Effect of chitooligosaccharides with different degrees of acetylation on wheat seedlings under salt stress

• Chitooligosaccharides (COSs) with different degrees of acetylation (DAs) were firstly applied to investigate the effect on salt-tolerance of plant.
• COS with DA 50% was more effective on alleviating salt stress than those with other DAs.
• Treatment with COS on wheat may modulate intracellular ion concentrations and enhance the antioxidant enzymes activities.

In this study, chitooligosaccharides (COSs) with varying degrees of acetylation (DAs) were applied to wheat seedlings in order to investigate their effect on the plants’ defence response under salt stress. The results showed that treatment with exogenous COSs that had different DAs could promote the growth of plants, decrease the concentration of malondialdehyde (MDA), improve the photosynthetic efficiency and enhance the activities of antioxidant enzymes. The mRNA expression level examination of several salt stress response genes suggested that COS could protect plants from the damage of salt stress by adjusting intracellular ion concentration and enhancing the activities of antioxidant enzymes. Furthermore, COS with DA 50% was the most effective in alleviating salt stress to wheat seedlings, which indicated that the activity of COS was closely related with its DAs.