Plant defense signal peptides

Abstract

A 23 amino acid peptide, AtPep1, plays an important role as a signaling component of the innate immune system of Arabidopsis . The peptide precursor gene is transcribed in response to elicitors generated by pathogens, and AtPep1 is produced to amplify the signaling pathways. Seven paralogs of the AtproPep1 gene have been identified in the Arabidopsis genome, and orthologs have been identified in species of several agriculturally important families. AtPep1 and its paralogs and orthologs play important roles as endogenous signals to amplify innate immunity. The sequences of two AtPep1 receptors from Arabidopsis are also provided.

1 . An isolated polynucleotide encoding a polypeptide comprising a 10 amino acid peptide motif wherein said 10 amino acid peptide motif consists of a glycine residue at position C-7 of said peptide, wherein said polypeptide causes a change of at least 0.2 pH units at a concentration of 25 pM/ml in a plant cell suspension, wherein said polynucleotide is isolated from genomic DNA, or synthesized based on genomic DNA, wherein said genomic DNA encodes three or more structural elements selected from the group consisting of: a first EDKR repeat, a 1-5-10 helix motif, a serine repeat, a second EDKR repeat, and a K/R positive charge region, wherein said structural elements are positioned 5′ of said polynucleotide. 
     
     
         2 . A transgenic plant comprising said isolated polynucleotide of  claim 1 . 
     
     
         3 . The isolated polynucleotide of  claim 1 , wherein said isolated polynucleotide encodes a defense signal peptide selected from the group consisting of TcPep1, GhPep2, SePep1, PtPep2, VvPep2, VvPep3, HaPep1, HaPep2, OsPep3b, OsPep8, SoPep1a, SoPep2a, PvPep1, OsPep3c, OsPep4b, OsPep4c, OsPep5b, OsPep5c, OsPep6b, ZmPep4b, ZmPep4c, TaPep3b, TaPep3c, HvPep1b, HvPep1c, SoPep1b, SoPep1c, SoPep1d, SoPep1e, SoPep1f, SoPep2b, SoPep2c, SoPep2d, and SoPep2e. 
     
     
         4 . A transgenic plant comprising said isolated polynucleotide of  claim 3 . 
     
     
         5 . The polypeptide of  claim 1 , wherein said polypeptide is an isolated polypeptide. 
     
     
         6 . A transgenic plant comprising said isolated polypeptide of  claim 5 . 
     
     
         7 . The polypeptide of  claim 5 , wherein said isolated polypeptide comprises a defense signal peptide selected from the group consisting of TcPep1, GhPep2, SePep1, PtPep2, VvPep2, VvPep3, HaPep1, HaPep2, OsPep3b, OsPep8, SoPep1a, SoPep2a, PvPep1, OsPep3c, OsPep4b, OsPep4c, OsPep5b, OsPep5c, OsPep6b, ZmPep4b, ZmPep4c, TaPep3b, TaPep3c, HvPep1b, HvPep1c, SoPep1b, SoPep1c, SoPep1d, SoPep1e, SoPep1f, SoPep2b, SoPep2c, SoPep2d, and SoPep2e. 
     
     
         8 . A transgenic plant comprising said isolated polypeptide of  claim 7 . 
     
     
         9 . The polypeptide of  claim 5 , wherein said polypeptide is a propeptide. 
     
     
         10 . The propeptide of  claim 9 , wherein said propeptide is between 75 and 154 amino acid residues in length. 
     
     
         11 . The propeptide of  claim 9 , wherein said propeptide comprises one or more defense signal peptides selected from the group consisting of TcPep1, GhPep2, SePep1, PtPep2, VvPep2, VvPep3, HaPep1, HaPep2, OsPep3b, OsPep8, SoPep1a, SoPep2a, PvPep1, OsPep3c, OsPep4b, OsPep4c, OsPep5b, OsPep5c, OsPep6b, ZmPep4b, ZmPep4c, TaPep3b, TaPep3c, HvPep1b, HvPep1c, SoPep1b, SoPep1c, SoPep1d, SoPep1e, SoPep1f, SoPep2b, SoPep2c, SoPep2d, and SoPep2e. 
     
     
         12 . A transgenic plant comprising said propeptide of  claim 11 . 
     
     
         13 . The propeptide of  claim 9 , wherein said propeptide is processed in a plant to produced one or more defense signal peptides selected from the group consisting of TcPep1, GhPep2, SePep1, PtPep2, VvPep2, VvPep3, HaPep1, HaPep2, OsPep3b, OsPep8, SoPep1a, SoPep2a, PvPep1, OsPep3c, OsPep4b, OsPep4c, OsPep5b, OsPep5c, OsPep6b, ZmPep4b, ZmPep4c, TaPep3b, TaPep3c, HvPep1b, HvPep1c, SoPep1b, SoPep1c, SoPep1d, SoPep1e, SoPep1f, SoPep2b, SoPep2c, SoPep2d, and SoPep2e. 
     
     
         14 . An isolated polynucleotide encoding a polypeptide comprising a defense signal peptide receptor protein, wherein said defense signal peptide receptor protein is selected from the group consisting of AtPepR1, AtPepR2, GmPepR1a, GmPepR1b, GmPepR2, P93194 (In), 803073 (Pt), 765043 (Pt), CAO23192 (Vv), OsPepR1, OsPepR2, GRMZM2G011806 (Zm), GRMZM2G128602 (Zm), and Sb07g021950 (Sb). 
     
     
         15 . A transgenic plant comprising said isolated polynucleotide of  claim 14 . 
     
     
         16 . The isolated polypeptide of  claim 14 . 
     
     
         17 . A transgenic plant comprising said isolated polypeptide of  claim 16 . 
     
     
         18 . The transgenic plant of  claim 17 , further comprising one or more defense signal peptides selected from the group consisting of TcPep1, GhPep2, SePep1, PtPep2, VvPep2, VvPep3, HaPep1, HaPep2, OsPep3b, OsPep8, SoPep1a, SoPep2a, PvPep1, OsPep3c, OsPep4b, OsPep4c, OsPep5b, OsPep5c, OsPep6b, ZmPep4b, ZmPep4c, TaPep3b, TaPep3c, HvPep1b, HvPep1c, SoPep1b, SoPep1c, SoPep1d, SoPep1e, SoPep1f, SoPep2b, SoPep2c, SoPep2d, and SoPep2e. 
     
     
         19 . The isolated polynucleotide of  claim 1 , further comprising a promoter, wherein expression of said isolated polynucleotide in a cell of a plant causes said plant to exhibit an improvement compared to a control plant lacking said polynucleotide, wherein said improvement is selected from the group consisting of improved yield of plant product, reduced disease symptoms, and enhanced resistance to disease infestation. 
     
     
         20 . A composition comprising one or more of said defense signal peptides of  claim 7  and a biologically acceptable carrier. 
     
     
         21 . A plant comprising said composition of  claim 20  applied to a surface of said plant. 
     
     
         22 . A seed comprising said composition of  claim 20  applied to a surface of said seed.