The core metabolome and root exudation dynamics of three phylogenetically distinct plant species

Abstract

Root exudates are plant-derived, exported metabolites likely shaping root-associated microbiomes by acting as nutrients and signals. However, root exudation dynamics are unclear and thus also, if changes in exudation are reflected in changes in microbiome structure. Here, we assess commonalities and differences between exudates of different plant species, diurnal exudation dynamics, as well as the accompanying methodological aspects of exudate sampling. We find that exudates should be collected for hours rather than days as many metabolite abundances saturate over time. Plant growth in sterile, nonsterile, or sugar-supplemented environments significantly alters exudate profiles. A comparison of Arabidopsis thaliana, Brachypodium distachyon, and Medicago truncatula shoot, root, and root exudate metabolite profiles reveals clear differences between these species, but also a core metabolome for tissues and exudates. Exudate profiles also exhibit a diurnal signature. These findings add to the methodological and conceptual groundwork for future exudate studies to improve understanding of plant-microbe interactions.

Exogenously applied sodium nitroprusside alleviates nickel toxicity in maize by regulating antioxidant activities and defense‐related gene expression

“…For root organic acid exudates analysis, two maize plants from each plastic container having uniform size were cautiously uprooted, cleansed with ddH 2 O, and transferred to the rhizobox system for organic acid collection (Figure S1; McLaughlin et al, 2023). The rhizobox system comprised a nylon net (25 mm) enveloped around plant roots and 200-g autoclaved moist soil.…”

Listening to plant's Esperanto via root exudates: reprogramming the functional expression of plant growth‐promoting rhizobacteria

“…In addition, there is evidence that specific compounds associated with more specialized plant–microbe interactions, such as triterpenes and benzoxazinoids, are exuded by Arabidopsis and grasses, respectively (Hu et al ., 2018; Huang et al ., 2019). Root exudate metabolite profiles of A. thaliana , Brachypodium distachyon , and Medicago truncatula showed significant differences among different species (Brecht et al ., 2022). Microbiome composition and root exudates varies with plant developmental stage (Aulakh et al ., 2001; Bulgarelli et al ., 2013), for example, in Arabidopsis , altered triterpene exudation changed microbiome composition (Huang et al ., 2019).…”

Convergent and divergent responses of the rhizosphere chemistry and bacterial communities to a stress gradient in the Atacama Desert

“…Studies have shown a strong phylogenetic signal in plant-soil feedback, while metabolic convergence was observed in aerial plant parts in response to abiotic threats (35,38,65,66). However, root and root exudate metabolic profiles tend to present less variation between species when compared to aerial plant parts (15). Here, while certain markers differed between vegetation belts ( e.g.…”

“…Overall, recent efforts improved our understanding of some biochemical mechanisms used by plants to interact with the microbial community (26). Nevertheless, it is reasonable to say that a significant portion of rhizosphere chemicals remains to be discovered and that little is known about how these signals shape the surrounding microbe community (15,18,27). Moreover, most studies were performed on single species.…”