Raji Mohammad Reza, Sanjari Sepideh, Derikvand Fatemeh, Khademi Mitra, Farajpour Mostafa
Department of Horticultural Science, Faculty of Agriculture, Lorestan University, Khorramabad, Iran.
Department of Agronomy and Plant Breeding, College of Abourihan, University of Tehran, Tehran, Iran.
Biochem Biophys Rep. 2025 Jul 17;43:102166. doi: 10.1016/j.bbrep.2025.102166. eCollection 2025 Sep.
Apples () are widely enjoyed but are prone to fungal infections, notably brown rot caused by Monilinia spp., which significantly impacts postharvest quality. This study evaluated the activities of catalase (CAT), peroxidase (POD), phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO), along with the expression of in two apple cultivars (Gala Imperial and Lebanese) after inoculation with over 1, 2, and 7 days. Results showed that enzyme activities and expression significantly increased post-infection, indicating their roles in the defense against brown rot. Notably, a strong positive correlation was found between upregulation and the activities of PAL, POD, and PPO. PAL activity peaked at 2 days post-inoculation, while expression, along with POD and PPO activities, reached their highest levels by day 7. These findings suggest that expression enhances the activities of these defense enzymes, with PAL initiating the response by producing phenolic compounds that serve as substrates for PPO and POD, aiding in disease resistance. Although PAL, POD, and PPO activities increased after inoculation, no significant differences in PPO and POD activities were observed between cultivars, while Gala Imperial displayed higher PAL activity, enhancing its resistance to infection. The study highlights as a potential candidate for breeding programs aimed at improving brown rot resistance in apples.
苹果（）广受喜爱，但容易受到真菌感染，尤其是由链核盘菌属引起的褐腐病，这对采后品质有显著影响。本研究评估了过氧化氢酶（CAT）、过氧化物酶（POD）、苯丙氨酸解氨酶（PAL）和多酚氧化酶（PPO）的活性，以及在两个苹果品种（帝国嘎啦和黎巴嫩苹果）接种后1、2和7天的表达情况。结果表明，感染后酶活性和表达显著增加，表明它们在抵御褐腐病中发挥作用。值得注意的是，上调与PAL、POD和PPO的活性之间存在很强的正相关。PAL活性在接种后2天达到峰值，而表达以及POD和PPO活性在第7天达到最高水平。这些发现表明，表达增强了这些防御酶的活性，PAL通过产生作为PPO和POD底物的酚类化合物引发反应，有助于抗病。虽然接种后PAL、POD和PPO活性增加，但品种间PPO和POD活性未观察到显著差异，而帝国嘎啦表现出较高的PAL活性，增强了其对感染的抗性。该研究强调作为旨在提高苹果对褐腐病抗性的育种计划的潜在候选者。
