Auxins (Aux) are primary growth regulators that regulate almost every aspect of growth and development in plants. It plays a vital role in various plant processes besides controlling the key aspects of cell division, cell expansion, and cell differentiation. Considering the significance of Aux, and its potential applications, a study was conducted to observe the impact of indole acetic acid (IAA), a most active and abundant form of Aux on Brassica juncea plants growing under natural environmental conditions. Different concentrations (0, 10⁻¹⁰, 10⁻⁸, 10⁻⁶ M) of IAA were applied once in a day at 25-day stage of growth for 5 days, consecutively. Various parameters (growth, photosynthetic, biochemical, oxidative biomarkers and nutrient composition) were assessed at different days after sowing (DAS). Scanning electron microscopy (SEM) of leaf stomata, reactive oxygen species (ROS) localization in leaf and roots, and confocal microscopy were also conducted. The results revealed that all the IAA concentrations were effective in growth promotion and ROS reduction, however, the 10⁻⁸ M of IAA exhibited the maximum improvement in all the above mentioned parameters as compared to the control.

生长素 (Aux) 是主要的生长调节剂，可调节植物生长和发育的几乎所有方面。除了控制细胞分裂、细胞扩增和细胞分化的关键方面外，它在各种植物过程中起着至关重要的作用。考虑到 Aux 的重要性及其潜在应用，进行了一项研究以观察吲哚乙酸 (IAA)（一种最活跃和最丰富的 Aux 形式）对在自然环境条件下生长的芥菜植物的影响。不同浓度 (0, 10 ^-10 , 10 ^-8 , 10 ^-6 M) IAA 在 25 天的生长阶段每天施用一次，连续 5 天。在播种后的不同天数 (DAS) 评估各种参数（生长、光合作用、生化、氧化生物标志物和营养成分）。还进行了叶气孔的扫描电子显微镜 (SEM)、叶和根中的活性氧 (ROS) 定位以及共聚焦显微镜检查。结果表明，所有IAA浓度均能有效促进生长和减少ROS，然而， 与对照相比，10 ^-8 M IAA在所有上述参数中表现出最大改善。