Leaf health status regulates endophytic microbial community structure, network complexity and assembly processes in the leaves of the rare and endangered plant species Abies fan-jingshanensis

The rare and endangered plant species Abies fanjingshanensis, which has a limited habitat, a limited distribution area and a small population, is under severe threat, particularly due to poor leaf health. The plant endophytic microbiome is an integral part of host, and increasing evidence indicates that the interplay between plants and endophytic microbes is a key determinant for sustaining plant fitness. However, little attention has been given to the differences in the endophytic microbial community structure, network complexity and assembly processes in the leaves with different leaf health statuses. Here, we investigated the endophytic bacterial and fungal communities in healthy leaves and nonhealthy leaves of A. fanjingshanensis using 16S rRNA gene and internal transcribed spacer sequencing and evaluated how leaf health status affects the co-occurrence patterns and assembly processes of leaf endophytic microbial communities based on the co-occurrence network, the niche breadth index, a neutral community model and C-score metrics.