植物促生微生物挥发性物质的生态功能研究进展

植物促生微生物通过各种途径有益于植物的生长发育,而其产生的挥发性物质在这一过程中的作用不可忽视。挥发性物质低分子量、弱极性、高蒸汽压、低沸点、亲脂性的特点使其与微生物其他性质的代谢产物相比,具有能够长距离传播、介导生物体间非接触的相互作用、低浓度即可被感知等优势。本文从植物促生微生物挥发性物质促进植物生长发育、对植物的化感作用、诱导植物系统抗性、促进植物次级代谢产物积累、抑制植物病虫害的发生与发展、阻碍食草动物取食等方面综述了植物促生微生物挥发性物质重要的生态功能及这些功能间的相互关系和具体作用机制,并对植物促生微生物挥发性物质今后的研究方向和应用前景进行了展望。

Ecological functions of volatiles produced by plant growth-promoting micro-organisms

Various kinds of endophytic and rhizospheric micro-organisms were closely related with various plants. Most of these micro-organisms were potential promoters of plant growth and development as they produced phytohormones that increased available nutrients to plants, controlled plant pathogens, etc. These microbes were collectively defined as plant growth-promoting micro-organisms. Furthermore, volatiles released by these plant growth-promoting micro-organisms were critical for mutual symbiosis of the host plants and plant-associated micro-organisms. Many endophytic and rhizospheric micro-organisms were reported to be capable of producing varieties of volatiles as secondary metabolites. Volatiles produced by plant growth-promoting micro-organisms had many essential ecological functions and the relationships among the functions were often quite complex. Some volatiles produced by plant growth-promoting micro-organisms were capable of promoting growth and development of plants. These volatiles induced systemic resistance in plants such that survival rates of plants in negative conditions improved. Also these compounds altered the constituents and contents of valuable secondary metabolites in plants, which in turn enhanced plants biotic resistance. Finally, some volatiles inhibited growth or reproduction of pathogens or insects and prevented herbivores from grazing on the host plants. Given these functions and several more, these critical metabolites enhanced host plants' competitive advantages over non-host plants. Because of these valuable ecological functions, further research studies needed to be done on beneficial effects of mutual symbiosis of micro-organisms and host plants. Several volatiles produced by plants affected signaling pathways or gene expression of host plants. In summary, studies on volatiles produced by plant growth-promoting micro-organisms enabled us to better understand the complex relationships among plants and micro-organisms. For in-depth research on volatiles produced by plant growth-promoting micro-organisms, this review summarized the results of current studies and discussed further development in this field.