Abstract

The leaves of spring wheat (Triticum aestivum L.) and winter rye (Secale cerealе L.) were used to examine the dynamics of peroxidase activity and the content of hydrogen peroxide, proline, flavonoids, and organic acids (oxalic, succinic, malic, and citric) at early stages of alkaline (pH 10) and acidic (pH 3) stresses imposed by the pH change in the root medium. The results are discussed on the basis of oxidative stress theory and the mechanisms of intracellular pH homeostasis. The dynamics of hydrogen peroxide content and the increased peroxidase activity provided evidence for the enhancement of redox processes. The accumulation of low-molecular-weight polyfunctional compounds, such as proline and flavonoids, indicated the mobilization of plant defense systems. At the same time, stress-related adaptive changes differed qualitatively in different treatments: the leaves of wheat plants transferred to acidic media accumulated proline, while alkaline-treated plants accumulated predominantly flavonoids. The peroxidase activation and proline accumulation after pH changes in the root medium were more strongly pronounced in rye than in wheat plants. A comparatively stable trend to the decrease in the total amount of malic, citric, and succinic acids was observed within 24 h after the onset of stress treatment; in rye leaves, this trend was apparent both with acidic and alkaline root media, while it was evident in wheat leaves under acidic pH of the solution. The observed changes in the content of organic acids that are involved in the Krebs cycle are regarded as a manifestation of the pH-stat mechanism.

中文翻译：

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根系培养基的碱度和酸度对普通小麦和麦麸防御系统的影响

摘要

春小麦（Triticum aestivum L.）和冬黑麦（Secale谷物）的叶子L.）用于检查碱性（pH 10）和酸性（pH 3）早期的过氧化物酶活性的动态以及过氧化氢，脯氨酸，类黄酮和有机酸（草酸，琥珀酸，苹果酸和柠檬酸）的含量）根培养基中pH值变化所施加的压力。根据氧化应激理论和细胞内pH稳态机制对结果进行了讨论。过氧化氢含量的动态变化和过氧化物酶活性的增加为氧化还原过程的增强提供了证据。低分子量多官能化合物（例如脯氨酸和类黄酮）的积累表明植物防御系统的动员。同时，与压力相关的适应性变化在不同的治疗方法上存在质的差异：转移到酸性介质中的小麦植株叶片积累了脯氨酸，而经碱处理的植株则主要积累了类黄酮。在黑麦中，根系培养基中pH改变后，过氧化物酶的活化和脯氨酸的积累比小麦植株更明显。应激处理开始后24小时内，苹果酸，柠檬酸和琥珀酸总量减少的趋势相对稳定。在黑麦叶片中，这种趋势在酸性和碱性根介质中均很明显，而在酸性pH溶液中在小麦叶片中则很明显。观察到的与克雷布斯循环有关的有机酸含量的变化被认为是pH-stat机制的一种表现。在黑麦中，根系培养基中pH改变后，过氧化物酶的活化和脯氨酸的积累比小麦植株更明显。应激处理开始后24小时内，苹果酸，柠檬酸和琥珀酸总量减少的趋势相对稳定。在黑麦叶片中，这种趋势在酸性和碱性根介质中均很明显，而在酸性pH溶液中在小麦叶片中则很明显。观察到的与克雷布斯循环有关的有机酸含量的变化被认为是pH-stat机制的一种表现。在黑麦中，根系培养基中pH改变后，过氧化物酶的活化和脯氨酸的积累比小麦植株更明显。应激处理开始后24小时内，苹果酸，柠檬酸和琥珀酸总量减少的趋势相对稳定。在黑麦叶片中，这种趋势在酸性和碱性根介质中均很明显，而在酸性pH溶液中在小麦叶片中则很明显。观察到的与克雷布斯循环有关的有机酸含量的变化被认为是pH-stat机制的一种表现。应激治疗后24小时内观察到琥珀酸。在黑麦叶片中，这种趋势在酸性和碱性根介质中均很明显，而在酸性pH溶液中在小麦叶片中则很明显。观察到的与克雷布斯循环有关的有机酸含量的变化被认为是pH-stat机制的一种表现。应激治疗后24小时内观察到琥珀酸。在黑麦叶片中，这种趋势在酸性和碱性根介质中均很明显，而在酸性pH溶液中在小麦叶片中则很明显。观察到的与克雷布斯循环有关的有机酸含量的变化被认为是pH-stat机制的一种表现。