Figure 4 - uploaded by Murad Ghanim
Content may be subject to copyright.
2 Schematic of the structural proteins of Potato leafroll virus (PLRV) encoded by ORF 3 (CP) and ORF 5 (RTD) that together comprise the readthrough protein (RTP), and the average predicted disorder plot of the RTP from 15 species of luteovirids. Mutagenesis studies defined regions and residues along the RTP that function in RNA-CP contacts, capsid assembly, a conserved proline hinge, aphid transmission at the gut and accessory salivary gland, and virus-host interactions. The VLS2 disorder plot predicts high disorder in various regions of the luteovirid structural proteins that correspond to known biological functions of the capsid. Values greater than 0.5 are predicted to have high disorder. The plot shows striking conservation of overall flexibility and disordered topology. Four cross-linked sites are shown in colors, yellow: K188-K188 homodimer and K188-K408; green: K230-K351; blue: K405-470.
Source publication
Species of plant viruses within the Luteoviridae, Geminiviridae, and Nanoviridae are transmitted by phloem-feeding insects in a circulative, nonpropagative manner. The precise route of virus movement through the vector can differ across and within virus families, but these viruses all share many biological, biochemical, and ecological features. All...
Similar publications
Objective:
The objective of the study was to discuss the classification, virus characteristics, detection methods, and control measures of chickpea virus, with an aim to provide a theoretical basis for identification of new chickpea virus and control of chickpea virus disease.
Methods:
The domestic and foreign studies were reviewed, and the viru...
Citations
... [90][91][92] Virus particles protects itself from degradation through binding with GroEL protein in hemolymph node [93] and is later spit up with salivary secretion to the phloem cells where it ejaculates ssDNA through virions in the plant cell. [94][95][96] ...
During plant–pathogen interaction, plant exhibits a strong defense system utilizing diverse groups of proteins to suppress the infection and subsequent establishment of the pathogen. However, in response, pathogens trigger an anti‐silencing mechanism to overcome the host defense machinery. Among plant viruses, geminiviruses are the second largest virus family with a worldwide distribution and continue to be production constraints to food, feed, and fiber crops. These viruses are spread by a diverse group of insects, predominantly by whiteflies, and are characterized by a single‐stranded DNA (ssDNA) genome coding for four to eight proteins that facilitate viral infection. The most effective means to managing these viruses is through an integrated disease management strategy that includes virus‐resistant cultivars, vector management, and cultural practices. Dynamic changes in this virus family enable the species to manipulate their genome organization to respond to external changes in the environment. Therefore, the evolutionary nature of geminiviruses leads to new and novel approaches for developing virus‐resistant cultivars and it is essential to study molecular ecology and evolution of geminiviruses. This review summarizes the multifunctionality of each geminivirus‐encoded protein. These protein‐based interactions trigger the abrupt changes in the host methyl cycle and signaling pathways that turn over protein normal production and impair the plant antiviral defense system. Studying these geminivirus interactions localized at cytoplasm‐nucleus could reveal a more clear picture of host–pathogen relation. Data collected from this antagonistic relationship among geminivirus, vector, and its host, will provide extensive knowledge on their virulence mode and diversity with climate change.
... Upon feeding, virion particles of geminivirus is ingested into the esophagus, entering to the hemolymph which transport virion particles further to the salivary glands of the B. tabaci (McGRATH & Harrison, 1995;Douglas, 1998;Pan et al. , 2017). Virus particles protects itself from degradation through binding with GroEL protein in haemolymph node (Miao et al. , 2016) and is later spit up with salivary secretion to the phloem cells where it ejaculates ssDNA through virions in the plant cell (Torres-delosSantos et al. , 2022) (Gray et al. , 2014;Luo et al. , 2019). ...
During plant-pathogen interaction, plant exhibits a strong defense system utilizing diverse groups of proteins to suppress the infection and subsequent establishment of the pathogen. However, in response, pathogens trigger an anti-silencing mechanism to overcome the host defense machinery. Among plant viruses, geminiviruses are the second largest virus family with a worldwide distribution and continue to be production constraints to food, feed, and fiber crops. These viruses are spread by a diverse group of insects, predominantly by whiteflies, and are characterized by a single-stranded DNA (ssDNA) genome coding for four to eight proteins that facilitate viral infection. The most effective means to managing these viruses is through an integrated disease management strategy that includes virus-resistant cultivars, vector management, and cultural practices. Dynamic changes in this virus family enable the species to manipulate their genome organization to respond to external changes in the environment. Therefore, the evolutionary nature of geminiviruses leads to new and novel approaches for developing virus-resistant cultivars and it is essential to study molecular ecology and evolution of geminiviruses. This review summarizes the multifunctionality of each geminivirus-encoded protein. These protein-based interactions trigger the abrupt changes in the host methyl cycle and signaling pathways that turn over protein normal production and impair the plant antiviral defense system. Studying these geminivirus interactions localized at cytoplasm-nucleus could reveal a more clear picture of host-pathogen relation. Data collected from this antagonistic relationship among geminivirus, vector, and its host, will provide extensive knowledge on their virulence mode and diversity with climate change
... This indicates that there are several compatible (competent or efficient) and incompatible (incompetent or inefficient) vector-virus combinations within the aphid-YDV system. The mechanisms behind this vector-variant specificity are believed to involve compatible and incompatible interactions between different virus variants and the basal lamina of the salivary gland of a given vector species, leading to selective uptake of the virus by the vector (Gildow & Gray, 1993); selectivity can also occur in the midgut and hindgut (Gray et al., 2014). ...
Cereals are some of the most important global crops that contribute directly and indirectly to the production of food for human consumption. Cereal aphids can cause significant damage to wheat, barley and oats, particularly via the transmission of plant viruses that cause devastating plant diseases, such as yellow dwarf disease. High levels of yellow dwarf disease can result in yield losses of around 20%, rising to 80% if infection is severe. Yellow dwarf disease is caused by multiple viruses, including viruses within the families Tombusviridae and Solemoviridae. These include yellow dwarf virus species within the genus Luteovirus (Barley yellow dwarf virus) and Polerovirus (Cereal yellow dwarf virus, Wheat yellow dwarf virus, Maize yellow dwarf virus). Some yellow dwarf virus species are primarily vectored by one aphid species whereas others can be transmitted by multiple vectors. Biological diversity within a given vector species (e.g., genotype, biotype) can influence virus transmission efficiency. However, it is unclear what biological factors drive this variation within a given vector species. Understanding how biological variation in vector populations influences virus transmission efficiency can help to identify biological traits that underpin successful transmission in competent vector populations. Here, the available literature on yellow dwarf virus transmission efficiency is synthesized and significant variation in yellow dwarf virus transmission efficiency is detected between different populations for several vector species. Three biological mechanisms that potentially underpin this variation are proposed.
... Vector-virus interactions are also influenced by vector endosymbionts (Pinheiro et al., 2015); mutualistic symbiotic microbes living in the vector are manipulated by the plant virus, which may influence host-vector-virus interactions. It has been hypothesized that the endosymbionts living in the vector can support the transmission processes of the plant virus, such as some luteovirids and geminiviruses (Gray et al., 2014). ...
Plant viruses can modulate insect vector behaviour directly and/or indirectly by altering plant biochemistry. In many instances, such behavioural alterations increase the frequency of encounters between host and vector, leading to enhanced virus dispersal in ecosystems. In the current study using Cucumber mosaic virus (CMV), Capsicum annuum L. (Solanaceae), and Myzus persicae (Sulzer) (Hemiptera: Aphididae) as a pathosystem, we evaluated the direct and indirect effects of CMV on M. persicae biology and behavioural responses. Data showed that CMV indirectly modulates the aphid vector by providing fitness benefits to aphids, leading to enhanced aphid reproduction on CMV‐infected pepper plants in comparison with non‐infected C. annuum plants. Furthermore, CMV can also alter aphid behaviour directly by modulating the behavioural response of viruliferous aphids towards non‐infected plants. We demonstrate that CMV directly and indirectly modulates the insect vector thereby enhancing its transmission in agroecosystems.
... As persistent virus, acquisition of BBTV requires prolonged feeding for at least a few hours on an infected plant. Virions must pass through the insect gut to survive in the haemolymph to transverse salivary tissues (hence "circulatory transmission"), without replicating in the banana aphid (hence "nonpropagative") 12,13 . ...
Pentalonia nigronervosa Coquerel ( Hemitera: Aphididae ) is the vector agent of Banana Bunchy Top Virus (BBTV), the most serious viral disease of banana ( Musa spp) in the world. Before acquiring the virus, the vector is more attracted to infected banana plants thanks to increased emissions of volatile organic compounds (VOCs). Here, we test the hypothesis that BBTV acquisition directly modifies the preference of P. nigronervosa for infected banana plants, and if this change in behaviour could result from the alteration of the organs linked to the VOC detection or linked to the flight of the vector. We found that the preference of P. nigronervosa for infected banana plants reverses with virus acquisition in dessert banana, while it remains similar between healthy and infected banana plants before and after the acquisition of BBTV. At the same time, aphids reared on infected bananas had smaller forewing areas and hind tibia length than aphids reared on healthy bananas, while the number of secondary rhinaria on the antennae was lower on dessert banana reared aphids than plantain reared aphids, regardless of infection status. These results support the "Vector Manipulation Hypothesis - VMH" of pathogens to promote their spread. They have implications for the BBTV management.
... genus Polerovirus, ScYLV is phloem-limited, with secondary transmission taking place through extensive feeding by aphids in a persistent circulative manner [14]. Among aphid species that colonize sugarcane, Melanaphis sacchari (Hemiptera: Aphididae) has been reported as the most prominent vector of ScYLV [15][16][17][18]. ...
Citation: Bertasello, L.E.T.; da Silva, M.F.; Pinto, L.R.; Nóbile, P.M.; Carmo-Sousa, M.; dos Anjos, I.A.; Perecin, D.; Spotti Lopes, J.R.; Gonçalves, M.C. Yellow Leaf Disease Resistance and Melanaphis sacchari Preference in Commercial Sugarcane Cultivars. Plants 2023, 12, 3079. Abstract: Sugarcane yellow leaf disease (YLD) caused by sugarcane yellow leaf virus (ScYLV) is a major threat for the sugarcane industry worldwide, and the aphid Melanaphis sacchari is its main vector. Breeding programs in Brazil have provided cultivars with intermediate resistance to ScYLV, whereas the incidence of ScYLV has been underestimated partly due to the complexity of YLD symptom expression and identification. Here, we evaluated YLD symptoms in a field assay using eight sugarcane genotypes comprising six well-established commercial high-sucrose cultivars, one biomass yield cultivar, and a susceptible reference under greenhouse conditions, along with estimation of virus titer through RT-qPCR from leaf samples. Additionally, a free-choice bioassay was used to determine the number of aphids feeding on the SCYLV-infected cultivars. Most of the cultivars showed some degree of resistance to YLD, while also revealing positive RT-qPCR results for ScYLV and virus titers with non-significant correlation with YLD severity. The cultivars IACSP01-5503 and IACBIO-266 were similar in terms of aphid preference and ScYLV resistance traits, whereas the least preferred cultivar by M. sacchari, IACSP96-7569, showed intermediate symptoms but similar virus titer to the susceptible reference, SP71-6163. We conclude that current genetic resistance incorporated into sugarcane commercial cultivars does not effectively prevent the spread of ScYLV by its main aphid vector.
... The variation in time between detection of successful transmission by the same aphid can be explained by the persistent, circulative nature of this virus. Persistent viruses transmitted by aphids may have a latent period lasting anywhere from minutes to hours, depending on the species and aphids often transmit for their entire lifespan (Hogenhout et al. 2008), even if they do not support virus replication (Gray et al. 2014). Persistently transmitted virions travel passively in the hemocoel from the gut to reach the accessory salivary gland (ASG), and therefore, reach the ASG at different times (Katis et al. 2007), before they can be egested into plant tissue during feeding. ...
Cotton leafroll dwarf virus (CLRDV) is a yield-limiting, aphid-transmitted virus that was identified in cotton, Gossypium hirsutum L., in the United States of America in 2017. CLRDV is currently classified in the genus Polerovirus, family Solemoviridae. Although 8 species of aphids (Hemiptera: Aphididae) are reported to infest cotton, Aphis gossypii Glover is the only known vector of CLRDV to this crop. Aphis gossypii transmits CLRDV in a persistent and nonpropagative manner, but acquisition and retention times have only been partially characterized in Brazil. The main objectives of this study were to characterize the acquisition access period, the inoculation access period, and retention times for a U.S. strain of CLRDV and A. gossypii population. A sub-objective was to test the vector competence of Myzus persicae Sulzer and Aphis craccivora Koch. In our study, A. gossypii apterous and alate morphs were able to acquire CLRDV in 30 min and 24 h, inoculate CLRDV in 45 and 15 min, and retain CLRDV for 15 and 23 days, respectively. Neither M. persicae nor A. craccivora acquired or transmitted CLRDV to cotton.
... All members of the polerovirus are transmitted persistently, circulatively and nonpropagatively by aphids and are characterized by phloem limitation [9]. The genome of BrYV contains a single positive RNA with a 5 -terminal modification of VPg. ...
Citation: Peng, Q.; Li, W.; Zhou, X.; Sun, C.; Hou, Y.; Hu, M.; Fu, S.; Zhang, J.; Kundu, J.K.; Lei, L. Genetic Diversity Analysis of Brassica Yellows Virus Causing Aberrant Color Symptoms in Oilseed Rape. Abstract: The emergence of brassica yellow virus (BrYV) has increasingly damaged crucifer crops in China in recent years. In 2020, a large number of oilseed rape in Jiangsu showed aberrant leaf color. A combined RNA-seq and RT-PCR analysis identified BrYV as the major viral pathogen. A subsequent field survey showed that the average incidence of BrYV was 32.04%. In addition to BrYV, turnip mosaic virus (TuMV) was also frequently detected. As a result, two near full-length BrYV isolates, BrYV-814NJLH and BrYV-NJ13, were cloned. Based on the newly obtained sequences and the reported BrYV and turnip yellow virus (TuYV) isolates, a phylogenetic analysis was performed, and it was found that all BrYV isolates share a common root with TuYV. Pairwise amino acid identity analysis revealed that both P2 and P3 were conserved in BrYV. Additionally, recombination analysis revealed seven recombinant events in BrYV as TuYV. We also attempted to determine BrYV infection by quantitative leaf color index, but no significant correlation was found between the two. Systemic observations indicated that BrYV-infected plants had different symptoms, such as no symptom, purple stem base and red old leaves. Overall, our work proves that BrYV is closely related to TuYV and could be considered as an epidemic strain for oilseed rape in Jiangsu.
... This composition seems to be much more complex and diverse based on many factors such as climate condition, plant cultivars, and the ecosystem. It also further helps us to identify and determine the biological aspects and possible interaction with the host because the midgut serves as a critical barrier for the replication and transmission of insect-borne pathogens [42,58,59]. It is intriguing to understand how these psyllid-specific viruses, either DNAor RNA-based, face host defense machinery and interact with other gut symbionts or pathogens such as CLas or CTV. ...
Asian citrus psyllid (Diaphorina citri) transmits the bacterial pathogen Candidatus Liberibacter asiaticus (CLas), the putative causative agent of citrus Huanglongbing disease (HLB). Insect-specific viruses can act against insects as their natural enemies, and recently, several D. citri-associated viruses were discovered. The insect gut plays an important role as not only a pool for diverse microbes but also as a physical barrier to prevent the spread of pathogens such as CLas. However, there is little evidence of the presence of D. citri-associated viruses in the gut and of the interaction between them and CLas. Here, we dissected psyllid guts collected from five growing regions in Florida, and the gut virome was analyzed by high throughput sequencing. Four insect viruses, including D. citri-associated C virus (DcACV), D. citri densovirus (DcDV), D. citri reovirus (DcRV), and D. citri flavi-like virus (DcFLV), were identified, and their presence in the gut, including an additional D. citri cimodo-like virus (DcCLV), were confirmed with PCR-based assays. Microscopic analysis showed that DcFLV infection leads to morphological abnormalities in the nuclear structure in the infected psyllid gut cells. The complex and diverse composition of microbiota in the psyllid gut suggests a possible interaction and dynamics between CLas and the D. citri-associated viruses. Our study identified various D. citri-associated viruses that localized in the psyllid gut and provided more information that helps to evaluate the potential vectors for manipulating CLas in the psyllid gut.
... Initially, virion interactions occur with the epithelial cells of the gut having receptors which facilitate the adherence to midgut and or hindgut via endocytosis. Afterwards, with the help of the exocytosis phenomenon virus particles travel to the haemocoel, which passes through, subsequently, virions reach to salivary glands for its transmissibility via saliva while probing for the plant sap (Garret et al., 1996;Gildow, 1993;Gray et al., 2014). ...
Diseases of Sugarcane (Saccharum officinarum)
and Their Integrated Management
