Priming of plant growth promotion by volatile compounds of root-associated Microbacterium

TY - JOUR

T1 - Priming of plant growth promotion by volatile compounds of root-associated Microbacterium

AU - Cordovez, V.

AU - Schop, S.

AU - Hordijk, C.A.

AU - Dupré de Boulois, H.

AU - Coppens, F.

AU - Hanssen, I.

AU - Raaijmakers, J.M.

AU - Carrion, V.J.

N1 - 6582, ME; Data Archiving: data archived at NCBI . Raw RNA-seq data are deposited in the National Center for Biotechnology Information (NCBI) Sequence Read Archive (www.ncbi.nlm.nih.gov/sra) and assigned to BioProject accession no. PRJNA492842 and BioSample accession numbers SAMN09711604 to SAMN09711619.

PY - 2018

Y1 - 2018

N2 - Volatile compounds produced by plant-associated microorganisms represent a diverse resource to promote plant growth and health. Here we investigated the effect of volatiles from root-associated Microbacterium species on plant growth and development. Volatiles of eight strains induced significant increases in shoot and root biomass of Arabidopsis, but differed in their effects on root architecture. Microbacterium strain EC8 also enhanced root and shoot biomass of lettuce and tomato. Biomass increases were also observed for plants exposed only shortly to volatiles from EC8 prior to transplantation of the seedlings to soil. These results indicate that volatiles from EC8 can prime plants for growth promotion without direct and prolonged contact. We further showed that the induction of plant growth promotion is tissue specific: exposure of roots to volatiles from EC8 led to an increase in plant biomass whereas shoot exposure resulted in no or less growth promotion. GC-QTOF analysis revealed that EC8 produces a wide array of sulfur containing compounds as well as ketones. Bioassays with synthetic sulfur volatile compounds revealed that the plant growth response to dimethyl trisulfide was concentration-dependent with a significant increase in shoot weight at 1 μM and negative effects on plant biomass at concentrations higher than 1 mM. Genome-wide transcriptome analysis of volatile-exposed Arabidopsis seedlings showed up-regulation of genes involved in assimilation and transport of sulfate and nitrate. Collectively, these results show that root-associated Microbacterium primes plants, via the roots, for growth promotion most likely via modulation of sulfur and nitrogen metabolism.Importance In the past decade, various studies have described the effects of microbial volatiles on other (micro)organisms in vitro, but their broad-spectrum activity in vivo and the mechanisms underlying volatile-mediated plant growth promotion have not been addressed in detail. Here, we revealed that volatiles from root-associated bacteria of the genus Microbacterium can enhance growth of different plant species and can prime plants for growth promotion without direct and prolonged contact between the bacterium and the plant. Collectively, these results provide new opportunities for sustainable agriculture and horticulture by exposing roots of plants only briefly to a specific blend of microbial volatile compounds prior to transplantation of the seedlings to the greenhouse or field. This strategy has no need for large-scale introduction, root colonization and survival of the microbial inoculant.

AB - Volatile compounds produced by plant-associated microorganisms represent a diverse resource to promote plant growth and health. Here we investigated the effect of volatiles from root-associated Microbacterium species on plant growth and development. Volatiles of eight strains induced significant increases in shoot and root biomass of Arabidopsis, but differed in their effects on root architecture. Microbacterium strain EC8 also enhanced root and shoot biomass of lettuce and tomato. Biomass increases were also observed for plants exposed only shortly to volatiles from EC8 prior to transplantation of the seedlings to soil. These results indicate that volatiles from EC8 can prime plants for growth promotion without direct and prolonged contact. We further showed that the induction of plant growth promotion is tissue specific: exposure of roots to volatiles from EC8 led to an increase in plant biomass whereas shoot exposure resulted in no or less growth promotion. GC-QTOF analysis revealed that EC8 produces a wide array of sulfur containing compounds as well as ketones. Bioassays with synthetic sulfur volatile compounds revealed that the plant growth response to dimethyl trisulfide was concentration-dependent with a significant increase in shoot weight at 1 μM and negative effects on plant biomass at concentrations higher than 1 mM. Genome-wide transcriptome analysis of volatile-exposed Arabidopsis seedlings showed up-regulation of genes involved in assimilation and transport of sulfate and nitrate. Collectively, these results show that root-associated Microbacterium primes plants, via the roots, for growth promotion most likely via modulation of sulfur and nitrogen metabolism.Importance In the past decade, various studies have described the effects of microbial volatiles on other (micro)organisms in vitro, but their broad-spectrum activity in vivo and the mechanisms underlying volatile-mediated plant growth promotion have not been addressed in detail. Here, we revealed that volatiles from root-associated bacteria of the genus Microbacterium can enhance growth of different plant species and can prime plants for growth promotion without direct and prolonged contact between the bacterium and the plant. Collectively, these results provide new opportunities for sustainable agriculture and horticulture by exposing roots of plants only briefly to a specific blend of microbial volatile compounds prior to transplantation of the seedlings to the greenhouse or field. This strategy has no need for large-scale introduction, root colonization and survival of the microbial inoculant.

KW - international

UR - https://www.ncbi.nlm.nih.gov/bioproject/PRJNA492842

U2 - 10.1128/AEM.01865-18

DO - 10.1128/AEM.01865-18

M3 - Article

SN - 0099-2240

VL - 84

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

IS - 22

M1 - e01865-18.

ER -