Wang Weixuan, Zhang Chenglong, Shang Meixin, Lv Haofeng, Liang Bin, Li Junliang, Zhou Weiwei
College of Resource and Environment, Qingdao Agricultural University, Qingdao 266000, China.
Food Chem X. 2022 Oct 17;16:100481. doi: 10.1016/j.fochx.2022.100481. eCollection 2022 Dec 30.
Reduced nitrogen availability is an efficient strategy for increasing the accumulation of phenolic compounds in vegetables, but related mechanisms remain unknown. Here, the production of hydrogen peroxide (HO) and its potential roles in regulating phenolic biosynthesis and enhancing the antioxidant quality of lettuce under low nitrogen (LN) conditions were investigated. The LN treatment caused a rapid production of HO, which effectively increased lettuce quality by enhancing the levels of phenolic compounds and other nutrients such as ascorbic acid, glutathione, soluble sugar, and soluble protein. The increased phenolic content was related to the higher expression levels of phenolic biosynthesis genes, including PAL, CHS, DFR, F35H, and UFGT, and higher photosynthetic capacity after HO addition under LN conditions. However, these positive effects were suppressed by dimethylthiourea (DMTU), a scavenger of HO. These results suggest that HO as an important signal molecular mediates the LN-caused phenolic accumulation and antioxidant quality enhancement in lettuce.
减少氮素供应是增加蔬菜中酚类化合物积累的有效策略，但相关机制尚不清楚。在此，研究了过氧化氢（H₂O₂）的产生及其在低氮（LN）条件下调节生菜酚类生物合成和提高抗氧化品质中的潜在作用。LN处理导致H₂O₂快速产生，通过提高酚类化合物以及其他营养物质（如抗坏血酸、谷胱甘肽、可溶性糖和可溶性蛋白质）的水平有效提高了生菜品质。酚类含量的增加与酚类生物合成基因（包括PAL、CHS、DFR、F3′5′H和UFGT）的较高表达水平以及在LN条件下添加H₂O₂后较高的光合能力有关。然而，这些积极作用被H₂O₂清除剂二甲基硫脲（DMTU）抑制。这些结果表明，H₂O₂作为一种重要的信号分子介导了LN诱导的生菜中酚类积累和抗氧化品质提高。
