Molecular Pathogens, 2025, Vol.16, No.5, 207-216 http://microbescipublisher.com/index.php/mp 211 Figure 2 Rx1 localization variants Rx1-NLS and Rx1-NES failed to block PVX-GFP infection (Adopted from Richard et al., 2021) 5 Comparison of Virus Resistance Mechanisms among Solanaceae Crops 5.1 Differences and commonalities in resistance among tomatoes, peppers, and eggplants Tomatoes and peppers are the crops with the most intensive antiviral research among the Solanaceae vegetables. The identified antiviral genes in tomatoes include: Tm-2² for TMV, Sw-5b for TSWV (both CNL proteins), Ty-1/Ty-3 for TYLCV, etc., most of which come from wild relatives. Sw-5b can recognize the viral movement protein NSₘ and trigger immunity. The resistance of peppers to TSWV mainly relies on the Tsw gene, which recognizes the viral NSs protein; it also contains Pvr4 (dominant) and pvr2 (recessive) genes, which can resist PVY. Pepper breeding often combines dominant and recessive genes to enhance resistance (Ordaz et al., 2023). There are few antiviral studies on eggplant, but some wild species show resistance to CMV. Resistance in tomatoes and peppers is often accompanied by local necrosis (HR), while potato Rx1 resistance to PVX is asymptomatic (ER). The resistance of different crops relies on NLR recognition and systemic acquired resistance (SAR) activation, showing a common signaling pathway (Chen et al., 2021). In addition, disease resistance gene clusters in different crops are often located in homologous genomic regions, indicating a common evolutionary origin. 5.2 Analysis of evolution and selection pressure of resistance genes Antiviral genes in Solanaceae crops are subject to continuous selection pressure from virus communities during the evolution process. Wild species often co-evolve with viruses in long-term arms races, resulting in high diversity and rapid evolution of resistance gene families. This is especially true for the NLR gene family, where positive selection often occurs in the LRR region, accelerating the accumulation of amino acid variations to identify constantly changing pathogenic effectors (Seong et al., 2020). For example, a comparison of allelic variations in Rx genes in multiple Solanum species found that the LRRs of Rx proteins in different species are very different, reflecting traces of directed evolution. On the other hand, some highly conserved important resistance genes may experience a bottleneck effect during the domestication process, leading to a decrease in allelic richness within cultivated species and a narrowing of the genetic basis of resistance. In Solanaceae crops,
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