Transcriptome analysis reveals novel insights into the mechanisms of Davidia involucrata Baill. response to high-light stress.

Davidia involucrata Baill. is a rare and endangered plant species that exhibits high sensitivity to environmental stressors. High-light stress significantly impedes its growth and development. However, the molecular mechanisms underlying Davidia involucrata Baill.'s response to high-light stress remain poorly understood. In this study, transcriptome sequencing and bioinformatics analyses were employed to systematically investigate the response of Davidia involucrata Baill. to high-light stress under varying soil moisture and air humidity conditions. The results revealed that under different soil moisture conditions, Davidia involucrata Baill. significantly activated pathways related to reactive oxygen species and heat stress responses in reaction to high-light stress. However, notable differences were observed in the extent of pathway activation: under moist soil conditions, Davidia involucrata Baill. primarily responded to high-light stress via reactive oxygen species-related pathways, whereas under dry soil conditions, it predominantly relied on heat stress response pathways. Furthermore, under non-humidified air conditions, Davidia involucrata Baill. responded to high-light stress and combined stress by activating the MAPK signaling pathway and indole-containing compound biosynthetic process, respectively. We also found that when high-light stress and drought stress occur simultaneously, Davidia involucrata Baill. prioritizes mitigating the damage caused by high-light stress. In summary, this study elucidated the key molecular mechanisms underlying Davidia involucrata Baill.'s response to high-light stress, providing a theoretical foundation for the conservation of rare plant species, enhancement of environmental adaptability, and development of stress-resistant cultivation strategies.