Plant haemoglobin

Abstract

The invention relates generally to a method for improving growth of plants, under normal and under stress conditions, more particularly under osmotic stress and/or temperature extremes, comprising modifying plant haemoglobin gene expression and/or by modifying plant haemoglobin protein levels in a plant. The invention furthermore relates to a method for increasing yield of a plant, comprising modifying plant gene expression and/or by modifying plant haemoglobin levels in a plant. The invention also relates to a nucleic acid encoding a haemoglobin conferring this altered growth and stress tolerance.

We claim: 
     
         1 . An isolated polynucleotide encoding a polypeptide comprising SEQ ID NO: 2. 
     
     
         2 . The isolated nucleic acid of  claim 1 , wherein the polynucleotide comprises SEQ ID NO: 1. 
     
     
         3 . A transgenic plant transformed with an expression vector comprising a promoter operatively linked to a polynucleotide encoding a polypeptide comprising SEQ ID NO: 2. 
     
     
         4 . The transgenic plant of  claim 3 , wherein the polynucleotide comprises SEQ ID NO: 1. 
     
     
         5 . The transgenic plant of  claim 3 , wherein the plant is a monocot. 
     
     
         6 . The transgenic plant of  claim 5 , wherein the monocot is rice, maize, or wheat. 
     
     
         7 . The transgenic plant of  claim 3 , wherein the plant is a dicot. 
     
     
         8 . The transgenic plant of  claim 7 , wherein the dicot is soybean, cotton, canola, sugar cane, or sugar beet.