Establishment of an Infection System for Gentian ( spp.) Sclerotial Flower Blight Disease.

Gentians ( spp.) as floriculture crops are constantly exposed to several fungal and viral pathogens in the field. Among the fungal diseases afflicting gentian production, gentian sclerotial flower blight caused by incurs economic losses, as it affects flowers before and after harvest.

Infectious in vitro transcripts from a cDNA clone of a Japanese gentian isolate of Sikte waterborne virus, which shows host-specific low-temperature-dependent replication.

Tombusviruses have been identified in several crops, including gentian virus A (GeVA) in Japanese gentian. In this study, we isolated another tombusvirus, Sikte waterborne virus strain C1 (SWBV-C1), from Japanese gentian. Although SWBV-C1 and GeVA are not closely related, SWBV-C1, like GeVA, showed host-specific low-temperature-dependent replication in gentian and arabidopsis.

Cooperative effect of two amino acid mutations in the coat protein of Pepper mild mottle virus overcomes L3-mediated resistance in Capsicum plants.

We found that an L3 resistance-breaking field isolate of Pepper mild mottle virus (PMMoV), designated PMMoV-Is, had two amino acid changes in its coat protein (CP), namely leucine to phenylalanine at position 13 (L13F) and glycine to valine at position 66 (G66V), as compared with PMMoV-J, which induces a resistance response in L3-harboring Capsicum plants. The mutations were located to a CP domain corresponding to the outer surface of PMMoV particles in computational molecular modeling. Analyses of PMMoV CP mutants containing either or both of these amino acid changes revealed that both changes were required to efficiently overcome L3-mediated resistance with systemic necrosis induction.