Vitamin E in Plants: Biosynthesis, Transport, and Function

• Published in: Trends in plant science 2019-11, Vol.24 (11), p.1040-1051
• Main Authors: Muñoz, Paula, Munné-Bosch, Sergi
• Format: Article
• Language: English
• Subjects: Antioxidants; Biosynthesis; Chlorophyll; Chloroplasts; Environmental stress; Free radicals; Lipid bilayers; Lipid peroxidation; Lipids; Peroxidation; Plants (botany); Protein biosynthesis; retrograde signaling; Tocopherol; Tocopherols; Tocotrienols; Tomatoes; Transport; Vitamin E
• ISSN: 1360-1385; 1878-4372
• DOI: 10.1016/j.tplants.2019.08.006

Vitamin E, which includes both tocopherols and tocotrienols, comprises lipid-soluble antioxidants that modulate lipid peroxidation. Recently, significant advances have been made in our understanding of vitamin E biosynthesis, transport, and function. The phytyl moiety from chlorophyll degradation is used for tocopherol biosynthesis. An α-tocopherol-binding protein (TBP) has been identified in tomato (SlTBP) serving in intraorganellar vitamin E transport in plants. Moreover, α-tocopherol not only scavenges free radicals through flip-flop movements in the lipid bilayer, but may also contribute to fine-tuning the transmission of specific signals outside chloroplasts. Vitamin E, and α-tocopherol in particular, appear to be essential for plant development and help to provide the most suitable response to a number of environmental stresses. α-Tocopherol is a lipophilic antioxidant synthesized from the methylerythritol and shikimate pathways in chloroplasts that modulate the extent of lipid peroxidation in plants.Increased α-tocopherol content, which is both biochemically and functionally related to chlorophyll loss, improves photoprotection.The recent discovery of an α-tocopherol-binding protein sheds light on intraorganellar prenyllipid transport in plants.High α-tocopherol content in some nonphotosynthetic tissues poses intriguing questions about the biosynthesis, transport, and function of vitamin E in plants.