Golgi‐localised manganese transporter PML3 regulates Arabidopsis growth through modulating Golgi glycosylation and cell wall biosynthesis

• Published in: The New phytologist Vol. 231; no. 6; pp. 2200 - 2214
• Main Authors: Yang, Chang‐Hong, Wang, Chao, Singh, Somesh, Fan, Ni, Liu, Shuo, Zhao, Li, Cao, Hengliang, Xie, Wenxiang, Yang, Chengwei, Huang, Chao‐Feng
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.09.2021
• Subjects: Alleles; Arabidopsis; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Biosynthesis; Cation Transport Proteins - metabolism; cell wall; Cell Wall - metabolism; Cell walls; Detoxification; Glycosylation; Golgi Apparatus - metabolism; Golgi glycosylation; Hypersensitivity; Manganese; Manganese - metabolism; manganese transporter; manganese utilisation; Mutants; Mutation; Plant growth; PML3; Proteins; Transport; Uptake; Yeasts; Arabidopsis thaliana; PML3; manganese utilisation; cell wall; manganese transporter; Golgi glycosylation
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.17209

Summary Golgi is a critical compartment for both the reutilisation of the essential micronutrient manganese (Mn) and its detoxification. However, whether Mn plays a role in the Golgi remains to be demonstrated in plants. We characterised the function of PML3, a member of the Unknown Protein Family UPF0016, in Mn transport and the regulation of plant growth, Golgi glycosylation and cell wall biosynthesis in Arabidopsis. We also investigated the relationship of PML3 with NRAMP2, a trans‐Golgi network localised Mn transporter. PML3‐GFP is preferentially localised in the cis‐Golgi. PML3 can transport Mn to rescue the hypersensitivity of yeast mutant Δpmr1 to excess Mn. Two mutant alleles of PML3 displayed reduced plant growth and impaired seed development under Mn‐deficient conditions. The pml3 mutants also showed impaired Golgi glycosylation and cell wall biosynthesis under Mn deficiency. Double mutations of PML3 and NRAMP2 showed improved plant growth compared with that of single mutants under Mn deficiency, implying that PML3 and NRAMP2 play opposite roles in the regulation of Golgi Mn levels. Our results suggest that PML3 mediates Mn uptake into the Golgi compartments, which is required for proper protein glycosylation and cell wall biosynthesis under Mn‐deficient conditions. See also the Commentary on this article by Thomine & Merlot, 231: 2107–2109.