| Title: | Polyphenol oxidase as a biochemical seed defense mechanism |
| Author(s): | Fuerst EP; Okubara PA; Anderson JV; Morris CF; |
| Address: | "Department of Crop and Soil Sciences, Washington State University Pullman, WA, USA. Root Disease and Biological Control Research Unit, United States Department of Agriculture - Agricultural Research Service, Washington State University Pullman, WA, USA. Biosciences Research Laboratory, United States Department of Agriculture - Agricultural Research Service Fargo, ND, USA. Western Wheat Quality Laboratory, United States Department of Agriculture - Agricultural Research Service, Washington State University Pullman, WA, USA" |
| ISSN/ISBN: | 1664-462X (Print) 1664-462X (Electronic) 1664-462X (Linking) |
| Abstract: | "Seed dormancy and resistance to decay are fundamental survival strategies, which allow a population of seeds to germinate over long periods of time. Seeds have physical, chemical, and biological defense mechanisms that protect their food reserves from decay-inducing organisms and herbivores. Here, we hypothesize that seeds also possess enzyme-based biochemical defenses, based on induction of the plant defense enzyme, polyphenol oxidase (PPO), when wild oat (Avena fatua L.) caryopses and seeds were challenged with seed-decaying Fusarium fungi. These studies suggest that dormant seeds are capable of mounting a defense response to pathogens. The pathogen-induced PPO activity from wild oat was attributed to a soluble isoform of the enzyme that appeared to result, at least in part, from proteolytic activation of a latent PPO isoform. PPO activity was also induced in wild oat hulls (lemma and palea), non-living tissues that cover and protect the caryopsis. These results are consistent with the hypothesis that seeds possess inducible enzyme-based biochemical defenses arrayed on the exterior of seeds and these defenses represent a fundamental mechanism of seed survival and longevity in the soil. Enzyme-based biochemical defenses may have broader implications since they may apply to other defense enzymes as well as to a diversity of plant species and ecosystems" |
| Keywords: | seed decay seed defense seed longevity weed seed bank; |
| Notes: | "PubMed-not-MEDLINEFuerst, E Patrick Okubara, Patricia A Anderson, James V Morris, Craig F eng Switzerland 2014/12/30 Front Plant Sci. 2014 Dec 10; 5:689. doi: 10.3389/fpls.2014.00689. eCollection 2014" |
