Nasiri Minoo, Niknam Vahid, Rahnama Hassan, Rezayian Maryam, Ahmadi-Sakha Sedigheh
School of Biology, College of Science, University of Tehran, Tehran, Iran.
Faculty of Biology, Institute of Botany, Technische Universität Dresden, Dresden, Germany.
Sci Rep. 2025 Jun 2;15(1):19324. doi: 10.1038/s41598-025-03374-0.
We investigated the effects of PEG-induced drought on the antioxidative mechanisms of Crocus sativus L. and the mitigating effects of PEN on drought tolerance. Contents of H₂O₂ and MDA in fibrous roots were considerably lower than those in leaves and were attenuated by PEN pretreatment. Activities of CAT, SOD, and POX were significantly higher in fibrous roots than in leaves. Among antioxidative enzymes, POX activity in fibrous roots was 600-2000-fold higher than that in leaves. The increase in CAT and SOD activities under the influence of PEN in the fibrous roots is the main reason for the decrease in MDA levels and highlights the important role of this organ in the response to drought stress. A somewhat similar increase in CAT activity was also observed in the leaves under drought conditions due to PEN. Under drought, PEN led to a significant increase in carotenoid content and an elevated ratio of Chl a to Chl b in the leaves. However, in spite of the higher content of non-enzymatic antioxidants in leaves than in fibrous roots, the lower MDA levels in fibrous roots indicated greater efficiency of antioxidative enzymes in controlling membrane lipid peroxidation. In conclusion, the results demonstrate that PEN can mitigate oxidative damage in saffron under drought conditions by enhancing the activity of SOD (up to 275%) and CAT (up to 189%) and by increasing proline content (up to 50%) in fibrous roots.
我们研究了聚乙二醇（PEG）诱导的干旱对藏红花抗氧化机制的影响以及脯氨酸（PEN）对耐旱性的缓解作用。须根中过氧化氢（H₂O₂）和丙二醛（MDA）的含量明显低于叶片，且经PEN预处理后有所降低。须根中过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和过氧化物酶（POX）的活性显著高于叶片。在抗氧化酶中，须根中POX的活性比叶片高600 - 2000倍。PEN影响下须根中CAT和SOD活性的增加是MDA水平降低的主要原因，突出了该器官在应对干旱胁迫中的重要作用。由于PEN的作用，在干旱条件下叶片中也观察到CAT活性有类似的增加。干旱条件下，PEN导致叶片中类胡萝卜素含量显著增加，叶绿素a与叶绿素b的比值升高。然而，尽管叶片中非酶抗氧化剂的含量高于须根，但须根中较低的MDA水平表明抗氧化酶在控制膜脂过氧化方面效率更高。总之，结果表明PEN可通过增强须根中SOD（高达275%）和CAT（高达189%）的活性以及增加脯氨酸含量（高达50%）来减轻干旱条件下藏红花的氧化损伤。
