School of Environmental Science, Liaoning University, Shenyang, 110036, China.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
Planta. 2023 May 3;257(6):108. doi: 10.1007/s00425-023-04136-w.
This review summarizes the anti-stress effects of flavonoids in plants and highlights its role in the regulation of polar auxin transport and free radical scavenging mechanism. As secondary metabolites widely present in plants, flavonoids play a vital function in plant growth, but also in resistance to stresses. This review introduces the classification, structure and synthetic pathways of flavonoids. The effects of flavonoids in plant stress resistance were enumerated, and the mechanism of flavonoids in plant stress resistance was discussed in detail. It is clarified that plants under stress accumulate flavonoids by regulating the expression of flavonoid synthase genes. It was also determined that the synthesized flavonoids are transported in plants through three pathways: membrane transport proteins, vesicles, and bound to glutathione S-transferase (GST). At the same time, the paper explores that flavonoids regulate polar auxin transport (PAT) by acting on the auxin export carrier PIN-FORMED (PIN) in the form of ATP-binding cassette subfamily B/P-glycoprotein (ABCB/PGP) transporter, which can help plants to respond in a more dominant form to stress. We have demonstrated that the number and location of hydroxyl groups in the structure of flavonoids can determine their free radical scavenging ability and also elucidated the mechanism by which flavonoids exert free radical removal in cells. We also identified flavonoids as signaling molecules to promote rhizobial nodulation and colonization of arbuscular mycorrhizal fungi (AMF) to enhance plant-microbial symbiosis in defense to stresses. Given all this knowledge, we can foresee that the in-depth study of flavonoids will be an essential way to reveal plant tolerance and enhance plant stress resistance.
本文综述了植物中类黄酮的抗应激作用，并强调了其在调节极性生长素运输和清除自由基机制中的作用。类黄酮作为广泛存在于植物中的次生代谢物，在植物生长中起着至关重要的作用，但也能抵抗应激。本文介绍了类黄酮的分类、结构和合成途径。列举了类黄酮在植物抗应激中的作用，并详细讨论了类黄酮在植物抗应激中的作用机制。阐明了植物通过调节类黄酮合酶基因的表达来积累类黄酮以应对胁迫。还确定了植物通过三种途径将合成的类黄酮在植物中运输：膜转运蛋白、囊泡和与谷胱甘肽 S-转移酶（GST）结合。同时，本文探讨了类黄酮通过作用于生长素输出载体 PIN 形成蛋白（PIN）以 ABCB/PGP 转运体的形式调节极性生长素运输（PAT），从而帮助植物以更占优势的形式应对胁迫。我们已经证明，类黄酮结构中羟基的数量和位置可以决定其清除自由基的能力，并阐明了类黄酮在细胞中发挥自由基清除作用的机制。我们还将类黄酮鉴定为信号分子，以促进根瘤菌的结瘤和丛枝菌根真菌（AMF）的定殖，从而增强植物与微生物共生体在抵御胁迫中的防御能力。鉴于所有这些知识，我们可以预见，深入研究类黄酮将是揭示植物耐受性和增强植物抗应激能力的重要途径。
