Data_Sheet_2_Giant pandas’ staple food bamboo phyllosphere fungal community and its influencing factors.docx

Giant pandas have developed a series of foraging strategies to adapt to their special bamboo diets. Although bamboo is an important food resource for giant pandas in Liziping National Nature Reserve (Liziping NR), China, there are relatively few studies on their phyllosphere fungal community and its influencing factors. Herein, we used ITS1 amplification and metagenomic sequencing to analyze the phyllosphere fungi diversity and functions (KEGG, CAZyme, and antibiotic resistance gene) and explore the influencing factors for the three giant pandas foraging bamboo species (Arundinaria spanostachya, AS; Yushania lineolate, YL; and Fargesia ferax, FF) over different seasons (spring vs. autumn) in Liziping NR, China. We found that Ascomycota and Basidiomycota were the most dominant phyla in the bamboo phyllosphere. The alpha diversity (e.g., the Sobs index and Shannon index) was relatively higher in autumn samples than in spring samples, and the community structure differed significantly between the three bamboo species in spring and autumn. Some biotic and abiotic variables (e.g., the elevation and mean base diameter of bamboo) significantly influenced the abundance, diversity, and community structure of the bamboo phyllosphere fungal community. Moreover, the functional analysis showed the differences in the glycoside hydrolase community and antibiotic resistance gene (ARG) profile between spring and autumn samples. Co–occurrence network modeling suggested that AS phyllosphere fungal communities in autumn employed a much more complex network than that in spring, and the abundance of multidrug, tetracycline, and glycopeptide resistance genes was high and closely correlated with other ARGs. These results indicate that fungal community’s abundance, diversity, and community structure are mainly affected by the season, host species, and elevation. The season and host species are major factors affecting the biological functions (KEGG and CAZyme), ARGs, and interactions between sympatric bacterial and fungal communities in bamboo phyllosphere. This integrated study can provide a reference basis for the seasonal management of bamboo resources foraged by wild giant pandas, and predict the risk of antibiotic resistance in bamboo phyllosphere fungal flora in Liziping NR (Xiaoxiangling mountains), China.

大熊猫演化出一系列觅食策略以适应其特有的竹类食性。尽管竹子是中国栗子坪国家级自然保护区（Liziping NR）内大熊猫的重要食物资源，但针对该区域竹类叶围（phyllosphere）真菌群落及其影响因素的研究相对较少。本研究通过ITS1扩增与宏基因组测序（metagenomic sequencing）技术，分析了中国栗子坪国家级自然保护区内，大熊猫觅食的三种竹类——箭竹（Arundinaria spanostachya, AS）、玉山竹（Yushania lineolate, YL）以及拐棍竹（Fargesia ferax, FF）——在不同季节（春季与秋季）的叶围真菌多样性与功能（KEGG、碳水化合物活性酶（CAZyme）及抗生素抗性基因（ARG）），并探究了其影响因素。研究发现，子囊菌门（Ascomycota）与担子菌门（Basidiomycota）是竹类叶围中的最优势菌门。秋季样本的α多样性（如Sobs指数、Shannon指数）相对春季样本更高，且春秋两季三种竹类的叶围真菌群落结构均存在显著差异。部分生物与非生物变量（如海拔、竹子平均基径）显著影响竹类叶围真菌群落的丰度、多样性及群落结构。此外，功能分析显示，春秋两季样本的糖苷水解酶类群落与抗生素抗性基因谱存在显著差异。共现网络建模结果表明，AS竹类的秋季叶围真菌群落网络复杂度显著高于春季，且多重耐药、四环素耐药及糖肽类耐药基因的丰度较高，并与其他ARG呈紧密相关关系。本研究结果显示，真菌群落的丰度、多样性及群落结构主要受季节、宿主物种及海拔的影响；季节与宿主物种是影响竹类叶围生物功能（KEGG与CAZyme）、ARG以及同域细菌与真菌群落互作的核心因素。本综合性研究可为野生大熊猫觅食竹类资源的季节性管理提供参考依据，并可预测中国栗子坪国家级自然保护区（小相岭山脉）竹类叶围真菌菌群的抗生素抗性风险。