| Title: | Antisense-mediated depletion of a potato lipoxygenase reduces wound induction of proteinase inhibitors and increases weight gain of insect pests |
| Author(s): | Royo J; Leon J; Vancanneyt G; Albar JP; Rosahl S; Ortego F; Castanera P; Sanchez-Serrano JJ; |
| Address: | "Departamento, Centro Nacional de Biotecnologia, Consejo Superior de Investigaciones Cientificas, Campus Cantoblanco Universidad Autonotia de Tiadrid, 28049 Madrid, Spain" |
| ISSN/ISBN: | 0027-8424 (Print) 1091-6490 (Electronic) 0027-8424 (Linking) |
| Abstract: | "De novo jasmonic acid (JA) synthesis is required for wound-induced expression of proteinase inhibitors and other defense genes in potato and tomato. The first step in JA biosynthesis involves lipoxygenase (LOX) introducing molecular oxygen at the C-13 position of linolenic acid. We previously have shown that, in potato, at least two gene families code for 13-LOX proteins. We have now produced transgenic potato plants devoid of one specific 13-LOX isoform (LOX-H3) through antisense-mediated depletion of its mRNA. LOX-H3 depletion largely abolishes accumulation of proteinase inhibitors on wounding, indicating that this specific LOX plays an instrumental role in the regulation of wound-induced gene expression. As a consequence, weight gain of Colorado potato beetles fed on antisense plants is significantly larger than those fed on wild-type plants. The poorer performance of LOX-H3-deficient plants toward herbivory is more evident with a polyphagous insect; larvae of beet armyworm reared on the antisense lines have up to 57% higher weight than those fed on nontransformed plants. LOX-H3 thus appears to regulate gene activation in response to pest attack, and this inducible response is likely to be a major determinant for reducing performance of nonspecialized herbivores. However, the regulatory role of LOX-H3 is not caused by its involvement in the wound-induced increase of JA, as wild-type and LOX-H3 deficient plants have similar jasmonate levels after wounding. LOX-H3-deficient plants have higher tuber yields. The apparent effect of suppressing the inducible defensive response on plant vigor suggests that it may pose a penalty in plant fitness under nonstress situations" |
| Keywords: | "Agrobacterium tumefaciens/genetics Amino Acid Sequence Animals Antibodies Coleoptera/*growth & development Cyclopentanes/*metabolism *DNA, Antisense *Gene Expression Regulation, Plant Larva Lipoxygenase/analysis/chemistry/*genetics/metabolism Molecular Se;" |
| Notes: | "MedlineRoyo, J Leon, J Vancanneyt, G Albar, J P Rosahl, S Ortego, F Castanera, P Sanchez-Serrano, J J eng Research Support, Non-U.S. Gov't 1999/02/03 Proc Natl Acad Sci U S A. 1999 Feb 2; 96(3):1146-51. doi: 10.1073/pnas.96.3.1146" |
