Premium
NtTPN1 : a RPP8 ‐like R gene required for Potato virus Y ‐induced veinal necrosis in tobacco
Author(s) -
Michel Vincent,
Julio Emilie,
Candresse Thierry,
Cotucheau Julien,
Decorps Christophe,
Volpatti Roxane,
Moury Benoît,
Glais Laurent,
Dorlhac de Borne François,
Decroocq Véronique,
GermanRetana Sylvie
Publication year - 2018
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.13980
Subject(s) - biology , potato virus y , potyvirus , genetics , nicotiana tabacum , gene , locus (genetics) , allele , population , virology , plant virus , virus , sociology , demography
Summary Potato virus Y ( PVY ) is one of the most damaging viruses of tobacco. In particular, aggressive necrotic strains ( PVY N ) lead to considerable losses in yield. The main source of resistance against PVY is linked to the va locus. However, va ‐overcoming PVY isolates inducing necrotic symptoms were observed in several countries. In this context, it is important to find va ‐independent protection strategies. In a previous study, the phenotyping of 162 tobacco varieties revealed 10 accessions that do not carry the va allele and do not exhibit typical PVY N ‐induced veinal necrosis. Despite the absence of necrotic symptoms, normal viral accumulation in these plants suggests a va ‐independent mechanism of tolerance to PVY N ‐induced systemic veinal necrosis. Fine mapping of the genetic determinant(s) was performed in a segregating F2 population. The tolerance trait is inherited as a single recessive gene, and allelism tests demonstrated that eight of the 10 tolerant varieties carry the same determinant. Anchoring the linkage map to the tobacco genome physical map allowed the identification of a RPP 8‐like R gene, called Nt TPN 1 (for N icotiana t abacum T olerance toP VY ‐induced N ecrosis1 ), with the same single‐nucleotide polymorphism in the eight tolerant accessions. Functional assays using homozygous Nt TPN 1 EMS mutants confirmed the role of Nt TPN 1 in the tolerance phenotype. PVY N ‐induced systemic veinal necrosis in tobacco likely represents an inefficient defense response with hypersensitive response‐like characteristics. The identification of Nt TPN 1 opens breeding options to minimize the impact of emerging and so far uncontrolled va ‐breaking necrotic PVY isolates.