Author(s):  
Natalia E. Yelina ◽  
Eugene I. Savenkov ◽  
Andrey G. Solovyev ◽  
Sergey Y. Morozov ◽  
Jari P. T. Valkonen
Keyword(s):  
Transgenic Plants ◽  
Viral Infection ◽  
Symptom Severity ◽  
Rna Silencing ◽  
Systemic Infection ◽  
Stress Factors ◽  
Viral Gene ◽  
Long Distance ◽  
Silencing Suppression ◽  
Long Distance Movement

ABSTRACT RNA silencing is a natural defense mechanism against genetic stress factors, including viruses. A mutant hordeivirus (Barley stripe mosaic virus [BSMV]) lacking the γb gene was confined to inoculated leaves in Nicotiana benthamiana, but systemic infection was observed in transgenic N. benthamiana expressing the potyviral silencing suppressor protein HCpro, suggesting that the γb protein may be a long-distance movement factor and have antisilencing activity. This was shown for γb proteins of both BSMV and Poa semilatent virus (PSLV), a related hordeivirus. Besides the functions in RNA silencing suppression, γb and HCpro had analogous effects on symptoms induced by the hordeiviruses. Severe BSMV-induced symptoms were correlated with high HCpro concentrations in the HCpro-transgenic plants, and substitution of the γb cistron of BSMV with that of PSLV led to greatly increased symptom severity and an altered pattern of viral gene expression. The efficient systemic infection with the chimera was followed by the development of dark green islands (localized recovery from infection) in leaves and exemption of new developing leaves from infection. Recovery and the accumulation of short RNAs diagnostic of RNA silencing in the recovered tissues in wild-type N. benthamiana were suppressed in HCpro-transgenic plants. These results provide evidence that potyviral HCpro and hordeivirus γb proteins contribute to systemic viral infection, symptom severity, and RNA silencing suppression. HCpro's ability to suppress the recovery of plants from viral infection emphasizes recovery as a manifestation of RNA silencing.

scholarly journals Bromovirus Movement Protein Conditions for the Host Specificity of Virus Movement Through the Vascular System and Affects Pathogenicity in Cowpea

2000 ◽  
Vol 13 (11) ◽  
pp. 1195-1203 ◽  
Author(s):  
Yasunari Fujita ◽  
Miki Fujita ◽  
Kazuyuki Mise ◽  
Takashi Kobori ◽  
Takeshi Osaki ◽  
...  
Keyword(s):  
Movement Protein ◽  
Vascular System ◽  
Systemic Infection ◽  
Brome Mosaic Virus ◽  
Long Distance ◽  
Mesophyll Cells ◽  
Cowpea Chlorotic Mottle Virus ◽  
Chlorotic Mottle Virus ◽  
Chlorotic Mottle ◽  
Long Distance Movement

Previously, we reported that CCMV(B3a), a hybrid of bromovirus Cowpea chlorotic mottle virus (CCMV) with the 3a cell-to-cell movement protein (MP) gene replaced by that of cowpea-nonadapted bromovirus Brome mosaic virus (BMV), can form small infection foci in inoculated cowpea leaves, but that expansion of the foci stops between 1 and 2 days postinoculation. To determine whether the lack of systemic movement of CCMV(B3a) is due to restriction of local spread at specific leaf tissue interfaces, we conducted more detailed analyses of infection in inoculated leaves. Tissue-printing and leaf press-blotting analyses revealed that CCMV(B3a) was confined to the inoculated cowpea leaves and exhibited constrained movement into leaf veins. Immunocytochemical analyses to examine the infected cell types in inoculated leaves indicated that CCMV(B3a) was able to reach the bundle sheath cells through the mesophyll cells and successfully infected the phloem cells of 50% of the examined veins. Thus, these data demonstrate that the lack of long-distance movement of CCMV(B3a) is not due to an inability to reach the vas-culature, but results from failure of the virus to move through the vascular system of cowpea plants. Further, a previously identified 3a coding change (A776C), which is required for CCMV(B3a) systemic infection of cowpea plants, suppressed formation of reddish spots, mediated faster spread of infection, and enabled the virus to move into the veins of inoculated cowpea leaves. From these data, and the fact that CCMV(B3a) directs systemic infection in Nicotiana benthamiana, a permissive systemic host for both BMV and CCMV, we conclude that the bromovirus 3a MP engages in multiple activities that contribute substantially to host-specific long-distance movement through the phloem.

scholarly journals Host-Specific Involvement of the HC Protein in the Long-Distance Movement of Potyviruses

2002 ◽  
Vol 76 (4) ◽  
pp. 1922-1931 ◽  
Author(s):  
Pilar Sáenz ◽  
Beatriz Salvador ◽  
Carmen Simón-Mateo ◽  
Kristin D. Kasschau ◽  
James C. Carrington ◽  
...  
Keyword(s):  
Potato Virus X ◽  
Tobacco Etch Virus ◽  
Plum Pox Virus ◽  
Transgenic Tobacco Plants ◽  
Relevant Factor ◽  
Apparent Effect ◽  
Long Distance ◽  
Tobacco Plants ◽  
Coding Sequences ◽  
Long Distance Movement

ABSTRACT Plum pox virus (PPV) is a member of the Potyvirus genus that, in nature, infects trees of the Prunus genus. Although PPV infects systemically several species of the Nicotiana genus, such as N. clevelandii and N. benthamiana, and replicates in the inoculated leaves of N. tabacum, it is unable to infect systemically the last host. The long-distance movement defect of PPV was corrected in transgenic tobacco plants expressing the 5"-terminal region of the genome of tobacco etch virus (TEV), a potyvirus that infects systemically tobacco. The fact that PPV was unable to move to upper noninoculated leaves in tobacco plants transformed with the same TEV transgene, but with a mutation in the HC protein (HC-Pro)-coding sequences, identifies the multifunctional HC-Pro as the complementing factor, and strongly suggests that a defect in an HC-Pro activity is responsible for the long-distance movement defect of PPV in tobacco. Whereas PPV HC-Pro strongly intensifies the symptoms caused by potato virus X (PVX) in the PPV systemic hosts N. clevelandii and N. benthamiana, it has no apparent effect on PVX pathogenicity in tobacco, supporting the hypothesis that long-distance movement and pathogenicity enhancement are related activities of the potyviral HC proteins. The movement defect of PPV in tobacco could also be complemented by cucumber mosaic virus in a mixed infection, demonstrating that at least some components of the long-distance machinery of the potyviruses are not strictly virus specific. A general conclusion of this work is that the HC-Pro might be a relevant factor for controlling the host range of the potyviruses.

Juvenile Dispersal and Development of Site-Fidelity in the Black-Capped Chickadee

The Auk ◽  
1979 ◽  
Vol 96 (1) ◽  
pp. 40-55 ◽  
Author(s):  
Charles M. Weise ◽  
John R. Meyer
Keyword(s):  
Site Fidelity ◽  
Breeding Population ◽  
Dispersal Distance ◽  
Long Distance ◽  
Parus Atricapillus ◽  
Juvenile Dispersal ◽  
Dispersal Mechanism ◽  
Site Tenacity ◽  
Long Distance Movement ◽  
First Time

Abstract Dispersal of young was studied in a non-migratory population of the Black-capped Chickadee (Parus atricapillus) in southeastern Wisconsin. Eighty-eight chickadees were color-banded as nestlings. After fledging, the birds remained with their parents on or near the parental territory for about 3 weeks. In late June or early July family breakup occurred suddenly, with the young moving rapidly away. Most of the birds disappeared completely from the area; 6 were later discovered in the breeding population at distances of 0.4 to ca. 11 km, with a median dispersal distance of 1.1 km. This movement appeared to be an innate dispersal mechanism. In contrast, among 103 chickadees first trapped in July and early August as independent juveniles and later found on their breeding territories, the median distance from point where banded to territory was 204 m (maximum = 1,160 m). As distances up to 2.4 km could have been detected in our study area, we conclude that by late July and August chickadees have virtually finished dispersing and are developing site tenacity in the places where they will subsequently breed. Whether dispersal also occurs in spring was investigated using the monthly patterns of arrivals and disappearances from winter feeders. Adults and summer-banded juveniles inhabiting the parts of the study area nearest the feeders arrived for the first time at the feeders in November and December, but birds from more remote areas continued to arrive through the winter and spring. In previously unbanded juveniles there was an increase in arrivals in March and April. On the basis of an analysis of loss rates by sex and age, we conclude that only about 5% of yearling males and 9% of yearling females undertake some dispersal or spacing movements in spring. Thus, in the Black-capped Chickadee the main dispersal mechanism is an innate, rapid, fairly long-distance movement of the juvenile, taking place in summer just after family breakup. A small fraction of the yearling population undertakes some dispersal movement in the winter or spring.

scholarly journals Citrus Tristeza Virus: Survival at the Edge of the Movement Continuum

2008 ◽  
Vol 82 (13) ◽  
pp. 6546-6556 ◽  
Author(s):  
Svetlana Y. Folimonova ◽  
Alexey S. Folimonov ◽  
Satyanarayana Tatineni ◽  
William O. Dawson
Keyword(s):  
Citrus Tristeza Virus ◽  
Cell Movement ◽  
Systemic Infection ◽  
Sour Orange ◽  
Citrus Species ◽  
Long Distance ◽  
Susceptible Host ◽  
Long Distance Movement ◽  
Tristeza Virus ◽  
Citrus Tristeza

ABSTRACT Systemic invasion of plants by viruses is thought to involve two processes: cell-to-cell movement between adjacent cells and long-distance movement that allows the virus to rapidly move through sieve elements and unload at the growing parts of the plant. There is a continuum of proportions of these processes that determines the degrees of systemic infection of different plants by different viruses. We examined the systemic distribution of Citrus tristeza virus (CTV) in citrus species with a range of susceptibilities. By using a “pure” culture of CTV from a cDNA clone and green fluorescent protein-labeled virus we show that both cell-to-cell and long-distance movement are unusually limited, and the degree of limitation varies depending on the citrus host. In the more-susceptible hosts CTV infected only a small portion of phloem-associated cells, and moreover, the number of infection sites in less-susceptible citrus species was substantially decreased further, indicating that long-distance movement was reduced in those hosts. Analysis of infection foci in the two most differential citrus species, Citrus macrophylla and sour orange, revealed that in the more-susceptible host the infection foci were composed of a cluster of multiple cells, while in the less-susceptible host infection foci were usually single cells, suggesting that essentially no cell-to-cell movement occurred in the latter host. Thus, CTV in sour orange represents a pattern of systemic infection in which the virus appears to function with only the long-distance movement mechanism, yet is able to survive in nature.

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