You don’t win friends with bad salad! A gene editing approach to enhance the powdery mildew resistance in cucumber

One of the biggest challenges for agriculture lies in finding strategies that minimize crop yield loss due to pests and diseases.Powdery mildew (PM) is a widespread fungal disease that affects a diverse range of crops, for example, in cucumber (Cucumis sativus L.), PM can cause losses of up to 40% (He et al. 2022).Various studies have focused on identifying PM resistance (PMR) genes that benefit cucumber breeding programs (Liu et al. 2008).The characterization of quantitative trait loci (QTL) for mapping PMR linked the disruption of the Mildew resistance Locus 8 (CsMLO8) gene with the PM resistance in cucumber.However, although the loss of function of CsMLO8 is indispensable for the PMR, it is not enough to generate a complete resistance (Nie et al. 2015a, b; Berg et al. 2015).The PM-resistant QTL also contains other members of the CsMLO family, pointing out that more than one CsMLO gene is involved in PM resistance (Schouten et al. 2014).A recent study characterized the MLO proteins as calmodulin-gated calcium channel proteins (Gao et al. 2022), suggesting that calcium signaling is involved in mlo-mediated PM resistance.However, both the components and mechanism of PM resistance remain not fully understood.In this issue of Plant Physiology, Ma et al. 2024 identify the CsMLO genes involved in the resistance against PM infection.In addition, they validated the link between the Csmlo-mediated PM resistance and the calcium signaling pathway through the identification of novel calcium-related proteins in the PM resistance.