Higher Institution Centre of Excellence (HICoE), UM Power Energy Dedicated Advanced Centre (UMPEDAC), Level 4, Wisma R&D University of Malaya, Jalan Pantai Baharu, 59990, Kuala Lumpur, Malaysia.
Institute for Advanced Studies, University of Malaya, 50603, Malaysia.
Plant Physiol Biochem. 2024 Dec;217:109252. doi: 10.1016/j.plaphy.2024.109252. Epub 2024 Nov 2.
Stevia rebaudiana is a high-value crop due to the strong commercial demand for its metabolites (steviol glycosides, SG) as an organic low-caloric sweetener with up to 300 times the sweetness of conventional sugar. Two experiments were conducted in this study. In the first experiment, treatments with varying green (GR1 & GR2), UVA (UV1 & UV2) and treatments that had both (UVGR1, UVGR2) were used. In the second experiment, separate set of plants were grown under base red-blue (RB) and natural sunlight before being transferred to GR2, UV2, UVGR2, and monochromatic light treatments of blue, green and UVA, for 3 and 10 days before harvest. RB and sunlight were used as the control for artificial and natural light respectively. Plants grown under the UVGR1 had the highest dry leaf biomass accumulation of 4.75 g plant (P < 0.05), 458% and 660% higher than the RB (0.98 g plant) and natural sunlight (0.72 g plant) controls. UVA had the highest metabolite (Stevioside + Rebaudioside A) concentration of 27% (P < 0.05) compared to the RB and sunlight controls at 17.24% and 15% respectively. The 10 day pre-harvest treatment with blue supplemented light yielded a dry biomass of 1.87 g plant1, a 190% increase compared to the RB control. However, the 3 day pre-harvest treatment had higher metabolite yields improvements compared to 10 day treatments with the highest yield obtained of 21.10% in 3-day pre-harvest irradiation that had supplemental UVA and blue light. UVGR1 was the most productive lighting strategy, resulting in the highest overall metabolite yield per plant.
甜菊糖 Rebaudioside A 是一种高附加值作物，因其代谢物（甜菊糖苷，SG）具有商业价值，可用作有机低热值甜味剂，甜度可达普通糖的 300 倍。本研究共进行了两项实验。在第一项实验中，采用不同的绿光（GR1 和 GR2）、UVA（UV1 和 UV2）和同时包含这两种光的处理方式（UVGR1、UVGR2）。在第二项实验中，另一组植物先在基础红蓝光（RB）和自然光下生长，然后转移到 GR2、UV2、UVGR2 以及单色光（蓝光、绿光和 UVA）下，分别培养 3 天和 10 天后进行收获。RB 和自然光分别作为人工光和自然光的对照。在 UVGR1 光下生长的植物具有最高的干叶生物量积累，为 4.75 g 株（P < 0.05），比 RB（0.98 g 株）和自然光（0.72 g 株）对照分别高 458%和 660%。与 RB 和自然光对照相比，UVA 光的代谢物（甜菊苷+瑞鲍迪苷 A）浓度最高，为 27%（P < 0.05），而 RB 和自然光对照分别为 17.24%和 15%。与 RB 对照相比，补充蓝光的 10 天预收获处理的干生物量为 1.87 g 株，增加了 190%。然而，与 10 天处理相比，3 天预收获处理的代谢物产量提高幅度更大，在补充 UVA 和蓝光的 3 天预收获辐照处理中获得的最高产量为 21.10%。UVGR1 是最具生产力的照明策略，使植物的总体代谢物产量最高。
