The Arabidopsis thaliana–Streptomyces Interaction Is Controlled by the Metabolic Status of the Holobiont

Abstract

How specific interactions between plant and pathogenic, commensal, or mutualistic microorganisms are mediated and how bacteria are selected by a plant are important questions to address. Here, an Arabidopsis thaliana mutant called chs5 partially deficient in the biogenesis of isoprenoid precursors was shown to extend its metabolic remodeling to phenylpropanoids and lipids in addition to carotenoids, chlorophylls, and terpenoids. Such a metabolic profile was concomitant to increased colonization of the phyllosphere by the pathogenic strain Pseudomonas syringae pv. tomato DC3000. A thorough microbiome analysis by 16S sequencing revealed that Streptomyces had a reduced colonization potential in chs5. This study revealed that the bacteria–Arabidopsis interaction implies molecular processes impaired in the chs5 mutant. Interestingly, our results revealed that the metabolic status of A. thaliana was crucial for the specific recruitment of Streptomyces into the microbiota. More generally, this study highlights specific as well as complex molecular interactions that shape the plant microbiota.

Soil conditions and the plant microbiome boost the accumulation of monoterpenes in the fruit of Citrus reticulata ‘Chachi’

“…Root exudates and phytohormones play an important role in modulating microbial colonization of the root zone [ 51 ]. A recent study showed that the Arabidopsis thaliana mutant chs5 remoulded the profile of isoprenoid-derived metabolites (including monoterpenoids and sesquiterpenoids), which further impacted the specific recruitment of Streptomyces into the microbiota [ 52 ]. SA, a key immune regulator, also modulates colonization of the root microbiome by specific bacterial taxa, including Streptomyces and Bacillus [ 53 ].…”

“…The available N, P and K in soil were determined according to the previous literature [ 58 ]. Soil micronutrient concentrations were measured using the diethylenetriaminepentaacetic acid (DTPA) extraction method [ 52 ]. A total of 10 g of air-dried soil was mixed with 20 ml of DTPA extraction solution (0.005 M DTPA, 0.01 M CaCl 2 , 0.1 M triethanolamine, pH 7.3) by shaking for 2 h at room temperature.…”

Phyllosphere Microbiome in Plant Health and Disease

“…For example, cytokinin has been reported to act as a signaling molecule that drives phyllosphere bacterial community assembly and increases disease resistance [32]. Graindorge et al (2022) revealed that the metabolic status of the plant is vital for the recruitment of Streptomyces into the microbiota [33]. This evidence indicates that the plant could favor specific microorganisms by releasing specific volatile compounds.…”