Drought stress is an important environmental stress that clearly affect biological systems of plants. There is a possibility that growth regulators are able to protect plants under drought conditions. Ascorbic acid (AsA) plays a particular role on growth of plants and protects cells from oxidative damage caused by environmental stresses. This study emphasized the impacts of AsA on improving the drought tolerance of the pepper plants. Based on a factorial arrangement in a completely randomized design, the experiment had two factors. The first factor was drought: irrigation within the field capacity, moderate stress (irrigation within the 60% field capacity) and severe stress (irrigation within the 30% field capacity). The second factor was AsA: 0 mM sprayed with distilled water, 0.5 mM and 1 mM. The experiment had three replications. Drought stress inhibited plant growth parameters including fruit number, height, weight, yield, chlorophyll a and b, total chlorophyll, carotenoid contents, it caused improvement in activity of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), proline content, anthocyanins, soluble sugars, malondialdehyde (MDA) and H₂O₂ in the leaves of sweet pepper. Application of AsA contributes to an increase in antioxidant enzymes activity such as SOD, CAT, POD and proline contents, chlorophyll a and b, total chlorophyll, carotenoids, soluble carbohydrates. However, it reduced the content of anthocyanins, MDA and H₂O₂. Based on this study, it can be suggested that ascorbic acid adjusted antioxidant activity, especially after it has been subjected to drought stress.

中文翻译：

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抗坏血酸对辣椒（Capsicum annuum L）植物干旱胁迫耐受性的改善作用。

干旱胁迫是一种重要的环境胁迫，明显影响植物的生物系统。生长调节剂有可能在干旱条件下保护植物。抗坏血酸（AsA) 在植物生长中发挥特殊作用，并保护细胞免受环境压力引起的氧化损伤。本研究强调了 AsA 对提高辣椒植物耐旱性的影响。基于完全随机设计中的因子安排，该实验有两个因子。第一个因素是干旱：田间灌溉、中等压力（60%田间灌溉）和重度胁迫（30%田间灌溉）。第二个因素是 AsA：0 mM 用蒸馏水喷洒，0.5 mM 和 1 mM。实验重复 3 次。干旱胁迫抑制植物生长参数，包括果实数量、高度、重量、产量、叶绿素 a 和 b、总叶绿素、类胡萝卜素含量，导致过氧化氢酶 (CAT)、过氧化物酶 (POD)、₂ O ₂甜椒的叶子。AsA 的应用有助于增加抗氧化酶活性，如 SOD、CAT、POD 和脯氨酸含量、叶绿素 a 和 b、总叶绿素、类胡萝卜素、可溶性碳水化合物。然而，它降低了花青素、MDA和H ₂ O ₂的含量。基于这项研究，可以认为抗坏血酸调节了抗氧化活性，特别是在它受到干旱胁迫之后。