Kitwetch Benyapa, Rangseekaew Pharada, Chromkaew Yupa, Pathom-Aree Wasu, Srinuanpan Sirasit
Interdisciplinary Program in Biotechnology, Graduate School, Chiang Mai University, Chiang Mai 50200, Thailand.
Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand.
Plants (Basel). 2023 Nov 7;12(22):3793. doi: 10.3390/plants12223793.
The consumption of lettuce is associated with an increased risk of ingesting nitrate, a naturally occurring and potentially harmful compound that can have adverse effects on human health. Hydroponic cultivation systems serve as effective tools for regulating nutrient solutions and nitrogen availability, which are essential for controlling nitrate levels. However, the techniques for reducing nutrient levels need to be appropriately calibrated based on lettuce growth responses and their interactions with the environment and growing conditions. Previous studies have demonstrated that plant probiotic actinomycetes can alleviate nutritional stress in various crops. However, there is a noticeable gap in research concerning the effects of actinomycetes on hydroponically grown lettuce, particularly under nutrient-limiting conditions. This study aimed to evaluate the effectiveness of the actinomycete S3 in enhancing lettuce growth in a nutrient-restricted hydroponic system. The results indicated that the detrimental effects of nutrient stress on lettuce were mitigated by the inoculation of lettuce with S3. This mitigation was evident in various growth parameters, including leaf count, shoot length, and the fresh and dry weights of both shoots and roots. In the presence of nutritional stress, S3 likely mitigated the negative effects on lettuce by reducing hydrogen peroxide levels, presumably through the synthesis of HO-scavenging enzymes. Furthermore, S3 successfully survived and colonized lettuce roots. Therefore, the inoculation of lettuce with S3 offers significant advantages for promoting lettuce growth in nutrient-limited hydroponic systems.
食用生菜与摄入硝酸盐的风险增加有关，硝酸盐是一种天然存在且可能有害的化合物，会对人体健康产生不利影响。水培种植系统是调节营养液和氮素供应的有效工具，而营养液和氮素供应对于控制硝酸盐水平至关重要。然而，降低养分水平的技术需要根据生菜的生长反应及其与环境和生长条件的相互作用进行适当校准。先前的研究表明，植物益生菌放线菌可以减轻各种作物的营养胁迫。然而，关于放线菌对水培生菜的影响，特别是在养分限制条件下的影响，研究中存在明显差距。本研究旨在评估放线菌S3在养分受限的水培系统中促进生菜生长的有效性。结果表明，用S3接种生菜可减轻养分胁迫对生菜的有害影响。这种减轻在各种生长参数中都很明显，包括叶片数量、茎长以及茎和根的鲜重和干重。在存在营养胁迫的情况下，S3可能通过降低过氧化氢水平（大概是通过合成清除HO的酶）来减轻对生菜的负面影响。此外，S3成功在生菜根部存活并定殖。因此，用S3接种生菜对于在养分受限的水培系统中促进生菜生长具有显著优势。
