Abstract:Eucalyptus spp., as an important fast-growing economic tree species in southern China, plays a significant role in forestry production. However, with the large-scale use of single clone and the continuous expansion of plantation area, the risk of biotic and abiotic stress faced by Eucalyptus has significantly increased. Endoplasmic reticulum (ER) stress is an important organelle stress response mechanism formed during the evolution of eukaryotes, which plays a key role in maintaining protein homeostasis within cells and resisting adverse environments. The EgrUTr1 gene was successfully cloned from E. grandis. The full-length coding sequence (CDS) of EgrUTr1 is 1 023 bp encoding a putative transmembrane protein of 340 amino acids. Subcellular localization analysis confirmed that EgrUTr1 was located in ER. EgrUTr1 was expressed in all tissues of E. grandis, and its expression was significantly upregulated under the induction of ER stress inducers dithiothreitol (DTT) and tunicamycin (TM). Heterologous expression of EgrUTr1 in the model plant Arabidopsis thaliana significantly enhanced the plant resistance to TM stress, indicating that EgrUTr1 might be involved in the ER stress response pathway and play an important regulatory role in the process of plants responding to ER stress. These would provide important clues for further understanding the molecular mechanism of ER stress response in E. grandis.
