Soil microbial load modulation improves plant-microbe interactions and bioinoculant efficacy in pathogen-stressed...

Area of Science:

• Plant Science
• Microbiology
• Soil Science

Background:

• The resident soil microbiome is crucial for plant health but can hinder bioinoculant success.
• High soil microbial load and its dynamics impact bioinoculant efficacy, yet remain understudied.
• Understanding these factors is key to improving agricultural practices and plant resilience.

Purpose of the Study:

• To investigate the impact of soil microbial load modulation on plant responses and bioinoculant efficacy.
• To analyze the transcriptomic and rhizosphere microbiome changes induced by soil dysbiosis.
• To identify strategies for enhancing bioinoculant performance in challenging soil conditions.

Main Methods:

• Induced soil dysbiosis using moist heat treatment (MHT) to create a microbial load gradient.
• Assessed phenotypic and transcriptomic responses of *Cucumis sativus* (cucumber) to bioinoculants.
• Performed rhizosphere microbiome profiling (relative and quantitative).

Main Results:

• MHT significantly reduced resident soil bacteria, with partial recovery post-planting, promoting plant growth.
• Dysbiotic soil facilitated rhizosphere restructuring and activated plant-microbe pathways (sugar/nitrogen metabolism).
• Native soil resisted restructuring, prioritizing microbial stability over plant health; bioinoculation in dysbiotic soil induced systemic resistance and growth-promoting transcriptomic shifts.

Conclusions:

• Microbial load modulation is a key strategy to enhance bioinoculant efficacy and plant growth.
• Restructuring the rhizosphere microbiome through controlled dysbiosis improves plant health and response to beneficial microbes.
• Targeting soil microbial dynamics offers a promising avenue for sustainable agriculture and improved crop yields.