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1.
Int J Mol Sci ; 23(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36362035

RESUMO

Grapevine red blotch virus (GRBV) is a recently identified virus. Previous research indicates primarily a substantial impact on berry ripening in all varieties studied. The current study analyzed grapes' primary and secondary metabolism across grapevine genotypes and seasons to reveal both conserved and variable impacts to GRBV infection. Vitis vinifera cv. Cabernet Sauvignon (CS) grapevines grafted on two different rootstocks (110R and 420A) were analyzed in 2016 and 2017. Metabolite profiling revealed a considerable impact on amino acid and malate acid levels, volatile aroma compounds derived from the lipoxygenase pathway, and anthocyanins synthesized in the phenylpropanoid pathway. Conserved transcriptional responses to GRBV showed induction of auxin-mediated pathways and photosynthesis with inhibition of transcription and translation processes mainly at harvest. There was an induction of plant-pathogen interactions at pre-veraison, for all genotypes and seasons, except for CS 110R in 2017. Lastly, differential co-expression analysis revealed a transcriptional shift from metabolic synthesis and energy metabolism to transcription and translation processes associated with a virus-induced gene silencing transcript. This plant-derived defense response transcript was only significantly upregulated at veraison for all genotypes and seasons, suggesting a phenological association with disease expression and plant immune responses.


Assuntos
Geminiviridae , Viroses , Vitis , Vitis/metabolismo , Antocianinas/metabolismo , Geminiviridae/metabolismo , Frutas/metabolismo , Viroses/metabolismo
2.
BMC Genomics ; 23(1): 767, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36418948

RESUMO

BACKGROUND: Maize-infecting viruses are known to inflict significant agronomic yield loss throughout the world annually. Identification of known or novel causal agents of disease prior to outbreak is imperative to preserve food security via future crop protection efforts. Toward this goal, a large-scale metagenomic approach utilizing high throughput sequencing (HTS) was employed to identify novel viruses with the potential to contribute to yield loss of graminaceous species, particularly maize, in North America. RESULTS: Here we present four novel viruses discovered by HTS and individually validated by Sanger sequencing. Three of these viruses are RNA viruses belonging to either the Betaflexiviridae or Tombusviridae families. Additionally, a novel DNA virus belonging to the Geminiviridae family was discovered, the first Mastrevirus identified in North American maize. CONCLUSIONS: Metagenomic studies of crop and crop-related species such as this may be useful for the identification and surveillance of known and novel viral pathogens of crops. Monitoring related species may prove useful in identifying viruses capable of infecting crops due to overlapping insect vectors and viral host-range to protect food security.


Assuntos
Geminiviridae , Tombusviridae , Humanos , Zea mays , Metagenômica , Metagenoma , Produtos Agrícolas , Geminiviridae/genética , América do Norte
3.
J Gen Virol ; 103(10)2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36205485

RESUMO

In this study 163 complete whole-genome sequences of the emerging pathogen grapevine red blotch virus (GRBV; genus Grablovirus, family Geminiviridae) were used to reconstruct phylogenies using Bayesian analyses on time-tipped (heterochronous) data. Using different combinations of priors, Bayes factors identified heterochronous datasets (3×200 million chains) generated from strict clock and exponential tree priors as being the most robust. Substitution rates of 3.2×10-5 subsitutions per site per year (95% HPD 4.3-2.1×10-5) across the whole of the GRBV genome were estimated, suggesting ancestral GRBV diverged from ancestral wild Vitis latent virus 1 around 9 000 years ago, well before the first documented arrival of Vitis vinifera in North America. Whole-genome analysis of GRBV isolates in a single infected field-grown grapevine across 12 years identified 12 single nucleotide polymorphisms none of which were fixed substitutions: an observation not discordant with the in silico estimate. The substitution rate estimated here is lower than those estimated for other geminiviruses and is the first for a woody-host-infecting geminivirus.


Assuntos
Geminiviridae , Vitis , Teorema de Bayes , Geminiviridae/genética , Filogenia , Doenças das Plantas
4.
Adv Virus Res ; 113: 1-23, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36307167

RESUMO

RNA silencing is an evolutionarily conserved and homology-dependent gene inactivation system that regulates most biological processes at either the transcriptional or post-transcriptional level. In plants, insects and certain mammalian systems, RNA silencing constitutes the basis of the antiviral defense mechanism. To counteract RNA silencing-based antiviral responses viruses adopt strategies of replication and host invasion that include mechanisms of RNA silencing suppression. Indeed, viruses can express proteins known as RNA silencing suppressors (RSSs). Over the last two decades, silencing studies in plant virology have been largely devoted to the discovery and description of RSSs. The result has been exciting and these studies have revealed (i) an incredible diversity of proteins and mechanisms of RSSs belonging to various viral taxonomic groups, (ii) the multifunctionality of RSSs: they can fulfill several functions during viral infection and target one or more key points in the RNA silencing machinery. Some RSSs of model viral systems have been the subject of exceptional in-depth studies; they have proven to be real molecular tools for studying plant physiology, plant biology and virus-plant interactions, even in some cases extending the knowledge of the response of plants to other biotic and abiotic stressors. RSS diversity in phylogenesis, in mechanism of action and the frequent presence of more than one RSS in a single viral genome all suggest that they are extremely plastic in evolving to overcome host defenses. In this chapter, we present and discuss the most recent findings related to the well-studied RSSs of four viral taxonomic groups: geminiviruses, potyviruses, tombusviruses and cucumoviruses.


Assuntos
Geminiviridae , Vírus de Plantas , Vírus , Animais , Interferência de RNA , Vírus/genética , Plantas/genética , Geminiviridae/genética , Antivirais , RNA Viral/genética , Vírus de Plantas/genética , Doenças das Plantas , Mamíferos/genética
5.
Viruses ; 14(10)2022 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-36298721

RESUMO

Recombination between isolates of different virus species has been known to be one of the sources of speciation. Weeds serve as mixing vessels for begomoviruses, infecting a wide range of economically important plants, thereby facilitating recombination. Chenopodium album is an economically important weed spread worldwide. Here, we present the molecular characterization of a novel recombinant begomovirus identified from C. album in Lahore, Pakistan. The complete DNA- A genome of the virus associated with the leaf distortion occurred in the infected C. album plants was cloned and sequenced. DNA sequence analysis showed that the nucleotide sequence of the virus shared 93% identity with those of the rose leaf curl virus and the duranta leaf curl virus. Interestingly, this newly identified virus is composed of open reading frames (ORFs) from different origins. Phylogenetic networks and complementary recombination detection methods revealed extensive recombination among the sequences. The infectious clone of the newly detected virus was found to be fully infectious in C. album and Nicotiana benthamiana as the viral DNA was successfully reconstituted from systemically infected tissues of inoculated plants, thus fulfilling Koch's postulates. Our study reveals a new speciation of an emergent ssDNA plant virus associated with C. album through recombination and therefore, proposed the tentative name 'Chenopodium leaf distortion virus' (CLDV).


Assuntos
Begomovirus , Geminiviridae , Geminiviridae/genética , DNA Viral/genética , Filogenia , Transferência Genética Horizontal , Paquistão , Doenças das Plantas , Análise de Sequência de DNA , Genoma Viral
6.
Cells ; 11(18)2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36139477

RESUMO

Upland cotton (Gossypium hirsutum), an allotetraploid, contains At- and Dt- subgenome and most genes have multiple homologous copies, which pose a huge challenge to investigate genes' function due to the functional redundancy. Therefore, it is of great significance to establish effective techniques for the functional genomics in cotton. In this study, we tested two novel genome editing vectors and compared them with the CRISPR/Cas9 system (pRGEB32-GhU6.7) developed in our laboratory previously. In the first new vector, the sgRNA transcription unite was constructed into the replicon (LIR-Donor-SIR-Rep-LIR) of the bean yellow dwarf virus (BeYDV) and named as pBeYDV-Cas9-KO and in the second vector, the ubiquitin promoter that drives Cas9 protein was replaced with a constitutive CaMV 35S promoter and defined as pRGEB32-35S. The results from transgenic cotton calli/plants revealed that pBeYDV-Cas9-KO vector showed the highest editing efficiency of GhCLA1 in At and Dt subgenomes edited simultaneously up to 73.3% compared to the 44.6% of pRGEB32-GhU6.7 and 51.2% of pRGEB32-35S. The editing efficiency of GhCLA1 in At and Dt subgenome by pBeYDV-Cas9-KO was 85.7% and 97.2%, respectively, whereas the efficiency by pRGEB32-GhU6.7 and pRGEB32-35S vectors was 67.7%, 86.5%, 84%, and 87.2%, respectively. The editing profile of pBeYDV-Cas9-KO was mainly composed of fragment deletion, accounting for 84.0% and ranging 1-10 bp in length. The main editing sites are located at positions 11-17 upstream of PAM site. The off-target effects were not detected in all potential off-target sites. Taken together, the pBeYDV-Cas9-KO system has high editing efficiency and specificity with wide editing range than the traditional CRISPR/Cas9 system, which provides a powerful tool for cotton functional genomics research and molecular breeding.


Assuntos
Geminiviridae , Edição de Genes , Proteína 9 Associada à CRISPR/metabolismo , Sistemas CRISPR-Cas/genética , Geminiviridae/genética , Geminiviridae/metabolismo , Edição de Genes/métodos , Gossypium/genética , Gossypium/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Ubiquitinas/metabolismo
7.
Mol Plant Pathol ; 23(11): 1671-1685, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36073369

RESUMO

Hemipteran insects that transmit plant viruses in a persistent circulative manner acquire, retain and transmit viruses for their entire life. The mechanism enabling this persistence has remained unclear for many years. Here, we determined how wheat dwarf virus (WDV) persists in its leafhopper vector Psammotettix alienus. We found that WDV caused the up-regulation of actin-depolymerizing factor (ADF) at the mRNA and protein levels in the midgut cells of leafhoppers after experiencing a WDV acquisition access period (AAP) of 6, 12 or 24 h. Experimental inhibition of F-actin depolymerization by jasplakinolide and dsRNA injection led to lower virus accumulation levels and transmission efficiencies, suggesting that depolymerization of F-actin regulated by ADF is essential for WDV invasion of midgut cells. Exogenous viral capsid protein (CP) inhibited ADF depolymerization of actin filaments in vitro and in Spodoptera frugiperda 9 (Sf9) cells because the CP competed with actin to bind ADF and then blocked actin filament disassembly. Interestingly, virions colocalized with ADF after a 24-h AAP, just as actin polymerization occurred, indicating that the binding of CP with ADF affects the ability of ADF to depolymerize F-actin, inhibiting WDV entry. Similarly, the luteovirus barley yellow dwarf virus also induced F-actin depolymerization and then polymerization in the gut cells of its vector Schizaphis graminum. Thus, F-actin dynamics are altered by nonpropagative viruses in midgut cells to enable virus persistence in vector insects.


Assuntos
Afídeos , Geminiviridae , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Animais , Proteínas do Capsídeo/metabolismo , Geminiviridae/metabolismo , RNA Mensageiro/metabolismo
8.
Gene ; 843: 146806, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35963497

RESUMO

Here, we report the identification and characterization of four novel DNA viruses from Welwitschia mirabilis transcriptomic and genomic datasets. Complete circular virus-like sequences with affinity to members of the Caulimoviridae and Geminiviridae families were detected and characterized from Welwitschia mirabilis genomic data. The two newly members of the Caulimoviridae family have been tentatively named as Welwitschia mirabilis virus 1 and 2 (WMV1-WMV2); whereas the two identified geminiviruses were named as Welwitschia mirabilis associated geminivirus A and B (WMaGVA-WMaGVB). Phylogenetic analysis suggests that WMV1-2 belong to a proposed genus of Caulimoviridae-infecting gymnosperms. WMaGVA-B are phylogenetically related with both mastreviruses and capulaviruses and likely represent a distinct evolutionary lineage within geminiviruses. Additionally, we detected several endogenous virus-like elements (EVE) linked to the discovered viruses in the recently reported W. mirabilis genome, suggesting a shared ancient evolutionary history of these viruses and the Welwithschia.


Assuntos
Geminiviridae , Mirabilis , DNA , Fósseis , Geminiviridae/genética , Genoma Viral , Humanos , Mirabilis/genética , Filogenia , Viroma
9.
New Phytol ; 236(4): 1358-1374, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35978547

RESUMO

Autophagy is an essential degradation pathway that assists eukaryote survival under multiple stress conditions. Autophagosomes engulfing cargoes accomplish degradation only when they have matured through fusing with lysosomes or vacuoles. However, the molecular machinery mediating autophagosome maturation in plants remains unknown. Using the combined approaches of mass spectrometry, biochemistry, reverse genetics and microscopy, we uncover that UVRAG, a subunit of the class III phosphatidylinositol 3-kinase complexes in Nicotiana benthamiana, plays an essential role in autophagsome maturation via ATG14-assisted recruitment to autophagosomes and by facilitating RAB7 activation. An interaction between N. benthamiana UVRAG and ATG14 was observed in vitro and in vivo, which strikingly differed from their mutually exclusive appearance in different PI3KC3 complexes in yeast and mammals. This interaction increased the localisation of UVRAG on autophagosomes and enabled the convergence of autophagic and late endosomal structures, where they contributed to fusions between these two types of organelles by recruiting the essential membrane fusion factors RAB7 GTPase and the homotypic fusion and protein sorting (HOPS) complex. In addition, we uncovered a joint contribution of ATG14 and UVRAG to geminiviral infection, beyond autophagy. Our study provides insights into the mechanisms of autophagosome maturation in plants and expands the understanding of organisations and roles of the PI3KC3 complexes.


Assuntos
Autofagossomos , Geminiviridae , Animais , Autofagossomos/metabolismo , Geminiviridae/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Autofagia/fisiologia , Classe III de Fosfatidilinositol 3-Quinases/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Mamíferos
10.
Viruses ; 14(8)2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-36016426

RESUMO

The selection of resistant crops is an effective method for controlling geminivirus diseases. ty-5 encodes a messenger RNA surveillance factor Pelota with a single amino acid mutation (PelotaV16G), which confers effective resistance to tomato yellow leaf curl virus (TYLCV). No studies have investigated whether ty-5 confers resistance to other geminiviruses. Here, we demonstrate that the tomato ty-5 line exhibits effective resistance to various geminiviruses. It confers resistance to two representative begomoviruses, tomato yellow leaf curl China virus/tomato yellow leaf curl China betasatellite complex and tomato leaf curl Yunnan virus. The ty-5 line also exhibits partial resistance to a curtovirus beet curly top virus. Importantly, ty-5 confers resistance to TYLCV with a betasatellite. Southern blotting and quantitative polymerase chain reaction analyses showed that significantly less DNA of these geminiviruses accumulated in the ty-5 line than in the susceptible line. Moreover, knockdown of Pelota expression converted a Nicotiana benthamiana plant from a geminivirus-susceptible host to a geminivirus-resistant host. Overall, our findings suggest that ty-5 is an important resistance gene resource for crop breeding to control geminiviruses.


Assuntos
Begomovirus , Geminiviridae , Lycopersicon esculentum , Begomovirus/genética , China , Geminiviridae/genética , Melhoramento Vegetal , Doenças das Plantas/genética
11.
Virus Genes ; 58(6): 550-559, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35960462

RESUMO

Beet curly top Iran virus (BCTIV) is a member of the genus Becurtovirus (Family Geminiviridae) with a circular single-strand DNA genome. BCTIV causes leaf curling and vein swelling symptoms in plants. However, the potential pathogenicity factor/s in BCTIV is/are not known. This study presents characterization of complementary-sense transcripts of BCTIV and the viral factors in directing the pathogenicity and hypersensitive response (HR) in Nicotiana benthamiana plants. In both local and systemic infection, splicing of the complementary transcripts of BCTIV was observed. Notably, a small number (8.3%) of transcripts were spliced to produce Rep (C1:C2) transcripts after deletion of 155 nt (position 1892-2046 from BCTIV). Expression of BCTIV genes in N. benthamiana using tobacco rattle virus (TRV)-based vector showed that Rep together with C1 are the main pathogenicity factors which cause typical viral leaf curling symptoms. In addition, the V2 caused a mild leaf curling, thickening, and asymmetric leaves, while the V1, V3, and C2 had no clear effect on the plant phenotype. Transient expression of individual viral genes showed that both the C1 and Rep trigger a HR response in N. benthamiana. The higher expression of HR marker genes, harpin-induced 1 (Hin1) and hypersensitivity-related (Hsr203JI), supported the role of C1 and Rep in HR response in plants. It is concluded that Rep and C1 are the main pathogenicity factors that also trigger HR response in plants.


Assuntos
Beta vulgaris , Geminiviridae , Tabaco , Fatores de Virulência/genética , Irã (Geográfico) , Doenças das Plantas , Plantas
12.
Int J Mol Sci ; 23(15)2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35897649

RESUMO

Beet curly top virus (BCTV) significantly reduces sugar beet yield in semi-arid production areas. Genetic resistance to BCTV is limited; therefore, identification of additional resistance-associated factors is highly desired. Using 16S rRNA sequencing and BCTV resistant (R) genotypes (KDH13, KDH4-9) along with a susceptible (S) genotype (KDH19-17), we investigated leaf bacteriome changes during BCTV post inoculation (pi). At day 6 (~6-week-old plants), Cyanobacteria were predominant (~90%); whereas, at week 4 (~10-week-old plants) Firmicutes (11-66%), Bacteroidetes (17-26%), and Verrucomicrobia (12-29%) were predominant phyla and genotype dependent. Both Bacteroidetes and Verrucomicrobia, increased post infection only in the R lines. The bacterial genera Brevibacillus increased at 6 dpi, and Akkermansia and Bacteroides at 4 wkpi in the R lines. Linear discriminant analysis effect size (LEfSe) identified potential biomarkers in the R vs. S lines. Functional profiling revealed bacterial enrichment associated with the TCA cycle, polyisoprenoid, and L-methionine biosynthesis pathways only in KDH4-9 at 6 dpi. At 4 wkpi, bacteria associated with tryptophan and palmitate biosynthesis in the R lines, and uridine monophosphate, phosphatidyl glycerol, and phospholipid biosynthesis in the S line, were enriched. Future characterization of bacterial genera with antiviral properties will help establish their use as biocontrol agents/biomarkers against BCTV.


Assuntos
Beta vulgaris , Geminiviridae , Beta vulgaris/genética , Suscetibilidade a Doenças , Geminiviridae/genética , Folhas de Planta , RNA Ribossômico 16S/genética , Açúcares , Verduras/genética
13.
BMC Plant Biol ; 22(1): 362, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35869422

RESUMO

BACKGROUND: Soybean is one of the four major crops in China. The occurrence of viruses in soybean causes significant economic losses. RESULTS: In this study, the soybean leaves from stay-green plants showing crinkle were collected for metatranscriptomic sequencing. A novel geminivirus, tentatively named soybean geminivirus A (SGVA), was identified in soybean stay-green plants. Sequence analysis of the full-length SGVA genome revealed a genome of 2762 nucleotides that contain six open reading frames. Phylogenetic analyses revealed that SGVA was located adjacent to the clade of begomoviruses in both the full genome-based and C1-based phylogenetic tree, while in the CP-based phylogenetic tree, SGVA was located adjacent to the clade of becurtoviruses. SGVA was proposed as a new recombinant geminivirus. Agroinfectious clone of SGVA was constructed. Typical systemic symptoms of curly leaves were observed at 11 dpi in Nicotiana benthamiana plants and severe dwarfism was observed after 3 weeks post inoculation. Expression of the SGVA encoded V2 and C1 proteins through a potato virus X (PVX) vector caused severe symptoms in N. benthamiana. The V2 protein inhibited local RNA silencing in co-infiltration assays in GFP transgenic 16C N. benthamiana plants. Further study revealed mild symptoms in N. benthamiana plants inoculated with SGVA-ZZ V2-STOP and SGVA-ZZ V2-3738AA mutants. Both the relative viral DNA and CP protein accumulation levels significantly decreased when compared with SGVA-inoculated plants. CONCLUSIONS: This work identified a new geminivirus in soybean stay-green plants and determined V2 as a pathogenicity factor and silencing suppressor.


Assuntos
Fabaceae , Geminiviridae , Fabaceae/genética , Geminiviridae/genética , Geminiviridae/metabolismo , Filogenia , Doenças das Plantas/genética , Plantas Geneticamente Modificadas/metabolismo , Soja/genética , Soja/metabolismo , Tabaco/metabolismo , Fatores de Virulência/metabolismo
14.
Nat Commun ; 13(1): 3933, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35798722

RESUMO

Cassava mosaic disease (CMD) suppresses cassava yields across the tropics. The dominant CMD2 locus confers resistance to cassava mosaic geminiviruses. It has been reported that CMD2-type landraces lose resistance after regeneration through de novo morphogenesis. As full genome bisulfite sequencing failed to uncover an epigenetic mechanism for this loss of resistance, whole genome sequencing and genetic variant analysis was performed and the CMD2 locus was fine-mapped to a 190 kilobase interval. Collectively, these data indicate that CMD2-type resistance is caused by a nonsynonymous, single nucleotide polymorphism in DNA polymerase δ subunit 1 (MePOLD1) located within this region. Virus-induced gene silencing of MePOLD1 in a CMD-susceptible cassava variety produced a recovery phenotype typical of CMD2-type resistance. Analysis of other CMD2-type cassava varieties identified additional candidate resistance alleles within MePOLD1. Genetic variation of MePOLD1, therefore, could represent an important genetic resource for resistance breeding and/or genome editing, and elucidating mechanisms of resistance to geminiviruses.


Assuntos
Begomovirus , Geminiviridae , Manihot , DNA Polimerase III/genética , Resistência à Doença/genética , Geminiviridae/genética , Manihot/genética , Mutação , Melhoramento Vegetal , Doenças das Plantas/genética
15.
Plant Biotechnol J ; 20(11): 2159-2173, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35869670

RESUMO

Microbiota colonize every accessible plant tissue and play fundamental roles in plant growth and health. Soybean stay-green syndrome (SGS), a condition that causes delayed leaf senescence (stay-green), flat pods and abnormal seeds of soybean, has become the most serious disease of soybean in China. However, the direct cause of SGS is highly debated, and little is known about how SGS affect soybean microbiome dynamics, particularly the seed microbiome. We studied the bacterial, fungal, and viral communities associated with different soybean tissues with and without SGS using a multi-omics approach, and investigated the possible pathogenic agents associated with SGS and how SGS affects the assembly and functions of plant-associated microbiomes. We obtained a comprehensive view of the composition, function, loads, diversity, and dynamics of soybean microbiomes in the rhizosphere, root, stem, leaf, pod, and seed compartments, and discovered that soybean SGS was associated with dramatically increased microbial loads and dysbiosis of the bacterial microbiota in seeds. Furthermore, we identified a novel geminivirus that was strongly associated with soybean SGS, regardless of plant cultivar, sampling location, or harvest year. This whole-plant microbiome profiling of soybean provides the first demonstration of geminivirus infection associated with microbiota dysbiosis, which might represent a general microbiological symptom of plant diseases.


Assuntos
Geminiviridae , Microbiota , Soja/genética , Soja/microbiologia , Disbiose , Microbiota/genética , Rizosfera , Bactérias , Raízes de Plantas/microbiologia
16.
Sci China Life Sci ; 65(8): 1498-1503, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35661965

RESUMO

Geminiviruses are a group of plant viruses that cause severe diseases in many economically important crops worldwide, leading to devastating losses to agricultural production. Here we summarize the occurrence and distribution of geminiviruses in China, which provides valuable information for further epidemiological studies and supports the development of effective disease management strategies.


Assuntos
Geminiviridae , Vírus de Plantas , China , Produtos Agrícolas , Geminiviridae/genética , Doenças das Plantas
17.
Viruses ; 14(6)2022 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-35746628

RESUMO

Grapevine red blotch disease emerged within the past decade, disrupting North American vine stock production and vineyard profitability. Our understanding of how grapevine red blotch virus (GRBV), the causal agent of the disease, interacts with its Vitis hosts and insect vector, Spissistilus festinus, is limited. Here, we studied the capabilities of S. festinus to transmit GRBV from and to free-living vines, identified as first-generation hybrids of V. californica and V. vinifera 'Sauvignon blanc' (Vcal hybrids), and to and from V. vinifera 'Cabernet franc' (Vvin Cf) vines. The transmission rate of GRBV was high from infected Vcal hybrid vines to healthy Vcal hybrid vines (77%, 10 of 13) and from infected Vvin Cf vines to healthy Vcal hybrid vines (100%, 3 of 3). In contrast, the transmission rate of GRBV was low from infected Vcal hybrid vines to healthy Vvin Cf vines (15%, 2 of 13), and from infected Vvin Cf vines to healthy Vvin Cf vines (19%, 5 of 27). No association was found between transmission rates and GRBV titer in donor vines used in transmission assays, but the virus titer was higher in the recipient leaves of Vcal hybrid vines compared with recipient leaves of Vvin Cf vines. The transmission of GRBV from infected Vcal hybrid vines was also determined to be trans-stadial. Altogether, our findings revealed that free-living vines can be a source for the GRBV inoculum that is transmissible by S. festinus to other free-living vines and a wine grape cultivar, illustrating the interconnected roles of the two virus hosts in riparian areas and commercial vineyards, respectively, for virus spread. These new insights into red blotch disease epidemiology will inform the implementation of disease management strategies.


Assuntos
Geminiviridae , Hemípteros , Vitis , Animais , Insetos Vetores , Doenças das Plantas
18.
BMC Res Notes ; 15(1): 213, 2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35725650

RESUMO

OBJECTIVE: Grapevine (Vitis spp.) viral infections, including those by Grapevine leafroll-associated virus 3 (GLRaV-3) and Grapevine red blotch virus (GRBV), greatly reduce fruit yields and quality. Evidence exists that host chemistry shifts result in reductions in fruit quality. However, changes over the season in foliar chemistry has not been well examined. Therefore, phenolic and amino acid levels were examined in leaves collected in grapevines with different rootstocks that were healthy or were infected with GLRaV-3 or GRBV. This was part of an effort to assess changes that different pathogens cause in grapevine tissues. RESULTS: Month and year appeared to account for the greatest variability in grapevine foliar phenolic or amino acid levels, followed by differences in rootstock, and then differences in infection status. GLRaV-3 infection significantly lowered levels of total and individual hydroxycinnamic acid derivatives, and GRBV lowered total phenolic levels, total and individual hydroxycinnamic acids. Amino acid levels were increased over controls in vines infected by GLRaV-3, but not with GRBV. Overall, changes within grapevine leaves due to viral infection were likely too small to overcome variability due to sampling time or rootstock cultivar, and therefore such factors should be considered in determining infection effects on plant foliar chemistry.


Assuntos
Closteroviridae , Geminiviridae , Vitis , Aminoácidos , Fenóis , Doenças das Plantas
19.
J Plant Physiol ; 275: 153742, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35696829

RESUMO

Geminiviruses are a large group of plant viruses that have been a serious threat to worldwide agriculture. Transcription of the virus-encoded genes is necessary for geminiviruses to complete their life cycle, but the host proteins which directly target geminivirus promoters for suppression of viral gene transcription remain to be identified. Using Beet severe curly top virus (BSCTV) which causes severe plant symptoms as a system, we performed a yeast one-hybrid screening and identified ABA INSENSITIVE 5 (ABI5), a critical transcription factor in Abscisic acid (ABA) signaling transduction, as an interactor with the viral promoter. Further data showed that an ABA-responsive element in the viral promoter is necessary for its interaction with ABI5 and symptom development. Overexpression of ABI5 suppresses the transcription activity of the viral promoter and BSCTV infection in Nicotiana benthamiana and Arabidopsis; whilst depletion of ABI5 enhances the infection of BSCTV in Arabidopsis. Taken together, our study uncovered the function of ABI5 in the plant-virus interaction and will provide us with a new strategy to protect crops from geminivirus infection.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Geminiviridae , Ácido Abscísico/metabolismo , Ácido Abscísico/farmacologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Geminiviridae/genética , Geminiviridae/metabolismo , Regulação da Expressão Gênica de Plantas , Germinação/genética , Plantas Geneticamente Modificadas/metabolismo
20.
Sci Rep ; 12(1): 8429, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35589977

RESUMO

There is widespread evidence of plant viruses manipulating behavior of their insect vectors as a strategy to maximize infection of plants. Often, plant viruses and their insect vectors have multiple potential host plant species, and these may not overlap entirely. Moreover, insect vectors may not prefer plant species to which plant viruses are well-adapted. In such cases, can plant viruses manipulate their insect vectors to preferentially feed and oviposit on plant species, which are suitable for viral propagation but less suitable for themselves? To address this question, we conducted dual- and no-choice feeding studies (number and duration of probing events) and oviposition studies with non-viruliferous and viruliferous [carrying beet curly top virus (BCTV)] beet leafhoppers [Circulifer tenellus (Baker)] on three plant species: barley (Hordeum vulgare L.), ribwort plantain (Plantago lanceolata L.), and tomato (Solanum lycopersicum L.). Barley is not a host of BCTV, whereas ribwort plantain and tomato are susceptible to BCTV infection and develop a symptomless infection and severe curly top symptoms, respectively. Ribwort plantain plants can be used to maintain beet leafhopper colonies for multiple generations (suitable), whereas tomato plants cannot be used to maintain beet leafhopper colonies (unsuitable). Based on dual- and no-choice experiments, we demonstrated that BCTV appears to manipulate probing preference and behavior by beet leafhoppers, whereas there was no significant difference in oviposition preference. Simulation modeling predicted that BCTV infection rates would to be higher in tomato fields with barley compared with ribwort plantain as a trap crop. Simulation model results supported the hypothesis that manipulation of probing preference and behavior may increase BCTV infection in tomato fields. Results presented were based on the BCTV-beet leafhopper pathosystem, but the approach taken (combination of experimental studies with complementary simulation modeling) is widely applicable and relevant to other insect-vectored plant pathogen systems involving multiple plant species.


Assuntos
Beta vulgaris , Geminiviridae , Hemípteros , Vírus de Plantas , Animais , Feminino , Insetos Vetores , Doenças das Plantas , Plantas
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