丛枝菌根真菌在药用植物中的作用及机制研究进展

丛枝菌根真菌(AMF)可与绝大部分陆生植物建立菌根共生体系,并在其生长发育过程中发挥着重要作用,但目前对其在药用植物生长、活性物质生物合成、积累中的作用和抗逆胁迫中的角色及相关机制尚无系统分析和梳理。该文首先对常见的AMF研究方法进行了整理,主要包括AMF孢子的分离、形态学鉴定、化学染色、分子鉴定等方法,并将常见AMF属种形态结构列表详述。在促生长方面,AMF通过菌丝体的延长,分泌磷酸酶、有机酸等物质活化土壤矿质营养元素,提高药用植物吸收效率,从而促进药用植物的生长;在提高药用植物活性物质合成和积累方面,AMF通过调控次级产物代谢通路相关信号分子及关键酶活性,从而促进黄酮类、萜类化合物的合成与积累,进而改善药用植物的品质和质量。此外,AMF还可通过提高抗氧化酶活性、提高植物自身清除自由基的能力、络合有毒重金属、稀释高盐浓度、诱导相关胁迫基因的表达等机制,缓解干旱、重金属、高盐及高温或低温胁迫。最后,对AMF在药用植物生态种植中的的应用前景和深入研究进行了展望,为推进相关研究提供借鉴和参考。

Effect and Mechanism of Arbuscular Mycorrhizal Fungi in Herbs

Arbuscular mycorrhizal fungi(AMF)can establish mycorrhizal symbiosis system with most terrestrial plants,and play important roles in their growth and development.However,there is no systematic analysis and summarization of their roles in the growth,biosynthesis and accumulation of active substances of herbs,as well as stress-resistance mechanism.First,the main research methods of AMF were summarized in the paper,including the separation of AMF spores,morphological identification,chemical staining and molecular identification.The main morphological structures of some AMF were detailed in the table.In terms of growth promotion,AMF promoted the growth by prolonging mycelium,enhancing phosphatase secretion,organic acid,activation of soil and increasing absorption efficiency.In the aspect of biosynthesis and accumulation of flavonoids,terpenoids and other active substances in herbs,AMF improved the contents by regulating activities of signal substances and key enzymes involved in the metabolism of secondary products. In addition,AMF couldalleviate a series of stresses caused by drought,heavy metal,high salt,high or low temperature by improving theactivity of antioxidant enzymes,enhancing the ability of plants to scavenge free radicals,complexing toxic heavymetals,diluting high salt concentration,or inducing the expressions of key genes. Finally,the applicationprospects and in-depth study of AMF in the ecological planting of herbs were discussed,in order to providereference for promoting relevant research.