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Biochemical and Molecular-Genetic Characterization of SFD1’s Involvement in Lipid Metabolism and Defense Signaling

By Katarzyna Lorenc-Kukula, Ratnesh Chaturvedi, Mary Roth, Ruth Welti and Jyoti Shah


The Arabidopsis thaliana SFD1 (suppressor of fatty acid desaturase deficiency1) gene (also known as GLY1) is required for accumulation of 34:6 (i.e., 18:3–16:3) monogalactosyldiacylglycerol (MGDG) and for the activation of systemic acquired resistance (SAR), an inducible defense mechanism that confers resistance against a broad spectrum of pathogens. SFD1, which has been suggested to be involved in lipid-based signaling in SAR, contains a putative chloroplast transit peptide and has glycerol-3-phosphate synthesizing dihydroxyacetone phosphate (DHAP) reductase (also referred as glycerol-3-phosphate dehydrogenase) activity. The goals of this study were to determine if the DHAP reductase activity and chloroplast localization are required for SFD1’s involvement in galactolipid metabolism and SAR signaling. The crystal structure of a Leishmania mexicana glycerol-3-phosphate dehydrogenase was used to model SFD1 structure and identify Lys194, Lys279, and Asp332 as potential catalytic site residues in SFD1. Mutational analysis of SFD1 confirmed that Lys194, Lys279, and Asp332 are critical for SFD1’s DHAP reductase activity, and its involvement in SAR. SFD1 proteins with these residues individually substituted by Ala lacked DHAP reductase activity and were unable to complement the SAR defect of the sfd1 mutant. The SFD1–Ala279 protein was also unable to restore 34:6-MGDG content when expressed in the sfd1 mutant. In vivo imaging of a green fluorescent protein-tagged SFD1 protein demonstrated that SFD1 is targeted to the chloroplast. The N-terminal 43 amino acids, which are required for proper targeting of SFD1 to the chloroplast, are also required for SFD1’s function in lipid metabolism and SAR. Taken together, these results demonstrate that SFD1’s DHAP reductase activity is required in the chloroplast for lipid metabolism and defense signaling

Topics: Plant Science
Publisher: Frontiers Research Foundation
OAI identifier: oai:pubmedcentral.nih.gov:3355749
Provided by: PubMed Central
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    1. (1991). A human nuclear uracil DNA glycosylase is the 37-kDa subunit of glyceraldehyde3-phosphate dehydrogenase.
    2. (1998). A new class of Arabidopsis mutants with reduced hexadecatrienoic acid fatty acid levels.
    3. (2000). A potential target enzyme for trypanocidal drugs revealed by the crystal structure of NAD-dependent glycerol3-phosphate dehydrogenase from Leishmania mexicana.
    4. and Shah,J.(2008).Plastidomega3-fatty acid desaturase-dependent accumulation of a systemic acquired resistance inducing activity in petiole exudates of Arabidopsis thaliana is independent of jasmonic acid.
    5. (2008). Association of Plastid Lipid Metabolism with the ActivationofSystemicAcquiredResistance in Arabidopsis thaliana.
    6. (2004). Bifunctional and moonlighting enzymes: lighting the way to regulatory control.
    7. (2012). Biochemical and molecular-genetic characterization of SFD1’s involvement in lipid metabolism and defense signaling.
    8. (2010). Chloroplast proteomics highlights the subcellular compartmentation of lipid metabolism.
    9. (1988). Dihydroxyacetone phosphate reductases in plants.
    10. (2009). Fatty acid-derived signals in plant defense.
    11. (2005). Ferredoxin-dependent glutamate synthase moonlights in plant sulfolipid biosynthesis forming a complex with SQD1.
    12. (1998). Floral dip: a simplified method for Agrobacterium-mediated transformationofArabidopsisthaliana.Plant
    13. (2003). Gateway cloning vector set for high-throughput functional analysis of genes in planta.
    14. (2011). Glycerol-3-phosphate is a critical mobile inducer of systemic immunity in plants.
    15. (2008). Glycerol-3-phosphate levels are associated with basal resistance to the hemibiotrophic fungus Colletotrichum higginsianum in Arabidopsis. Plant Physiol.
    16. (2003). Identification of a mitochondrial glycerol-3-phosphatedehydrogenasefromArabidopsis thaliana: evidence for a mitochondrialglycerol-3-phosphate shuttle in plants.
    17. (2006). Involvement of a glycerol-3-phosphate dehydrogenase in modulating the NADH/NAD+ ratio provides evidence of a mitochondrial glycerol-3-phosphate shuttle in Arabidopsis.
    18. (2003). Leishmania mexicana glycerol-3-phosphate dehydrogenase showed conformational changes upon binding a bisubstrate adduct.
    19. (2008). Longdistance signalling in plant defence.
    20. (2001). Molecular and biochemical characterizations of a plastidic glycerol3-phosphate dehydrogenase from Arabidopsis. Plant Physiol.
    21. (1999). Moonlighting proteins.
    22. (1974). Mutants of Escherichia coli defective in membrane phospholipid synthesis: mapping of the structural gene for L-glycerol 3-phosphate dehydrogenase.
    23. (2004). Oleic acid levels regulated by glycerolipid metabolismmodulatedefensegeneexpression in Arabidopsis.
    24. (2012). Plant plastidic DHAP reductase
    25. (2005). Premature leaf senescence modulated by the Arabidopsis thaliana PAD4 gene is associated with defense against the phloem-feeding green peach aphid.
    26. (2009). Priming in systemic plant immunity.
    27. (1987). Single-stepmethodofRNAisolation by acid guanidinium thiocyanatephenol-chloroformextraction.Anal.
    28. (2008). Systemic acquired resistance: the elusive signal(s).
    29. (2002). Systemic acquired resistance.
    30. (2004). The Arabidopsis thaliana dihydroxyacetone phosphate reductase gene SUPPRESSOR OF FATTY ACID DESATURASE DEFICIENCY1 is required for glycerolipid metabolism and for the activation of systemic acquired resistance.
    31. (2006). The SWISSMODEL Workspace: a web-based environment for protein structure homologymodelling.Bioinformatics 22,
    32. Thilmony,R.,He,S.-Y.,andZhou,J.-M.(2003).InterplayoftheArabidopsis non-host resistance gene NHO1 with bacterial virulence.

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