Involvement of auxin pathways in modulating root architecture during beneficial plant–microorganism interactions

Abstract

A wide variety of microorganisms known to produce auxin and auxin precursors form beneficial relationships with plants and alter host root development. Moreover, other signals produced by microorganisms affect auxin pathways in host plants. However, the precise role of auxin and auxinsignalling pathways in modulating plant-microbe interactions is unknown. Dissecting out the auxin synthesis, transport and signalling pathways resulting in the characteristic molecular, physiological and developmental response in plants will further illuminate upon how these intriguing interspecies interactions of environmental, ecological and economic significance occur. The present review seeks to survey and summarize the scattered evidence in support of known host root modifications brought about by beneficial microorganisms and implicate the role of auxin synthesis, transport and signal transduction in modulating beneficial effects in plants. Finally, through a synthesis of the current body of work, we present outstanding challenges and potential future research directions on studies related to auxin signalling in plant-microbe interactions.

Biosynthesis and Secretion of Indole-3-Acetic Acid and Its Morphological Effects on Tricholoma vaccinum-Spruce Ectomycorrhiza

“…Although ectomycorrhizal fungi have been reported to produce IAA, mainly with tryptophan as an IAA precursor (5,14,49), no single study has investigated the potential biosynthetic pathways and genes involved. Based on precursor feeding and isotope studies, we propose that T. vaccinum produces IAA through a tryptophan-indole pyruvate-indole acetaldehyde biosynthetic pathway.…”

“…Although many ectomycorrhizal fungi have been shown to produce IAA, the biosynthetic pathways and enzymes involved have not been investigated (14). Two different auxin biosynthetic pathways have been described for plants.…”

Application of PGPR and Antagonist Fungi-based Biofungicide for White Rust Disease Control and Its Economyc Analysis in Chrysanthemum Production

“…2003). Some PGPR are able to produce phytohormones such as auxins, cytokinins, gibberellins and ethylene that can induce cell ploriferation in the root by increasing lateral root growth and root hair development with a subsequent increment of nutrient and water uptake (Sukumar et al, 2013).…”

Exclusive networks in the sea

“…These phytoplankton live in a complex milieu with other microorganisms, many of which rely on the products of algal photosynthesis for growth 2 . Although chemical cross-talk between the microorganisms that inhabit the human body or the root zone of plants is well established [3][4][5] , it is difficult to imagine similarly intimate interactions in dilute ocean environments. Indeed, an enduring mystery of marine ecology and carbon-cycle science is whether there are specific mutualistic relationships between ocean microbes or whether exchanges are largely the result of random encounters between released compounds and free-living cells.…”

“…Amin et al postulate that the exchanges between these free-living microbes are coordinated through cycling of the hormone indole-3-acetic acid (IAA) and the amino acid tryptophan. Best known for its use by terrestrial plants to direct developmental processes such as the growth of new shoots, IAA also has a role in signalling between soil bacteria and plants 4 . The researchers demonstrate that P. multiseries and Sulfitobacter SA11 secrete tryptophan and IAA, respectively.…”