SUMOylation in plants is associated with biotic and abiotic stress responses, flowering, and other aspects of development. ICE1 protein SUMOylation by the SUMO E3 ligase SIZ1 plays important roles in plant cold tolerance. Here, we reported the subcellular localization of EcaICE1 and its interaction with EcaSIZ1 in Eucalyptus camaldulensis. The genes EcaICE1 and EcaSIZ1 were isolated by homologous cloning. The subcellular localization analysis showed that EcaICE1 was located in nucleus. Bimolecular fluorescence complementation (BiFC) analysis revealed that EcaICE1 could interact with EcaSIZ1 in the nucleus of Nicotiana benthamiana leaves. Moreover, yeast two-hybrid assay confirmed that the amino acid region from position 84 to 126 in EcaICE1 was critical for the strong transactivation activity of EcaICE1 and that the C-terminal region from position 361 to 557 in EcaICE1 was the key region for its interaction with EcaSIZ1 using different truncated lengths of non-transactivation activity of EcaICE1 as the bait protein. Collectively, our results showed that EcaICE1 may have a SUMOylation pathway similar to Arabidopsis thaliana.

植物中的SUMO化与生物和非生物胁迫反应，开花以及发育的其他方面有关。SUMO E3连接酶SIZ1对ICE1蛋白的SUMO酰化作用在植物耐寒性中起重要作用。在这里，我们报道了桉树中EcaICE1的亚细胞定位及其与EcaSIZ1的相互作用。通过同源克隆分离了基因EcaICE1和EcaSIZ1。亚细胞定位分析表明，EcaICE1位于细胞核中。双分子荧光互补（BiFC）分析表明，EcaICE1可以与本氏烟草核中的EcaSIZ1相互作用。树叶。此外，酵母双杂交试验证实，EcaICE1中84-126位的氨基酸区域对EcaICE1的强反式激活活性至关重要，EcaICE1中361-557位的C端区域是其相互作用的关键区域用EcaSIZ1使用截短长度的EcaICE1的非反式激活活性作为诱饵蛋白。总的来说，我们的结果表明EcaICE1可能具有类似于拟南芥的SUMOylation途径。