Effects of functional phylogeny of light-response-related orthologous genes on seedling survival in a subtropical forest.

Background: Light is an important environmental factor affecting the growth and survival of plants in forest communities. The competition for light resources and divergent responses to light may affect plant species coexistence in natural forests through niche partitioning and environmental filtering, respectively. Methods: In the present study, sequences of light-response-related functional genes were extracted from transcriptomic data of 99 tree species in a subtropical forest and average and nearest taxon phylogenetic diversity of adult (A_Apd', A_NTpd') and seedling neighbors (S_Apd', S_NTpd') around each focal seedling were calculated to evaluate effects of differentiation in light-response-related genes on community assembly processes. Results: The results showed that seedling survival was related to S_NTpd', S_ Apd' and A_Apd' of two chlorophyll ab-binding proteins involved in the assembly of photosystem II and two genes responsive to light intensity, indicating seedlings surrounded by neighbors with distinct light responses tended to have high survival rates. Conclusions: Our results indicated that niche partitioning due to competition for light resources between plants may act as the key mechanism in determining seedling dynamics in subtropical forests. [ABSTRACT FROM AUTHOR]