Increasing plant oil content by improving activity of acetyl coa carboxylase

Abstract

The present invention provides a method and means to change fatty acid and ultimately triacylglycerol production in plants and algae. Methods of the invention comprise the step of altering the activity levels of the committed step for de novo fatty acid biosynthesis, acetyl-CoA carboxylases (ACCase). More specifically, methods of the invention directly enhance the activity of ACCase by overexpression of α-CT or a catalytic portion thereof.

What is claimed is: 
     
         1 . A method of altering fatty acid and/or triacylglycerol production in plants and/or algae, comprising the step of altering activity levels of the committed step for de novo fatty acid biosynthesis, acetyl-CoA carboxylase (ACCase). 
     
     
         2 . The method of  claim 1 , wherein said altering step comprises increasing the activity level of ACCase by increasing expression of alpha-carboxyltransferase (α-CT) or a portion thereof. 
     
     
         3 . The method of  claim 2 , wherein said altering step comprises overexpression of an endogenous α-CT. 
     
     
         4 . The method of  claim 2 , wherein said altering step comprises expression or overexpression of a heterologous α-CT. 
     
     
         5 . The method of  claim 4 , wherein said heterologous α-CT comprises a  Pisum sativum  α-CT (SEQ ID NO:162). 
     
     
         6 . The method of  claim 2 , wherein said altering step comprises overexpression of a catalytic portion of an α-CT. 
     
     
         7 . The method of  claim 6 , wherein said altering step comprises expression or overexpression of a catalytic portion of a heterologous α-CT. 
     
     
         8 . The method of  claim 7 , wherein said catalytic portion of a heterologous α-CT comprises the catalytic portion of a  Pisum sativum  α-CT (SEQ ID NO:164). 
     
     
         9 . The method of  claim 2 , further comprising total or partial silencing of one or more BADC gene. 
     
     
         10 . The method of  claim 9 , wherein said BADC gene comprises genes and gene orthologs of BADC1, BADC2, and BADC3, or artificial genes containing essential BADC motifs. 
     
     
         11 . The method of  claim 10 , wherein said one or more BADC gene comprises from about 34% to about 100% sequence identity to a nucleotide sequence selected from the group consisting of SEQ ID NOs: 2, 4, 6, 7, and 138, or a complement thereof. 
     
     
         12 . The method of  claim 10 , wherein said one or more BADC gene encodes a polypeptide comprising from about 34% to about 100% sequence identity to a polypeptide sequence selected from the group consisting of SEQ ID NOs: 1, 3, 5, 8-137, and 139-143. 
     
     
         13 . The method of  claim 9 , wherein said silencing comprises expression of an RNAi cassette comprising SEQ ID NOs:7 or 138. 
     
     
         14 . The method of  claim 1 , wherein the plant is an  Amborella trichopoda, Arabidopsis lyrata, Arabidopsis alpine, Arachis hypogaea, Auxenochlorella protothecoides, Brassica napus, Brassica rapa, Camelina sativa, Capsella rubella, Cathamus tinctorius, Chlamydomonas reinhardtii, Chlorella variabilis, Cicer arietinum, Citrus clementina, Citrus sinensis, Coccomyxa subellipsoideas  C-169,  Coffea canephora, Cucumis melo, Cucumis sativus, Elaeis guineensis, Erythranthe guttata, Eucalyptus grandis, Eutrema salsugineum, Fragaria vesca, Genlisea aurea, Glycine max, Helianthus annuus, Helicosporidium  ATCC 50920 , Jatropha curcas, Lotus japonicas, Medicago truncatula, Morus notabilis, Musa acuminate, Nelumbo nucifera, Nicotiana sylvestris, Nicotiana tomentosiformis, Phaseolus vulgaris, Pheonix dactylifera, Physcomitrella patens, Picea sitchensis, Polytomella parva, Populus trichocarpa, Prunus mume, Prunes persica, Pyrus  x  bretschneideri, Ricinus communis, Selaginella moellendorffii, Sesamum indicum, Solanum lycopersicum, Solanum tuberosum, Theobroma cacao, Thlaspi arvense, Vitis vinifera , or  Volvox carteri  plant. 
     
     
         15 . The method of  claim 14 , wherein the plant is a  Camelina sativa, Glycine max, Brassica napus  or  Brassica rapa  plant. 
     
     
         16 . A plant or part thereof produced by the method of  claim 1 , wherein the plant produces seed comprising increased seed oil content. 
     
     
         17 . The plant or plant part of  claim 16 , wherein the method of producing the plant or plant part further comprises total or partial silencing of one or more BADC gene. 
     
     
         18 . The plant or plant part of  claim 16 , wherein the plant part is selected from the group consisting of a leaf, pollen, an ovule, a fruit, rootstock, a scion, a flower, and a cell. 
     
     
         19 . A seed that produces the plant of  claim 16 , wherein the seed comprises increased seed oil content. 
     
     
         20 . A tissue culture of regenerable cells of the plant or part thereof of  claim 16 .