Regional climate variation structures the phyllosphere microbiome of flue-cured tobacco

Cheng Zhang¹Lei Yang²Xiaohua Zhang¹Yuhang Zhao³Jiati Tang³Zhijun Cheng²Yi Cao³Wu Shengjiang³Guanhui LI³Long Yang^1*Wei Kesu^3*

• ¹Shandong Agricultural University, Taian, China
• ²China Tobacco Hunan Industrial Company Ltd, Changsha, China
• ³Guizhou Tobacco Science Research Institute, Guiyang, China

Climate change poses significant challenges to agricultural production, while the phyllosphere microbial community plays a crucial yet poorly understood role in host climate adaptation. This study investigated the structural and functional reorganization of the phyllosphere microbiota in flue-cured tobacco (Nicotiana tabacum L.) under climatic variations. Through multi-regional sampling combined with 16S rRNA gene and ITS high-throughput sequencing, we found significant differences in the contents of starch, total sugar, and reducing sugar in tobacco leaves under different climatic gradients, ranging from 26.87% to 32.25%, 14.24% to 16.74%, and 9.96% to 11.26%, respectively. Bacterial and fungal community compositions were driven by different climatic factors. Bacterial communities were primarily determined by precipitation (VPA explanatory degree: 41.7%), followed by sunlight duration, while fungal communities were mainly driven by temperature (explaining 27.3% of the variance). Microbial networks displayed climate-adaptive characteristics, with complex and cooperative bacterial networks (85.99% positive correlations) in high-precipitation areas, and simplified networks (Nodes: 93, Edges: 1124) dominated by tolerant taxa such as Sphingomonas (86.50%) and Methylobacterium (10.24%) in low-precipitation regions. The metabolic potential of the microbial communities shifted along the climatic gradient. Communities in low-precipitation areas were enriched with genes potentially encoding starch-degrading enzymes (e.g., α-amylase), while those in high-precipitation areas showed enhanced potential for sucrose synthesis (e.g., via sucrose synthase). These findings establish a mechanistic link between microbial community dynamics and host metabolic regulation under climatic stress, demonstrating functional network reorganization as an adaptive strategy. Our study provides a framework for developing microbiome-based approaches to enhance crop climate resilience, offering practical solutions for sustainable agriculture in changing environments.