Phyllosphere microbes in foxtail millet primarily affect quality by modulating coloration and bitter compounds

Area of Science:

• Agricultural Science
• Microbiology
• Plant Science

Background:

• Crop quality is influenced by genetics, metabolites, and environmental factors.
• Rhizosphere microbes impact crop quality, but phyllosphere microbes' roles are less understood.
• This study investigates phyllosphere microbes and metabolites in foxtail millet varieties with different eating qualities.

Purpose of the Study:

• To examine the interaction between phyllosphere metabolites and the microbiome in foxtail millet.
• To understand how phyllosphere microbes influence crop quality traits like bitterness and viscosity.

Main Methods:

• Field study comparing three foxtail millet varieties (two high-eating-quality, one low-eating-quality).
• Metabolomic analysis to identify compounds associated with eating quality.
• Microbiome profiling to identify microbial genera correlated with metabolite profiles.
• Synthetic microbial community experiments to validate findings.

Main Results:

• Thirteen metabolites were depleted in high-eating-quality varieties, including four bitter compounds.
• Depleted metabolites negatively correlated with Curtobacterium and Pseudomonas abundance.
• These microbes were associated with reduced bitterness and improved viscosity.
• Synthetic communities confirmed microbes enhanced quality by increasing yellow color and reducing bitterness.

Conclusions:

• Higher abundance of Curtobacterium and Pseudomonas in foxtail millet panicles correlates with reduced bitterness and improved quality.
• Phyllosphere microbes and metabolites play a significant role in determining crop quality.
• This research offers new insights into phyllosphere-mediated crop quality enhancement.