Drought is a major environmental stress factor that affects the growth and development of plants. All plants have to maintain the reactive oxygen species within certain levels for normal cellular homeostasis by means of their antioxidant systems, which can be classified as enzymatic and non-enzymatic. Plants under drought stress generate an excess production of reactive oxygen species. At high concentrations, this can be detrimental by producing damage to the protein structures and inhibiting enzymes, as well as oxidizing macromolecules, which may eventually lead to cell death. There has been increasing attention paid to the antioxidant capacity of aromatic/medicinal plants, with a high antioxidant content having been reported in some plant extracts, such as in Mentha piperita (peppermint). Peppermint plants cultivated under drought stress also present high levels of phenolic compounds, peroxidase enzyme activity and lipid peroxidation of membranes. A simple and inexpensive laboratory class is proposed for teaching some mechanisms that plants have evolved to avoid reactive oxygen species damage. The series of lab experiments described is aimed at demonstrating the antioxidant status in aromatic plants subjected to drought stress, by measuring total phenolic compound content (non-enzymatic antioxidant compound), peroxidase activity (enzymatic antioxidant) and malondialdehyde, as convenient biomarkers for lipid peroxidation. The proposed class will be carried out by undergraduate students of the advanced biochemistry course, as part of our biology and agronomy studies. The experiment presented is intended to be used as a vehicle to emphasize the concepts that students have learned in their lectures. This lab exercise to be carried out by the students has dual goals: to apply a methodology only learned superficially on previous courses, and also to increase their understanding of how plants developed resistance mechanisms in order to tolerate drought stress.

中文翻译：

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一种测定干旱胁迫下芳香植物抗氧化状态的简单方法

干旱是影响植物生长发育的主要环境胁迫因子。所有植物都必须通过其抗氧化系统将活性氧维持在一定水平以维持正常细胞稳态，抗氧化系统可分为酶促和非酶促。处于干旱胁迫下的植物会产生过量的活性氧。在高浓度下，这可能会破坏蛋白质结构并抑制酶以及氧化大分子，最终可能导致细胞死亡。人们越来越关注芳香/药用植物的抗氧化能力，据报道，一些植物提取物中的抗氧化剂含量很高，例如胡椒薄荷（薄荷）。在干旱胁迫下栽培的薄荷植物也存在高水平的酚类化合物、过氧化物酶活性和膜的脂质过氧化。提出了一个简单且廉价的实验室课程，用于教授植物进化以避免活性氧损伤的一些机制。所描述的一系列实验室实验旨在通过测量总酚类化合物含量（非酶抗氧化化合物）、过氧化物酶活性（酶抗氧化）和丙二醛作为脂质过氧化的便捷生物标志物来证明遭受干旱胁迫的芳香植物的抗氧化状态. 拟议的课程将由高级生物化学课程的本科生进行，作为我们生物学和农学研究的一部分。所展示的实验旨在用作强调学生在讲座中学到的概念的工具。这个由学生进行的实验练习有两个目标：应用在以前的课程中只从表面上学到的方法，以及增加他们对植物如何发展抗性机制以耐受干旱胁迫的理解。