N-Glycosylation is Important for Root Growth Under Alkaline Stress by Involving Auxin Transport and Proton Efflux

Abstract

Summary Asparagine (N)-linked glycosylation is a major modification of glycoproteins, and then class I α-mannosidases (MNS) are involved in early N-glycan processing which play crucial roles in root growth and stress response. However, their roles in alkaline stress are unclear. Using the α-mannosidases deficient Arabidopsis lines, we found that the root growth inhibition in mns1 mns2 mns3 were partially rescued under alkaline condition. N-glycoproteomic analysis revealed that N-glycoproteins associated with auxin action were changed by alkaline stress. Our previous studies have linked the alkaline adaptation of Arabidopsis to auxin transport and proton extrusion. Consistently, conversion of proton flux from inward to outward and inhibition of root growth by auxin transport inhibitor indicated the impacts of proton extrusion and auxin transport on alkaline-maintained root growth in mns1 mns2 mns3. Therefore, we suggested that N-glycosylation is important for root growth under alkaline stress probably by involving auxin transport and proton efflux.