mVOCs在根际免疫中的研究进展及思考

Research progress and prospects on the role of mVOCs in rhizosphere immunity

由土传病原菌引起的作物病害频发制约着世界农业的可持续发展。以根际微生物群落这一生物屏障为核心的根际免疫在抵御土传病原菌入侵中发挥着至关重要的作用。除竞争营养、产生抗生物质等外,根际微生物还通过分泌易挥发性有机物(Microbial volatile organic compounds,mVOCs)与病原菌、其他土著微生物以及宿主植物互作,以更好地适应根际环境和发挥抑病功能。由于具有作用浓度低、可在水-土-气等多界面自由迁移和长距离传播等优势,mVOCs日益成为根际免疫领域机理研究和产品开发的热点。本文首先介绍mVOCs参与土壤抑菌性的发现过程,系统梳理抑制土传病原菌的mVOCs及分泌源--有益微生物。其次,从抑制土传病原菌生长和致病、调控微生物群落互作以及激发植物抗性3个方面阐述mVOCs提升根际免疫的作用机理。随后,总结mVOCs在防控土传病害中的应用现状,并分析影响mVOCs产生和作用效果的土壤生物和非生物因素。最后,提出与根际免疫相关的mVOCs研究思考,呼吁关注mVOCs在根际免疫领域的理论和实践价值。

Soil-borne diseases are a common impediment to the sustainable development of agriculture worldwide. The rhizosphere microbiome plays an important role in the development of immune barriers against the invasion of soil pathogens. Rhizosphere microbes not only compete for nutrition and produce diffusible antimicrobial compounds, but also interact with other microorganisms and plants by secreting microbial volatile organic compounds(mVOCs)that play a role in disease suppression. Owing to the low effective concentration and long-distance diffusion at the water-soil-air interface, mVOCs have become a hot spot not only for mechanistic research but also for product development in the prevention and control of soil-borne diseases. In this review, we briefly discuss the initial reports describing the involvement of mVOCs in soil disease inhibition, and then systematically discuss the current advances in mVOCs research, specifically:the production of microbes with disease inhibition ability from indoor and field evidence;the mechanism of mVOCs participating in rhizosphere immunity, including suppression of pathogen growth and virulence traits;the microbial interactions in the rhizosphere;and the induction of plant resistance. We also analyzed the biotic and abiotic factors of soil affecting the production of mVOCs and proposed future research directions and theoretical and practical prospects relating to how to improve rhizosphere immunity against soil-borne plant diseases.