Editorial: Microbial Symbionts of Lower Plants

Sushma Mishra^1*Amritesh Chandra Shukla^1*Kelly Craven^2*

• ¹Department of Botany, University of Lucknow, Lucknow, India
• ²Oklahoma State University Oklahoma City, Oklahoma City, United States

plants adapt to and thrive in the challenging terrestrial environment. These symbiotic interactions likely facilitated nutrient acquisition from primitive soils deficient in organic matter. This symbiotic partnership not only improved plant survival but also played a crucial role in transforming once-barren landscapes into the lush, green ecosystems that characterize our planet today.Lower plants, including algae, bryophytes, and pteridophytes, represent some of the earliest lineages in plant evolution and occupy distinct ecological niches across diverse habitats. Despite their evolutionary importance and remarkable ecological adaptability, our understanding of their microbial associates remains limited compared to that of angiosperms.To address this knowledge gap, the Research Topic "Microbial Symbionts of Lower Plants" was conceived to present new insights into the microbial symbioses associated with bryophytes and pteridophytes. This collection aims to integrate perspectives from microbial ecology, plant-microbe interactions, and evolutionary biology. In essence, this special issue, comprising four research articles, highlights a relatively underexplored frontier of plant microbiome research that holds significant promise for advancing our understanding of plant-microbe coevolution and ecosystem functioning. (such as moisture, nutrients, available niches etc.) may shape microbial assemblages. The results outlined in the study reveal the complex microbial networks that may contribute to the longevity and adaptability of ferns in forest ecosystems.Using a similar approach of 16S rRNA gene and transcript sequencing, the rhizosphere microbiomes of field-grown Boechera stricta [https://doi.org/10.3389/fmicb.2025.1609057] was investigated over diel time (pre-dawn vs. early afternoon) in field conditions. Although B.stricta is an angiosperm, its inclusion in this Research Topic is justified by its broader relevance to understanding the stability and functional potential of plant-microbe associations. Besides shedding light on the microbial community dynamics, the researchers also investigated the protein synthesis potential (and hence microbial activity) of the rhizospheric microbes vis-àvis bulk soil communities. The study demonstrated the stability of rhizosphere communities even under daily environmental changes. This highlights the robust functional associations that sustain plant-microbe interactions in natural settings.Together, these contributions underscore the ecological and evolutionary significance of plant-microbe symbiotic associations, especially in lower plants. By exploring multiple plant groups and symbiotic strategies, this Research Topic provides a foundation for future studies on functional mechanisms and potential applications in ecosystem management and biotechnology. Lower plant-microbe symbioses remain an underexplored frontier, and continued research in this direction holds promise for unravelling fundamental biological processes and informing climate resilience strategies.