Pilidiella granati, also known as Coniella granati, is the etiological agent of pomegranate fruit dry rot. This fungal pathogen is also well-known as responsible for both plant collar rot and leaf spot. Because of its aggressiveness and the worldwide diffusion of pomegranate crops, the selection of cultivars less susceptible to this pathogen might represent an interesting preventive control measure. In the present investigation, the role of polyphenols in the susceptibility to P. granati of the two royalties-free pomegranate cultivars Wonderful and Mollar de Elche was compared. Pomegranate fruit were artificially inoculated and lesion diameters were monitored. Furthermore, pathogen DNA was quantified at 12–72 h post-inoculation within fruit rind by a real time PCR assay setup herein, and host total RNA was used in expression assays of genes involved in host-pathogen interaction. Similarly, protein extracts were employed to assess the specific activity of enzymes implicated in defense mechanisms. Pomegranate phenolic compounds were evaluated by HPLC-ESI-MS and MS2. All these data highlighted ‘Wonderful’ as less susceptible to P. granati than ‘Mollar de Elche’. In the first cultivar, the fungal growth seemed controlled by the activation of the phenylpropanoid pathway, the production of ROS, and the alteration of fungal cell wall. Furthermore, antifungal compounds seemed to accumulate in ‘Wonderful’ fruit following inoculation. These data suggest that pomegranate polyphenols have a protective effect against P. granati infection and their content might represent a relevant parameter in the selection of the most suitable cultivars to reduce the economic losses caused by this pathogen.

中文翻译：

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多酚对石榴果实对 Pilidiella granati 敏感性的影响提供了对疾病耐受机制的见解


Pilidiella granati，又名Coniella granati，是石榴果实干腐病的病原菌。众所周知，这种真菌病原体会导致植物颈腐病和叶斑病。由于其侵袭性和石榴作物在世界范围内的传播，选择对该病原体不易敏感的品种可能是一种有趣的预防控制措施。在本研究中，比较了多酚在两个免版税石榴品种 Wonderful 和 Mollar de Elche 对 P. granati 敏感性中的作用。对石榴果实进行人工接种并监测病斑直径。此外，通过本文设置的实时PCR测定装置在接种后12-72小时对果皮内的病原体DNA进行定量，并且宿主总RNA用于参与宿主-病原体相互作用的基因的表达测定。同样，蛋白质提取物用于评估防御机制中涉及的酶的比活性。通过 HPLC-ESI-MS 和 MS2 评估石榴酚类化合物。所有这些数据都表明“Wonderful”比“Mollar de Elche”更不易受到 P. granati 的影响。在第一个品种中，真菌生长似乎是由苯丙素途径的激活、ROS 的产生和真菌细胞壁的改变控制的。此外，接种后抗真菌化合物似乎在“奇妙”果实中积累。这些数据表明，石榴多酚对 P. granati 感染具有保护作用，其含量可能代表选择最合适品种以减少该病原体造成的经济损失的相关参数。