Physiological function analysis of multistep N-glycosylation in Arabidopsis
Chuanfa Liu, Guanting Niu, Shan Lu, Zhi Hong*

School of Life Sciences, Nanjing University, Nanjing 210093.
*Corresponding Author：Tel: (+8625) 84530931; E-mail: zhihong@nju.edu.cn

Abstract
Asparagine (Asn/N)-linked glycosylation is an important post-translational modification. It’s multiple steps and consists of lipid-linked glycan biosynthesis on ER membrane, transfer of glycan to the conserved glycosylation site, and the maturation of glycan in the Golgi apparatus. Recently, several studies have shown that a highly conserved N-glycosylation process also exists in plant cells. However, little is known about the biological function of each step during the glycosylation. In the present study, we collect mutants that defect at the different step during glycosylation, respectively. The preliminary analysis showed all mutants have no obvious growth defects compared to wild-type plants under normal growth condition. Interestingly, significant arrests of root-growth and swellings of root tips are observed in mutants aberrant in glycan transfer or glycan maturation when they are grown on the medium containing high dose of salinity, indicating N-glycan modification and maturation might be crucial for the activity of functional proteins involved in adaptive responses to salt stress. The detailed genetic and biochemical analysis is ongoing to study the expression and function of N-glycosylation-dependent protein RSW2 under the distinct mutant backgrounds. The results will supply us the insight on the role of N-glycosylation in plant cell in response to environmental stress.

Key Words: N-glycosylation; salt stress; root development; Arabidopsis