TY - JOUR AU - TEK, Mumin Ibrahim AU - CALIS, Ozer PY - 2022/05/13 Y2 - 2024/03/29 TI - Mechanisms of resistance to powdery mildew in cucumber JF - Phytopathologia Mediterranea JA - Phytopathol. Mediterr. VL - 61 IS - 1 SE - Articles DO - 10.36253/phyto-13313 UR - https://oajournals.fupress.net/index.php/pm/article/view/13313 SP - 119-127 AB - <p class="p1"><span class="s1"><em>Podosphaera xanthii</em> causes powdery mildew of cucumber, and is associated with significant yield and quality losses. Development of resistant or tolerant varieties is the most effective and eco-friendly strategy for powdery mildew management. An important host resistance mechanism is based on the recognition of conserved resistance genes, resulting in durable resistance. To determine powdery mildew resistance mechanisms in cucumber, total RNAs were isolated from the powdery mildew resistant cultivar Meltem, the tolerant line VT18, and the susceptible local variety Camlica. Expression levels of nine genes in these plants were analysed by Reverse Transcription Polymerase Chain Reaction (RT-PCR). The host reactions were assessed using microscope observations of stained specimens. <em>Serine/threonine</em> (<em>STN7)</em>, <em>transcription</em> <em>factor</em> (<em>WRKY22)</em>, <em>serine/threonine-protein kinase</em> (<em>D6PKL1</em>), and<em> serine/threonine receptor kinase </em>(<em>NFP</em>) genes were induced, as positive regulators in defence mechanisms against powdery mildew. <em>Polygalacturonase Inhibitor (PGIP</em>) did not express after <em>P. xanthii</em> inoculation of Camlica, resulting in susceptibility. After inoculation, <em>callose synthase (CALLOSE)</em> and <em>cinnamyl alcohol dehydrogenase</em> (<em>CAD</em>) gene expression levels were increased in resistant Meltem, but Hypersensitive Reaction (HR) and ROS formation were only linked in the tolerant VT18. Powdery mildew development was less in Meltem than in VT18, indicating that cell wall thickening and HR play separate roles in resistance to this disease.</span></p> ER -