Quantitative resistance to Plum pox virus in Prunus davidiana P1908 linked to components of the eukaryotic translation initiation complex

Abstract

A complex, polygenic resistance to Plum pox virus (PPV) was previously described in a wild peach-related species, Prunus davidiana clone P1908. In the current study, an analysis of quantitative trait loci (QTL) was performed on an F 2 population comprising 99 individuals obtained by selfing the F 1 individual #40 of an interspecific cross between susceptible nectarine cv. Summergrand and the resistant P. davidiana clone P1908. Six QTL were identified using both parametric and non-parametric methods of detection, individually explaining 5-28% of the phenotypic variance. The total phenotypic variation explained ranged from 29 to 58%. Alignment of the genetic map of the F 2 cross with the P. davidiana parent map showed consistency of QTL over generations, with three of the six QTL co-localizing at the 1-LOD interval and another one at the 2-LOD interval. Two of the QTL were mapped onto linkage group one, where resistance to PPV was previously mapped in apricot. Development and mapping of new microsatellite markers linked to candidate genes revealed a striking co-localization of three of the detected QTL with gene copies coding for eukaryotic translation initiation factors eIF4E and eIF(iso)4G. As co-localization of one QTL with candidate gene eIF(iso)4E was previously reported in the F 1 population, the results reported here strongly reinforce the idea that components of the eukaryotic translation initiation complex are correlated with resistance to PPV in P. davidiana P1908.

New approaches to Prunus transcriptome analysis

“…A group of DAM (dormancyassociated) SVP-like (Short Vegetative Phase) MADS-box genes have been described to be responsible for this absence of vegetative dormancy in peach Jiménez et al 2010a, b). In apricot, candidate genes have been assayed in the study of Plum pox virus (PPV) resistance including resistance gene analogs (RGA) (Dondini et al, 2004;Decroocq et al 2005;Lalli et al 2005), nucleotide binding site-leucine-rich repeat (NBS-LRR) (Soriano et al 2005), eukaryotic translation initiation factor (eIF4E), RNA helicase SDE3 (Cd93) and Argonaut AGO1 protein (Marandel et al 2009). In addition, several works have made possible the identification of candidate gene coding for enzymes involved in apricot ripening, such as ACC oxidase (Mbé-guié et al 1999); polyphenol oxidase (Chevalier et al 1999); enzymes involved in the softening process (Mbé-guié et al 2002); cell wall, sugar, lipid, organic acid, and protein metabolism (Geuna et al (2005) and enzymes involved in apricot aroma (González-Agüero et al 2009).…”

Quantitative trait loci analysis of Plum pox virus resistance in Prunus davidiana P1908: new insights on the organization of genomic resistance regions

“…During each growth period, seedlings were observed for leaf symptoms. Intensity of leaf symptoms (I) and distribution of symptoms on whole plant (D) were scored independently on each scion using the phenotypic scoring system and the ordinal scale from 0 (absence of symptoms) to 4 (numerous discolorations affecting the whole leaf and associated with leaf distortions for I; symptoms on more than 30% of leaves for D) described in Decroocq et al (2005) and Marandel et al (2009). In addition, a third parameter (G) was defined: the global behavior of each seedling; it was used by Decroocq et al (2005) and Marandel et al (2009) and corresponds to the mean of the sum of the intensity and distribution scores observed on each scion.…”

“…Intensity of leaf symptoms (I) and distribution of symptoms on whole plant (D) were scored independently on each scion using the phenotypic scoring system and the ordinal scale from 0 (absence of symptoms) to 4 (numerous discolorations affecting the whole leaf and associated with leaf distortions for I; symptoms on more than 30% of leaves for D) described in Decroocq et al (2005) and Marandel et al (2009). In addition, a third parameter (G) was defined: the global behavior of each seedling; it was used by Decroocq et al (2005) and Marandel et al (2009) and corresponds to the mean of the sum of the intensity and distribution scores observed on each scion. During the three cycles of evaluation, an enzyme-linked immunosorbent assay (ELISA)-double-antibody sandwich assay was applied to the leaves using a monoclonal antibody against the coat protein of PPV (BIOREBA®) to ascertain the presence or absence of PPV in the genotypes (one leaf with symptoms for symptomatic individuals and five leaves taken at random for the other ones).…”

“…It used the same F 1 population (referred to as SD) and genetic map as Foulongne et al (2003) and reported a quantitative trait loci (QTL) analysis which identified six genomic regions related to PPV resistance in P. davidiana P1908 and thus demonstrated the polygenic character of the resistance carried by this clone. The heritability of the PPV resistance originating from P. davidiana P1908 was further studied by Marandel et al (2009) in the F 2 population derived from the selfing of the individual (#40) of the F 1 population and demonstrated the conservation of four of the six F 1 QTLs. Both studies included the mapping of candidate genes or candidategene-linked simple sequence repeat (SSR) markers and suggested the possible involvement of components of the eukaryotic translation initiation complex in PPV resistance.…”

Evaluation of the Prunus interspecific progenies for resistance to Plum pox virus

“…It used an F 1 population derived from a cross between P. persica cultivar Summergrand and P. davidiana clone P1908 and reported a quantitative trait loci (QTLs) analysis which identified six genomic regions related to PPV resistance in P. davidiana P1908 and thus demonstrated the polygenic character of the resistance carried by this clone. The heritability of the PPV resistance originating from P. davidiana clone P1908 was further studied by Marandel et al (2009) in the F 2 population derived from the selfing of the individual (#40) of the F 1 population and demonstrated the conservation of four of the six F 1 QTLs. A total of nine Prunus davidiana QTLs involved in PPV resistance were identified in an F 1 population derived from the susceptible peach cultivar Rubira and P. davidiana clone P1908 (Rubio et al 2010).…”