| Title: | Parasitism by Cuscuta pentagona sequentially induces JA and SA defence pathways in tomato |
| Author(s): | Runyon JB; Mescher MC; Felton GW; De Moraes CM; |
| Address: | "Department of Entomology, Pennsylvania State University, University Park, PA 16802, USA" |
| DOI: | 10.1111/j.1365-3040.2009.02082.x |
| ISSN/ISBN: | 1365-3040 (Electronic) 0140-7791 (Linking) |
| Abstract: | "While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C(18) fatty acids in tomato attacked by the parasitic plant Cuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence-related phytohormones salicylic acid (SA) and jasmonic acid (JA). Parasite attachment to 10-day-old tomato plants elicited few biochemical changes, but a second attachment 10 d later elicited a 60-fold increase in JA, a 30-fold increase in SA and a hypersensitive-like response (HLR). Host age also influenced the response: neither Cuscuta seedlings nor established vines elicited a HLR in 10-day-old hosts, but both did in 20-day-old hosts. Parasites grew larger on hosts deficient in SA (NahG) or insensitive to JA [jasmonic acid-insensitive1 (jai1)], suggesting that both phytohormones mediate effective defences. Moreover, amounts of JA peaked 12 h before SA, indicating that defences may be coordinated via sequential induction of these hormones. Parasitism also induced increases in free linolenic and linoleic acids and abscisic acid. These findings provide the first documentation of plant hormonal signalling induced by a parasitic plant and show that tomato responses to C. pentagona display characteristics similar to both herbivore- and pathogen-induced responses" |
| Keywords: | Abscisic Acid/biosynthesis Cuscuta/*growth & development Cyclopentanes/*metabolism Linoleic Acid/biosynthesis Linolenic Acids/biosynthesis Solanum lycopersicum/*metabolism/parasitology Oxylipins/*metabolism Plant Growth Regulators/*metabolism Salicylic Ac; |
| Notes: | "MedlineRunyon, Justin B Mescher, Mark C Felton, Gary W De Moraes, Consuelo M eng Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2009/11/26 Plant Cell Environ. 2010 Feb; 33(2):290-303. doi: 10.1111/j.1365-3040.2009.02082.x. Epub 2009 Nov 17" |
