Transgenic crop plants with improved stress tolerance

Abstract

Disclosed herein are novel compositions of NF-YB proteins and recombinant DNA for expressing NF-YB proteins that are used to produce transgenic plants with enhanced yield and/or enhanced water deficit stress tolerance.

1 . A plant chromosomal DNA segment comprising a recombinant polynucleotide flanked by native plant DNA, wherein said polynucleotide provides for expression of at least an NF-YB protein and a marker protein, and wherein said NF-YB protein is produced in leaf cells of said plant at a level up to 40 picograms per microgram of total protein in said plant leaf tissue cells.  
     
     
         2 . A plant chromosomal DNA segment comprising a recombinant polynucleotide flanked by native plant DNA, wherein said polynucleotide provides for expression of a single protein, wherein said protein is an NF-YB protein, and wherein said NF-YB protein is produced in leaf cells of said plant at a level up to 40 picograms per microgram of total protein in said plant leaf tissue cells.  
     
     
         3 . A plant chromosomal DNA segment comprising a recombinant DNA construct for expressing an NF-YB protein comprising contiguous amino acids from SEQ ID NO:28, wherein said amino acids include: 
 (a) amino acids at position 49 thorough 122 of SEQ ID NO:28 and wherein one or more amino acids at position number 49, 73, 76, 83, 89, 102, 103, 109, 115, 118 or 122 are different; or    (b) amino acids at position 49 thorough 122 of SEQ ID NO: 28 and wherein one or more amino acids at position number 49, 73, 76, 83, 89, 102, 103, 109, 115, 118 or 122 are different and one or more of amino acids at position 55 through 61 are missing;    (c) amino acids of SEQ ID NO: 28 at position 29 through 134 and one or more of amino acids at position 2 through 28 are missing; or    (d) amino acids of SEQ ID NO: 28 at position 68 through 134 and one or more of amino acids at position 2 through 67 are missing.    
     
     
         4 . A plant chromosomal DNA segment of any of claims  1 - 3  wherein said recombinant polynucleotide comprises a promoter is selected from the group consisting of a rice alpha tubulin promoter, a rice actin promoter, a PPDK mesophyl tissue enhanced promoter, and a rubisco activase bundle sheath enhanced promoter.  
     
     
         5 . A plant chromosomal DNA segment of any of claims  1 - 3  and wherein said NF-YB protein is produced in leaf cells of said plant at a level between 0.1 and 11 picograms per microgram of total protein in said plant leaf tissue cells.  
     
     
         6 . A transgenic plant cell comprising a plant chromosomal DNA segment of any of claims  1 - 3 .  
     
     
         7 . A transgenic crop of water deficit stress tolerant plants comprising cells of  claim 6  wherein the harvested yield of said crop is comparable to or enhanced over the yield of a crop of control plants not having said plant chromosomal DNA segment when said crops are grown in water sufficient conditions.  
     
     
         8 . A transgenic crop of  claim 7  wherein said water deficit stress tolerant plants are corn, cotton, soybean, sugarcane, switchgrass, rice, wheat, alfalfa, or canola plants.  
     
     
         9 . A transgenic corn plant seed comprising a plant chromosomal DNA segment of any of claims  1 - 3  wherein said NF-YB protein is a native corn protein.  
     
     
         10 . A method of improving water stress tolerance and yield in a crop plant line comprising providing in the genome of said crop plant line a plant chromosomal DNA segment of any of claims  1 - 3 .  
     
     
         11 . A transgenic pollen grain comprising a haploid derivative of a plant cell containing a a plant chromosomal DNA segment of any of claims  1 - 3 .  
     
     
         12 . A method for manufacturing non-natural, transgenic seed that can be used to produce a crop of transgenic plants with enhanced water deficit stress tolerance resulting from expression of an NF-YB protein from a plant chromosomal DNA segment of any of claims  1 - 3 , wherein said method comprises: 
 (a) screening a population of plants having said plant chromosomal DNA segment and control plants for said enhanced yield when grown under deficit stress or enhanced or comparable yield as compared to the yield for control plants when grown under sufficient water conditions,    (b) selecting from said population one or more plants that exhibit enhanced yield as compared to the yield for control plants under water deficit stressed or enhanced or comparable yield as compared to the yield for control plants when grown under water sufficient conditions,    (c) verifying that said plant chromosomal DNA segment is stably integrated in said selected plants,    (d) analyzing leaf tissue of a selected plant to determine the production of transgenic NF-YB protein at a level up to 40 picograms of NF-YB protein per microgram of total protein in said leaf tissue; and    (e) collecting seed or a regenerative propagule from a selected plant.    
     
     
         13 . A method of  claim 12  wherein said seed is corn, cotton, soybean, sugarcane, switchgrass, rice, wheat, alfalfa, or canola seed.  
     
     
         14 . A method of producing inbred corn seed comprising: 
 (a) acquiring hybrid corn seed from a herbicide tolerant corn plant which also has stably-integrated, chromosomal DNA segment of any of claims  1 - 3 ;    (b) introgressing the chromosomal DNA segment from said acquired hybrid corn seed into a second corn line by allowing pollen grains comprising a haploid derivative with said chromosomal DNA segment to pollinate said second corn line to produce crossed seeds,    (c) producing a population of plants from crossed seeds wherein a fraction of the seeds produced from said pollination is homozygous for said chromosomal DNA segment, a fraction of the plants produced from said hybrid corn seed is hemizygous for said chromosomal DNA segment, and a fraction of the plants produced from said hybrid corn seed does not have said chromosomal DNA segment;    (d) selecting corn plants which are homozygous and hemizygous for said chromosomal DNA segment by treating with an herbicide;    (e) collecting seed from herbicide-treated-surviving corn plants and planting said seed to produce further progeny corn plants;    (f) backcrossing plants grown from said progeny seeds with said second corn line to produce an inbred corn line.    
     
     
         15 . The method of  claim 14  further comprising crossing said inbred corn line with a third corn line to produce hybrid seed.  
     
     
         16 . Anti-counterfeit milled seed having, as an indication of origin, a plant cell with said chromosomal DNA segment of any of claims  1 - 3 .  
     
     
         17 . A method of growing a corn, cotton, soybean, sugarcane, switchgrass, rice, wheat, alfalfa, or canola crop without irrigation water comprising planting seed having plant cells with a plant chromosomal DNA segment of any of claims  1 - 3  which are selected for enhanced water deficit tolerance.