Salam Abdul, Chang Jinzhe, Yang Liupeng, Zeeshan Muhammad, Iqbal Anas, Khan Ali Raza, Afridi Muhammad Siddique, Ulhassan Zaid, Azhar Wardah, Zhang Zhixiang, Zhang Peiwen
State Key Laboratory of Green Pesticide, South China Agricultural University, Guangzhou 510642, China.
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, College of Agriculture, South China Agricultural University, Guangzhou 510642, China.
Plants (Basel). 2025 Jul 7;14(13):2076. doi: 10.3390/plants14132076.
Brassinosteroids (BRs) play an essential role in regulating plant metabolic pathways that influence growth, development, and stress responses. However, their role in alleviating cobalt (Co) stress has not been extensively studied. This research aimed to assess the impact of exogenous BRs (0.1 µM) on maize subjected to Co stress (300 µM) in a hydroponic experiment. The results indicated that BR supplementation significantly decreased the accumulation of HO by 17.79 and 16.66%, O by 28.5 and 21.48%, and MDA by 37.5 and 37.9% in shoot and root, respectively, as compared to Co stress alone. Additionally, BRs enhanced endogenous levels of BRs (31.16%) and growth hormones (IAA 50.8%, JA 57.8%, GA 52.5%), and reduced Co contents by 26.3% in roots and 36.1% in shoots. BRs enhanced antioxidant enzyme activity both in the shoot and root, leading to reduced ROS levels as confirmed by laser scanning confocal microscopy. Furthermore, BRs increased phenols, flavonoids, and soluble sugars, and elevated total protein content. Observations from transmission electron microscopy indicated reduced ultrastructural damage in plants treated with BRs under Co stress. Taken together, this study highlights the role of BRs in alleviating Co stress in maize, demonstrating their efficiency in enhancing stress tolerance by modulating hormone levels and key metabolic processes.
油菜素甾醇（BRs）在调节影响植物生长、发育和应激反应的代谢途径中起着至关重要的作用。然而，它们在缓解钴（Co）胁迫方面的作用尚未得到广泛研究。本研究旨在通过水培实验评估外源BRs（0.1µM）对遭受Co胁迫（300µM）的玉米的影响。结果表明，与单独的Co胁迫相比，添加BRs后，地上部和根部的HO积累分别显著降低了17.79%和16.66%，O积累分别显著降低了28.5%和21.48%，MDA积累分别显著降低了37.5%和37.9%。此外，BRs提高了内源BRs水平（31.16%）和生长激素水平（IAA提高50.8%，JA提高57.8%，GA提高52.5%），并使根部Co含量降低了26.3%，地上部Co含量降低了36.1%。BRs提高了地上部和根部的抗氧化酶活性，激光扫描共聚焦显微镜证实这导致了ROS水平的降低。此外，BRs增加了酚类、黄酮类和可溶性糖的含量，并提高了总蛋白含量。透射电子显微镜观察表明，在Co胁迫下，用BRs处理的植物超微结构损伤减少。综上所述，本研究突出了BRs在缓解玉米Co胁迫中的作用，证明了它们通过调节激素水平和关键代谢过程来提高胁迫耐受性的效率。
