Gregory Pearce

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Innate immunity is initiated in animals and plants through the recognition of a variety of pathogen-associated molecules that in animals are called pathogen-associated molecular patterns and in plants are called elicitors. Some plant pathogen-derived elicitors have been identified as peptides, but peptide elicitors derived from the plant itself that(More)
A 5-kDa polypeptide was isolated from tobacco leaves that induced a rapid alkalinization of the culture medium of tobacco suspension-cultured cells and a concomitant activation of an intracellular mitogen-activated protein kinase. An N-terminal sequence was obtained, and a cDNA coding for the 49-aa polypeptide was isolated from a tobacco cDNA library. The(More)
Some animal and yeast hormone genes produce prohormone polypeptides that are proteolytically processed to produce multiple copies of hormones with the same or different functions. In plants, four polypeptides have been identified that can be classed as hormones (intercellular chemical messengers) but none are known to be produced as multiple copies from a(More)
AtPep1 is a 23-aa endogenous peptide elicitor from Arabidopsis leaves that signals the activation of components of the innate immune response against pathogens. Here, we report the isolation of an AtPep1 receptor from the surface of Arabidopsis suspension-cultured cells. An (125)I-labeled AtPep1 analog interacted with suspension-cultured Arabidopsis with a(More)
Defensive genes in plants can be activated by several different types of nonpeptide signaling molecules. An endogenous polypeptide, consisting of 18 amino acids, was isolated from tomato leaves and was able at very low concentrations to induce the synthesis of two wound-inducible proteinase inhibitor proteins when supplied to young tomato plants. The(More)
A gene that encodes systemin, a mobile 18-amino acid polypeptide inducer of proteinase inhibitor synthesis in tomato and potato leaves, has been isolated from tomato, Lycopersicon esculentum. Induction of proteinase inhibitors in plants is a response to insect or pathogen attacks. The gene has 10 introns and 11 exons, ten of which are organized as five(More)
A cDNA containing the complete amino acid-coding region of wound-induced tomato Inhibitor II was constructed in the plasmid pUC9. The open reading frame codes for 148 amino acids including a 25-amino acid signal sequence preceding the N-terminal lysine of the mature Inhibitor II. The Inhibitor II sequence exhibits two domains, one domain having a trypsin(More)
Tomato plants (Lycopersicon esculentum, var. Better Boy) were stably transformed with a gene consisting of the open reading frame of a prosystemin cDNA under the regulation of the cauliflower mosaic virus 35S promoter. The leaves of the transgenic plants constitutively produced proteinase inhibitor I and II proteins, which accumulated over time to levels(More)
Six small molecular mass, wound-inducible trypsin and chymotrypsin inhibitor proteins from tobacco (Nicotiana tabacum) leaves were isolated to homogeneity. The isoinhibitors, cumulatively called tobacco trypsin inhibitor (TTI), have molecular masses of approximately 5500 to 5800 D, calculated from gel filtration analysis and amino acid content. The amino(More)
An 18-amino acid peptide in tomato leaves called systemin is a primary signal released at wound sites in response to herbivory that systemically signals the activation of defense genes throughout the plants. We report here the isolation of three hydroxyproline-rich glycopeptides from tomato leaves, of 20, 18, and 15 amino acids in length, that signal the(More)