Oat Blue Dwarf Virus in Its Plant Host and Insect Vectors

Citrus greening, or Huanglongbing (HLB), currently is the most destructive disease of citrus. HLB disease is putatively caused by the phloem-restricted α-proteobacterium, ‛Candidatus Liberibacter asiaticus’. This bacterium is primarily transmitted by the Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae). Most animal pathogens are considered pathogenic to their insect vectors, whereas the relationships between plant pathogens and their insect vectors are variable. Lately, the relationship of ‛Ca. L. asiaticus’ with its insect vector, D. citri was well investigated at the molecular, biochemical, and biological levels in many studies. Herein, the findings concerning this relationship are discussed and molecular features of the acquisition of ‛Ca. L. asiaticus’ from the plant host and its growth and circulation within D. citri, as well as its transmission to plants, are presented. In addition, the effects of ‛Ca. L. asiaticus’ on the energy metabolism (respiration, TCA cycle, the ATP production), metabolic pathways, immune system, endosymbionts, and detoxification enzymes of D. citri are discussed together with other impacts such as shorter lifespan, altered feeding behavior, and higher fecundity. Overall, although ‛Ca. L. asiaticus’ has significant negative effects on its insect vector, it increases its vector fitness, indicating that it develops a mutualistic relationship with its vector. This review will help in understanding the specific interactions between ‛Ca. L. asiaticus’ and its psyllid vector in order to design innovative management strategies.

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Competitive Interactions Between Whitefly and Aphid Transmitted Poleroviruses within the Plant Host and the Insect Vectors

Phytopathology ◽

10.1094/phyto-08-20-0369-r ◽

2020 ◽

Cited By ~ 1

Author(s):

Vinicius Henrique Bello ◽

Saptarshi Ghosh ◽

Renate Krause-Sakate ◽

Murad Ghanim

Keyword(s):

Host Plant ◽

Infection Rate ◽

Transmission Rate ◽

Transmission Efficiency ◽

Competitive Interactions ◽

Insect Vector ◽

Insect Vectors ◽

Plant Host ◽

Transmission Rates ◽

Pepper Vein Yellows Virus

Pepper cultivation in Israel has recently been constrained by two sympatric poleroviruses, Pepper vein yellows virus-2 (PeVYV-2) and Pepper whitefly-borne vein yellows virus (PeWBVYV) which are transmitted specifically by aphids and whiteflies, respectively. The interaction between PeVYV-2 and PeWBVYV inside the host plant and the insect vectors were investigated in this study. Our results show that PeVYV-2 and PeWBVYV compete against each other inside the host plant and also inside aphids. PeWBVYV was the weaker competitor inside the host plant with diminished transmission rates when inoculated simultaneously or successively after PeVYV-2 and could only be transmitted efficiently when inoculated first and then challenged by PeVYV-2. Successive inoculations of plants with viruliferous whiteflies with PeWBVYV, followed by viruliferous aphids with PeVYV-2 led to co-infection rate of 60%, however with severely reduced titers of PeWBVYV in the co-infected plants compared to singly infected ones. In contrast, PeVYV-2 was the weaker competitor inside the insect vector with reduced quantities of the acquired virus and reduced transmission rate by aphids when given prior acquisition on PeWBVYV. However, we also show that transmission efficiency of PeVYV-2 and PeWBVYV from co-infected plants by whiteflies and aphids remain comparable to that from singly-infected plants. This is probably due to the reduced titers of PeWBVYV inside co-infected plants causing lesser impact on transmission of PeVYV-2 by aphids and the stronger competitiveness of PeWBVYV inside whitefly. Competitive interactions between PeVYV-2 and PeWBVYV inside the host plant and insect vector can thus be beneficial for their co-existence.

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Manipulation of Jasmonate Signaling by Plant Viruses and Their Insect Vectors

Viruses ◽

10.3390/v12020148 ◽

2020 ◽

Vol 12 (2) ◽

pp. 148 ◽

Cited By ~ 6

Author(s):

Xiujuan Wu ◽

Jian Ye

Keyword(s):

Crop Yield ◽

Plant Virus ◽

Plant Viruses ◽

Insect Vector ◽

Insect Vectors ◽

Plant Host ◽

Effective Strategies ◽

Secondary Damage ◽

Molecular And Biochemical Mechanisms ◽

Ja Signaling

Plant viruses pose serious threats to stable crop yield. The majority of them are transmitted by insects, which cause secondary damage to the plant host from the herbivore-vector’s infestation. What is worse, a successful plant virus evolves multiple strategies to manipulate host defenses to promote the population of the insect vector and thereby furthers the disease pandemic. Jasmonate (JA) and its derivatives (JAs) are lipid-based phytohormones with similar structures to animal prostaglandins, conferring plant defenses against various biotic and abiotic challenges, especially pathogens and herbivores. For survival, plant viruses and herbivores have evolved strategies to convergently target JA signaling. Here, we review the roles of JA signaling in the tripartite interactions among plant, virus, and insect vectors, with a focus on the molecular and biochemical mechanisms that drive vector-borne plant viral diseases. This knowledge is essential for the further design and development of effective strategies to protect viral damages, thereby increasing crop yield and food security.

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On Some Significant Phytoplasma Diseases of Forest Trees: An Update

Forests ◽

10.3390/f12040408 ◽

2021 ◽

Vol 12 (4) ◽

pp. 408

Author(s):

Carmine Marcone ◽

Deividas Valiunas ◽

Soma Mondal ◽

Ramachandran Sundararaj

Keyword(s):

Fruit Trees ◽

Detection Methods ◽

Insect Vectors ◽

Forest Trees ◽

Specific Detection ◽

Plant Host ◽

Pcr Technology ◽

Almost All ◽

Host Tolerance

This paper provides an updating of information of a selected number of major phytoplasma diseases of forest trees, with a focus on the associated phytoplasma taxa. Phytoplasma diseases of forest trees have been less extensively studied than those affecting fruit trees. Research on the role of phytoplasmas as the cause of diseases of forest trees has only in the last few years been intensified, after sensitive and specific detection methods greatly based on PCR technology became available. Various phytoplasma taxa have been identified in naturally infected elm, ash, conifer, sandal, and eucalyptus trees, whereas only one phytoplasma taxon has been recorded in naturally infected alder trees. However, for almost all of the reviewed diseases, there is still sparse information about insect vectors, plant host range, strain virulence, pathogenicity, and host tolerance and resistance. Knowledge of these aspects is the basis for appropriate disease management. In particular, further research is required to clarify the role of phytoplasmas in asymptomatic trees. In addition, the etiological role of various “non-specific” phytoplasma taxa, which have been recorded in forest trees, while no data from pathological studies are available, needs to be further investigated.

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Accumulation of Maize chlorotic dwarf virus proteins in its plant host and leafhopper vector

Virology ◽

10.1016/j.virol.2004.04.039 ◽

2004 ◽

Vol 325 (2) ◽

pp. 379-388 ◽

Cited By ~ 11

Author(s):

Rym Chaouch-Hamada ◽

Margaret G. Redinbaugh ◽

Roy E. Gingery ◽

Kristen Willie ◽

Saskia A. Hogenhout

Keyword(s):

Dwarf Virus ◽

Plant Host ◽

Leafhopper Vector ◽

Maize Chlorotic Dwarf Virus ◽

Virus Proteins

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Viral Release Threshold in the Salivary Gland of Leafhopper Vector Mediates the Intermittent Transmission of Rice Dwarf Virus

Frontiers in Microbiology ◽

10.3389/fmicb.2021.639445 ◽

2021 ◽

Vol 12 ◽

Author(s):

Qian Chen ◽

Yuyan Liu ◽

Zhirun Long ◽

Hengsong Yang ◽

Taiyun Wei

Keyword(s):

Salivary Gland ◽

Salivary Glands ◽

Horizontal Transmission ◽

Dwarf Virus ◽

Insect Vectors ◽

Rice Dwarf Virus ◽

Leafhopper Vector ◽

Gland Cells ◽

Viral Release ◽

Salivary Gland Cells

Numerous piercing-sucking insects can persistently transmit viral pathogens in combination with saliva to plant phloem in an intermittent pattern. Insect vectors maintain viruliferous for life. However, the reason why insect vectors discontinuously transmit the virus remains unclear. Rice dwarf virus (RDV), a plant reovirus, was found to replicate and assemble the progeny virions in salivary gland cells of the leafhopper vector. We observed that the RDV virions moved into saliva-stored cavities in the salivary glands of leafhopper vectors via an exocytosis-like mechanism, facilitating the viral horizontal transmission to plant hosts during the feeding of leafhoppers. Interestingly, the levels of viral accumulation in the salivary glands of leafhoppers during the transmitting period were significantly lower than those of viruliferous individuals during the intermittent period. A putative viral release threshold, which was close to 1.79 × 104 copies/μg RNA was proposed from the viral titers in the salivary glands of 52 leafhoppers during the intermittent period. Thus, the viral release threshold was hypothesized to mediate the intermittent release of RDV from the salivary gland cells of leafhoppers. We anticipate that viral release threshold-mediated intermittent transmission by insect vectors is the conserved strategy for the epidemic and persistence of vector-borne viruses in nature.

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