Maize synthesized benzoxazinoids affect the host associated microbiome

Area of Science:

• Plant Biology
• Microbiology
• Genetics

Background:

• Plants synthesize bioactive substances to shape microbial communities.
• Plant secondary metabolites, like benzoxazinoids (BXs) in maize, have roles in signaling and defense, but their impact on the microbiome is not fully understood.

Purpose of the Study:

• To investigate the effects of benzoxazinoids (BXs) on the structure of the host-associated microbial community in maize.
• To characterize the maize microbiome at early growth stages using BX knock-out mutants and parental lines.

Main Methods:

• Utilized 16S and ITS2 rRNA gene amplicon sequencing to analyze microbial communities.
• Employed a rhizo-box experiment to study effects in roots, shoots, and rhizosphere.
• Compared BX knock-out mutants with their W22 parental lines.

Main Results:

• BXs significantly altered microbial communities in roots, shoots, and the rhizosphere.
• Fungal richness in roots was more sensitive to BXs than bacterial richness.
• Maize genotype and age were key factors influencing microbial community structure, with genotypic effects more pronounced in roots.

Conclusions:

• BXs play a crucial role in microbial community assembly within maize roots, shoots, and the rhizosphere.
• BXs exhibit a gatekeeper function, correlating with specific microbial taxa and influencing fungal and bacterial communities.
• Co-occurrence network analysis revealed that BXs impact distinct microbial clusters in the maize root microbiome.