Rice stripe virus

Rice stripe virus is an RNA plant pathogen of the genus Tenuivirus. It is prevalent in Japan, China, and Korea and can infect plants of the family Poaceae, which include wheat and corn (see maize stripe virus). Damage from this disease causes major reductions in rice crop yield every year. It is spread primarily by Laodelphax striatellus, a small planthopper that feeds and damages rice plants by sap-sucking. Three other planthopper insects that transmit rice stripe virus include Unkanodes sapporona, Unkanodoes albifascia, and Terthron albovittatum. The virus propagates in the planthopper and is passed down to 90% of a female's eggs. However, mechanically transmitting the virus by injecting sap from an affected plant to a healthy plant has not been widely successful. Rice plants are susceptible to infection starting at the seedling age. The only known means of virus transmission is via planthoppers. Typical symptoms of rice stripe virus infection include pale and discontinuous yellow stripes, blotches, and dead tissue streaks on the leaves. Severe infections cause grey necrotic streaks and result in the death of the plant. Infection causes the most damage during seedling stage to maximum tillering stage because during this time interval, the plants are at a higher risk of death. Affected seedlings are stunted in growth with leaves that elongate without unfolding. Their color pales to white with drooped, curled, dead leaves. In Japan, this disease was called 'Yurei Byo' (ghost disease) because of these symptoms. If the plants grow, they produce few, if any, tillers and panicles with empty spikelets. Infected mature plants do not have severe chlorosis or blotches, but ripening may be hindered. They can still produce rice, but with less vigor. The virus is made up of four ssRNA segments, seven open reading frames, a nucleocapsid protein, and an RNA polymerase protein. It is 8 nm in diameter and 500-2000 nm long. This table from KnowledgeBank.irri.org summarizes reported epidemics of rice stripe virus.