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.

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.

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.

Abstract: A 23 amino acid peptide, AtPtpl, 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. AtPcpl and its paralogs and orthologs play important roles as endogenous signals to amplify innate immunity. The sequence of two AtPep1 receptors from Arabidopsis are also provided.

Abstract: In one aspect, the present invention provides potato tubers that each include water-soluble protein at a concentration of at least 5 mg/ml. Some potato tubers of the invention include an exogenous nucleic acid molecule that encodes a systemin molecule, or a prosystemin molecule, that is expressed in the potato tubers, whereby the synthesis of at least one water-soluble protein is induced by the expressed systemin molecule (or the systemin molecule derived from processed prosystemin). In another aspect, the present invention provides methods for increasing the amount of water-soluble protein in a potato tuber.

Abstract: A method for removing protein impurities from extracts of protease inhibitor-containing plant material. Plant materials containing protease inhibitors, such a potato tubers that contain protease inhibitor II, are extracted using an alcohol-free solvent. The proteins present in the extract include impurities other than the protease inhibitor, specifically Kunitz, Bowman-Birk and carboxypeptidase inhibitors. The extract is subjected to heat treatment to denature and precipitate the unstable protein impurities followed by centrifugation to remove the precipitate. Ultrafiltration in the presence of a buffer removes the Bowman-Birk and carboxypeptidase inhibitors. The resulting purified protease inhibitor has applicability in the control of obesity and diabetes.

Abstract: In one aspect, the present invention provides isolated RALF polypeptides that are useful for stimulating the growth of plant meristem cells. In another aspect, the present invention provides isolated nucleic acid molecules that are at least 90% identical to a nucleic acid molecule (SEQ ID NO: 2) that encodes a tobacco RALF precursor polypeptide (SEQ ID NO: 3). In a further aspect, the present invention provides isolated polypeptides that are at least 90% identical to the amino acid sequence of a tobacco RALF precursor polypeptide (SEQ ID NO: 3). In another aspect, the present invention provides vectors and plant cells comprising a vector of the invention. In other aspects, the present invention provides methods of inhibiting meristem growth in a plant, and methods of enhancing meristem growth in a plant.

Abstract: The present invention provides methods for identifying and isolating signalling molecules, such as signalling molecules that interact with a plant cell membrane receptor molecule. In the practice of the present invention, the ability of a sample of biological material to induce a pH change in a liquid plant cell culture is used as an assay for the presence of one or more signalling molecules in the biological material.

Abstract: A method for removing protein impurities from extracts of protease inhibitor-containing plant material. Plant materials containing protease inhibitors, such a potato tubers that contain protease inhibitor II, are extracted using an alcohol-free solvent. The proteins present in the extract include impurities other than the protease inhibitor, specifically Kunitz, Bowman-Birk and carboxypeptidase inhibitors. The extract is subjected to heat treatment to denature and precipitate the unstable protein impurities followed by centrifugation to remove the precipitate. Ultrafiltration in the presence of a buffer removes the Bowman-Birk and carboxypeptidase inhibitors. The resulting purified protease inhibitor has applicability in the control of obesity and diabetes.

Abstract: A rapid and simple method of isolating heat stable proteinase inhibitor proteins from plant tissues such as potato tubers is disclosed. The method comprises three steps. Proteins from potato tubers are extracted in an aqueous/alcohol extraction medium to form an alcohol extract. The alcohol extract is heated to a first temperature then cooled to a second temperature to form an insoluble precipitate phase containing debris and a soluble phase that contains the heat stable proteinase inhibitor proteins. The heat stable proteinase inhibitor proteins are precipitated from the soluble phase by dialysis against a suitable dialysis medium. The precipitated proteins may include a single inhibitor protein, or a mixture thereof.

Abstract: A rapid and simple method of isolating heat stable proteinase inhibitor proteins from plant tissues such as potato tubers is disclosed. The method comprises three steps. Proteins from potato tubers are extracted in an aqueous/alcohol extraction medium to form an alcohol extract. The alcohol extract is heated to a first temperature then cooled to a second temperature to form an insoluble precipitate phase containing debris and a soluble phase that contains the heat stable proteinase inhibitor proteins. The heat stable proteinase inhibitor proteins are precipitated from the soluble phase by dialysis against a suitable dialysis medium. The precipitated proteins may include a single inhibitor protein, or a mixture thereof.

Abstract: Systemin, an 18 amino acid peptide hormone and first polypeptide hormone found in plants, induces expression of defense genes in plants wounded mechanically or by predators including herbivores, insects, bacteria and viruses. The precursor for systemin is encoded as a 200 amino acid prosystemin molecule that has the systemin peptide sequence located near the carboxyl-terminus. Both a 951 bp cDNA for prosystemin and 4526 bp genomic DNA were cloned and the organization of the gene was determined. Transgenic plants constructed with antisense prosystemin DNA fail to mount a defensive response to wounding. Transgenic plants constructed with increased copy number of prosystemin genes exhibit increased resistance to wounding. Insect larval that feed on transgenic plants constructed with increased copy number of prosystemin genes exhibit decreased growth weight compared to larval that feed on wild type plants.

Abstract: The expression of plant defense proteins is induced in plant tissue by contacting plants to be treated with a defense protein inducing agent. The inducing agent, which may be jasmonic acid, lower alkyl esters of jasmonic acid or jasmonic acid-like derivative compounds, induces the expression of genes in the plants resulting in the production of defense proteins, such as proteinase inhibitors, thionins, chitinases and .beta.-glucanases. Plants may be contacted with the inducing agent by direct application to plant tissue or by airborne transmission of the inducing agent.

Abstract: Systemin, an 18 amino acid peptide hormone and first polypeptide hormone found in plants, induces expression of defense genes in plants wounded mechanically or by predators including herbivores, insects, bacteria and viruses. The precursor for systemin is encoded as a 200 amino acid prosystemin molecule that has the systemin peptide sequence located near the carboxyl-terminus. Both a 951 bp cDNA for prosystemin and 4526 bp genomic DNA were cloned and the organization of the gene was determined. Transgenic plants constructed with antisense prosystemin DNA fail to mount a defensive response to wounding. Transgenic plants constructed with increased copy number of prosystemin genes exhibit increased resistance to wounding. Insect larval that feed on transgenic plants constructed with increased copy number of prosystemin genes exhibit decreased growth weight compared to larval that feed on wild type plants. A tomato systemin polypeptide has an amino acid sequence NH.sub.3 -AVQSKPPSKRDPPKMQTD-COO-.

Abstract: Systemin is an 18 amino acid peptide hormone that induces expression of defense genes in plants wounded mechanically or by predators including herbivores, insects, bacteria and viruses. The precursor for systemin is encoded as a 200 amino acid prosystemin molecule that has the systemin peptide sequence located near the carboxy-terminus. Both a 951 bp cDNA for prosystemin and 4526 bp genomic DNA were cloned and the organization of the gene was determined. Transgenic plants constructed with antisense prosystemin DNA fail to mount a defensive response to wounding. Transgenic plants constructed with increased copy number of prosystemin genes exhibit increase resistance to wounding. A tomato systemin polypeptide has an amino acid sequence NH.sub.3 --AVQSKPPSKRDPPKMQTD--COO--.

Abstract: Compositions and methods for reducing the risk of skin cancer. The novel compositions include at least one effective protease inhibitor. Preferred protease inhibitors include serine protease inhibitors and metallo- protease inhibitors. The protease inhibitors are preferably included in concentrations ranging from approximately 10 picograms to 10 milligrams per milliliter of the skin-applicable topical mixtures. The topical mixtures preferably include a suitable topical vehicle such as a cream, lotion, or ointment. One class of anti-carcinogenic skin treatment compositions of this invention preferably includes the desired protease inhibitors in combination with a suitable sunscreen agent or agents, such as para-amino benzoic acid, to provide particularly advantageous compositions for reducing the risk of sunlight-induced skin cancer.