A natural recessive resistance gene against potato virus Y in pepper corresponds to the eukaryotic initiation factor 4E (eIF4E).
We show here that the pvr2 locus in pepper, conferring recessive resistance against strains of potato virus Y (PVY), corresponds to a eukaryotic initiation factor 4E (eIF4E) gene. RFLP analysis on the PVY-susceptible and resistant pepper cultivars, using an eIF4E cDNA from tobacco as probe, revealed perfect map co-segregation between a polymorphism in the eIF4E gene and the pvr2 alleles, pvr2(1) (resistant to PVY-0) and pvr2(2) (resistant to PVY-0 and 1). The cloned pepper eIF4E cDNA encoded a 228 amino acid polypeptide with 70-86% nucleotide sequence identity with other plant eIF4Es. The sequences of eIF4E protein from two PVY-susceptible cultivars were identical and differed from the eIF4E sequences of the two PVY-resistant cultivars Yolo Y (YY) (pvr2(1)) and FloridaVR2 (F) (pvr2(2)) at two amino acids, a mutation common to both resistant genotypes and a second mutation specific to each. Complementation experiments were used to show that the eIF4E gene corresponds to pvr2. Thus, potato virus X-mediated transient expression of eIF4E from susceptible cultivar Yolo Wonder (YW) in the resistant genotype YY resulted in loss of resistance to subsequent PVY-0 inoculation and transient expression of eIF4E from YY (resistant to PVY-0; susceptible to PVY-1) rendered genotype F susceptible to PVY-1. Several lines of evidence indicate that interaction between the potyvirus genome-linked protein (VPg) and eIF4E are important for virus infectivity, suggesting that the recessive resistance could be due to incompatibility between the VPg and eIF4E in the resistant genotype.
Ruffel
Sandrine
S
Genetics and Breeding of Fruits and Vegetable, Dom St Maurice, BP94, F-84143 Montfavet.
Dussault
Marie-Hélène
MH
Palloix
Alain
A
Moury
Benoît
B
Bendahmane
Abdelhafid
A
Robaglia
Christophe
C
Caranta
Carole
C
D000483:Alleles; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D002212:Capsicum / Q000235:genetics* / Q000821:virology; D003001:Cloning, Molecular; D039561:Eukaryotic Initiation Factor-4E / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D015967:Gene Expression Regulation, Viral; D005808:Genes, Recessive / Q000235:genetics; D005816:Genetic Complementation Test; D007113:Immunity, Innate / Q000235:genetics; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000235:genetics / Q000821:virology*; D017800:Potyvirus / Q000235:genetics / Q000254:growth & development*; D014758:Viral Core Proteins / Q000235:genetics / Q000378:metabolism
D039561:Eukaryotic Initiation Factor-4E; D014758:Viral Core Proteins