Drought is a common abiotic stress that influences crop production to a large extent all over the world. Wheat crop experiences drought at main stages during its life cycle, which induces oxidative stress in the plants. The antioxidant mechanisms of the plant have a significant role in providing tolerance against the water stress. The objective of this work was to investigate the antioxidant activity and transcript profile of antioxidant enzyme related genes in three wheat genotypes to be TN4228 (drought tolerant), TN1399 (moderately tolerant) and TN3737 (susceptible) at control [80% Field capacity (FC)] medium (40% FC) and severe stress (25% FC). Water-limited conditions led to a decrease in relative water content (RWC). However, drought increased malondialdehyde (MDA), hydrogen peroxide (H2O2), proline content, and antioxidant enzyme activities [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX)]. In addition, we observed the enhancement of the delta-1-pyrroline-5-carboxylate synthase (P5CS), CAT, APX and SOD gene expressions at drought stress conditions. Both moderate and severe stresses caused genotype-specific responses, which were dependent on stress severity. According to drought stress and defense systems in TN4228, it was obtained that the engaged genes and enzymes play significant roles in defense responses and could be viable targets to determine the level of drought tolerance.

中文翻译：

---

干旱胁迫下耐旱、中度和易感小麦基因型抗氧化酶活性和基因表达谱的变化

干旱是一种常见的非生物胁迫，在很大程度上影响着全世界的作物生产。小麦作物在其生命周期的主要阶段经历干旱，这会导致植物发生氧化应激。植物的抗氧化机制在提供对水分胁迫的耐受性方面具有重要作用。这项工作的目的是研究三种小麦基因型中抗氧化酶相关基因的抗氧化活性和转录谱，它们是 TN4228（耐旱）、TN1399（中度耐受）和 TN3737（易感）在控制 [80% 田间持水量 (FC )] 中等 (40% FC) 和严重压力 (25% FC)。水限制条件导致相对水含量 (RWC) 降低。然而，干旱增加了丙二醛 (MDA)、过氧化氢 (H2O2)、脯氨酸含量、和抗氧化酶活性 [超氧化物歧化酶 (SOD)、过氧化氢酶 (CAT)、抗坏血酸过氧化物酶 (APX)]。此外，我们观察到干旱胁迫条件下 delta-1-pyrroline-5-carboxylate 合酶 (P5CS)、CAT、APX 和 SOD 基因表达的增强。中度和重度压力都会引起基因型特异性反应，这取决于压力的严重程度。根据TN4228中的干旱胁迫和防御系统，获得参与的基因和酶在防御反应中起重要作用，并且可能是确定耐旱水平的可行目标。中度和重度压力都会引起基因型特异性反应，这取决于压力的严重程度。根据TN4228中的干旱胁迫和防御系统，获得参与的基因和酶在防御反应中起重要作用，并且可能是确定耐旱水平的可行目标。中度和重度压力都会引起基因型特异性反应，这取决于压力的严重程度。根据TN4228中的干旱胁迫和防御系统，获得参与的基因和酶在防御反应中起重要作用，并且可能是确定耐旱水平的可行目标。