INRAE, Pathologie Végétale, 84140 Montfavet, France.
UMR Biologie du Fruit et Pathologie, INRAE, Université de Bordeaux, CS 20032, 33882 Villenave d'Ornon, France.
Viruses. 2023 Apr 28;15(5):1081. doi: 10.3390/v15051081.
The dominant gene in pepper () confers resistance to members of six potyvirus species, all of which belong to the (PVY) phylogenetic group. The corresponding avirulence factor in the PVY genome is the NIb cistron (i.e., RNA-dependent RNA polymerase). Here, we describe a new source of potyvirus resistance in the Guatemalan accession cv. PM949. PM949 is resistant to members of at least three potyvirus species, a subset of those controlled by . The F progeny between PM949 and the susceptible cultivar Yolo Wonder was susceptible to PVY, indicating that the resistance is recessive. The segregation ratio between resistant and susceptible plants observed in the F progeny matched preferably with resistance being determined by two unlinked recessive genes independently conferring resistance to PVY. Inoculations by grafting resulted in the selection of PVY mutants breaking PM949 resistance and, less efficiently, -mediated resistance. The codon substitution EK in the NIb cistron of PVY, which was shown previously to be sufficient to break resistance, was also sufficient to break PM949 resistance, a rare example of cross-pathogenicity effect. In contrast, the other selected NIb mutants showed specific infectivity in PM949 or plants. Comparison of and PM949 resistance, which share the same target in PVY, provides interesting insights into the determinants of resistance durability.
辣椒中的显性基因赋予其对六种马铃薯 Y 病毒属病毒（均属于 PVY 系统发育群）成员的抗性。PVY 基因组中的相应无毒因子是 NIb 顺式元件（即 RNA 依赖性 RNA 聚合酶）。在此，我们描述了来自危地马拉品系 PM949 的一种新型马铃薯 Y 病毒属抗性来源。PM949 对至少三种马铃薯 Y 病毒属成员具有抗性，这是由 控制的成员的一个子集。PM949 与易感品种 Yolo Wonder 之间的 F1 后代对 PVY 敏感，表明该抗性是隐性的。在 F1 后代中观察到的抗性和敏感植物之间的分离比最好与由两个独立赋予 PVY 抗性的隐性基因决定的抗性相匹配。通过嫁接接种导致选择打破 PM949 抗性的 PVY 突变体，并且效率较低，打破 介导的抗性。先前已显示足以打破 抗性的 PVY NIb 顺式元件中的 EK 密码子取代也足以打破 PM949 抗性，这是交叉致病性效应的罕见例子。相比之下，其他选择的 NIb 突变体在 PM949 或 植物中显示出特定的感染力。对 和 PM949 抗性的比较，它们在 PVY 中有相同的靶标，为抗性耐久性的决定因素提供了有趣的见解。
