Nucleic acid encoding GAI gene of Arabidopsis thaliana

Abstract

The GAI gene of Arabidopsis thaliana has been cloned, along with mutant and homologue gene sequences. Expression of such genes in plants affects characteristics of the plants including growth. GAI expression inhibits growth of plants, which inhibition is antagonised by gibberellin (GA). Expression of gai mutants confers a dwarf phenotype which is GA-insensitive. Manipulation of expression of GAI and gai genes in plants results in tall or dwarfed plants. Dwarf plants are useful in particular for reduction in crop losses resulting from lodging.

1 - 48 . (Cancel).  
     
     
         49 . An isolated nucleic acid having a nucleotide sequence coding for a polypeptide of which the amino acid sequence has at least 75% amino acid sequence identity with the amino acid sequence shown in  FIG. 4  (SEQ ID NO. 2) except that the polypeptide does not contain the 17 amino acid sequence underlined in  FIG. 4   wherein expression of said isolated nucleic acid in a plant confers a phenotype on the plant which is gibberellin-unresponsive dwarfism.    
     
     
         50 . The nucleic acid according to any  claim 49  further comprising a regulatory sequence for expression.  
     
     
         51 . The nucleic acid according to  claim 50  wherein the regulatory sequence comprises an inducible promoter.  
     
     
         52 . A nucleic acid vector suitable for transformation of a plant cell and comprising the nucleic acid according to  claim 49 .  
     
     
         53 . A host cell containing the nucleic acid according to  claim 49 , wherein said cell is a microbial or plant cell and said nucleic acid is heterologous to said cell.  
     
     
         54 . A host cell according to claim  53 which is a plant cell.  
     
     
         55 . A plant cell according to  claim 54  having said heterologous nucleic acid within its genome.  
     
     
         56 . A plant cell according to  claim 55  which is comprised in a plant, a plant part or a plant propagule.  
     
     
         57 . A method of producing a cell according to  claim 54  the method comprising incorporating said nucleic acid into the cell by means of transformation.  
     
     
         58 . A method according to  claim 57 , wherein said nucleic acid is stably incorporated into the genome of said cell.  
     
     
         59 . A method according to  claim 57  further comprising regenerating a plant from one or more transformed cells.  
     
     
         60 . A method according to  claim 59  further comprising sexually or asexually propagating or growing off-spring or a descendant of the plant regenerated from said plant cell, wherein said off-spring or said descendent comprises said nucleic acid.  
     
     
         61 . A plant comprising a plant cell according to  claim 54 .  
     
     
         62 . A plant according to  claim 61  which is an ornamental plant.  
     
     
         63 . A plant according to  claim 62  having a dwarf phenotype.  
     
     
         64 . A plant according to  claim 63  wherein said phenotype is gibberellin unresponsive.  
     
     
         65 . A plant according to  claim 61  which is a crop plant, tree or fruit tree.  
     
     
         66 . A plant according to  claim 65  having a dwarf phenotype.  
     
     
         67 . A plant according to  claim 66  wherein said phenotype is gibberellin unresponsive.  
     
     
         68 . A method of producing a plant, the method comprising incorporating nucleic acid according to  claim 49  into a plant cell and regenerating a plant from said plant cell.  
     
     
         69 . A method of delaying the flowering time of a plant, the method comprising introducing the nucleic acid according to  claim 49  into cells of the plant and expressing said nucleic acid, wherein expression of said nucleic acid delays flowering time.  
     
     
         70 . A method of repressing the growth of a plant, the method comprising introducing the nucleic acid according to  claim 49  into cells of the plant and expressing said nucleic acid, wherein expression of said nucleic acid represses plant growth.