Coat protein of Chinese wheat mosaic virus upregulates and interacts with cytosolic glyceraldehyde-3-phosphate dehydrogenase, a negative regulator of plant autophagy, to promote virus infection.

Autophagy is an intracellular degradation mechanism involved in antiviral defense, but the strategies employed by plant viruses to counteract autophagy-related defense remain unknown for the majority of the viruses. Herein, we describe how the Chinese wheat mosaic virus (CWMV, genus Furovirus) interferes with autophagy and enhances its infection in Nicotiana benthamiana. Yeast two-hybrid screening and in vivo/in vitro assays revealed that the 19 kDa coat protein (CP19K) of CWMV interacts with cytosolic glyceraldehyde-3-phosphate dehydrogenases (GAPCs), negative regulators of autophagy, which bind autophagy-related protein 3 (ATG3), a key factor in autophagy.

Autophagy Inhibits Intercellular Transport of Citrus Leaf Blotch Virus by Targeting Viral Movement Protein.

Autophagy is an evolutionarily conserved cellular-degradation mechanism implicated in antiviral defense in plants. Studies have shown that autophagy suppresses virus accumulation in cells; however, it has not been reported to specifically inhibit viral spread in plants. This study demonstrated that infection with citrus leaf blotch virus (CLBV; genus , family ) activated autophagy in plants as indicated by the increase of autophagosome formation.

Facilitative and synergistic interactions between fungal and plant viruses.

Plants and fungi are closely associated through parasitic or symbiotic relationships in which bidirectional exchanges of cellular contents occur. Recently, a plant virus was shown to be transmitted from a plant to a fungus, but it is unknown whether fungal viruses can also cross host barriers and spread to plants. In this study, we investigated the infectivity of Cryphonectria hypovirus 1 (CHV1, family ), a capsidless, positive-sense (+), single-stranded RNA (ssRNA) fungal virus in a model plant, CHV1 replicated in mechanically inoculated leaves but did not spread systemically, but coinoculation with an unrelated plant (+)ssRNA virus, tobacco mosaic virus (TMV, family ), or other plant RNA viruses, enabled CHV1 to systemically infect the plant.

Symptomatic plant viroid infections in phytopathogenic fungi.

Viroids are pathogenic agents that have a small, circular noncoding RNA genome. They have been found only in plant species; therefore, their infectivity and pathogenicity in other organisms remain largely unexplored. In this study, we investigate whether plant viroids can replicate and induce symptoms in filamentous fungi.