Sreekissoon Amrisha, Chen Weiyang, Viljoen Alvaro M, Finnie Jeffrey F, Van Staden Johannes
Research Centre for Plant Growth and Development, School of Life Sciences, University of KwaZulu-Natal Pietermaritzburg, Scottsville, South Africa.
Department of Pharmaceutical Sciences, Tshwane University of Technology, Pretoria, South Africa.
Physiol Plant. 2025 Jul-Aug;177(4):e70385. doi: 10.1111/ppl.70385.
Mesembryanthemum tortuosum is a valuable South African medicinal plant. A wide range of pharmacological and therapeutic actions have been ascribed to the plants' mesembrine-type alkaloids. Alkaloids are naturally produced in minute quantities in plants; however, production is often increased in stress conditions. This study aimed to determine the effects of abiotic stress on M. tortuosum growth and mesembrine-type alkaloid production. Light (0, 8, 16, and 24 h), salt (0, 50, 100, and 200 μM NaCl), and osmotic stress (0, 25, 50, and 100 g L polyethylene glycol; PEG) were applied to M. tortuosum cultures in vitro. Growth effects were recorded after 28 days. Alkaloid extracts were analyzed with UPLC-MS. Total mesembrine-type alkaloid contents were significantly increased by 0 h light and 100 g l PEG (9.16 ± 0.12 and 6.74 ± 0.30 μg mg DW, respectively), in comparison to the controls (2.93 ± 0.16 and 3.73 ± 0.014 μg mg DW, respectively). Zero h light allowed for more optimal plantlet growth than osmotic stress treatments. Growth effects and conservation of secondary metabolite pools in the presence of salt confirmed that M. tortuosum has a halophytic nature. Abiotic stress application is a simplistic and inexpensive method of enhancing mesembrine-type alkaloid production in M. tortuosum. With some modification, these methods could prove valuable to small- and large-scale growers of M. tortuosum, along with biotechnologists and pharmaceutical companies. The growing need for commercial availability of these phytochemicals could possibly be satiated with the appropriate use of the stress conditions described.
扭果日中花是一种珍贵的南非药用植物。该植物的中膜碱型生物碱具有广泛的药理和治疗作用。生物碱在植物中天然微量产生；然而，在胁迫条件下其产量通常会增加。本研究旨在确定非生物胁迫对扭果日中花生长和中膜碱型生物碱产生的影响。对扭果日中花离体培养物施加光照（0、8、16和24小时）、盐（0、50、100和200μM NaCl）和渗透胁迫（0、25、50和100 g/L聚乙二醇；PEG）。28天后记录生长效应。用超高效液相色谱-质谱联用仪分析生物碱提取物。与对照（分别为2.93±0.16和3.73±0.014μg/mg干重）相比，0小时光照和100 g/L PEG使中膜碱型生物碱总含量显著增加（分别为9.16±0.12和6.74±0.30μg/mg干重）。0小时光照比渗透胁迫处理更有利于植株生长。盐存在下的生长效应和次生代谢产物库的保存证实扭果日中花具有盐生植物的特性。施加非生物胁迫是一种简单且廉价的提高扭果日中花中膜碱型生物碱产量的方法。经过一些改进，这些方法可能对扭果日中花的小规模和大规模种植者以及生物技术专家和制药公司具有价值。通过适当利用所述胁迫条件，可能满足对这些植物化学物质商业可得性日益增长的需求。
