Natural resistance to Clover yellow vein virus in beans controlled by a single recessive locus.
We characterized the resistance of the common bean cv. Jolanda to Clover yellow vein virus no. 30 (ClYVV). After inoculation, the virus was detected in neither inoculated nor upper leaves, suggesting that the resistance operates at either the viral replication or cell-to-cell movement level. To analyze the mechanism of resistance, we developed a green fluorescent protein (GFP)-tagged ClYVV, and monitored GFP fluorescence at sites of infection on ClYVV-inoculated leaves. No GFP fluorescence was detected in Jolanda, whereas its expression in single cells and spread on inoculated leaves were observed clearly in susceptible cultivars. ClYVV-introduced Jolanda cells were found to be still viable; therefore, it is unlikely that the restriction of multiplication was due to rapid cell death. Genetic analysis indicated that a single recessive locus controlled the resistant phenotype of Jolanda. We designated this locus desc (determinant of susceptibility to ClYVV). Meanwhile, a spontaneous mutant virus that overcomes the resistance (ClYVV-Br) was isolated. Inoculation assays using chimeric viruses suggested that a viral genome-linked protein (VPg) might be the avirulence determinant. The resistance mechanism may be associated with the role of VPg in the viral infection cycle.
Pathogen-Plant Interactions Group, Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
Masanao
M
Sato
Chikara
C
Masuta
Ichiro
I
Uyeda
D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers; D017343:Genes, Plant; D005808:Genes, Recessive; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins; D007091:Image Processing, Computer-Assisted; D007113:Immunity, Innate; D008164:Luminescent Proteins / Q000235:genetics; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000145:classification / Q000235:genetics / Q000821:virology*; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000235:genetics / Q000821:virology; D010942:Plant Viruses / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity* / Q000648:ultrastructure; D030821:Plants, Genetically Modified; D013045:Species Specificity; D031307:Vicia faba / Q000145:classification / Q000235:genetics / Q000821:virology*
D017931:DNA Primers; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins