Oxidative stress resistance gene

Abstract

The invention relates to plants, especially transgenic plants, plant parts and plant cells overproducing an iron binding protein (e.g. ferritin) and having an enhanced resistance against a wide range of abiotic and biotic oxidative stress conditions (e.g. against treatment with paraquat or fusaric acid and against viral, bacterial and fungal infections). The invention also comprises nucleic acid sequences encoding an alfalfa ferritin or functional variants thereof and the use of said sequences for rendering plants resistant against oxidative stress conditions. The invention is useful for reducing environmental damages of crops caused by a wide variety of stress conditions.

1 . A plant cell which overproduces an iron binding protein characterised in that the protein is at least 90% homologous to that of SEQ ID No 2.  
     
     
         2 . A plant cell of    claim 1    characterised in that the iron binding protein has at least 50% sequence identity to the protein having the amino acid sequence of SEQ ID No 2.  
     
     
         3 . A plant cell according to claims  1  or  2  characterised in that it has been transformed by the introduction of a nucleic acid coding for the expression of an iron binding protein.  
     
     
         4 . A plant cell of any one of    claims 1    to    3    characterised in that the iron binding protein is a ferritin.  
     
     
         5 . A plant or a plant part comprising a cell according to anyone of    claims 1    to    4   .  
     
     
         6 . A plant or plant part according to    claim 5    in the leaves of which the intensity of the photosynthetic reactions is not decreased by more than 10% following, a 70 hours treatment with 10 μM paraquat.  
     
     
         7 . A plant or plant part as claimed in    claim 6    characterised in that the intensity is not decreased following the treatment.  
     
     
         8 . A plant or a plant part according to claims  5 ,  6  or  7  characterised in that it has an enhanced resistance against fusaric acid treatment and/or infections of viral and/or bacterial and/or fungal origin.  
     
     
         9 . A plant or plant part as claimed in any one of    claims 5    to    8    characterised in that the iron binding protein is ectopically expressed in vegetative tissues.  
     
     
         10 . A plant or plant part as claimed in any one of    claims 1    to    9    characterised in that the protein is expressed under control of a promoter comprising the ribulose-1,5-biphosphate carboxylase small subunit gene promoter.  
     
     
         11 . A plant as claimed in any one of    claims 1    to    10    characterised in that the protein is truncated at the N-terminal transit region.  
     
     
         12 . Use of a nucleotide sequence coding for a ferritin having the sequence of SEQ ID No 1 or a sequence having at least 90% homology thereto for the preparation of a plant cell, plant or plant part as claimed in any one of    claims 1    to    11   .  
     
     
         13 . Use of a nucleotide sequence encoding for an iron binding protein as a molecular biological agent for transforming a plant cell, plant or plant part for the purpose of making the plant cell, plant or part resistant to oxidative stress.  
     
     
         14 . Use as claimed in    claim 13   , characterised in that it is for making the plant cell, plant or part resistant to the damaging effects of abiotic and biotic stresses.  
     
     
         15 . Use as claimed in    claim 14    characterised in that the stresses include one or more of oxidatively induced free radicals, viral, bacterial and fungal infections, low and high temperatures and drought.  
     
     
         16 . Use as claimed in    claim 14    characterised in that the stresses include all of oxidatively induced free radicals, and viral, bacterial and fungal infections  
     
     
         17 . Isolated, enriched, cell free and/or recombinant nucleic acid comprising the sequence SEQ ID No 1 or having at least 90% homology therewith or complementary sequences to such sequences.  
     
     
         18 . Nucleic acid as claimed in    claim 17    having at least 95% homology therewith or a complementary sequence thereto.  
     
     
         19 . Nucleic acid as claimed in any one of    claims 16    to    18    not including a ferritin leader sequence from  Medicago saliva L.    
     
     
         20 . A method of providing crops in an environment subject to oxidative stress whereby the crop is able to resist at least 20% increased oxidative stress as compared to a naturally provided counterpart crops characterised in that it comprises transforming a natural counterpart crop plant cell or plant with a nucleotide sequence encoding for an iron binding protein and growing said plant in that environment.  
     
     
         21 . A method or use as claimed in any one of    claims 13    to    16    and    20    characterised in that the nucleotide sequence encodes for a ferritin of at least 90% homology to that of SEQ ID No 2.