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, 100101, China.
College of Agronomy and Biotechnology, China Agricultural University, Beijing, 100193, China.
Nat Commun. 2020 Feb 3;11(1):680. doi: 10.1038/s41467-020-14294-0.
Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most destructive diseases that pose a great threat to wheat production. Wheat landraces represent a rich source of powdery mildew resistance. Here, we report the map-based cloning of powdery mildew resistance gene Pm24 from Chinese wheat landrace Hulutou. It encodes a tandem kinase protein (TKP) with putative kinase-pseudokinase domains, designated WHEAT TANDEM KINASE 3 (WTK3). The resistance function of Pm24 was validated by transgenic assay, independent mutants, and allelic association analyses. Haplotype analysis revealed that a rare 6-bp natural deletion of lysine-glycine codons, endemic to wheat landraces of Shaanxi Province, China, in the kinase I domain (Kin I) of WTK3 is critical for the resistance function. Transgenic assay of WTK3 chimeric variants revealed that only the specific two amino acid deletion, rather than any of the single or more amino acid deletions, in the Kin I of WTK3 is responsible for gaining the resistance function of WTK3 against the Bgt fungus.
小麦白粉病由禾本科布氏白粉菌小麦专化型（Bgt）引起，是严重威胁小麦生产的最具破坏性病害之一。小麦地方品种蕴藏着丰富的白粉病抗性资源。本研究从中国小麦地方品种虎大头中克隆到一个对白粉病抗性基因 Pm24，该基因编码一个串联激酶蛋白（TKP），包含假定的激酶-假激酶结构域，被命名为小麦串联激酶 3（WTK3）。通过转基因、独立突变体和等位基因关联分析验证了 Pm24 的抗性功能。单倍型分析表明，WTK3 激酶 I 结构域（Kin I）中赖氨酸-甘氨酸密码子的罕见 6bp 自然缺失，在中国陕西省小麦地方品种中普遍存在，对其抗性功能至关重要。WTK3 嵌合变体的转基因分析表明，只有 Kin I 中两个特定氨基酸的缺失，而不是任何单个或多个氨基酸的缺失，赋予了 WTK3 对 Bgt 真菌的抗性功能。
