Gray leaf spot, northern leaf blight and southern leaf blight are three of the most destructive foliar diseases affecting maize (Zea mays L.). Here we identified a gene, ZmCPK39, that encodes a calcium-dependent protein kinase and negatively regulates quantitative resistance to these three diseases. The ZmCPK39 allele in the resistant line displayed significantly lower pathogen-induced gene expression than that in the susceptible line. A marked decrease in ZmCPK39 abundance mitigated the phosphorylation and degradation of the transcription factor ZmDi19. This led to elevated expression of ZmPR10, a gene known to encode an antimicrobial protein, thereby enhancing maize resistance to foliar diseases. Moreover, the F₁ hybrid with reduced ZmCPK39 expression favored disease resistance, thereby increasing yield. Hence, the discovery of the ZmCPK39–ZmDi19–ZmPR10 immune module provides insight into the mechanisms underlying broad-spectrum quantitative disease resistance and also offers a new avenue for the genetic control of maize foliar diseases.

灰叶斑病、北方叶枯病和南方叶枯病是影响玉米 （Zea mays L.） 的三种最具破坏性的叶面病害。在这里，我们鉴定了一个基因 ZmCPK39，它编码钙依赖性蛋白激酶并负向调节对这三种疾病的数量耐药性。抗性品系中的 ZmCPK39 等位基因表现出显著低于易感品系的病原体诱导基因表达。ZmCPK39 丰度的显着降低减轻了转录因子 ZmDi19 的磷酸化和降解。这导致 ZmPR10 的表达升高，ZmPR10 是一种已知编码抗菌蛋白的基因，从而提高了玉米对叶面病害的抵抗力。此外，ZmCPK39 表达降低的 F₁ 杂交体有利于抗病性，从而提高产量。因此，ZmCPK39-ZmDi19-ZmPR10免疫模块的发现为广谱定量病害抗性的潜在机制提供了见解，也为玉米叶面病害的遗传控制提供了一条新的途径。