Mechanisms for the formation and maintenance of microhabitat self-organization in the root system of orchid.

Orchid species, globally valued for their ornamental qualities, serve as a model system for studying plant-microbe symbiosis. Most orchid species establish characteristic mycorrhizal associations, with their root microhabitats playing pivotal roles in host growth, development, and ecological adaptation through dynamic soil-plant-microbe interactions. Despite their ecological importance, orchid species remain underrepresented in symbiosis research compared to other plant. This paper reviews recent research advances on the formation and maintenance mechanisms of root microhabitat self-organization in orchids (Orchidaceae). The review covers the techniques and methodologies for orchid root microhabitat research, the relationship between orchid roots and rhizosphere soil, the relationship between orchid endophytic and rhizosphere microorganisms and rhizosphere soil, the relationship between orchid roots and endophytic and rhizosphere microorganisms, the tripartite interaction among orchid roots, rhizosphere soil and endophytic/rhizosphere microorganisms, as well as the relationship between root exudates, microbial metabolites and soil biofilms. The mechanisms underlying orchid root-soil-microorganism interactions are discussed. On this basis, the concept and relevant theories of orchid root microhabitat self-organization are proposed, and the formation and maintenance mechanisms of this self-organization process are elaborated. Finally, the prospects for future research on orchid root microhabitat self-organization are presented. This paper aims to provide references for the research on plant root microhabitat self-organization, as well as the conservation and utilization of orchid resources.