Growth regulation mechanism of Rhododendron moulmainense to high-temperature stress: integrated physiological, transcriptomic, and metabolomic insights

作者：Zaid Khan, Sijia Liu, Jingen Peng, Hongyue Cai, Yuqing Bai, Bing Hu, Luwen Zhang, Peng Zhuang, Zipeng Cai, Lijuan Xie · 发表于：Frontiers in Plant Science · 年份：2025 · DOI：10.3389/fpls.2025.1680853 · 被引用次数：4 · 研究领域：Plant biochemistry and biosynthesis、Essential Oils and Antimicrobial Activity、Phytochemistry and Biological Activities

Rhododendrons domestication in urban habitats is limited due to their vulnerability to higher air temperatures, and their adaptive mechanisms are poorly understood. In this study, we evaluated the growth response and regulatory mechanisms of Rhododendron moulmainense to high-temperature stress of T35 (35°C) and T42 (42°C). The findings demonstrated that high-temperature stress decreased chlorophyll fluorescence and contents, which was validated by the damaged chloroplast structure in transmission electron microscopy. Scanning electron microscopy resulted in reduced leaf stomatal traits, altering gas exchange, and thus, photosynthetic rates were decreased. High-temperature or heat stress (HT) increased the activities of antioxidants and osmolytes under T42 to counteract the damage of reactive oxygen species (ROS). Transcriptome and metabolome analysis using Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment upregulated 9 differentially expressed genes (DEGs) out of 16 and 9 differentially accumulated metabolites (DAMs) out of 10 of the starch-sucrose metabolism pathway and 11 DEGs out of 16 and 9 DAMs out of 13 of ABC transporters metabolism under high-temperature stress of 42°C to reveal the synergistic effects of these pathways. HT induced expression of genes and metabolites in the starch-sucrose metabolism pathway, which likely increased the photosynthesis and sugar metabolism enzymes such as Rubisco, citrate synthase, sucrose synthase, and sucrose phosphate syntheta...