| Title: | Herbivore-induced jasmonic acid bursts in leaves of Nicotiana attenuata mediate short-term reductions in root growth |
| Author(s): | Hummel GM; Schurr U; Baldwin IT; Walter A; |
| Address: | "ICG-3 (Phytosphere), Research Center Julich, D-52425, Julich, Germany" |
| DOI: | 10.1111/j.1365-3040.2008.01905.x |
| ISSN/ISBN: | 1365-3040 (Electronic) 0140-7791 (Linking) |
| Abstract: | "Root growth in Nicotiana attenuata is transiently reduced after application of oral secretions (OS) of Manduca sexta larvae to wounds in leaves. Feeding of M. sexta or OS elicitation is known to result in jasmonic acid (JA) and ethylene bursts, and activates a suite of defence responses. Because both plant hormones are known to strongly reduce root growth, their activation might account for the observed reduction of root growth following herbivory. To test this hypothesis, we measured primary root growth with digital image sequence processing at high temporal resolution in antisense-lipoxygenase 3 (asLOX3) and inverted repeat-coronatin-insensitive 1 (irCOI1) seedlings which are impaired in JA biosynthesis and perception, respectively, and wild-type (WT) seedlings. Higher root growth rates in irCOI1 compared with WT were observed after OS elicitation. The dynamics of wound-induced root growth reduction coincide with the dynamics of root growth reduction induced by external application of methyl JA. In an experiment with 1-methylcyclopropen (1-MCP), a potent ethylene receptor blocker, no wounding-specific difference between growth of 1-MCP-treated plants and non-treated plants was observed, suggesting that wound-induced endogenous JA and not ethylene mediates the wounding-specific reduction in root growth. Yet, inhibiting the ethylene response by applying 1-MCP led to markedly increased root growth compared with that of control plants, indicating that ethylene normally suppresses plant growth in N. attenuata seedlings" |
| Keywords: | "Animals Cyclopentanes/*metabolism Cyclopropanes/pharmacology Ethylenes/metabolism Gene Expression Regulation, Plant Manduca/physiology Oxylipins/*metabolism Plant Growth Regulators/*metabolism Plant Leaves/genetics/growth & development/*metabolism Plant R;" |
| Notes: | "MedlineHummel, Gregoire M Schurr, Ulrich Baldwin, Ian T Walter, Achim eng Research Support, Non-U.S. Gov't 2008/12/05 Plant Cell Environ. 2009 Feb; 32(2):134-43. doi: 10.1111/j.1365-3040.2008.01905.x. Epub 2008 Nov 14" |
