School of Life Sciences, Jiangsu University, Zhenjiang, China.
State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2024 Aug 2;15(1):6512. doi: 10.1038/s41467-024-50909-6.
Many disease resistance genes have been introgressed into wheat from its wild relatives. However, reduced recombination within the introgressed segments hinders the cloning of the introgressed genes. Here, we have cloned the powdery mildew resistance gene Pm13, which is introgressed into wheat from Aegilops longissima, using a method that combines physical mapping with radiation-induced chromosomal aberrations and transcriptome sequencing analysis of ethyl methanesulfonate (EMS)-induced loss-of-function mutants. Pm13 encodes a kinase fusion protein, designated MLKL-K, with an N-terminal domain of mixed lineage kinase domain-like protein (MLKL_NTD domain) and a C-terminal serine/threonine kinase domain bridged by a brace. The resistance function of Pm13 is validated through transient and stable transgenic complementation assays. Transient over-expression analyses in Nicotiana benthamiana leaves and wheat protoplasts reveal that the fragment Brace-Kinase of MLKL-K is capable of inducing cell death, which is dependent on a functional kinase domain and the three α-helices in the brace region close to the N-terminus of the kinase domain.
许多抗病基因已从其野生近缘种中被导入小麦。然而，导入片段内重组的减少阻碍了导入基因的克隆。在这里，我们使用结合物理图谱、辐射诱导的染色体畸变和 EMS 诱导的功能丧失突变体的转录组测序分析的方法，克隆了来自长穗偃麦草的白粉病抗性基因 Pm13。Pm13 编码一个激酶融合蛋白，称为 MLKL-K，具有混合谱系激酶结构域样蛋白（MLKL_NTD 结构域）的 N 端结构域和丝氨酸/苏氨酸激酶结构域的 C 端，由一个连接子桥接。通过瞬时和稳定的转基因互补测定验证了 Pm13 的抗性功能。在烟草原生质体和小麦原生质体中的瞬时过表达分析表明，MLKL-K 的 Brace-Kinase 片段能够诱导细胞死亡，这依赖于一个功能激酶结构域和靠近激酶结构域 N 端的 Brace 区域的三个α-螺旋。
