Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Northwest University, Xi'an, China.
Physiol Plant. 2021 Aug;172(4):1966-1982. doi: 10.1111/ppl.13407. Epub 2021 Apr 12.
Flavonoids with great medicinal value play an important role in plant individual growth and stress resistance. Flavonol synthetase (FLS) is one of the key enzymes to synthesize flavonoids. However, the role of the FLS gene in flavonoid accumulation and tolerance to abiotic stresses, as well as its mechanism has not yet been investigated systematically in plants. The aim of this research is to evaluate the effect of FLS overexpression on the accumulation of active ingredients and stress resistance in Euphorbia kansui Liou. The results showed that when the EkFLS gene was overexpressed in Arabidopsis thaliana, the accumulation of flavonoids was improved. In addition, when the wild-type and EkFLS overexpressed Arabidopsis plants were treated with ABA and MeJA, compared with WT Arabidopsis, EkFLS overexpressed Arabidopsis promoted stomatal aperture to influence photosynthesis of the plants, which in turn can promote stress resistance. Meanwhile, under MeJA, NaCl, and PEG treatment, EkFLS overexpressed in Arabidopsis induced higher accumulation of flavonoids, which significantly enhanced peroxidase (POD) and superoxide dismutase (SOD) activities that can scavenge reactive oxygen species in cells to protect the plant. These results indicated that EkFLS overexpression is strongly correlated to the increase of flavonoid synthesis and therefore the tolerance to abiotic stresses in plants, providing a theoretical basis for further improving the quality of medicinal plants and their resistance to abiotic stresses simultaneously.
具有重要药用价值的类黄酮在植物个体生长和抗逆性方面发挥着重要作用。黄酮醇合酶（FLS）是合成类黄酮的关键酶之一。然而，FLS 基因在类黄酮积累和耐受非生物胁迫方面的作用及其机制尚未在植物中得到系统研究。本研究旨在评估 FLS 过表达对甘遂活性成分积累和抗逆性的影响。结果表明，当 EkFLS 基因在拟南芥中过表达时，类黄酮的积累得到了改善。此外，当野生型和 EkFLS 过表达的拟南芥植物用 ABA 和 MeJA 处理时，与 WT 拟南芥相比，EkFLS 过表达的拟南芥促进了气孔开度，影响了植物的光合作用，从而可以促进植物的抗逆性。同时，在 MeJA、NaCl 和 PEG 处理下，过表达的 EkFLS 在拟南芥中诱导了更高水平的类黄酮积累，显著提高了过氧化物酶（POD）和超氧化物歧化酶（SOD）的活性，从而可以清除细胞内的活性氧，保护植物。这些结果表明，EkFLS 过表达与类黄酮合成的增加密切相关，因此与植物的非生物胁迫耐受性相关，为进一步提高药用植物的质量和提高其对非生物胁迫的抗性提供了理论依据。
