User:Error 4001/Nilaparvata lugens commensal X virus

Lead
The brown plant hopper is a pest affecting primarily rice plants.

Nilaparvata lugens commensal X virus

The brown plant hopper, or Nilaparvata lugens, is a species of hoppers that feeds primarily on rice plants and acts as a pest for this crop causing mainly sucking damage. Rice is one of the main food sources for the world population, with major plantations in South and Southeast Asia and Oceania. Therefore, the brown plant hopper has been identified Australia, Fiji, Guam, Federated States of Micronesia, New Caledonia among other Asian nations.

In addition to this, the BPH pest has been shown to facilitate the transmission of multiple highly infectious diseases including rice ragged stunt virus and rice grassy stunt virus.

Agricultural significance

Rice has been historically one of the main crops that human populations around the world have relied on as a source of food. Currently, rice still represents about a 20% of the calories consumed by humans around the world. This is why rice pests are a major concern, since not only are they responsible for the loss of millions of dollars a year in crops damage, but they also contribute to world hunger and public health issues especially surrounding nations that rely on rice as their main source of calorie intake.

The brown plant hopper is one of the main pests of rice plants, and it is directly responsible for damage and loss of rice crops every year. The BPH affects rice plants by disrupting the vacuole structure the stem cells of rice plants and thus causing many of these cells to die, leading to the death of the plant. In addition, the BPH also contributes to the infection of rice plants with diseases as rice ragged stunt virus (RRSV) and rice grassy stunt virus (RGSV), which have led to the destruction of entire rice plantations with an estimated gross value of over 120 million dollars.

Virus structure

The NLCXV is thought to be in the Dicistroviridae family, closely related to the Cripavirus (CrPV). Further information about its taxonomy is still missing.

Initially, scientist isolated the Nilaparvata lugens reovirus (NLRV) and found two more distinct viral particles, one of them being the Nilaparvata lugens commensal X virus (NLCXV). At about 30 nm in diameter, the NLCXV has a spherical envelope with a rough surface. Furthermore, NLCXV has a positive-stranded RNA genome of about 1647 nucleotides in length.

Studies suggest that this virus only encodes its capsid proteins and one or two minor proteins of unknown function. Also, protein analysis has confirmed that the NLCXV does not encode a replicase enzyme, confirming that this is a satellite virus, as it is dependent on host’s virus cell machinery to replicate.

Next, research has shown that the NLCXV is mostly transmitted vertically with only very little evidence showing isolated cases of horizontal transmission of the virus.

Tissue tropism

The Nilaparvata lugens commensal X virus was found in the ovaries of females at the highest numbers closely followed by the testis in males.

Host

Although researchers have attempted to identify the NLCXV host requirement, they have not been able to determine the identify of this host virus. Some evidence suggested that the NLCXV is co-infected with the Nilaparvata lugens reovirus (NLRV) or with the Himetobi P virus Izumo isolate (HiPV-Iz). However, further research indicated that these are not linked to the NLCXV, therefore the identity of its host is still unknown to this date.