scholarly journals Quantitative Real-Time PCR Analysis of Individual Flue-Cured Tobacco Seeds and Seedlings Reveals Seed Transmission of Tobacco Mosaic Virus

2020 ◽  
Vol 110 (1) ◽  
pp. 194-205 ◽  
Author(s):  
Madeleine D. Ellis ◽  
Jessica M. Hoak ◽  
Bradley W. Ellis ◽  
Jessica A. Brown ◽  
Tim L. Sit ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Seed Coat ◽  
Rna Virus ◽  
Seed Transmission ◽  
Pcr Analysis ◽  
Infected Seed ◽  
Tobacco Seed ◽  
Individual Seed ◽  
Tobacco Seeds

Tobacco mosaic virus (TMV) is an extensively studied RNA virus known to infect tobacco (Nicotiana tabacum) and other solanaceous crops. TMV has been classified as a seedborne virus in tobacco, with infection of developing seedlings thought to occur from contact with the TMV-infected seed coat. The mechanism of TMV transmission through seed was studied in seed of the K 326 cultivar of flue-cured tobacco. Cross pollinations were performed to determine the effect of parental tissue on TMV infection in seed. Dissection of individual tobacco seeds into seed coat, endosperm, and embryo was performed to determine TMV location within a seed, while germination tests and separation of the developing seedling into seed coat, roots, and cotyledons were conducted to estimate the percent transmission of TMV. A reverse-transcriptase quantitative PCR (RT-qPCR) assay was developed and used to determine TMV concentrations in individual seed harvested from pods that formed on plants from TMV-infected and noninfected crosses. The results showed maternal transmission of TMV to tobacco seed and seedlings that developed from infected seed, not paternal transmission. RT-qPCR and endpoint PCR assays were also conducted on the separated seed coat, endosperm, and embryo of individual seed and separated cotyledons, roots, and seed coats of individual seedlings that developed from infected tobacco seed to identify the location of the virus in the seed and the subsequent path the virus takes to infect the developing seedling. RT-qPCR and endpoint PCR assay results showed evidence of TMV infection in the endosperm and embryo, as well as in the developing seedling roots and cotyledons within 10 days of initiating seed germination. To our knowledge, this is the first report of TMV being detected in embryos of tobacco seed, demonstrating that TMV is seedborne and seed-transmitted in flue-cured tobacco.

scholarly journals Evaluation of Seed Transmission of Turnip yellow mosaic virus and Tobacco mosaic virus in Arabidopsis thaliana

2000 ◽  
Vol 90 (11) ◽  
pp. 1233-1238 ◽  
Author(s):  
F. M. de Assis Filho ◽  
J. L. Sherwood
Keyword(s):  
Arabidopsis Thaliana ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Seed Coat ◽  
Virus Transmission ◽  
Systemic Infection ◽  
Seed Transmission ◽  
Yellow Mosaic Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Turnip Yellow Mosaic Virus

The mechanism of virus transmission through seed was studied in Arabidopsis thaliana infected with Turnip yellow mosaic virus (TYMV) and Tobacco mosaic virus (TMV). Serological and biological tests were conducted to identify the route by which the viruses reach the seed and subsequently are located in the seed. Both TYMV and TMV were detected in seed from infected plants, however only TYMV was seed-transmitted. This is the first report of transmission of TYMV in seed of A. thaliana. Estimating virus seed transmission by grow-out tests was more accurate than enzyme-linked immunosorbent assay due to the higher frequency of antigen in the seed coat than in the embryo. Virus in the seed coat did not lead to seedling infection. Thus, embryo invasion is necessary for seed transmission of TYMV in A. thaliana. Crosses between healthy and virus-infected plants indicated that TYMV from either the female or the male parent could invade the seed. Conversely, invasion from maternal tissue was the only route for TMV to invade the seed. Pollination of flowers on healthy A. thaliana with pollen from TYMV-infected plants did not result in systemic infection of healthy plants, despite TYMV being carried by pollen to the seed.

scholarly journals Multiple Loci Condition Seed Transmission of Soybean mosaic virus (SMV) and SMV-Induced Seed Coat Mottling in Soybean

2011 ◽  
Vol 101 (6) ◽  
pp. 750-756 ◽  
Author(s):  
Leslie L. Domier ◽  
Houston A. Hobbs ◽  
Nancy K. McCoppin ◽  
Charles R. Bowen ◽  
Todd A. Steinlage ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Seed Coat ◽  
Soybean Mosaic Virus ◽  
Seed Transmission ◽  
Primary Sources ◽  
Posttranscriptional Gene Silencing ◽  
Plant Introductions ◽  
Multiple Loci ◽  
Soybean Plants ◽  
Simple Sequence

Infection of soybean plants with Soybean mosaic virus (SMV), which is transmitted by aphids and through seed, can cause significant reductions in seed production and quality. Because seedborne infections are the primary sources of inoculum for SMV infections in North America, host-plant resistance to seed transmission can limit the pool of plants that can serve as sources of inoculum. To examine the inheritance of SMV seed transmission in soybean, crosses were made between plant introductions (PIs) with high (PI88799), moderate (PI60279), and low (PI548391) rates of transmission of SMV through seed. In four F2 populations, SMV seed transmission segregated as if conditioned by two or more genes. Consequently, a recombinant inbred line population was derived from a cross between PIs 88799 and 548391 and evaluated for segregation of SMV seed transmission, seed coat mottling, and simple sequence repeat markers. Chromosomal regions on linkage groups C1 and C2 were significantly associated with both transmission of isolate SMV 413 through seed and SMV-induced seed coat mottling, and explained ≈42.8 and 46.4% of the variability in these two traits, respectively. Chromosomal regions associated with seed transmission and seed coat mottling contained homologues of Arabidopsis genes DCL3 and RDR6, which encode enzymes involved in RNA-mediated transcriptional and posttranscriptional gene silencing.

Comparison of some pea seed-borne mosaic virus isolates and their detection by dot-immunobinding assay

1991 ◽  
Vol 42 (3) ◽  
pp. 441 ◽  
Author(s):  
JS Ligat ◽  
D Cartwright ◽  
JW Randles
Keyword(s):  
Pisum Sativum ◽  
Mosaic Virus ◽  
Limit Of Detection ◽  
Germination Rate ◽  
Seed Transmission ◽  
Healthy Plant ◽  
Chenopodium Amaranticolor ◽  
Infected Seed ◽  
The Us ◽  
Pea Seed

Five isolates of pea seed-borne mosaic virus (US, S4, S6, Q and T) were compared by host range and symptomatology on 16 Pisum sativum cultivars and lines, 21 lines of Lathyrus and Lens spp. and several indicator species. All selections of Pisum sativum, except cv. Greenfeast, were susceptible to all isolates, but Greenfeast was susceptible to the US isolate. All isolates except T infected the Lathyrus and Lens spp. through mechanical and aphid transmissions. Chenopodium amaranticolor and Vicia faba reacted similarly to all isolates, Phaseolus vulgaris cv. Hawkesbury Wonder reacted to none. The North American isolate (US) was distinguished from the Australian S4, S6, Q, and T isolates by infecting Nicotiana clevelandii and Greenfeast pea. In all cases the highest rate of seed transmission occurred in the largest seed (82-91%) and the lowest was in the smallest seed (27-40%). Infected seed in the largest size classes was lighter in weight than the corresponding uninfected seed. Infected seed in all classes had a significantly lower germination rate than uninfected seed although the greatest reduction in germinability was in the smallest seed. In each size class uninfected seed was heavier than infected seed and germinated better. Two-dimensional immunodiffusion tests showed that precipitin lines between all the isolates and either the US and S6 antisera were confluent with no evidence of spurs. A rapid and sensitive indirect dot-immunobinding assay on nitrocellulose membrane for PSbMV was developed in which non-specific reactions were eliminated by using mannose and glucose in buffers, and healthy plant sap as a blocking agent. The limit of detection of antigen was about 32 ng per sample. Both of the antisera detected antigen in sap extracted from peas infected with the 6 PSbMV isolates, originating from the USA, Australia, New Zealand and Denmark and all isolates were detected at similar antiserum dilution endpoints.

Further studies on Pea seed-borne mosaic virus in cool-season crop legumes: responses to infection and seed quality defects

2008 ◽  
Vol 59 (12) ◽  
pp. 1130 ◽  
Author(s):  
B. A. Coutts ◽  
R. T. Prince ◽  
R. A. C. Jones
Keyword(s):  
Mosaic Virus ◽  
Seed Coat ◽  
Faba Bean ◽  
Seed Quality ◽  
Broad Bean ◽  
Seed Transmission ◽  
Field Pea ◽  
Cool Season ◽  
Moderately Resistant ◽  
Pea Seed

Field and glasshouse experiments (3 of each) were done during 2003–06 to determine the responses of a range of genotypes belonging to 13 species of cool-season crop legumes to infection with Pea seed-borne mosaic virus (PSbMV). Seed quality defects were determined and genotypes of some species were also tested for seed transmission of the virus. In field experiments, of 39 genotypes of field pea (Pisum sativum) evaluated, 15 were ranked as highly susceptible, 10 susceptible, 9 moderately resistant, and 5 resistant, while all 7 lupin species (Lupinus spp.) tested were resistant. In glasshouse sap and graft inoculations with PSbMV to genotypes not found infected in the field and 2 additional lupin species, no virus was detected in any of the 9 lupin species or in 5 field pea genotypes tested. Thus, the lupins all appeared to be non-hosts and the 5 field pea genotypes had resistance to the 2 PSbMV isolates used to inoculate them. All 14 genotypes of faba bean (Vicia faba) evaluated in the field were ranked highly susceptible, while 12 out of 16 lentil (Lens culinaris) genotypes were ranked as highly susceptible and 4 as susceptible. Chickpea (Cicer arietinum) genotypes were moderately resistant (50) or susceptible (7). Once infected, plant sensitivities (symptom severities) ranged from low in some field pea and most lentil genotypes to high in most faba bean genotypes. Chickpea genotypes all were ranked as moderately sensitive. Seed lots harvested from PSbMV-infected plants of field pea, faba bean, and chickpea all showed severe seed quality defects, but lentil was usually less affected. The predominant seed symptoms were necrotic rings and line markings on the seed coat, malformation, reduced size, and splitting. Kabuli chickpea types also showed darkening of the seed coat. Seed transmission of PSbMV was detected in faba bean (0.2%) and field pea (5–30%). When PSbMV infection foci were introduced into plots of lentil cv. Nugget, the virus spread to the lentil plants and decreased shoot dry weight by 23%, seed yield by 96%, and individual seed weight by 58%. Seed transmission of PSbMV (6%) was detected in seed from the infected lentil plants. In a survey for possible viral seed symptoms, all seed lots of kabuli chickpea (5) and field pea (70), and 10 of 18 of faba bean were affected, but none of the 23 of lentil. When seedlings from 16 faba bean and 7 field pea seed lots were tested for 3 viruses, neither Broad bean stain virus nor Broad bean true mosaic virus was detected, but PSbMV was found in 5 field pea seed lots at incidences of <1–14%. PSbMV was detected in commercial field pea seed stocks of cvv. Kaspa (33) and Parafield (12) at incidences of 0.5–47% and 0.3–30%, respectively. The implications of these findings in terms of genotype susceptiblility and sensitivity to PSbMV infection and their importance for the management of PSbMV in legume crops are discussed.

scholarly journals The Effect of Developing Embryos on Plant Viruses

1957 ◽  
Vol 10 (4) ◽  
pp. 443 ◽  
Author(s):  
NC Crowley
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Seed Transmission ◽  
Plant Viruses

The theory that inactivation of tobacco mosaic virus by developing embryos prevents its seed transmission was tested by growing tomato embryos in media containing the virus. In many trials, using a variety of techniques, no evidence of any virus�inactivating activity was detected.

scholarly journals Seed Transmissibility of Alfalfa mosaic virus in Soybean

2010 ◽  
Vol 11 (1) ◽  
pp. 41 ◽  
Author(s):  
B. He ◽  
O. L. Fajolu ◽  
R.-H. Wen ◽  
M. R. Hajimorad
Keyword(s):  
Mosaic Virus ◽  
Alfalfa Mosaic Virus ◽  
Seed Transmission ◽  
Infected Seed ◽  
Seed Transmissibility

Collectively, this report provides unequivocal evidence on Alfalfa mosaic virus (AMV) seed transmission in soybean. Infected seed may serve as a reservoir for survival and spread of AMV in soybean. Accepted for publication 18 November 2010. Published 27 December 2010.

Selectable marker-free co-expression of Nicotiana rustica CN and Nicotiana tabacum HAK1 genes improves resistance to tobacco mosaic virus in tobacco

2015 ◽  
Vol 42 (8) ◽  
pp. 802 ◽  
Author(s):  
Li-Jun Qin ◽  
Dan Zhao ◽  
Yi Zhang ◽  
De-Gang Zhao
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Plant Cells ◽  
Viral Disease ◽  
Breeding Strategy ◽  
Pcr Analysis ◽  
Physiological Status ◽  
Plant Responses ◽  
Biotic Stresses ◽  
Marker Free

The viral disease caused by tobacco mosaic virus (TMV) is the most prevalent viral disease in many tobacco production areas. A breeding strategy based on resistance genes is an effective method for improving TMV resistance in tobacco. Also, the physiological status of plants is also critical to disease resistance improvement. Potassium ion is one of the most abundant inorganic nutrients in plant cells, and mediates plant responses to abiotic and biotic stresses. Improving K+ content in soil by fertilising can enhance diseases resistance of crops. However, the K+ absorption in plants depends mostly on K+ transporters located in cytoplasmic membrane. Therefore, the encoding genes for K+ transporters are putative candidates to target for improving tobacco mosaic virus resistance. In this work, the synergistic effect of a N-like resistance gene CN and a tobacco putative potassium transporter gene HAK1 was studied. The results showed that TMV-resistance in CN-HAK1-containing tobaccos was significantly enhanced though a of strengthening leaf thickness and reduction in the size of necrotic spots compared with only CN-containing plants, indicating the improvement of potassium nutrition in plant cells could increase the tobacco resistance to TMV by reducing the spread of the virus. Quantitative real-time polymerase chain reaction (qRT–PCR) analysis for TMV-CP expression in the inoculated leaf of the transgenic and wild-type plants also supported the conclusion. Further, the results of defence-related determination including antioxidative enzymes (AOEs) activity, salicylic acid (SA) content and the expression of resistance-related genes demonstrated CN with HAK1 synergistically enhanced TMV-resistance in transgenic tobaccos. Additionally, the HAK1- overexpression significantly improved the photosynthesis and K+-enriching ability in trans-CN-HAK1 tobaccos, compared with other counterparts. Finally, this work provides a method for screening new varieties of marker-free and safe transgenic antiviral tobacco.

scholarly journals Quantifying Effects of Seedborne Inoculum on Virus Spread, Yield Losses, and Seed Infection in the Pea seed-borne mosaic virus–Field Pea Pathosystem

2009 ◽  
Vol 99 (10) ◽  
pp. 1156-1167 ◽  
Author(s):  
B. A. Coutts ◽  
R. T. Prince ◽  
R. A. C. Jones
Keyword(s):  
Mosaic Virus ◽  
Seed Yield ◽  
Seed Transmission ◽  
Seed Infection ◽  
Virus Spread ◽  
Yield Losses ◽  
Seeding Rate ◽  
Transmission Rates ◽  
Infected Seed ◽  
Pea Seed

Field experiments examined the effects of sowing field pea seed with different amounts of infection with Pea seed-borne mosaic virus (PSbMV) on virus spread, seed yield, and infection levels in harvested seed. Plots were sown with seed with actual or simulated seed transmission rates of 0.3 to 6.5% (2005) or 0.1 to 8% (2006), and spread was by naturally occurring migrant aphids. Plants with symptoms and incidence increased with the amount of primary inoculum present. When final incidence reached 97 to 98% (2005) and 36% (2006) in plots sown with 6.5 to 8% infected seed, yield losses of 18 to 25% (2005) and 13% (2006) resulted. When incidence reached 48 to 76% in plots sown with 1.1-2 to 2% initial infection, seed yield losses were 15 to 21% (2005). Diminished seed weight and seed number both contributed to the yield losses. When the 2005 data for the relationships between percent incidence and yield or yield gaps were plotted, 81 to 84% of the variation was explained by final incidence and, for each 1% increase, there was a yield decline of 7.7 to 8.2 kg/ha. Seed transmission rates in harvested seed were mostly greater than those in the seed sown when climatic conditions favored early virus spread (1 to 17% in 2005) but smaller when they did not (0.2 to 2% in 2006). In 2007, sowing infected seed at high seeding rate with straw mulch and regular insecticide application resulted in slower spread and smaller seed infection than sowing at standard seeding rate without straw mulch or insecticide. When data for the relationship between final percent incidence and seed transmission in harvested seed were plotted (all experiments), 95 to 99% of the variation was explained by PSbMV incidence. A threshold value of <0.5% seed infection was established for sowing in high-risk zones.

Accumulation of necrotic lesion inducing variants in TMV-infected plantlets derived from leaf disks of Nicotiana sylvestris

1989 ◽  
Vol 67 (4) ◽  
pp. 984-989 ◽  
Author(s):  
Iqrar A. Khan ◽  
Gary E. Jones
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Rna Virus ◽  
Leaf Tissue ◽  
Nicotiana Sylvestris ◽  
Wild Type Virus ◽  
Type Virus ◽  
Variant Type ◽  
Whole Plants ◽  
Leaf Disks

In an isolate of tobacco mosaic virus strain U1 there exists a small subpopulation containing a variant strain of the virus that induces the hypersensitive response on Nicotiana sylvestris Spegazzini & Comes. This type of variant is strongly selected for during the regeneration of plantlets from mature leaf tissue of plants infected with tobacco mosaic virus U1. When whole plants derived from disks were transferred into a glasshouse, those containing this type of variant were severely stunted, showed mosaic symptoms, and most of them died. Some that had originally contained lower titers of variant-type virus survived to flower but produced only a few seeds. Plants that initially contained only wild-type virus had high titers of tobacco mosaic virus, survived and grew well, exhibited mosaic symtoms, and flowered and set seed normally. Repeated assays of virus in these plants revealed no detectable variant-type virus. Apparently, during callus development and organogenesis in culture, partial segregation of the mixed U1 population occurred, and variants preferentially infected the developing tissues. This represents a situation in which dramatic change in the genetic structure of an RNA virus population occurs during development of the host plant.

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