Maize ethylene signaling genes and modulation of same for improved stress tolerance in plants

Abstract

The invention provides isolated maize EIN3, EBF1 and EIN5 nucleic acids and encoded proteins which are associated with ethylene signaling in plants. The present invention provides methods and compositions relating to altering ethylene sensitivity in plants. The invention further provides recombinant expression cassettes, host cells, transgenic plants and antibody compositions.

1 . A recombinant expression cassette comprising a polynucleotide selected from the group consisting of:
 (a) a polynucleotide encoding a polypeptide which has at least 95% sequence identity, as determined by the GAP algorithm under default parameters, to a polypeptide of SEQ ID NO: 8;   (b) a polynucleotide encoding the polypeptide of SEQ ID NO: 8;   (c) a polynucleotide of SEQ ID NO: 7;   (d) a polynucleotide which has at least 95% sequence identity, as determined by the GAP algorithm under default parameters, to the full length of SEQ ID NO: 7;   (e) a polynucleotide which has at least 95% sequence identity, as determined by the GAP algorithm under default parameters, to the full length of the coding sequence of SEQ ID NO: 7; and   (f) a polynucleotide which is complementary to the polynucleotide of (a), (b), (c), (d), or (e),   wherein said polynucleotide is operably linked, in sense or anti-sense orientation, to a regulatory sequence.   
     
     
         2 . A host cell comprising the recombinant expression cassette of  claim 1 . 
     
     
         3 . A transgenic plant comprising the recombinant expression cassette of  claim 1 . 
     
     
         4 . The transgenic plant of  claim 3 , wherein said plant is a monocot. 
     
     
         5 . The transgenic plant of  claim 3 , wherein said plant is selected from the group consisting of: maize, soybean, sunflower, sorghum, canola, wheat, alfalfa, cotton, rice, barley and millet. 
     
     
         6 . A seed from the transgenic plant of  claim 3 , wherein said seed comprises the recombinant expression cassette of  claim 1 . 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . A method of modulating ethylene response in a plant, comprising:
 (a) introducing into a plant cell a recombinant expression cassette comprising a promoter operably linked to a polynucleotide complementary to SEQ ID NO: 7;   (b) culturing the plant cell under plant cell growing conditions;   (c) regenerating a plant from said cultured plant cell; and   (c) inducing expression of said polynucleotide by drought, ABA, or ethylene for a time sufficient to modulate the level of EIN5 in said plant.   
     
     
         13 . The method of  claim 12 , wherein the level or activity of EIN5 in aerial parts of the plant is decreased, relative to a control. 
     
     
         14 . The method of  claim 12 , wherein the plant is selected from the group consisting of: maize, soybean, sorghum, canola, wheat, alfalfa, cotton, rice, barley, millet, peanut and cocoa. 
     
     
         15 . The method of  claim 12 , wherein said plant cell is from a monocot. 
     
     
         16 . A transgenic plant produced by the method of  claim 12 , wherein the plant has decreased ethylene sensitivity when compared to a control plant. 
     
     
         17 . A method of modulating ethylene response in a maize plant, the method comprising reducing the endogenous expression of a polynucleotide encoding a polypeptide comprising an amino acid sequence that is at least 95% to SEQ ID NO: 7, wherein the reduction in the endogenous expression is due to a heterologous genetic modification, compared to a control plant not having the modification. 
     
     
         18 . The method of  claim 17 , wherein the plant is exposed to a drought stress. 
     
     
         19 . The method of  claim 17 , wherein the polypeptide is SEQ ID NO: 7. 
     
     
         20 . The method of  claim 17 , wherein the heterologous genetic modification is in the regulatory region of the polynucleotide.