A single-stranded conformational polymorphism (SSCP)-derived quantitative variable to monitor the virulence of a Barley yellow dwarf virus-PAV (BYDV-PAV) isolate during adaptation to the TC14 resistant wheat line.
A standardized single-stranded conformational polymorphism (SSCP) procedure is proposed as an alternative to the time-consuming biological characterization of Barley yellow dwarf virus-PAV (BYDV-PAV) isolates. Using this procedure, six of 21 overlapping regions used to scan the viral genome gave patterns specific to '4E' (avirulent) or '4T' ('4E'-derived virulent) isolates. The calibration of samples and integration of SSCP patterns corresponding to the nucleotide region 1482-2023 allowed the estimation of P(T) values that reflect the proportions of a '4T'-specific band. Analysis of the biological (area under the pathogen progress curve) and molecular (P(T)) data suggested a positive linear relation between these variables. Moreover, sequence analysis of the nucleotide region 1482-2023 highlighted the presence of a nucleotide polymorphism (C/A(1835)) which can be considered as a candidate for virus-host interactions linked to the monitored virulence. According to these parameters, P(T) values associated with '4E'- and '4T'-derived populations show that: (i) long-term infection of a BYDV-PAV isolate on the 'TC14' resistant host leads to the fixation of virulent individuals in viral populations; and (ii) the introduction of susceptible hosts in successive 'TC14' infections results in the maintenance of low virulence of the populations. Thus, the presented study demonstrates that SSCP is a useful tool for monitoring viral populations during the host adaptation process. The described impact of host alternation provides new opportunities for the use of the 'TC14' resistance source in BYDV-resistant breeding programmes. This study is part of the global effort made by the scientific community to propose sustainable alternatives to the chemical control of this viral disease.
Delaunay
Agnes
A
INRA-Agrocampus Ouest-Université Rennes 1, UMR1099 BiO3P (Biology of Organisms and Populations Applied to Plant Protection), Le Rheu, France.
Lacroix
Christelle
C
Morliere
Stephanie
S
Riault
Gerard
G
Chain
Florian
F
Trottet
Maxime
M
Jacquot
Emmanuel
E
D000222:Adaptation, Physiological / Q000235:genetics*; D019540:Area Under Curve; D016679:Genome, Viral / Q000235:genetics; D007113:Immunity, Innate / Q000276:immunology*; D017793:Luteovirus / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D010935:Plant Diseases / Q000276:immunology* / Q000821:virology; D018807:Polymorphism, Single-Stranded Conformational / Q000235:genetics*; D014908:Triticum / Q000235:genetics / Q000276:immunology / Q000821:virology*; D014774:Virulence