College of Horticulture, Gansu Agricultural University, Lanzhou, China.
Agro-Biological Gene Research Center, Guangdong Academy of Agriculture, China.
Physiol Plant. 2024 May-Jun;176(3):e14330. doi: 10.1111/ppl.14330.
Wall-associated kinases (WAKs) have been determined to recognize pathogenic signals and initiate plant immune responses. However, the roles of the family members in host resistance against Valsa canker, a serious fungal disease of apples and pears, are largely unknown. Here, we identified MbWAK1 in Malus baccata, a resistant germplasm differentially expressed during infection by Valsa mali (Vm). Over-expression of MbWAK1 enhanced the Valsa canker resistance of apple and pear fruits and 'Duli-G03' (Pyrus betulifolia) suspension cells. A large number of phloem, cell wall, and lipid metabolic process-related genes were differentially expressed in overexpressed suspension cell lines in response to Valsa pyri (Vp) signals. Among these, the expression of xyloglucan endotransglucosylase/hydrolase (XTH) gene PbeXTH1 and sieve element occlusion B-like (SEOB) gene PbeSEOB1 were significantly inhibited. Transient expression of PbeXTH1 or PbeSEOB1 compromised the expressional induction of MbWAK1 and the resistance contributed by MbWAK1. In addition, PbeXTH1 and PbeSEOB1 suppressed the immune response induced by MbWAK1. Our results enriched the molecular mechanisms for MbWAK1 against Valsa canker and resistant breeding.
壁相关激酶（WAKs）已被确定能够识别致病信号并启动植物免疫反应。然而，该家族成员在宿主抵抗苹果腐烂病菌（Valsa canker）方面的作用在很大程度上是未知的，苹果腐烂病菌是一种严重影响苹果和梨的真菌病害。在这里，我们在山荆子（Malus baccata）中鉴定出 MbWAK1，它是在感染苹果腐烂病菌（Vm）时差异表达的抗性种质。MbWAK1 的过表达增强了苹果和梨果实以及‘Duli-G03’（山梨）悬浮细胞对腐烂病菌的抗性。在响应腐烂病菌信号时，大量与韧皮部、细胞壁和脂质代谢过程相关的基因在过表达的悬浮细胞系中差异表达。其中，木葡聚糖内转葡糖苷酶/水解酶（XTH）基因 PbeXTH1 和筛管阻塞 B 样（SEOB）基因 PbeSEOB1 的表达显著受到抑制。PbeXTH1 或 PbeSEOB1 的瞬时表达削弱了 MbWAK1 的表达诱导和 MbWAK1 所贡献的抗性。此外，PbeXTH1 和 PbeSEOB1 抑制了 MbWAK1 诱导的免疫反应。我们的研究结果丰富了 MbWAK1 抵抗腐烂病菌和抗性育种的分子机制。
