The discovery of new herbicides is one of the most significant challenges of modern agriculture. Estimates indicate that for every 200,000 molecules assessed, only one will have promising characteristics. We evaluated the effects of 0, 125, 250, 500, 1000, 1500, 2000, and 2500 µM 3-cyanobenzoic acid, a synthetic compound derived from benzoic acid, on the growth and antioxidant and energy metabolism of maize seedlings grown in a hydroponic medium for 96 h. The root length and fresh and dry weights of roots and leaves were significantly reduced by 3-cyanobenzoic acid, probably due to increased reactive oxygen species (ROS) generation. In contrast, the activities of peroxidase, catalase, and superoxide dismutase were stimulated in roots. Increases in potassium cyanide (KCN)-sensitive and salicylhydroxamic acid (SHAM) respiration were evident in the root apexes. Interestingly, the ATP contents were up to 2-fold greater in the treated roots than in the control roots. However, 3-cyanobenzoic acid did not influence oxygen consumption by isolated mitochondria when succinate and/or L-malate were used as substrates. Altogether, our data suggest that 3-cyanobenzoic acid reduces the growth of maize seedlings through the induction of oxidative stress. The stimulation of respiration sensitive to SHAM was due to the electron drain of the cytochrome oxidase (COX) pathway to the alternative oxidase pathway (AOX), with a consequent increase in ROS production. In addition, 3-cyanobenzoic acid should stimulate respiration sensitive to KCN (via cytochrome oxidase, COX) and AOX indirectly by a mechanism not yet known.

Graphical Abstract

中文翻译：

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3-氰基苯甲酸对玉米幼苗初期生长的抑制作用及其对抗氧化和能量代谢的生化影响

新除草剂的发现是现代农业最重大的挑战之一。据估计，每 200,000 个被评估的分子中，只有一个具有有希望的特性。我们评估了 0、125、250、500、1000、1500、2000 和 2500 µM 3-氰基苯甲酸（一种从苯甲酸衍生的合成化合物）对水培玉米幼苗的生长、抗氧化和能量代谢的影响中等96小时。3-氰基苯甲酸显着降低了根长以及根和叶的鲜重和干重，这可能是由于活性氧（ROS）生成增加所致。相反，根部的过氧化物酶、过氧化氢酶和超氧化物歧化酶的活性受到刺激。根尖的氰化钾（KCN）敏感性和水杨异羟肟酸（SHAM）呼吸作用明显增加。有趣的是，处理过的根部的 ATP 含量比对照根部高出 2 倍。然而，当琥珀酸盐和/或L-苹果酸用作底物。总而言之，我们的数据表明 3-氰基苯甲酸通过诱导氧化应激来减少玉米幼苗的生长。对 SHAM 敏感的呼吸刺激是由于细胞色素氧化酶 (COX) 途径的电子流失到替代氧化酶途径 (AOX)，从而导致 ROS 产量增加。此外，3-氰基苯甲酸应通过尚不清楚的机制间接刺激对 KCN（通过细胞色素氧化酶，COX）和 AOX 敏感的呼吸。

图形概要