Abstract

Currently, melatonin (N-acetyl-5-methoxytryptamine) is considered as a multifunctional bioregulator not only in mammals but also in plants. The aim of this work was to study the effect of melatonin on the resistance of seedlings of wheat (Triticum aestivum L., Dosconala variety) and rye (Secale cereale L., Pamyat’ Khudoyerka variety) to high temperature and the functioning of key cellular protection systems (antioxidant and osmoprotective). Rye seedlings were different from wheat seedlings by higher heat resistance, which was manifested in less inhibition of the growth after a 6-h heating at 44°C and less manifestation of the oxidative stress effects. The treatment of wheat seeds with melatonin in concentrations of 20–100 μM significantly decreased the inhibition of the shoot and root growth caused by the effect of a high temperature. The rye seedlings were less affected by melatonin, reducing only the inhibition of the shoot growth. The treatment with melatonin prevented the development of the oxidative stress caused by the effect of high temperature, which was manifested in a decrease in the indices of superoxide radical generation, the content of hydrogen peroxide and malondialdehyde in the shoots of wheat and rye seedlings. The treatment of caryopses of both cereal species with melatonin caused an increase in the catalase activity against the background of the heat stress as well as contributed to the stabilization of peroxidase activity under stress conditions in wheat and caused its increase in rye. In addition, the treatment of caryopses with melatonin caused an increase in the content of soluble carbohydrates under stress conditions but did not affect significantly the content of proline in the shoots of seedlings of both species. In general, a less noticeable effect of melatonin treatment on the functioning of the protective systems in rye was noted. A decrease in the oxidative damage to the cells, an increase in the activity of antioxidant enzymes, and an increase in the accumulation of soluble carbohydrates are the key effects of melatonin under stress conditions.

中文翻译：

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褪黑激素诱导小麦和黑麦细胞在高温作用下的细胞保护反应

摘要

目前，褪黑激素 (N-acetyl-5-methoxytryptamine) 被认为是一种多功能生物调节剂，不仅在哺乳动物中而且在植物中也是如此。这项工作的目的是研究褪黑激素对小麦（ Triticum aestivum L.，Dosconala 品种）和黑麦（Secale cereale）幼苗抗性的影响L., Pamyat' Khudoyerka 品种）对高温和关键细胞保护系统（抗氧化和渗透保护）的功能。黑麦幼苗与小麦幼苗的不同之处在于具有更高的耐热性，表现为在 44℃ 加热 6 小时后对生长的抑制较少，氧化应激效应的表现也较少。用浓度为 20-100 μM 的褪黑激素处理小麦种子，显着降低了高温效应对芽和根生长的抑制作用。黑麦幼苗受褪黑激素的影响较小，仅减少了对芽生长的抑制。褪黑激素治疗阻止了高温作用引起的氧化应激的发展，这表现为超氧自由基生成指数的降低，小麦和黑麦幼苗中过氧化氢和丙二醛的含量。用褪黑激素处理两种谷物的颖果导致热胁迫背景下的过氧化氢酶活性增加，并有助于小麦在胁迫条件下稳定过氧化物酶活性，并导致黑麦过氧化物酶活性增加。此外，用褪黑激素处理颖果会导致胁迫条件下可溶性碳水化合物含量增加，但不会显着影响两个物种幼苗芽中脯氨酸的含量。一般来说，褪黑激素处理对黑麦保护系统功能的影响不太明显。减少对细胞的氧化损伤，增加抗氧化酶的活性，