College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
Carbohydr Polym. 2024 Jan 1;323:121422. doi: 10.1016/j.carbpol.2023.121422. Epub 2023 Sep 20.
Alginate oligosaccharides (AOS) have various biological activities in the regulation of plant growth and development. However, little is known about the effect on fruit coloration. We assessed the impacts of varying Mannuronate/Guluronate ratio (M/G ratios) of AOS, namely oligoguluronate (GAOS), oligomannuronate (MAOS), and heterogeneous AOS (HAOS), and delved into the structure-function relationship, as well as the mechanisms of regulation. The promotion of strawberry coloration was observed in HAOS (M/G ratio ≈ 1.58; Mw = 2800 Da) and MAOS (M/G ratio ≈ 6.77; Mw = 6000 Da), whereas GAOS (M/G ratio ≈ 0.2; Mw = 5500 Da) did not exhibit any significant effect. The metabolomics analysis revealed that the impact of AOS was predominantly observed on the biosynthesis of flavonoids. The predominant flavonoids present in strawberries were anthocyanins. The application of HAOS and MAOS on strawberries increased anthocyanin content. This was accompanied by an up-regulation of genes related to the JA synthesis pathway. Additionally, transcription factors and structural genes related to anthocyanin synthesis and transport were up-regulated. The findings suggest that HAOS and MAOS may trigger the JA pathway, leading to an elevation in anthocyanin metabolism and consequent enhancement of strawberry coloration.
海藻酸盐寡糖（AOS）在调节植物生长发育方面具有多种生物活性。然而，关于其对果实着色的影响知之甚少。我们评估了不同的甘露糖醛酸/古洛糖醛酸比（M/G 比）的 AOS，即寡聚古洛糖醛酸盐（GAOS）、寡聚甘露糖醛酸盐（MAOS）和杂合 AOS（HAOS），并深入研究了结构-功能关系以及调节机制。在 HAOS（M/G 比约为 1.58；Mw=2800Da）和 MAOS（M/G 比约为 6.77；Mw=6000Da）中观察到草莓着色的促进作用，而 GAOS（M/G 比约为 0.2；Mw=5500Da）则没有表现出任何显著的效果。代谢组学分析表明，AOS 的影响主要体现在类黄酮的生物合成上。草莓中主要存在的类黄酮是花青素。HAOS 和 MAOS 在草莓上的应用增加了花青素的含量。这伴随着与 JA 合成途径相关的基因的上调。此外，与花青素合成和转运相关的转录因子和结构基因也被上调。研究结果表明，HAOS 和 MAOS 可能触发 JA 途径，导致花青素代谢升高，从而增强草莓的着色。
