Department of Plant Physiology, Biotechnology and Bioinformatics, Biological Institute, National Research Tomsk State University, Lenin Avenue 36, Tomsk 634050, Russia.
K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia.
Molecules. 2023 Feb 22;28(5):2077. doi: 10.3390/molecules28052077.
Heavy metals and aluminum are among the most significant abiotic factors that reduce the productivity and quality of crops in acidic and contaminated soils. The protective effects of brassinosteroids containing lactone are relatively well-studied under heavy metal stress, but the effects of brassinosteroids containing ketone are almost unstudied. Moreover, there are almost no data in the literature on the protective role of these hormones under polymetallic stress. The aim of our study was to compare the stress-protective effects of lactone-containing (homobrassinolide) and ketone-containing (homocastasterone) brassinosteroids on the barley plant's resistance to polymetallic stress. Barley plants were grown under hydroponic conditions; brassinosteroids, increased concentrations of heavy metals (Mn, Ni, Cu, Zn, Cd, and Pb), and Al were added to the nutrient medium. It was found that homocastasterone was more effective than homobrassinolide in mitigating the negative effects of stress on plant growth. Both brassinosteroids had no significant effect on the antioxidant system of plants. Both homobrassinolide and homocastron equally reduced the accumulation of toxic metals (except for Cd) in plant biomass. Both hormones improved Mg nutrition of plants treated with metal stress, but the positive effect on the content of photosynthetic pigments was observed only for homocastasterone and not for homobrassinolide. In conclusion, the protective effect of homocastasterone was more prominent compared to homobrassinolide, but the biological mechanisms of this difference remain to be elucidated.
重金属和铝是降低酸性和污染土壤中作物生产力和质量的最重要非生物因素之一。含有内酯的油菜素内酯在重金属胁迫下的保护作用研究得比较充分，但含有酮的油菜素内酯的作用几乎没有研究过。此外，关于这些激素在多金属胁迫下的保护作用，文献中几乎没有数据。我们的研究目的是比较含有内酯（表油菜素内酯）和含有酮（高同型 castasterone）的油菜素内酯对大麦植物耐多金属胁迫的应激保护作用。大麦植物在水培条件下生长；油菜素内酯、重金属（Mn、Ni、Cu、Zn、Cd 和 Pb）浓度增加以及 Al 被添加到营养培养基中。结果发现，高同型 castasterone 比表油菜素内酯更能减轻胁迫对植物生长的负面影响。两种油菜素内酯对植物抗氧化系统均没有显著影响。两种油菜素内酯均能降低植物生物量中有毒金属（除 Cd 外）的积累。两种激素均改善了受金属胁迫处理的植物的 Mg 营养，但仅对高同型 castasterone 而非表油菜素内酯观察到对光合色素含量的积极影响。总之，与表油菜素内酯相比，高同型 castasterone 的保护作用更为显著，但这种差异的生物学机制仍有待阐明。
