| Title: | Systemin: a polypeptide signal for plant defensive genes |
| Address: | "Institute of Biological Chemistry, Washington State University, Pullman 99164-6340, USA" |
| DOI: | 10.1146/annurev.cellbio.14.1.1 |
| ISSN/ISBN: | 1081-0706 (Print) 1081-0706 (Linking) |
| Abstract: | "Damage to leaves of several plant species by herbivores or by other mechanical wounding induces defense gene activation throughout the plants within hours. An 18-amino acid polypeptide, called systemin, has been isolated from tomato leaves that is a powerful inducer of over 15 defensive genes when supplied to the tomato plants at levels of fmol/plant. Systemin is readily transported from wound sites and is considered to be the primary systemic signal. The polypeptide is processed from a 200-amino acid precursor called prosystemin, analogous to polypeptide hormones in animals. However, the plant prohormone does not possess typical dibasic cleavage sites, nor does it contain a signal sequence or any typical membrane-spanning regions. The signal transduction pathway that mediates systemin signaling involves linolenic acid release from membranes and subsequent conversion to jasmonic acid, a potent activator of defense gene transcription. The pathway exhibits analogies to arachidonic acid/prostaglandin signaling in animals that leads to inflammatory and acute phase responses" |
| Keywords: | "Amino Acid Sequence Animals *Gene Expression Regulation, Plant Solanum lycopersicum/genetics/physiology Molecular Sequence Data Peptides/physiology Plant Physiological Phenomena Plant Proteins/genetics/*physiology Plants/*genetics Signal Transduction Tran;Animals;" |
| Notes: | "MedlineRyan, C A Pearce, G eng Review 1999/01/19 Annu Rev Cell Dev Biol. 1998; 14:1-17. doi: 10.1146/annurev.cellbio.14.1.1" |
