Flowering Plant Microbiomes and Network Interactions Across an Urban Gradient.

Area of Science:

• Microbiology
• Ecology
• Plant Science

Background:

• Ephemeral anthosphere microbiomes, the microbial communities on flowers, are crucial for plant health and ecosystem function.
• Understanding microbiome diversity across plant species and urban gradients is essential for ecological and conservation efforts.

Purpose of the Study:

• To investigate how bacterial and fungal microbiomes of flowers differ among plant species.
• To assess the impact of urbanisation on anthosphere microbiome composition and diversity.
• To identify key microbial taxa and their interactions within flower-associated communities.

Main Methods:

• DNA sequencing of 16S rRNA (bacteria), ITS1 (fungi), and rbcL (plant DNA) from 10 plant species.
• Analysis of microbiome diversity and composition across different plant species and an urban land use gradient.
• Construction of flower-plant interaction networks.

Main Results:

• Bacterial and fungal flower microbiomes showed significant diversity differences across plant species, particularly within Asteraceae and Fabaceae families.
• The bacteria Pantoea and Rosenbergiella, and fungi Alternaria and Cladosporium were prevalent and major contributors to inter-species microbiome variation.
• Despite urbanisation, the plant community's bacterial and fungal microbiomes remained stable and consistent across the land use gradient.
• Flower-plant networks indicated shared pollinators between focal flowers and the Paulowniaceae family.

Conclusions:

• Anthosphere microbiomes exhibit significant diversity at the plant community level.
• These microbial communities are notably robust and consistent, even in the face of urbanisation.
• Specific bacterial and fungal taxa play a key role in shaping plant-specific microbiomes, with implications for plant-microbe interactions.