Abstract:

Aim: Tropical tree communities are renowned for their species diversity, with large genera playing a key role in promoting community diversity. However, the mechanisms underlying the coexistence of closely related species within these genera remain a central question in tropical ecology. Traditional approaches, often based on functional traits, have provided insights into niche differentiation but fall short of fully explaining the complex coexistence patterns. 

Methods: This study focuses on representative Ficus species in tropical communities. By combining transcriptomics and metabolomics with phylogenetic analysis and functional traits measurements, it explores how differences in phylogenetic relationships, physical defense traits, defense genes, and metabolic products’ diversity influence interspecific interactions among Ficus species, thereby promoting and maintaining their coexistence in local communities. 

Results: In locally coexisting Ficus species, (1)No significant phylogenetic signals were detected in defensive traits except for C:N ratio; (2) Physical defense traits, defense-related genes, and metabolite diversity exhibited significantly lower values than random structure (P < 0.01), indicating divergent patterns, whereas phylogenetic relationships did not significantly differ from random structure (P = 0.194); (3) The diversity pattern of defensive traits shows habitat heterogeneity. 

Conclusion: This study shows that locally coexisting Ficus species promote defensive niche differentiation via the divergent pattern of defensive traits. The diversity of defense genes and metabolites provided new evidence for this, which is expected to provide new insights and ideas in this field.

Key words: local species coexistence, metabolome, transcriptome, functional trait, phylogenetic relationships