Abstract Detail
Cell-to-Cell and Long Distance Signaling Koo, Abraham Jeong-Kyu [1], Howe, Gregg [2]. Role of jasmonic acid in long-distance defense signaling. Jasmonic acid (JA) production in response to wounding and herbivore attack results in genome-wide changes in transcription, including increased expression of JA biosynthetic genes. Recent studies with tomato indicate that JA biosynthesis is required for production of the mobile wound signal that initiates systemic defense responses, and further suggest that JA itself may act as this signal. To study the role of de novo JA synthesis in the systemic defense response in Arabidopsis, we developed a transgenic system in which JA synthesis can be restricted to specific tissues of the plant. Injury to wild type Arabidopsis leaves by mechanical wounding or insect feeding resulted in JA accumulation in local damaged leaves but not in systemic undamaged leaves. A mutant that is defective in a peroxisomal JA biosynthetic enzyme (OPDA reducase3; OPR3) accumulated about 5% wild-type levels of JA in response to wounding. As a consequence, opr3 mutant plants were impaired in local and systemic expression of several wound-responsive genes. A transgene encoding a GFP-OPR3 fusion protein expressed from a dexametazone (DEX)-inducible promoter was introduced into the opr3 mutant. Leaves treated with 30 uM DEX accumulated GFP-OPR3 mRNA and protein within 6 hr of treatment. DEX-induced expression of GFP-OPR3 complemented the JA deficiency of opr3 plants, and was largely restricted to the area of DEX application. This transgenic approach for manipulating the spatial pattern of JA synthesis is currently being used to examine the role of local JA production in systemic spread of the wound signal.
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1 - Michigan State University, DOE-Plant Research Laboratory, 122 Plant Biology Building, East Lansing, MI, 48824, USA
2 - Michigan State University, DOE-Plant Research Laboratory, Department of Biochemistry and Molecular Biology
Keywords:
jasmonic acid
Signaling
long-distance
dexamethasone
wounding.
Presentation Type: Plant Biology Abstract
Session: P
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM
Number: P34012
Abstract ID:1144 | 