To compare the phenolic responses under oxidative stressors, plants of two Italian cultivars of durum wheat (Claudio and Mongibello) were (a) exposed to ozone (O₃) (80 ppb, 5 hr/day for 70 consecutive days), with the aim to investigate the changes of phenolic compound contents in their leaves, or (b) flooded (seven consecutive days). Plants showed O₃‐induced visible injury, but their photosynthetic performance was not affected by the pollutant. Specifically, Claudio showed a higher O₃ tolerance than Mongibello. The major value of the present study is undoubtedly the pioneering investigation of phenolic metabolism of durum wheat under O₃. We identified 12 foliar phenolic compounds in all leaf samples (i.e. controls, exposed to O₃ and flooded): ten phenolic acids, a flavanol (catechin hydrate) and a phenolic aldehyde (syringaldehyde). Overall, O₃ exposure resulted in accumulations of phenolic compounds, especially in Claudio. These responses can be likely considered a fine‐regulated repair process that equipped Claudio stressed plants with an antioxidant system capable of scavenging oxidative stress. Different phenolic variations were found in flooded plants, suggesting that phenolic response to environmental constraints is stress specific. Our study confirms that investigations and characterization of specific phenolic profiles of crop cultivars under oxidative stress may be helpful in breeding programmes.

中文翻译：

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臭氧和水淹胁迫对硬粒小麦两个品种（Triticum durum Desf。）的苯酚代谢

为了比较氧化应激条件下的酚类反应，将两个意大利硬粒小麦品种（Claudio和Mongibello）的植物（a）暴露于臭氧（O ₃）（80 ppb，每天5小时/连续70天），目的是以调查叶片中酚类化合物含量的变化，或（b）淹没（连续七天）。植物显示出O ₃引起的可见伤害，但其光合性能不受污染物的影响。具体而言，克劳迪奥表现出比蒙比贝洛更高的O ₃耐受性。本研究的主要价值无疑是在O ₃条件下硬粒小麦酚类代谢的开创性研究。我们在所有叶片样品中（即对照中，暴露于O中）鉴定出12种叶酚类化合物₃（充满水）：十种酚酸，黄烷醇（儿茶素水合物）和酚醛（丁香醛）。总体而言，O ₃暴露导致酚类化合物的积累，尤其是在克劳迪奥中。这些响应可能被认为是精细调节的修复过程，该过程为Claudio强调的植物配备了能够清除氧化应激的抗氧化剂系统。在淹没的植物中发现了不同的酚类变化，这表明酚类对环境限制的反应是胁迫特异性的。我们的研究证实，对氧化胁迫下农作物品种的特定酚类特征进行调查和表征可能有助于育种计划。