Research progress and future directions of arbuscular mycorrhizal fungi-plant-rhizosphere microbial interaction

Microecology of rhizosphere, a key area of soil ecology, affects plant growth and metabolism in many ways. Many scientists regard the root system as key to the second green revolution. Arbuscular mycorrhizal (AM) is one of the most common mycorrhizal symbiotic categories of plants and is closely related to the evolutionary history of terrestrial plants. Mycorrhizal symbionts formed by arbuscular mycorrhizal fungi (AMF) and host plant roots can change plant root morphology and improve nutritional status to promote the growth and development of host plants, improve stress resistance and disease resistance, participate in many physiological metabolic processes of plants, and indirectly affect plant growth through the regulation of soil structure and microbial community structure. This paper briefly describes the interaction between AMF and plants, rhizosphere microorganisms, and mycorrhizal helper bacteria (MHB); and discusses the important role of mycorrhizal symbiosis in plant establishment, competition, maintenance of biodiversity, and its role in the Earth’s ecology. Although the symbiosis between AMF and plants has shown good production benefits, most of the studies reported in the scientific literatures have been carried out under controlled conditions (growth chamber or greenhouse, sterile substrate). Because the response of AMF in the natural environment may differ significantly, it is also needed to evaluate the ability of AMF under field conditions. It is also very important to further explore the symbiotic gene network and key transcription factors in the molecular dialogue between plants and fungi, and decipher the key metabolic signaling pathway of MHB.