Production of polyhydroxyalkanoate in plants

Abstract

The invention relates to the genetic manipulation of plants to produce polyhydroxyalkanoate, particularly in the peroxisomes. Methods for producing such polymers in plants and host cells are provided. Such methods find use in producing biodegradable thermoplastics in plants and other organisms. Nucleotide molecules, expression cassettes, and genetically manipulated host cell, plants, plant tissues, and seeds are also provided.

1 . A plant genetically manipulated to produce polyhydroxyalkanoate in its peroxisomes, said plant comprising in its genome: 
 a stably integrated first DNA construct comprising a promoter that drives expression in a plant cell operably linked to a first coding sequence, wherein said first coding sequence encodes a polyhydroxyalkanoate synthase and is operably linked to a nucleotide sequence encoding a peroxisome-targeting signal;    a stably integrated second DNA construct comprising a promoter that drives expression in a plant cell operably linked to a second coding sequence, wherein said second coding sequence encodes an acetyl-CoA:acetyl transferase and is operably linked to a nucleotide sequence encoding a peroxisome-targeting signal; and    a stably integrated third DNA construct comprising a promoter that drives expression in a plant cell operably linked to a third coding sequence, wherein said third coding sequence is operably linked to a nucleotide sequence encoding a peroxisome-targeting signal and said third coding sequence is selected from the group consisting of: 
 (a) a nucleotide sequence encoding a 3-ketoacyl-CoA reductase that is capable of utilizing NADH;  
 (b) a nucleotide sequence set forth in SEQ ID NO: 3;  
 (c) a nucleotide sequence set forth in SEQ ID NO: 22;  
 (d) the nucleotide sequence set forth in SEQ ID NO: 1;  
 (e) a nucleotide sequence encoding a multifunctional protein-2, wherein the hydratase activity of said multifunctional protein has been eliminated; and  
 (f) the nucleotide sequence set forth in SEQ ID NO: 6.  
 capable of catalyzing the synthesis of polyhydroxyalkanoate copolymers.  
   
     
     
         2 . The plant of  claim 1 , wherein said second coding sequence comprises at least a portion of the nucleotide sequence set forth in SEQ ID NO: 24.