Table I.

Estimated size of lipid metabolism gene families in Arabidopsis and rice deduced from analysis of available sequences1-a

Gene Product ArabidopsisRice
MinMaxMinMax
Glycerolipid biosynthesis enzymes and proteins
 1. ACCases (EC 6.4.1.2)
  1a. Homomeric acetyl-CoA carboxylase2212
  1b. Heteromeric acetyl-CoA carboxylase BC subunit1100
  1c. Heteromeric acetyl-CoA carboxylase BCCP subunit2200
  1d. Heteromeric acetyl-CoA carboxylase α-CT subunit1100
  1e. Heteromeric acetyl-CoA carboxylase β-CT subunit1100
 2. Acyl carrier proteins (ACP)
   Plastidial isoforms5555
   Mitochondrial isoforms3311
 3. Malonyl-CoA:ACP transacylase (EC2.3.1.39)11n.d.1-b n.d.
 4. Ketoacyl-ACP synthase (KAS) (EC 2.3.1.41)
   4a. KAS I1111
   4b. KAS II1111
   4c. KAS III1111
   4d. Putative mitochondrial KAS11n.d.n.d.
 5. Ketoacyl-ACP reductase (EC1.1.1.100)11n.d.n.d.
 6. 3-hydroxyacyl-ACP dehydrase (EC4.2.1.17)22n.d.n.d.
 7. Enoyl-ACP reductase (EC1.3.1.44)11n.d.n.d.
 8. Stearoyl-ACP desaturase (EC 1.14.99.6)4449
 9. Acyl-ACP thioesterase (EC 3.1.2.14)
  9a. FatA2211
  9b. FatB1123
 10. Glycerol-3-phosphate acyltransferase (EC2.3.1.15)11n.d.n.d.
 11. 1-Acyl-sn-glycerol-3-phosphate acyltransferase (EC2.3.1.51)11n.d.n.d.
 12. Plastidial cytidine-5′-diphosphate-diacylglycerol synthase (EC2.7.7.41)Unknown
 13. Plastidial phosphatidylglycerophosphate synthase (EC 2.7.8.5)4411
 14. Plastidial phosphatidylglycerol-3-phosphate phosphatase (EC3.1.3.27)Unknown
 15. Phosphatidylglycerol desaturase (palmitate specific) (FAD4) (EC 1.14.99.-)Unknown
 16. Plastidial oleate desaturase (FAD6) (EC 1.14.99.-)1111
 17. Plastidial linoleate desaturase (FAD7/FAD8)(EC 1.14.99.-)22n.d.n.d.
 18. Plastidial phosphatidic acid phosphatase (EC3.1.3.4)n.d.n.d.n.d.n.d.
 19. Monogalactosyldiacylglycerol synthase (EC 2.4.1.46)3313
 20. Monogalactosyldiacylglycerol desaturase (palmitate-specific) (FAD5) (EC 1.14.99.-)Unknown
 21. Digalactosyldiacylglycerol synthase (EC 2.4.1.184)1222
 22. Sulfolipid biosynthesis protein1111
 23. Long-chain acyl-CoA synthetase (EC 6.2.1.3)1825518
 24. ER glycerol-3-phosphate acyltransferase (EC2.3.1.15)Unknown
 25. ER 1-acyl-sn-glycerol-3-phosphate acyltransferase (EC2.3.1.51)4411
 26. ER phosphatidic acid phosphatase (EC 3.1.3.4)2244
 27. Diacylglycerol cholinephosphotransferase (EC 2.7.8.2)2212
 28. ER oleate desaturase (FAD2) (EC 1.14.99.-)1112
 29. ER linoleate desaturate (FAD3) (EC 1.14.99.-)1112
 30. ER cytidine-5′-diphosphate-diacylglycerol synthase (EC2.7.7.41)5523
 31. ER phosphatidylglycerophosphate synthase (EC 2.7.8.5)15n.d.n.d.
 32. ER phosphatidylglycerol-3-phosphate phosphatase (EC3.1.3.27)Unknown
 33. Phosphatidylinositol synthase (EC 2.7.8.11)3312
 34. Acyl-CoA:diacylglycerol acyltransferase (EC2.3.1.20)1111
Other enzymes and proteins involved in lipid metabolism
 Acyl-ACP desaturases other than stearoyl-ACP desaturase (EC 1.14.99.-)No indication of presence
 Related to linoleoyl desaturase (EC 1.14.99.-)No indication of presence
 Δ8 Sphingolipid desaturase (EC 1.14.99.-)22n.d.n.d.
 Oleate 12-hydroxylaseNo indication of presence
 Bifunctional oleate 12-hydroxylase:desaturaseNo indication of presence
 Δ12 Fatty acid acetylenaseNo indication of presence
 Δ12 Fatty acid epoxygenaseNo indication of presence
 Diacylglycerol kinase (EC 2.7.1.107)8911
 Cholinephosphate cytidylyltransferase (EC2.7.7.15)5513
 Similar to acyl-CoA desaturase (EC 1.14.99.-)56n.d.n.d.
 Choline kinase (EC 2.7.1.32)7924
 Phospholipase C (EC3.1.4.11)101135
 Phospholipase D (EC3.1.4.4)172059
 Phosphatidylserine decarboxylase (EC 4.1.1.65)22n.d.n.d.
 Phosphatidylinositol-3-kinase (EC 2.7.1.137)1111
 Phosphatidylinositol-4-kinase (EC 2.7.1.67)3322
 Ketoacyl-CoA synthase (KCS)212648
 3-Ketoacyl reductase (involved in wax biosynthesis)3323
 Wax synthase99n.d.n.d.
 Possible aldehyde decarbonylase CER1 involved in wax biosynthesis2211
 Putative transcription factor CER2 involved in wax biosynthesis2211
 CER3 protein involved in wax biosynthesis1112
 Oleosin7656
 3-Ketoacyl-CoA thiolase (EC2.3.1.16)7757
 Acyl-CoA dehydrogenase (EC1.3.99.3)3326
 Enoyl-CoA hydratase (EC4.2.1.17)11n.d.n.d.
 Acyl-CoA oxidase (EC 1.3.3.6)5524

Plant enzymes and proteins searched in GenBank, dbEST, and Arabidopsis Database (AtDB), Stanford University.

    • F1-a Gene number estimates are based on the results of multiple alignment of homologous amino acid and nucleotide sequences. The minimal number refers to the number of distinct sequences with overlapping regions. The maximal number refers to non-overlapping sequences and contigs and thus shows only the potential number of genes.

    • F1-b n.d., Not detected.