Expression of somatotropin in plant seeds

Abstract

The present invention provides a method of preparing somatotropins in plants and transgenic plant seeds containing somatotropins. The method provides an economical way to produce somatotropins.

We claim:  
     
         1 . A method for the expression of a somatotropin in plants said method comprising: 
 (a) introducing into a plant cell a chimeric nucleic acid sequence comprising: 
 (1) a first nucleic acid sequence capable of regulating the transcription in said host cell of  
 (2) a second nucleic acid sequence, wherein said second sequence encodes a recombinant fusion polypeptide and comprises (i) a nucleic acid sequence encoding a sufficient portion of an oleosin protein to provide targeting of the recombinant fusion polypeptide to a lipid phase, linked in frame to (ii) a nucleic acid sequence encoding said somatotropin; and  
 (3) a third DNA sequence encoding a termination region functional in said plant cell; and  
   (b) growing said plant cell to produce said recombinant fusion polypeptide.    
     
     
         2 . The method according to  claim 1  further including separating the recombinant fusion polypeptide from cellular host cell components by selective partitioning into a lipid phase.  
     
     
         3 . The method according to  claim 1  further including separating the recombinant fusion polypeptide from cellular host components by selective partitioning into a lipid phase comprising oil bodies.  
     
     
         4 . The method according to  claim 3  wherein said recombinant fusion polypeptide is separated by addition of oil body components and reconstitution of the oil bodies.  
     
     
         5 . A method according to  claim 1  wherein said somatotropin is a fish growth hormone.  
     
     
         6 . A method according to  claim 5  wherein said fish growth hormone is carp growth hormone.  
     
     
         7 . A chimeric nucleic acid sequence encoding a recombinant fusion polypeptide comprising (i) a nucleic acid sequence encoding a sufficient portion of an oleosin protein to provide targeting of the recombinant fusion polypeptide to a lipid phase, linked in reading frame to (ii) a nucleic acid sequence encoding a somatotropin.  
     
     
         8 . A chimeric nucleic acid sequence according to  claim 7  having the nucleic acid sequence shown in SEQ.ID.NO.:1.  
     
     
         9 . A chimeric nucleic acid sequence, capable of being expressed in association with an oil body of a plant cell, comprising: 
 (1) a first nucleic acid sequence capable of regulating the transcription in said plant cell    (2) a second nucleic acid sequence, wherein said second sequence encodes a recombinant fusion polypeptide and comprises (i) a nucleic acid sequence encoding a sufficient portion of an oleosin protein to provide targeting of the recombinant fusion polypeptide to a lipid phase, linked in reading frame to (ii) a nucleic acid sequence encoding a somatotropin; and    (3) a third nucleic acid sequence encoding a termination region functional in said host cell.    
     
     
         10 . A chimeric nucleic acid sequence according to  claim 9  wherein said somatotropin is a fish growth hormone.  
     
     
         11 . A chimeric nucleic acid sequence according to  claim 10  wherein said fish growth hormone is carp growth hormone.  
     
     
         12 . A plant transformed with a chimeric nucleic acid sequence according to  claim 9 .  
     
     
         13 . A plant according to  claim 10  wherein said plant is selected from the group comprising rapeseed (Brassica spp.), linseed/flax ( Linum usitatissimum ), safflower ( Carthamus tinctorius ), sunflower ( Helianthus annuus ), maize ( Zea mays ), soybean ( Glycine max ), mustard (Brassica spp. and  Sinapis alba ), crambe, ( Crambe abyssinica ), eruca ( Eruca sativa ), oil palm ( Elaeis guineeis ), cottonseed (Gossypium spp.), groundnut ( Arachis hypogaea ), coconut ( Cocus nucifera ), castor bean ( Ricinus communis ), coriander ( Coriandrum sativum ), squash, ( Cucurbita maxima ), Brazil nut ( Bertholletia excelsa ) and jojoba ( Simmondsia chinensis ).  
     
     
         14 . A plant seed containing a chimeric nucleic acid sequence according to  claim 9 .  
     
     
         15 . A plant seed according to  claim 14  wherein said seed is obtained from a dicotelydenous plant.  
     
     
         16 . A plant seed according to  claim 14  wherein said somatotropin is expressed in the embryogenic tissue of the seed.  
     
     
         17 . A plant seed comprising a recombinantly expressed somatotropin.  
     
     
         18 . A plant seed according to  claim 17  wherein said somatotropin is expressed as a fusion protein.  
     
     
         19 . A plant seed according to  claim 18  wherein said fusion protein comprises an oleosin.  
     
     
         20 . A plant seed according to  claim 17  wherein said somatotropin is expressed in the embryogenic tissue of said seed.  
     
     
         21 . A plant seed according to  claim 19  wherein said somatotropin is expressed in the embryogenic tissue of said seed.  
     
     
         22 . A plant seed according to  claim 21  wherein said somatotropin is fish growth hormone.  
     
     
         23 . A plant seed according to  claim 18  wherein said plant seed is obtained from a dicotelydenous plant.  
     
     
         24 . A plant seed according to  claim 18  wherein said seed is exalbuminous seed.  
     
     
         25 . A plant seed according to  claim 18  wherein said plant seed is obtained from the group of plants comprising rapeseed (Brassica spp.), linseed/flax ( Linum usitatissimum ), safflower ( Carthamus tinctorius ), sunflower ( Helianthus annuus ), maize ( Zea mays ), soybean ( Glycine max ), mustard (Brassica spp. and  Sinapis alba ), crambe, ( Crambe abyssinica ), eruca ( Eruca sativa ), oil palm ( Elaeis guineeis ), cottonseed (Gossypium spp.), groundnut ( Arachis hypogaea ), coconut ( Cocus nucifera ), castor bean ( Ricinus communis ), coriander ( Coriandrum sativum ), squash, ( Cucurbita maxima ), Brazil nut ( Bertholletia excelsa ) and jojoba ( Simmondsia chinensis ).  
     
     
         26 . A fusion polypeptide encoded for by a chimeric nucleic acid sequence comprising (i) a nucleic acid sequence encoding a sufficient portion of an oil body protein to provide targeting of the fusion polypeptide to an oil body linked in reading frame to (ii) a nucleic acid sequence encoding a somatotropin.  
     
     
         27 . A fusion polypeptide comprising a somatotropin linked to an oil body protein.  
     
     
         28 . A fusion polypeptide according to  claim 27  having the sequence shown in SEQ.ID.NO.:2.  
     
     
         29 . A fusion polypeptide according to  claim 27  wherein said somatotropin is biologically active.