Exploring the diversity and potential of host-associated microorganisms in Hypnum leptothallum to enhance plant resilience to drought stress for karst desertification restoration.

ABSTRACT:

Background

Karst rocky desertification poses a serious threat to the ecosystems of southwest China, where Hypnum leptothallum plays a crucial role in forming microbial crusts essential for restoration. However, the use of native microbial applications in this area remains largely unexplored.

Results

In this study, the host-associated microbial communities of H. leptothallum from four severely desertified regions in Guizhou Province were characterized using high-throughput sequencing. The results revealed conserved α- and β-diversity, with dominant bacterial phyla being Pseudomonadota (34-47%) and Actinomycetota (23-35%), and fungal phyla being Ascomycota (57-83%) and Basidiomycota (14-32%). Subsequent carbon-source preference analysis guided the formulation of specialized media (e.g., α-D-lactose, N-acetyl-D-glucosamine) to isolate culturable strains, with cross-referencing identifying 14 bacterial and 36 fungal species consistently shared between sequencing and cultivation. Functional evaluation demonstrated bacterial dominance in inorganic phosphorus solubilization (68% of strains), protease synthesis (76%), ammonia production (56%), and indole-3-acetic acid biosynthesis (62%), while fungi excelled in organophosphorus solubilization. Further drought tolerance and gametophyte co-culture assays identified 10 drought-resistant bacterial strains and 16 strains significantly enhancing H. leptothallum growth within 7 days.

Conclusions

These functionally validated strains, particularly drought-adapted and growth-stimulating species closely related to Rhodococcus erythropolis, provide targeted microbial resources for developing synthetic inoculants to optimize artificial crust propagation in karst restoration.

SUBMITTER: Wu S 

PROVIDER: S-EPMC12911403 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature