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), wherein expression of said nucleic acid in a plant results in inhibition of growth of the plant, the inhibition being reversed by gibberellin (GA).  
     
     
         50 . An isolated nucleic acid having a nucleotide sequence coding for a polypeptide which includes an amino acid sequence which has at least 75% identity with the amino acid sequence shown in  FIG. 4  (SEQ ID NO. 2), wherein expression of said nucleic acid complements a GAI null mutant phenotype in a plant, such phenotype being resistance to the dwarfing effect of paclobutrazol.  
     
     
         51 . The isolated nucleic acid according to any one of claims  49  and  50  wherein said plant is  Arabidopsis thaliana.    
     
     
         52 . The nucleic acid according to any one of claims  49  and  50  further comprising a regulatory sequence for expression.  
     
     
         53 . The nucleic acid according to  claim 52  wherein the regulatory sequence comprises an inducible promoter.  
     
     
         54 . A nucleic acid vector suitable for transformation of a plant cell and comprising the nucleic acid according to any one of claims  49  and  50 .  
     
     
         55 . A host cell containing the nucleic acid according to any one of claims  49  and  50 , wherein said cell is a plant cell or a bacterial cell and wherein said nucleic acid is heterologous to said cell.  
     
     
         56 . The plant cell according to  claim 55  having said heterologous nucleic acid within its genome.  
     
     
         57 . The plant cell according to  claim 56  which is comprised in a plant, a plant part or a plant propagule.  
     
     
         58 . A method of producing the cell according to  claim 55 , the method comprising incorporating said nucleic acid into the cell by means of transformation.  
     
     
         59 . The method according to  claim 58 , wherein said nucleic acid is stably incorporated into the genome of said cell.  
     
     
         60 . The method according to  claim 58  further comprising regenerating a plant from one or more transformed cells.  
     
     
         61 . The method according to  claim 60  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.  
     
     
         62 . A plant comprising a plant cell according to  claim 55 .  
     
     
         63 . The plant according to  claim 62  which is an ornamental plant.  
     
     
         64 . The plant according to  claim 63  having a dwarf phenotype.  
     
     
         65 . The plant according to  claim 64  wherein said phenotype is gibberellin responsive.  
     
     
         66 . The plant according to  claim 65  which is a crop plant, tree or fruit tree.  
     
     
         67 . The plant according to  claim 66  having a dwarf phenotype.  
     
     
         68 . The plant according to  claim 67  wherein said phenotype is gibberellin responsive.  
     
     
         69 . A method of producing a plant, the method comprising incorporating the nucleic acid according to any one of claims  49  and  50  into a plant cell and regenerating a plant from said plant cell.  
     
     
         70 . A method of repressing the growth of a plant, the method comprising introducing the nucleic acid according to any one of claims  49  and  50  into cells of the plant and expressing said nucleic acid, wherein expression of said nucleic acid represses plant growth.  
     
     
         71 . A method of delaying the flowering time of a plant, the method comprising introducing the nucleic acid according to any one of claims  49  and  50  into cells of the plant and expressing said nucleic acid, wherein expression of said nucleic acid delays flowering time.