Etp1 and etp2 regulate plant ethylene response

Abstract

ETP1 and ETP2 bind to EIN2 and modulate plant ethylene sensitivity.

What is claimed is: 
     
         1 . A plant comprising a heterologous recombinant expression cassette, wherein the plant has altered sensitivity to ethylene compared to a control plant lacking the expression cassette, the expression cassette comprising a promoter operably linked to a polynucleotide, which polynucleotide, when expressed, modulates expression of an ETP1 or ETP2 polypeptide, wherein modulated expression of the ETP1 or ETP2 polypeptide results in altered ethylene sensitivity. 
     
     
         2 . The plant of  claim 1 , wherein expression of the ETP1 and/or ETP2 polypeptide is increased compared to a control plant lacking the expression cassette, wherein the plant has reduced ethylene sensitivity compared to the control plant. 
     
     
         3 . The plant of  claim 2 , wherein the polynucleotide encodes a polypeptide comprising an amino acid sequence substantially identical to any of SEQ ID NOS:1-8 or 18-22. 
     
     
         4 . The plant of  claim 1 , wherein expression of the ETP1 and/or ETP2 polypeptide is decreased compared to a control plant lacking the expression cassette, wherein the plant has increased ethylene sensitivity compared to the control plant. 
     
     
         5 . The plant of  claim 4 , wherein the polynucleotide comprises at least 20 contiguous nucleotides, or the complement thereof, of a nucleic acid encoding any of SEQ ID NOS:1-8 or 18-22, such that expression of the polynucleotide inhibits expression of an endogenous ETP1 or ETP2 gene. 
     
     
         6 . The plant of  claim 5 , wherein the polynucleotide comprises a sequence at least 80% identical to at least 100 contiguous nucleotides, or the complement thereof, of a nucleic acid encoding any of SEQ ID NOS:1-8 or 18-22. 
     
     
         7 . The plant of  claim 4 , wherein the polynucleotide encodes an siRNA, antisense polynucleotide, a microRNA, or a sense suppression nucleic acid, thereby suppressing expression of an endogenous ETP1 or ETP2 protein. 
     
     
         8 . The plant of  claim 5 , wherein the endogenous ETP1 or ETP2 gene encodes a polypeptide at least 80% identical to any of SEQ ID NOS:1-8 or 18-22, respectively. 
     
     
         9 . The plant of  claim 6 , wherein the sequence is at least 95% identical to at least 100 contiguous nucleotides encoding any of SEQ ID NOS:1-8 or 18-22. 
     
     
         10 . The plant of  claim 6 , wherein the sequence is 100% identical to at least 100 contiguous nucleotides encoding any of SEQ ID NOS:1-8 or 18-22. 
     
     
         11 . The plant of  claim 4 , comprising at least two heterologous expression cassettes wherein expression from one expression cassette inhibits expression of an endogenous ETP1 and expression from a second expression cassette inhibits expression of an endogenous ETP2 gene. 
     
     
         12 . A method of making a plant of  claim 1 , the method comprising
 introducing the expression cassette into a plurality of plants; and   selecting a plant that expresses the polynucleotide from the plurality of plants.   
     
     
         13 . The method of  claim 12 , wherein the selecting step comprising selecting a plant that has altered ethylene sensitivity. 
     
     
         14 . A recombinant expression cassette comprising a promoter operably linked to a polynucleotide, which polynucleotide, when expressed in a plant, modulates expression of an endogenous ETP1 or ETP2 gene. 
     
     
         15 . The expression cassette of  claim 14 , wherein expression of ETP1 and/or ETP2 is increased when the expression cassette is introduced into a plant compared to a control plant lacking the expression cassette, and wherein the promoter is heterologous to the polynucleotide. 
     
     
         16 . The expression cassette of  claim 15 , wherein the polynucleotide encodes a polypeptide substantially identical to any of SEQ ID NOS:1-8 or 18-22. 
     
     
         17 . The expression cassette of  claim 14 , wherein expression of ETP1 and/or ETP2 is decreased when the expression cassette is introduced into a plant compared to a control plant lacking the expression cassette, and wherein the promoter is heterologous to the polynucleotide. 
     
     
         18 . The expression cassette of  claim 17 , wherein the polynucleotide comprises at least 20 contiguous nucleotides, or the complement thereof, of a nucleic acid encoding any of SEQ ID NOs: 1-8 or 18-22, such that expression of the polynucleotide inhibits expression of an endogenous ETP1 or ETP2 gene. 
     
     
         19 . The expression cassette of  claim 18 , wherein the endogenous ETP1 or ETP2 gene encodes a polypeptide at least 80% identical to any of SEQ ID NOS:1-8 or 18-22, respectively. 
     
     
         20 . The expression cassette of  claim 18 , wherein the polynucleotide comprises a sequence at least 80% identical to at least 100 contiguous nucleotides, or the complement thereof, of a nucleic acid encoding any of SEQ ID NOS:1-8 or 18-22. 
     
     
         21 . The expression cassette of  claim 21 , wherein the sequence is at least 95% identical to at least 100 contiguous nucleotides encoding any of SEQ ID NOs: 1-8 or 18-22. 
     
     
         22 . The expression cassette of  claim 21 , wherein the sequence is 100% identical to at least 100 nucleotides encoding any of SEQ ID NOs: 1-8 or 18-22. 
     
     
         23 . A method of identifying an agent that modulates the interaction of an ETP1 or ETP2-binding fragment of an EIN2 protein to ETP1 or ETP2, the method comprising
 contacting a plurality of agents to the fragment in the presence of an ETP1 or ETP2 polypeptide under conditions such that the fragment would bind to the ETP1 or ETP2 polypeptide in the absence of the agents;   determining whether the contacting step modulates binding of the fragment to the ETP1 or ETP2 polypeptide compared to the absence of the agents; and   selecting an agent that modulates the interaction of an ETP1 or ETP2-binding fragment of an EIN2 protein to ETP1 or ETP2.