The Volatile Pentadecane From Bacillus Alleviates Plant Iron Deficiency Through Activating the Reduction-Based...

Area of Science:

• Plant Biology
• Microbiology
• Biochemistry

Background:

• Iron (Fe) is vital for plant growth, with rhizosphere microbes influencing Fe nutrition.
• Mechanisms by which microbes affect plant Fe uptake are not fully understood.
• Volatile organic compounds (VOCs) produced by bacteria are emerging as signaling molecules in plant-microbe interactions.

Purpose of the Study:

• To investigate the impact of Bacillus velezensis SQR9-derived VOCs on iron uptake in Arabidopsis.
• To elucidate the molecular mechanisms underlying VOC-mediated Fe uptake enhancement.
• To identify specific VOCs responsible for promoting plant Fe nutrition.

Main Methods:

• Arabidopsis thaliana were exposed to SQR9 VOCs under iron-limited conditions.
• Gene expression analysis (FIT, FRO2, IRT1) and biochemical assays (nitric oxide accumulation) were performed.
• Genetic knockout mutants were used to confirm gene function; chemical analysis identified active VOCs.

Main Results:

• SQR9 VOCs significantly improved Fe uptake, chlorophyll content, biomass, and root development.
• Upregulation of Fe uptake genes (FIT, FRO2, IRT1) and nitric oxide accumulation were observed.
• Pentadecane was identified as a key active VOC mediating NO signaling and enhancing Fe uptake.

Conclusions:

• Bacillus velezensis SQR9 VOCs, particularly pentadecane, promote plant iron uptake via nitric oxide signaling.
• This mechanism involves the upregulation of key iron uptake-related genes in Arabidopsis.
• SQR9 shows potential as a plant growth-promoting rhizobacterium for iron biofortification in crops.