Molecular Microbiology Research 2024, Vol.14, No.4, 171-180 http://microbescipublisher.com/index.php/mmr 175 4.2 Enhancing tree resilience to stress Symbiotic microbes also enhance tree resilience to various biotic and abiotic stresses. Plants under stress conditions, such as drought, tend to assemble beneficial microbes in their rhizosphere to maximize survival and growth. For example, specific bacterial taxa in the root microbiome are associated with increased drought tolerance in plants (Fitzpatrick et al., 2018). Moreover, the rhizosphere microbiome acts as an indirect layer of the plant immune system, providing a barrier against pathogen invasion and inducing systemic resistance. The co-evolution of plants with arbuscular mycorrhizal (AM) fungi and rhizobia further supports plant resilience by promoting nutrient exchange and enhancing microbial community stability in the rhizosphere. 4.3 Role in soil structure and health Symbiotic microbes contribute significantly to soil structure and health. The activities of PGPR and other beneficial microbes improve soil structure by producing cell lytic enzymes, secondary metabolites, and stress-alleviating compounds (Figure 2) (Hakim et al., 2021). These activities enhance soil aggregation, porosity, and water retention, which are critical for maintaining soil health. The microbial community structure in the rhizosphere influences soil properties and processes, such as carbon biomass and enzyme activity, which are essential for soil fertility and ecosystem stability (Elsheikh et al., 2021). The diversity and composition of microbial communities in the rhizosphere are shaped by plant and soil types, which in turn affect soil health and quality. By promoting beneficial microbial interactions, plants can positively influence soil structure and health, leading to more sustainable and productive ecosystems (López-Lozano et al., 2020). Figure 2 The benefits of PGPR-mediated rhizosphere engineering to the plant growth (Adopted from Hakim et al., 2021) 5 Case Studies of Tree-Microbe Interactions 5.1 Symbiosis in forest ecosystems In forest ecosystems, the symbiotic relationships between trees and rhizosphere microbes play a crucial role in nutrient cycling and carbon sequestration. For instance, the interaction between Pinus tabuliformis and Quercus
RkJQdWJsaXNoZXIy MjQ4ODYzNA==