RESUMEN
Objective: To investigate the subcellular localization of a sesquiterpene synthase from Aquilaria sinensis (ASS) and compare three transient expression systems in the subcellular localization study. Methods: An ASS gene was amplified by RT-PCR using specific primers and cloned into the pEZS-NL and pFGC5941GFP to generate two plant expression vectors: pEZS-NL-ASS- GFP and p5941-GFP-ASS. Three transient expression systems, agroinfiltration of tobacco leaves, particle bombardment of onion epidermal cells, and PEG transformation of protoplasts isolated from ASS calli were adopted and compared. The expression of the GFP fusion proteins were observed by a confocal laser scanning microscopy. Results: The green fluorescence could be observed in all the three systems. However, the results were comparatively different. The cytoplasm and plastid localization of the GFP fusion protein observed in protoplasts was comparatively clear and was consistent with the studies in other plant species. Conclusion: The results demonstrate that the ASS is located in the cytoplasm and plastid in the ASS protoplasts and the different locations in three systems might be caused by the distinct characters of the heterologous or homologous cells.