Understanding plant-microorganism interactions: The key roles of soil, rhizosphere, and direct and indirect mechanisms

Abstract

Soil, the Earth's upper crust layer, is crucial for ecological processes, comprising mineral, organic, and biological components that determine fertility and multifuncionality. Human-induced degradation necessitates advancements in pedology and soil conservation. The rhizosphere, surrounding plant roots, houses a diverse microbial community, notably bacteria, which enhance plant growth and disease resistance. Root exudates fuel biological activity and nutrient cycling, supporting microbial growth, improving soil structure, and reducing plant stress. Plant-microorganism interactions in ecological and agricultural systems play a vital role for maintaining primary production and ecosystem sustainability. Moreover, arbuscular mycorrhizae and nitrogen-fixing bacteria are essential, influencing plant development, sustainability, and ecosystem health. Specific bacterial phyla populate the rhizosphere and endosphere, with Plant Growth-Promoting Rhizobacteria (PGPR), such as Pseudomonas spp. and Bacillus spp., playing a prominent role. PGPR employ direct and indirect mechanisms, including phytohormone production, mineral solubilization, systemic resistance induction, antibiosis, competition for resources, and ACC deaminase activity, The amalgamation of these traits underscores the conceptual foundation for comprehending the ecological and agricultural implications of employing microbes. This inquiry is particularly relevant to sustainable agriculture, where the use of microbes, including PGPR, plays a crucial role in biofertilization and mitigating environmental stressors. Thus, investigating the ecological and agricultural implications through multi-omics approaches such as genomics, transcriptomics, proteomics, and metabolomics offers valuable insights. The integration of these multi-omics data provides a comprehensive framework for understanding the complex interactions between plants, bacteria, and fungi. This holistic perspective not only deepens our understanding of soil ecology but also lays the groundwork for informed and sustainable agricultural practices, fostering resilience against environmental stresses.