skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Lipid transport mediated by Arabidopsis TGD proteins is unidirectional from the endoplasmic reticulum to the plastid

Abstract

The transfer of lipids between the endoplasmic reticulum (ER) and the plastid in Arabidopsis involves the TRIGALACTOSYLDIACYLGLYCEROL (TGD) proteins. Lipid exchange is thought to be bidirectional based on the presence of specific lipid molecular species in Arabidopsis mutants impaired in the desaturation of fatty acids of membrane lipids in the ER and plastid. However, it was unclear whether TGD proteins were required for lipid trafficking in both directions. This question was addressed through the analysis of double mutants of tgd1-1 or tgd4-3 in genetic mutant backgrounds leading to a defect in lipid fatty acid desaturation either in the ER (fad2) or the plastid (fad6). The fad6 tgd1-1 and fad6 tgd4-3 double mutants showed drastic reductions in the relative levels of polyunsaturated fatty acids and of galactolipids. The growth of these plants and the development of photosynthetic membrane systems were severely compromised, suggesting a disruption in the import of polyunsaturated fatty acid-containing lipid species from the ER. Furthermore, a forward-genetic screen in the tgd1-2 dgd1 mutant background led to the isolation of a new fad6-2 allele with a marked reduction in the amount of digalactosyldiacylglycerol. In contrast, the introduction of fad2, affecting fatty acid desaturation of lipids in the ER, intomore » the two tgd mutant backgrounds did not further decrease the level of fatty acid desaturation in lipids of extraplastidic membranes. These results suggest that the role of TGD proteins is limited to plastid lipid import, but does not extend to lipid export from the plastid to extraplastidic membranes.« less

Authors:
; ;
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
BNL-OFFICE OF INTELLECTUAL PROPERTY
OSTI Identifier:
1015130
Report Number(s):
BNL-90636-2010-JA
Journal ID: ISSN 0032-0781; R&D Project: R-09-009; TRN: US201111%%495
DOE Contract Number:  
DE-AC02-98CH10886
Resource Type:
Journal Article
Journal Name:
Plant Cell Physiology
Additional Journal Information:
Journal Volume: 51; Journal Issue: 6; Journal ID: ISSN 0032-0781
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; ARABIDOPSIS; CARBOXYLIC ACIDS; DEFECTS; ENDOPLASMIC RETICULUM; EXPORTS; GENETICS; IMPORTS; LIPIDS; MEMBRANES; MUTANTS; PHOTOSYNTHETIC MEMBRANES; PROTEINS; SCREENS; TRANSPORT

Citation Formats

Xu, C, Moellering, E. R., Muthan, B., Fan, J, and Benning, C. Lipid transport mediated by Arabidopsis TGD proteins is unidirectional from the endoplasmic reticulum to the plastid. United States: N. p., 2010. Web. doi:10.1093/pcp/pcq053.
Xu, C, Moellering, E. R., Muthan, B., Fan, J, & Benning, C. Lipid transport mediated by Arabidopsis TGD proteins is unidirectional from the endoplasmic reticulum to the plastid. United States. https://doi.org/10.1093/pcp/pcq053
Xu, C, Moellering, E. R., Muthan, B., Fan, J, and Benning, C. 2010. "Lipid transport mediated by Arabidopsis TGD proteins is unidirectional from the endoplasmic reticulum to the plastid". United States. https://doi.org/10.1093/pcp/pcq053.
@article{osti_1015130,
title = {Lipid transport mediated by Arabidopsis TGD proteins is unidirectional from the endoplasmic reticulum to the plastid},
author = {Xu, C and Moellering, E. R., Muthan, B. and Fan, J and Benning, C},
abstractNote = {The transfer of lipids between the endoplasmic reticulum (ER) and the plastid in Arabidopsis involves the TRIGALACTOSYLDIACYLGLYCEROL (TGD) proteins. Lipid exchange is thought to be bidirectional based on the presence of specific lipid molecular species in Arabidopsis mutants impaired in the desaturation of fatty acids of membrane lipids in the ER and plastid. However, it was unclear whether TGD proteins were required for lipid trafficking in both directions. This question was addressed through the analysis of double mutants of tgd1-1 or tgd4-3 in genetic mutant backgrounds leading to a defect in lipid fatty acid desaturation either in the ER (fad2) or the plastid (fad6). The fad6 tgd1-1 and fad6 tgd4-3 double mutants showed drastic reductions in the relative levels of polyunsaturated fatty acids and of galactolipids. The growth of these plants and the development of photosynthetic membrane systems were severely compromised, suggesting a disruption in the import of polyunsaturated fatty acid-containing lipid species from the ER. Furthermore, a forward-genetic screen in the tgd1-2 dgd1 mutant background led to the isolation of a new fad6-2 allele with a marked reduction in the amount of digalactosyldiacylglycerol. In contrast, the introduction of fad2, affecting fatty acid desaturation of lipids in the ER, into the two tgd mutant backgrounds did not further decrease the level of fatty acid desaturation in lipids of extraplastidic membranes. These results suggest that the role of TGD proteins is limited to plastid lipid import, but does not extend to lipid export from the plastid to extraplastidic membranes.},
doi = {10.1093/pcp/pcq053},
url = {https://www.osti.gov/biblio/1015130}, journal = {Plant Cell Physiology},
issn = {0032-0781},
number = 6,
volume = 51,
place = {United States},
year = {Tue Jun 01 00:00:00 EDT 2010},
month = {Tue Jun 01 00:00:00 EDT 2010}
}