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Mottle Virus (mottle + virus)

Distribution by Scientific Domains

Life Sciences	90%
2 Other Domains	10%

Selected Abstracts

Carbon Metabolism Alterations in Sunflower Plants Infected with the Sunflower Chlorotic Mottle Virus

JOURNAL OF PHYTOPATHOLOGY, Issue 5 2003
M. C. Arias
Abstract Sunflower chlorotic mottle virus (SuCMoV) causes chlorotic mottling symptoms and important growth reductions and yield losses in sunflower (Helianthus annuus L., cv. Contiflor 7). This paper describes the effects of SuCMoV on some aspects of carbon metabolism of sunflower plants. After symptoms became evident, CO2 fixation rates decreased, nevertheless, soluble sugars and starch increased in infected leaves. High H2O2 accumulation, lipid peroxidation and chlorophyll degradation were, like the other changes, observed only after symptom expression. Increased soluble carbohydrate accumulation was not related to changes in , -amylase (EC 3.2.1.1) activity, nor in the activities of enzymes associated with sugar import and hydrolysis such as invertase (EC 3.2.1.26) and sucrose synthase (EC 2.4.1.13), suggesting it did not derive from starch hydrolysis nor increased sugar import. Rather, it may derive from recycling of cell components associated with the development of oxidative damage. The physiological alterations caused by this virus share many common features with the development of senescence. [source]

Biology and control of Dicladispa gestroi Chapuis (Col., Chrysomelidae)

JOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2001
V. Delucchi
The beetle Dicladispa gestroi is known only from Madagascar, where it is considered to be a pest of rice. Research were carried out from 1885 to 1994 in the Alaotra lake region, the main rice-producing area of the country, characterized by a warm rainy season from October to April and a cool dry season from April to October. The adult beetles invade the rice nurseries and the first direct-seeded fields at the beginning of the rainy season; they have a gregarious behaviour and their feeding activity, together with the mines bored by the larvae, determines a change of colour from green to pale yellow in the damage areas, which resemble outbreak areas of rice leafhoppers. Oviposition takes place only on young rice plants in the tillering stage. Females emerging after the end of February enter a reproductive diapause and leave the rice fields to ,hibernate'. Temperature summations for the egg, larval, and pupal development, as well as for the preoviposition period have been calculated. There is no yield loss up to a larval density of 0.6 per leaf and this economic injury level is seldom exceeded in the Alaotra lake region. Life tables carried out under field conditions show that chalcid parasitoids are the main mortality factor and are responsible for the collapse of entire outbreak areas. Since the discovery of the rice yellow mottle virus in 1989 in the Alaotra lake region and the disease transmission by chrysomelids, the pest status of D. gestroi has changed and control measures have to be applied. However, to avoid interference with the action of the parasitoids, chemical applications should be limited to rice nurseries. [source]

Biology of the European large raspberry aphid (Amphorophora idaei): its role in virus transmission and resistance breakdown in red raspberry

AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009
Lindsay S. McMenemy
Abstract 1,The European large raspberry aphid Amphorophora idaei Börner is the most important vector of viral diseases afflicting commercially grown red raspberry (Rubus idaeus L.) in Northern Europe, with European raspberry production amounting to 416 000 tonnes per annum. This review synthesizes existing knowledge on its biology and interactions with other organisms, including its host plant and the viral pathogens it vectors. 2,Information about trophic interactions with other insect herbivores and natural enemies is reviewed. Vine weevils Otiorhynchus sulcatus compromise aphid resistance in some raspberry cultivars, increasing A. idaei abundance by 80%. Parasitoids show mixed success in parasitizing A. idaei, although Aphidius ervi attack rates more than doubled when A. idaei fed on a partially susceptible raspberry cultivar, compared with a resistant variety. These findings are discussed in the context of potential biological control as part of an integrated pest and disease management framework. 3,Amphorophora idaei transmits four known viruses: Black raspberry necrosis virus, Raspberry leaf mottle virus, Raspberry leaf spot virus and Rubus yellow net virus, with A. idaei taking as little as 2 min to transmit some viruses. 4,Existing control strategies, including resistant cultivars, insecticides and eradication of disease from parent plants, are described. In particular, strong selection pressures have resulted in A. idaei overcoming genetic resistance in many raspberry cultivars and most insecticides are now ineffective. 5,Future directions for the sustained control of A. idaei are suggested, taking into consideration the possible effects of climate change and also changes in agronomic practices in U.K. agriculture. [source]

Carbon Metabolism Alterations in Sunflower Plants Infected with the Sunflower Chlorotic Mottle Virus

Unravelling the genetic diversity of the three main viruses involved in Sweet Potato Virus Disease (SPVD), and its practical implications

MOLECULAR PLANT PATHOLOGY, Issue 2 2005
FRED TAIRO
SUMMARY Sweetpotato (Ipomoea batatas) is a widely grown food crop, in which the most important diseases are caused by viruses. Genetic variability of three widely distributed sweetpotato viruses was analysed using data from 46 isolates of Sweet potato feathery mottle virus (SPFMV), 16 isolates of Sweet potato mild mottle virus (SPMMV) and 25 isolates of Sweet potato chlorotic stunt virus (SPCSV), of which 19, seven and six isolates, respectively, are newly characterized. Division of SPFMV into four genetic groups (strains) according to phylogenetic analysis of coat protein (CP) encoding sequences revealed that strain EA contained the East African isolates of SPFMV but none from elsewhere. In contrast, strain RC contained ten isolates from Australia, Africa, Asia and North America. Strain O contained six heterogeneous isolates from Africa, Asia and South America. The seven strain C isolates from Australia, Africa, Asia, and North and South America formed a group that was genetically distant from the other SPFMV strains. SPMMV isolates showed a high level of variability with no discrete strain groupings. SPCSV isolates from East Africa were phylogenetically distant to SPCSV isolates from elsewhere. Only from East Africa were adequate data available for different isolates of the three viruses to estimate the genetic variability of their local populations. The implications of the current sequence information and the need for more such information from most sweetpotato-growing regions of the world are discussed in relation to virus diagnostics and breeding for virus resistance. [source]

Characterization of Passionfruit severe leaf distortion virus, a novel begomovirus infecting passionfruit in Brazil, reveals a close relationship with tomato-infecting begomoviruses

PLANT PATHOLOGY, Issue 2 2010
S. S. Ferreira
Molecular and biological characterization of the begomovirus isolate BR:LNS2:Pas:01, obtained from yellow passionfruit plants in Livramento de Nossa Senhora, Bahia state, Brazil, was carried out. Sequence analysis demonstrated that the BR:LNS2:Pas:01 DNA-A had highest nucleotide sequence identity with Tomato chlorotic mottle virus (77%) and had five ORFs corresponding to the genes cp, rep, trap, ren and ac4. The DNA-B had highest nucleotide sequence identity with Tomato yellow spot virus (74%) and two ORFs corresponding to the genes mp and nsp. These identity values indicate that this isolate represents a new begomovirus species, for which the name Passionfruit severe leaf distortion virus (PSLDV), is proposed. Phylogenetic analysis clustered the PSLDV DNA-A and -B in a monophyletic branch with Brazilian tomato-infecting begomoviruses. The isolate's host range was restricted to species from the Passifloraceae and Solanaceae. PSLDV-[BR:LNS2:Pas:01] was capable of forming pseudorecombinants with tomato-infecting begomoviruses, reinforcing its close relationship with these viruses and suggesting a possible common origin. However, the virus was not capable of infecting tomato. [source]

Molecular characterization of the CP gene and 3,UTR of Chilli veinal mottle virus from South and Southeast Asia

PLANT PATHOLOGY, Issue 3 2008
W. S. Tsai
Twenty-four isolates of Chilli veinal mottle virus (ChiVMV) from China, India, Indonesia, Taiwan and Thailand were analysed to determine their genetic relatedness. Pathogenicity of virus isolates was confirmed by induction of systemic mosaic and/or necrotic ringspot symptoms on Capsicum annuum after mechanical inoculation. The 3, terminal sequences of the viral genomic RNA were determined. The coat protein (CP) coding regions ranged from 858 to 864 nucleotides and the 3, untranslated regions (3,UTR) from 275 to 289 nucleotides in length. All isolates had the inverted repeat sequence GUGGNNNCCAC in the 3,UTR. The DAG motif, conserved in aphid-transmitted potyviruses, was observed in all isolates. All 24 isolates were considered as belonging to ChiVMV because of their high CP amino acid and nucleotide identity (more than 94·8 and 89·5%, respectively) with the reported ChiVMV isolates including the pepper vein banding virus (PVBV), the chilli vein-banding mottle virus (CVbMV) and the CVbMV Chiengmai isolate (CVbMV-CM1). Based on phylogenetic analysis, ChiVMV isolates including all 24 isolates tested, PVBV, CVbMV and CVbMV-CM1 can be classified into three groups. In addition, a conserved region of 204 amino acids with more than 90·2% identity was identified in the C terminal of the CP gene of ChiVMV and Pepper veinal mottle virus (PVMV), and may explain the serological cross reaction between these two viruses. The conserved region may also provide useful information for developing transgenic resistance to both ChiVMV and PVMV. [source]

Occurrence of Cherry green ring mottle virus in Turkey

PLANT PATHOLOGY, Issue 2 2008
H. M. Sipahioglu
No abstract is available for this article. [source]

Identification and transmission of Piper yellow mottle virus and Cucumber mosaic virus infecting black pepper (Piper nigrum) in Sri Lanka

PLANT PATHOLOGY, Issue 5 2002
D. P. P. De Silva
Sri Lankan black pepper with symptoms of yellow mottle disease contained a mixture of viruses: Piper yellow mottle virus (PYMV) particles (30 × 130 nm), Cucumber mosaic virus (CMV, 30 nm diameter isometric particles), and unidentified, isometric virus-like particles (30 nm diameter). An effective purification procedure is described for PYMV. Immunosorbent and conventional electron microscopy successfully detected badnavirus particles only when at least partially purified extracts were used. PYMV was confirmed as the cause of the disease, with the other two viruses apparently playing no part in producing symptoms. PYMV was transmitted by grafting, by the insect vectors citrus mealy bug (Planococcus citri) and black pepper lace bug (Diconocoris distanti), but not by mechanical inoculation or through seeds. The CMV isolate was transmitted to indicator plants by mechanical inoculation and by the vector Aphis gossypii, but not by Myzus persicae; but neither mechanical nor insect transmission of CMV to black pepper was successful. A sensitive polymerase chain reaction assay was developed to detect PYMV in black pepper. [source]

Incidence of cereal and pasture viruses in New Zealand's native grasses

ANNALS OF APPLIED BIOLOGY, Issue 1 2010
C. Delmiglio
This study provides evidence for frequent and multiple invasions of New Zealand's native grasses by exotic cereal and pasture viruses. Fifteen native and three exotic grasses from 29 North Island and six South Island sites were surveyed for the presence of viruses using enzyme-linked immunosorbent assay (ELISA). Barley yellow dwarf virus and Cereal yellow dwarf virus (BYDV, CYDV: Luteoviridae) and Cocksfoot mottle virus (CoMV, Sobemovirus) are widespread throughout New Zealand. CoMV, previously considered to have a natural host range restricted to Dactylis and Triticum, was detected in Poa anceps, P. cita, Festuca novae-zelandiae, and Chionochloa rubra. New virus host reports include BYDV-PAV in Microlaena stipoides and Dichelachne crinita; BYDV-MAV in P. cita, F. novae-zelandiae and Hierochloe redolens; and CYDV-RPV in P. cita and M. stipoides. Nominal logistic regression analyses showed a correlation between the presence of exotic grass species and virus incidence. Host range experiments for BYDV-PAV and CoMV were performed with selected native and exotic grasses, and the results are discussed in context of the field-survey findings. [source]

Sequence similarities between Raspberry leaf mottle virus, Raspberry leaf spot virus and the closterovirus Raspberry mottle virus

ANNALS OF APPLIED BIOLOGY, Issue 3 2010
W.J. McGavin
A sequencing study was performed to determine the relationship between Raspberry mottle virus (RMoV), a newly identified tentative closterovirus found in the United States, and Raspberry leaf mottle virus (RLMV) and Raspberry leaf spot virus (RLSV), which have been known for many years to be components of Raspberry mosaic disease (RMD) in the UK and Europe but which have not been characterised at the molecular level. Cloning and sequencing of cDNAs amplified by reverse transcription-PCR revealed the presence of closteroviruses with high sequence similarity to RMoV in infected plants from the SCRI Rubus virus collection, as well as in a number of samples collected from RMD-symptomatic raspberry plants located at different farms in Scotland and England. These results suggest that RMoV, RLMV and RLSV are isolates of the same virus and we propose that they all should be referred to as RLMV, which was the first of these viruses to be described. Many of the field samples were also infected with a second closterovirus isolate, parts of which could be amplified using RLMV-derived primers. The coat protein amino acid sequences of RLMV and the second virus (PM1) were only 78% identical, even though helicase domain and RNA-dependent RNA polymerase (RDRP) domain sequences were more than 97% identical between RLMV and PM1. [source]

Survey of the incidence and distribution of viruses infecting yam (Dioscorea spp.) in Ghana and Togo

ANNALS OF APPLIED BIOLOGY, Issue 2 2010
A.O. Eni
Yam leaves were collected during surveys of major yam producing agro-ecological zones (AEZs) in Ghana (n = 628) and Togo (n = 218) respectively, in 2005. Leaf tissues were tested for Cucumber mosaic virus (CMV), Dioscorea mottle virus (DMoV), Yam mild mosaic virus (YMMV), Yam mosaic virus (YMV) and badnaviruses by enzyme-linked immunosorbent assay (ELISA), immunocapture-polymerase chain reaction (IC-PCR) and/or IC-reverse transcription-PCR (IC-RT-PCR). Eighty-one percent (370/459) and 78.9% (127/161) of symptomatic leaf samples from Ghana and Togo, respectively and 56.2% (95/169) and 57.9% (33/57) of non-symptomatic leaf samples, reacted positive to CMV, YMMV, YMV and/or badnaviruses, but DMoV was not detected. The highest incidence of YMV and badnaviruses was observed in the forest,savannah transition and Guinea savannah AEZ respectively in Ghana. In Togo, incidence of badnaviruses across the four AEZ ranged from 50 to 57.9%; however, Savane Derivée Seche AEZ had the highest incidence of badnaviruses (57.9%), YMV (34.2%) and CMV (7.9%). Mixed infection of badnaviruses and YMMV was the most frequent (105 of 276 mixed infections) in the two countries and Dioscorea alata was more heavily infected than D. rotundata in both countries. [source]

Cryotherapy of shoot tips: a technique for pathogen eradication to produce healthy planting materials and prepare healthy plant genetic resources for cryopreservation

ANNALS OF APPLIED BIOLOGY, Issue 3 2009
Q.C. Wang
Abstract Cryotherapy of shoot tips is a new method for pathogen eradication based on cryopreservation techniques. Cryopreservation refers to the storage of biological samples at ultra-low temperature, usually that of liquid nitrogen (,196°C), and is considered as an ideal means for long-term storage of plant germplasm. In cryotherapy, plant pathogens such as viruses, phytoplasmas and bacteria are eradicated from shoot tips by exposing them briefly to liquid nitrogen. Uneven distribution of viruses and obligate vasculature-limited microbes in shoot tips allows elimination of the infected cells by injuring them with the cryo-treatment and regeneration of healthy shoots from the surviving pathogen-free meristematic cells. Thermotherapy followed by cryotherapy of shoot tips can be used to enhance virus eradication. Cryotherapy of shoot tips is easy to implement. It allows treatment of large numbers of samples and results in a high frequency of pathogen-free regenerants. Difficulties related to excision and regeneration of small meristems are largely circumvented. To date, severe pathogens in banana (Musa spp.), Citrus spp., grapevine (Vitis vinifera), Prunus spp., raspberry (Rubus idaeus), potato (Solanum tuberosum) and sweet potato (Ipomoea batatas) have been eradicated using cryotherapy. These pathogens include nine viruses (banana streak virus, cucumber mosaic virus, grapevine virus A, plum pox virus, potato leaf roll virus, potato virus Y, raspberry bushy dwarf virus, sweet potato feathery mottle virus and sweet potato chlorotic stunt virus), sweet potato little leaf phytoplasma and Huanglongbing bacterium causing ,citrus greening'. Cryopreservation protocols have been developed for a wide variety of plant species, including agricultural and horticultural crops and ornamental plants, and can be used as such or adjusted for the purpose of cryotherapy. [source]

Identification and distribution of viruses infecting sweet potato in Kenya

ANNALS OF APPLIED BIOLOGY, Issue 3 2004
E M ATEKA
Summary Four hundred and forty-eight symptomatic and 638 asymptomatic samples were collected from sweet potato fields throughout Kenya and analysed serologically using antibodies to Sweet potato feathery mottle virus (SPFMV), Sweet potato chlorotic stunt virus (SPCSV), Sweet potato mild mottle virus (SPMMV), Cucumber mosaic virus (CMV), Sweet potato chlorotic fleck virus (SPCFV), Sweet potato latent virus (SwPLV), Sweet potato caulimo-like virus (SPCaLV), Sweet potato mild speckling virus (SPMSV) and C-6 virus in enzyme-linked immunosorbent assays (ELISA). Only SPFMV, SPMMV, SPCSV, and SPCFV were detected. Ninety-two percent and 25% of the symptomatic and asymptomatic plants respectively tested positive for at least one of these viruses. Virus-infected plants were collected from 89% of the fields. SPFMV was the most common and the most widespread, detected in 74% of the symptomatic plants and 86% of fields surveyed. SPCSV was also very common, being detected in 38% of the symptomatic plants and in 50% of the fields surveyed. SPMMV and SPCFV were detected in only 11% and 3% of the symptomatic plant samples respectively. Eight different combinations of these four viruses were found in individual plants. The combination SPFMV and SPCSV was the most common, observed in 22% of symptomatic plants. Virus combinations were rare in the asymptomatic plants tested. Incidence of virus infection was highest (18%) in Kisii district of Nyanza province and lowest (1%) in Kilifi and Malindi districts of Coast province. [source]

The circulative pathway of begomoviruses in the whitefly vector Bemisia tabaci, insights from studies with Tomato yellow leaf curl virus

ANNALS OF APPLIED BIOLOGY, Issue 3 2002
HENRYK CZOSNEK
Summary Our current knowledge concerning the transmission of begomoviruses by the whitefly vector Bemisia tabaci is based mainly on research performed on the Tomato yellow leaf curl virus (TYLCV) complex and on a number of viruses originating from the Old World, such as Tomato leaf curl virus, and from the New World, including Abutilon mosaic virus, Tomato mottle virus, and Squash leaf curl virus. In this review we discuss the characteristics of acquisition, transmission and retention of begomoviruses by the whitefly vector, concentrating on the TYLCV complex, based on both published and recent unpublished data. We describe the cells and organs encountered by begomoviruses in B. tabaci. We show immunolocalisation of TYLCV to the B. tabaci stylet food canal and to the proximal part of the descending midgut, and TYLCV-specific labelling was also associated with food in the lumen. The microvilli and electron-dense material in the epithelial cells of the gut wall were also labelled by the anti TYLCV serum, pointing to a possible virus translocation route through the gut wall and to a putative site of long-term virus storage. We describe the path of begomoviruses in their vector B. tabaci and in the non-vector whitefly Trialeurodes vaporariorum, and we follow the rate of virus translocation in these insects. We discuss TYLCV transmission between B. tabaci during mating, probably by exchange of haemolymph. We show that following a short acquisition access to infected tomato plants, TYLCV remains associated with the B. tabaci vector for weeks, while the virus is undetectable after a few hours in the non-vector T. vaporariorum. The implications of the long-term association of TYLCV with B. tabaci in the light of interactions of the begomovirus with insect receptors are discussed. [source]

Preliminary X-ray data analysis of crystalline hibiscus chlorotic ringspot virus

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2009
Ao Cheng
Hibiscus chlorotic ringspot virus (HCRSV) is a positive-sense monopartite single-stranded RNA virus that belongs to the Carmovirus genus of the Tombusviridae family, which includes carnation mottle virus (CarMV). The HCRSV virion has a 30,nm diameter icosahedral capsid with T = 3 quasi-symmetry containing 180 copies of a 38,kDa coat protein (CP) and encapsidates a full-length 3.9,kb genomic RNA. Authentic virus was harvested from infected host kenaf leaves and was purified by saturated ammonium sulfate precipitation, sucrose density-gradient centrifugation and anion-exchange chromatography. Virus crystals were grown in multiple conditions; one of the crystals diffracted to 3.2,Å resolution and allowed the collection of a partial data set. The crystal belonged to space group R32, with unit-cell parameters a = b = 336.4, c = 798.5,Å. Packing considerations and rotation-function analysis determined that there were three particles per unit cell, all of which have the same orientation and fixed positions, and resulted in tenfold noncrystallography symmetry for real-space averaging. The crystals used for the structure determination of southern bean mosaic virus (SBMV) have nearly identical characteristics. Together, these findings will greatly aid the high-resolution structure determination of HCRSV. [source]

Next-generation sequencing and metagenomic analysis: a universal diagnostic tool in plant virology

MOLECULAR PLANT PATHOLOGY, Issue 4 2009
IAN P. ADAMS
SUMMARY A novel, unbiased approach to plant viral disease diagnosis has been developed which requires no a priori knowledge of the host or pathogen. Next-generation sequencing coupled with metagenomic analysis was used to produce large quantities of cDNA sequence in a model system of tomato infected with Pepino mosaic virus. The method was then applied to a sample of Gomphrena globosa infected with an unknown pathogen originally isolated from the flowering plant Liatris spicata. This plant was found to contain a new cucumovirus, for which we suggest the name ,Gayfeather mild mottle virus'. In both cases, the full viral genome was sequenced. This method expedites the entire process of novel virus discovery, identification, viral genome sequencing and, subsequently, the development of more routine assays for new viral pathogens. [source]