Above-ground xylem genes and below-ground soil carbon genes analyses provide molecular insights into experimental warming in Phoebe chekiangensis.

Phoebe chekiangensis C. B. Shang is an endemic and endangered species in China, and it is widely used for furniture, building materials and artwork due to its high-quality wood properties and high economic value. However, the impact of spring warming on P. chekiangensis growth molecular dynamics are poorly understood. In this study, we used a year-long warming control experiment (CK, +2 °C, +4 °C) to explore the molecular dynamics of aboveground xylem genes and belowground soil carbon genes. Transcriptome results indicated that spring warming primarily affects genes and pathways related to cell growth, lignin, photosynthesis, and cell wall macromolecules. Carbon fixation genes abundance increased significantly over time in the CK and + 2 °C groups, but no significant increase was observed in the +4 °C group. In addition, spring warming reduced the diversity of microbial communities which may be one of the reasons for reduced tree growth. These findings revealed the mechanisms underlying xylem and carbon cycling genes responses to varying temperature increases in P. chekiangensis. Our results provided valuable insights for future research on wood-related molecular mechanisms and offer a foundational basis for uniting aboveground xylem growth and belowground carbon genes to together influence seasonal development of wood.