Volatile organic compounds emitted by Burkholderia pyrrocinia CNUC9 trigger induced systemic salt tolerance in Arabidopsis thaliana

Abstract

Salinity is among the most significant abiotic stresses that negatively affects plant growth and agricultural productivity worldwide. One ecofriendly tool for broadly improving plant tolerance to salt stress is the use of bio-inoculum with plant growth-promoting rhizobacteria (PGPR). In this study, a bacterium strain CNUC9, which was isolated from maize rhizosphere, showed several plant growth-promoting characteristics including the production of 1-aminocyclopropane-1-carboxylate deaminase, indole acetic acid, siderophore, and phosphate solubilization. Based on 16S rRNA and recA gene sequence analysis, we identified strain CNUC9 as Burkholderia pyrrocinia. Out of bacterial determinants to elicit plant physiological changes, we investigated the effects of volatile organic compounds (VOCs) produced by B. pyrrocinia CNUC9 on growth promotion and salinity tolerance in Arabidopsis thaliana. Higher germination and survival rates were observed after CNUC9 VOCs exposure under 100 mM NaCl stress. CNUC9 VOCs altered the root system architecture and total leaf area of A. thaliana compared to the control. A. thaliana exposed to VOCs induced salt tolerance by increasing its total soluble sugar and chlorophyll content. In addition, lower levels of reactive oxygen species, proline, and malondialdehyde were detected in CNUC9 VOCs-treated A. thaliana seedlings under stress conditions, indicating that VOCs emitted by CNUC9 protected the plant from oxidative damage induced by salt stress. VOC profiles were obtained through solid-phase microextraction and analyzed by gas chromatography coupled with mass spectrometry. Dimethyl disulfide (DMDS), methyl thioacetate, and 2-undecanone were identified as products of CNUC9. Our results indicate that optimal concentrations of DMDS and 2-undecanone promoted growth in A. thaliana seedlings. Our findings provide greater insight into the salt stress alleviation of VOCs produced by B. pyrrocinia CNUC9, as well as potential sustainable agriculture applications.

Bacterial volatile organic compounds from Bacillus zanthoxyli HS-1 enhance tolerance responses against salt and high temperature in cucumber and cabbage

“…In this study, BzaHS1 and its VOCs could decrease MDA concentrations in the leaves of cabbage and cucumber seedlings compared to mocktreated plant seedlings under stressed conditions. These ndings align with earlier observations that link reduced lipid peroxidation to improved stress tolerance mechanisms (57,59).…”

The Contribution of PGPR in Salt Stress Tolerance in Crops: Unravelling the Molecular Mechanisms of Cross-Talk between Plant and Bacteria

“…A reduction in oxidative stress markers such as ROS, MDA and proline was also found in A. thaliana grown under 100 mM NaCl exposed to VOCs produced by Burkholderia pyrrocinia CNUC9. Dimethyl disulfide (DMDS), methyl thioacetate, and 2-undecanone were identified as products of CNUC9 and their role in alleviating salt stress was confirmed using respective synthetic compounds [91].…”

Polysaccharides Produced by Plant Growth-Promoting Rhizobacteria Strain Burkholderia sp. BK01 Enhance Salt Stress Tolerance to Arabidopsis thaliana

“…The environmental and potentially beneficial plant-associated Burkholderia share characteristics such as a quorum sensing system, the presence of nitrogen fixation and/or nodulation genes, and the ability to degrade aromatic compounds [ 32 ]. PGPR strains such as Burkholderia phytofirmans PsJN [ 8 ] and Burkholderia pyrrocinia CNUC9 [ 33 ] were reported to enhance salt tolerance in Arabidopsis thaliana .…”