Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Szent-Györgyi A. U. 4., 2100, Gödöllő, Hungary.
Institute of Plant Biology, Biological Research Center, Eötvös Lóránd Research Network, Szeged, Hungary.
Theor Appl Genet. 2023 Mar 21;136(3):64. doi: 10.1007/s00122-023-04340-y.
The bs5 resistance gene against bacterial spot was identified by map-based cloning. The recessive bs5 gene of pepper (Capsicum annuum L.) conditions a non-hypersensitive resistance trait, characterized by a slightly swollen, pale green, photosynthetically active leaf tissue, following Xanthomonas euvesicatoria infection. The isolation of the bs5 gene by map-based cloning revealed that the bs5 protein was shorter by 2 amino acids as compared to the wild type Bs5 protein. The natural 2 amino acid deletion occurred in the cysteine-rich transmembrane domain of the tail-anchored (TA) protein, Ca_CYSTM1. The protein products of the wild type Bs5 and mutant bs5 genes were shown to be located in the cell membrane, indicating an unknown function in this membrane compartment. Successful infection of the Bs5 pepper lines was abolished by the 6 bp deletion in the TM encoding domain of the Ca_CYSTM1 gene in bs5 homozygotes, suggesting, that the resulting resistance might be explained by the lack of entry of the Xanthomonas specific effector molecules into the plant cells.
通过图谱克隆鉴定出对细菌性斑点具有抗性的 bs5 基因。辣椒（Capsicum annuum L.）的隐性 bs5 基因导致非超敏性抗性性状，其特征是在黄单胞菌属（Xanthomonas euvesicatoria）感染后，叶片组织略微肿胀，呈浅绿色，具有光合作用活性。通过图谱克隆分离 bs5 基因表明，与野生型 Bs5 蛋白相比，bs5 蛋白短了 2 个氨基酸。这种自然发生的 2 个氨基酸缺失发生在锚定（TA）蛋白的富含半胱氨酸的跨膜结构域中，即 Ca_CYSTM1。野生型 Bs5 和突变 bs5 基因的蛋白产物被证明位于细胞膜中，表明在这个膜结构域中具有未知的功能。在 bs5 纯合子中，Ca_CYSTM1 基因 TM 编码区的 6bp 缺失使 Bs5 辣椒系的成功感染被废除，这表明由此产生的抗性可能是由于黄单胞菌特异性效应分子无法进入植物细胞所导致的。
