Are plant viruses spread by insects?
Introduction—Insects as Plant Virus Vectors The majority of plant viruses that cause disease in agricultural crops rely on biotic vectors for transmission and survival [1]. The largest class of plant virus-transmitting vectors are insects but other vectors include mites, nematodes and chytrid fungi.
How do insects transfer plant viruses?
Most vectors are piercing-sucking insects that transmit plant viruses in either the circulative virus (CV) or noncirculative virus (NCV). NCV are carried on the lining cuticle of vectors stylets. CVs cross the vectors’ gut, move internally to the salivary glands (SG), cross the SG membranes to be ejected upon feeding.
What are the two phases of plant virus transmission by an insect vector?
Most plant viruses depend on insect vectors for their survival, transmission and spread. They trans- mit plant viruses by two principal modes, circula- tive (circulating through the insect’s haemocoel, CV) and non-circulative (carried on the cuticle lin- ing of mouthparts or foregut, NC).
What is Circulative transmission?
In circulative transmission, viruses move from the foregut further to the mid- and hindgut, from where they are transported to the hemolymph and further to the salivary gland, from where they are released into the plant tissue during feeding.
Which diseases is transmitted by an insect vector?
List of vector-borne diseases, according to their vector
| Vector | Disease caused | |
|---|---|---|
| Mosquito | Aedes | Chikungunya Dengue Lymphatic filariasis Rift Valley fever Yellow Fever Zika |
| Anopheles | Lymphatic filariasis Malaria | |
| Culex | Japanese encephalitis Lymphatic filariasis West Nile fever | |
| Aquatic snails | Schistosomiasis (bilharziasis) |
What are the major insect groups mainly responsible for virus transmission?
Insects (mosquitoes, lice, fleas, bed bugs) and ticks are able to transmit a number of diseases caused by infectious agents: viruses (chikungunya virus, yellow fever, dengue fever, etc.), bacteria (Lyme disease, plague, etc.), parasites (malaria, sleeping sickness, leishmaniasis, filariasis, etc.).
How do viruses enter plant cells and spread within a plant?
Plant and animal viruses can enter through endocytosis, in which the cell membrane surrounds and engulfs the entire virus. Some enveloped viruses enter the cell when the viral envelope fuses directly with the cell membrane.
What is an insect vector?
A vector is an organism that acts as an intermediary host for a parasite. Most importantly the vector transfers the parasite to the next host. Good examples of vectors are the mosquito in transmitting malaria and ticks in transferring Lyme disease.
What is semi persistent transmission?
Semi-persistent viral transmission involves the virus entering the foregut of the insect. Those viruses that manage to pass through the gut into the haemolymph and then to the salivary glands are known as persistent. There are two sub-classes of persistent viruses: propagative and circulative.
What is non Circulative transmission?
Abstract. Many viruses are transmitted by arthropod vectors. An important mode of transmission is the noncirculative or mechanical transmission where viruses attach to the vector mouthparts for transport to a new host.
Which insect carries the most diseases?
The most common insects that pass on disease are mosquitoes, sand flies, ticks, and fleas. For example, mosquitoes are known for spreading the Zika virus, Yellow Fever, and Malaria.
Which diseases are spread by flies and how?
The diseases that flies can transmit include enteric infections (such as dysen- tery, diarrhoea, typhoid, cholera and certain helminth infections), eye infections (such as trachoma and epidemic conjunctivitis) (Fig.
How can viruses be transmitted from one plant to another?
In the mechanical transmission of viruses, a virus from one kind of plant may be transmitted to dozens of unrelated herbaceous plants Transmitted from one plant to another through the bridge formed between two plants by twining the stem of parasitic plants, dodder (Cuscuta sp.)
What is a plant virus vector?
Most plant viruses depend on vectors for their survival and spread. Most vectors are piercing-sucking insects that transmit plant viruses in either the circulative virus (CV) or noncirculative virus (NCV). NCV are carried on the lining cuticle of vectors stylets.
How are viruses transmitted through SAP?
Mechanical Transmission of Viruses through Sap In nature, the direct transfer of sap through contact of one plant with another is uncommon and relatively unimportant This method of transmission happens when the plants are wounded during cultural practices by tools, hands, or clothes, or by animals feeding on the plants
How do insects help in the spread of pathogens?
Many insects facilitate the entry of a pathogen into its host through the wounds the insects make on aboveground or belowground plant organs. In some cases, insects help the survival of the pathogen by allowing it to overseason in the body of the insect.