Root Exudates and Their Molecular Interactions with Rhizospheric Microbes

Abstract

Biologically important plant-microbe interactions are mediated by a wide array of signal compounds rhizodeposited from both plant and microbial species. Root exudates are some of the potentially important low molecular weight compounds secreted from plant roots. They are involved in building a network of biointeractions through several physical, chemical, or biological interactions. Application of bioinoculums has signifi cantly improved growth parameters and yield of many economically valued crops. Root exudates mediate the plant-microbe interactions by colonizing the roots and promoting root growth. Also, root exudates improve chemical and physical characteristics of the rhizospheric soil. Some of the benefi cial plant-microbe associations include nitrogen fi xation by rhizobium, symbiotic biointeractions with AM (arbuscular mycorrhizal) fungi, and PGPR (plant-growth-promoting Rhizobacteria ). These interactions improve plant growth and quality, stress tolerance, and plant defense responses. Root exudates constitute a wide variety of secondary metabolite constituents that help plants to guard against microbial infections, insects, or herbivore attack. Root exudates secreted by plants act as antimicrobial agents to curb various harmful rhizospheric pathogens. In this chapter, we provide a summary of literatures on the signifi cance of plant-microbe interactions in the improvement of plant morphological and biochemical features. Further, detailed information on various types of root exudates and their role in mediating plant-microbe interactions and possible exploration of root exudates as a novel antimicrobial compounds are also discussed.

A predatory myxobacterium controls cucumber Fusarium wilt by regulating the soil microbial community

“…Root exudates play key roles in plant-microbe interactions and root colonization by rhizobacteria [28]. Based on the fact that strain EGB could migrate towards cucumber roots in soil, we deduced that root exudates play a role in the recruitment of strain EGB to the rhizosphere.…”

Evaluation of Bacteria Isolated from Olive Mill Wastewater as Plant Growth Promoter on Basil (Ocimum basilicum L.) plant

“…asburiae + half dose of N2 treatment increased the oil yield in the first cut of plant to (1.03%). Swamy et al (2016) reported that the essential oils have high potential in the field of biomedicine as they effectively destroy many of bacterial, fungal, and viral pathogens, due to several types of aldehydes, terpenes, phenolics and other antimicrobial compounds so that the essential oils are effective against a diverse range of pathogens.…”

Plant-bacteria synergism: An innovative approach for the remediation of crude oil-contaminated soils

“…This communication is of extreme significance for the persistence and colonization of applied bacteria in the plant rhizosphere. Numerous investigations have been executed to see persistence of inoculated bacteria, especially through labelling of inoculated bacterial strains with a marker gene, for example gfp encoding green fluorescent protein, gusA encoding ß-glucuronidase and so forth (Swamy et al, 2016).…”