A comparison study on the interactions of two oligosaccharides with tobacco cells by time-resolved fluorometric method.

The interactions of tobacco cells with two oceanic oligosaccharides, chitosan oligosaccharide (COS) and alginate derived oligosaccharide (AOS) were investigated and compared by time-resolved fluorometric method using two Eu(3+) complexes as luminescence probes. The binding processes of two oligosaccharides and tobacco leaf cells (epidermal and stomatal guard cells) were characterized by the luminescence imaging method based on the reaction of tobacco cells with oligosaccharide (COS or AOS) conjugated to a highly fluorescent Eu(3+) complex. In addition, the concentration changes of indole-3-acetic acid (IAA) and IAA-related peroxidase produced in the cells during the interaction of oligosaccharides (COS or AOS) and tobacco cells were also determined. The results indicate that the bioactivity of COS, with faster binding rate to the tobacco cells and stronger effect on the IAA generation in the cells, is remarkably higher than that of AOS. The comparison study on bioactivities of the two oligosaccharides reveals the relationship between structures and bioactivities of oligosaccharide, and suggests that COS should be more favorable to be used as a promotion reagent of plant growth in agriculture field.