Molecular Pathogens 2024, Vol.15, No.3, 155-169 http://microbescipublisher.com/index.php/mp 164 Figure 6 Candidate gene identification and allelic diversity assessment (Adopted from Alavilli et al., 2022) Image Caption: Panel A illustrates the gene structure of CmoAP2/ERF, highlighting the exon regions and the location of missense mutations. Panel B shows comparative Sanger sequencing chromatograms between PM susceptible (PMS) and resistant (PMR) lines. The upper panel (black inverted triangle) represents the PMS line or reference genome, while the lower panel (red inverted triangle) shows nucleotide changes in the PMR line. Asterisks indicate SNP variations that do not result in amino acid changes. This figure underscores the molecular differences contributing to disease resistance, vital for developing targeted breeding strategies (Adapted from Alavilli et al., 2022) 7 Molecular Mechanisms of Resistance to PM The molecular mechanisms of resistance to PM in Cucurbitaceae plants involve a complex interplay of genetic pathways, specific resistance genes, and the molecular interactions between host plants and pathogens. These mechanisms are mediated by a variety of molecular components, including transcription factors, signaling molecules, and noncoding RNAs, which together contribute to the plant's ability to resist infection by PM pathogens (Guo et al., 2018; 2019; Nie et al., 2021; Wang et al., 2021; Shnaider et al., 2022; Tian et al., 2022). 7.1 Genetic pathways involved in resistance The genetic pathways that confer resistance to PM in Cucurbitaceae plants involve a complex network of genes and molecular interactions. Recent studies have identified several key components of these pathways. For instance, the Mildew Resistance Locus O (MLO) gene family plays a crucial role in susceptibility to PM, with natural mutations in genes such as CsaMLO8 in cucumber conferring resistance to the pathogen P. xanthii (Shnaider et al., 2022). Additionally, the SGT1 gene, a component of the plant disease-associated signal transduction pathway, has been implicated in resistance. Overexpression of the Cucurbita moschata CmSGT1 gene in transgenic plants has been shown to enhance resistance to PM by accelerating cell necrosis and increasing the accumulation of hydrogen peroxide (H2O2), which is associated with the activation of salicylic acid (SA)-dependent defense genes (Guo et al., 2019). 7.2 Role of specific genes in conferring resistance Specific genes have been identified that play a direct role in conferring resistance to PM. For example, the CpPM10.1 gene in zucchini has been associated with dominant resistance to PM, and its expression is positively
RkJQdWJsaXNoZXIy MjQ4ODYzNA==