Abstract
Elevated temperatures significantly impaired the normal growth and development of plants. This study combined physiological and transcriptomic analyses to explore the potential mechanisms of response to heat stress in Abies beshanzuensis M. H. Wu. Under heat stress, A. beshanzuensis exhibited reduced photosynthetic rates and chlorophyll content, accompanied by marked downregulation of photosynthesis-associated genes, suggesting heat-induced photoinhibition and compromised carbon assimilation capacity. Furthermore, the increased activities of MDA, SOD, POD, and CAT suggested that A. beshanzuensis could withstand heat stress by enhancing the activity of antioxidant enzymes to mitigate excess reactive oxygen species and anions. Transcriptome analysis revealed the induction of genes related to heat shock proteins, plant hormone signaling, and antioxidants, which could enhance the tolerance of A. beshanzuensis to high temperatures. In summary, the research demonstrated that A. beshanzuensis could not tolerate high temperatures, which was identified as one of the primary reasons for its endangerment. This study offers a novel approach to investigating the regulatory mechanisms of heat stress.