Stress resistant plants

Abstract

Stress tolerance in plants and plant cells is achieved by using nucleotide sequences encoding enzymes involved in the NAD salvage synthesis pathway and/or the NAD de novo synthesis pathway from fungal or yeast like organisms other than Saccharomyces cereviseae, e.g., for overexpression in plants.

1 . A method for obtaining a plant with increased stress resistance comprising
 a. introducing a chimeric gene into a cells of a plant to obtain transgenic cells, said chimeric gene comprising the following operably linked DNA fragments:
 i. A plant-expressible promoter; 
 ii. A DNA region coding for a plant-functional enzyme of the nicotinamide adenine dinucleotide salvage synthesis pathway selected from nicotinamidase, nicotinate phosphoribosyltransferase, nicotinic acid mononucleotide adenyl transferase or nicotinamide adenine dinucleotide synthetase; 
 iii. A 3′end region involved in transcription termination and polyadenylation; 
   b. regenerating said transgenic cells to obtain a population of transgenic plants; and   
       selecting a plant from said population of transgenic plants which exhibits increased stress resistance or selecting a plant which exhibits a reduced level of reactive oxygen species or maintains a high level of NADH under stress conditions when compared to a similar non-transgenic plant characterized in that that the amino acid sequence encoded by the DNA region comprises the amino acid sequence of any one of SEQ ID Nos. 1 to 29, 31 to 47 or 49 to 66 or an amino acid sequence having at least 90% sequence identity to said amino acid sequences of any one of SEQ ID Nos. 1 to 29, 31 to 47 or 49 to 66. 
     
     
         2 . A chimeric gene as described in  claim 1 . 
     
     
         3 . A plant cell comprising a chimeric gene as described in  claim 3 . 
     
     
         4 . A plant comprising a chimeric gene as described in  claim 2 . 
     
     
         5 . The plant according to  claim 4 , further characterized in that it has a lower level of reactive oxygen species under stress conditions than a similar plant not comprising such a chimeric gene. 
     
     
         6 . A seed of a plant according to  claim 4  or  5  comprising a chimeric gene according to  claim 2 . 
     
     
         7 . Use of a chimeric gene according to  claim 2  to increase the stress resistance of a plant. 
     
     
         8 . Use of a chimeric gene according to  claim 2  to decrease the level of reactive oxygen species in a plant or a plant cell under stress conditions or to maintain the level of NAD in a plant or plant cell under stress conditions. 
     
     
         9 . Use of a DNA sequence encoding a plant functional enzyme of the nicotinamide adenine dinucleotide salvage synthesis pathway selected from nicotinamidase, nicotinate phosphoribosyltransferase, nicotinic acid mononucleotide adenyl transferase or nicotinamide adenine dinucleotide synthetase to increase the stress resistance of a plant characterized in that said plant functional enzyme is derived from a fungal or yeast-like organism different than  Saccharomyces cereviseae.    
     
     
         10 . Use of a DNA sequence encoding a plant functional enzyme of the nicotinamide adenine dinucleotide salvage synthesis pathway selected from nicotinamidase, nicotinate phosphoribosyltransferase, nicotinic acid mononucleotide adenyl transferase or nicotinamide adenine dinucleotide synthetase to decrease the level of reactive oxygen species in a plant or a plant cell under stress conditions or to maintain the level of NAD in a plant or plant cell under stress conditions characterized in that said plant functional enzyme is derived from a fungal or yeast-like organism different than  Saccharomyces cereviseae.