Protein O-glycosylation regulates diverse processes in plants.

Posttranslational modification affects protein functions and decisively control biological phenomena. Plants have unique types of O-glycosylation that are different from those of animals or prokaryotes. O-glycosylation in plants has a role in modulating the function of secretory proteins or nucleocytoplasmic proteins by regulating transcription and mediating localization and degradation. O-glycosylation is complex because of the dozens of different O-glycan types, widespread existence of hydroxyproline (Hyp), serine (Ser) and threonine (Thr) residues in proteins attached by O-glycans, and variable modes of linkages connecting the sugars. Thus, O-glycosylation specifically interferes with development and environmental acclimatization by affecting diverse physiological processes. This review describes recent studies on the detection and function of protein O-glycosylation in plants, which provides the framework of an O-glycosylation network underlying plant development and resistance.