The Rm1 and Rm2 Resistance Genes to Green Peach Aphid (Myzus persicae) Encode the Same TNL Proteins in Peach (Prunus persica L.)

Abstract

The green peach aphid (GPA), Myzus persicae, is an important pest of the peach crop. Three major dominant resistance genes have already been detected, Rm1 in the Weeping Flower Peach (WFP) clone, Rm2 in the Rubira clone, and Rm3 in the Fen Shouxing clone. In this study, after NGS resequencing of WFP and Rubira, we found that their genomic sequences in the Rm1 and Rm2 region were similar but very different from that of the susceptible reference peach Lovell. We constructed a BAC library for the GPA-resistant WFP and screened four BAC clones to sequence the target region. The new sequence was 61.7 Kb longer than Lovell and was annotated with four different TIR_NBS_LRR genes. Among them, the TNL1 gene was very overexpressed in WFP leaves 24 h after GPA infestation. This gene was also present and expressed in the Rubira clone and had the same sequence as the candidate Rm3 gene, supporting the hypothesis that the three genes share the same origin. In addition, we identified a second TNL, TNL2, located at 35.4 Kb from TNL1 and slightly overexpressed after GPA infestation. Kasp and size molecular markers were designed for use in marker-assisted selection and were validated in a peach segregating population.

Unraveling Jasmonate-Mediated Plant Immunity Against Green Peach Aphid (Myzus persicae) in Peach: An Integrated Transcriptomic and RNA Sequencing Approach

“…Notably, in Weeping Flower Peach (WFP), two TIR_NBS_LRR genes (TNL1 and TNL2) were identi ed as potential resistance genes against M. persicae. Of these, TNL1 exhibited signi cant upregulation in WFP leaves 24 h after GPA infestation, while TNL2 gene displayed a slight overexpression following GPA infestation (Duval et al, 2022). Additionally, the nucleotide-binding site-leucine-rich repeat (NLR) gene within the ne-mapping interval of Rm3 emerged as a robust candidate for the GPA resistance trait in peach (Pan et al, 2022).…”

Dare to be resilient: the key to future pesticide-free orchards?

“…Among available alternatives, breeding trees for pest and disease resistance is an efficient strategy to cope with biotic pressures. For instance some resistance mechanisms have already been identified for sharka and bacterial canker in apricot ( Lambert et al , 2009 ; Rubio et al , 2014 ; Omrani et al , 2019 ), and for aphids and powdery mildew in peach ( Sauge et al , 2012 ; Lambert et al , 2016 ; Pascal et al , 2017 ; Duval et al , 2022 ). Likewise, in apple, the pyramiding of functionally different major resistance genes has shown great efficiency in fighting individually scab, powdery mildew, or fire blight ( Baumgartner et al , 2015 ).…”