Succession patterns of foliar endophytic fungal communities during different leaf growth stages in Lycium barbarum

Lycium barbarum (Goji) is an important traditional Chinese medicinal plant widely distributed across Northwest China. Its young leaves are usually developed into tea or vegetables. Foliar endophytic fungi respond to leaves development, growth and health. Herein, high-throughput amplicon sequencing was used to assess dynamic changes in foliar endophytic fungal communities in young, mature, and old L. barbarum leaves. Results revealed that as leaf growth progressed, a decrease was observed in the diversity and evenness of foliar endophytic fungal communities, whereas an initial increase followed by a decrease was observed in community richness and the number of total and specific amplicon sequence variants (ASVs). The potential pathogen Alternaria was dominant genus in young and mature leaves, another potential pathogen Arthrocladiella was dominant genus in old leaves. The foliar endophytic fungal co-occurrence networks were initially complex but simplified with leaf growth. The function prediction stated the potential plant pathogen of foliar endophytic fungal communities gradually increased with leaf growth. Except for the leaf soluble sugar content, all other factors, including average temperature, average humidity, leaf transpiration rate, leaf net photosynthetic rate, leaf ammonium nitrogen content, and leaf ammonia nitrogen content, exhibited a significant correlation with the structure of foliar endophytic fungal communities at different growth stages of L. barbarum leaves ( p < 0.05). Altogether, this study reveals the dynamics and function of foliar endophytic fungal communities during different growth stages of L. barbarum leaves, providing novel insights into the composition, diversity, and function of these communities and their relationship with host plants.