Tissue-specific PhBPBT expression is differentially regulated in response to endogenous ethylene
Richard J Dexter1, Julian C Verdonk, Beverly A Underwood
1Department of Environmental Horticulture, University of Florida, Gainesville, FL 32611, USA.
Journal of Experimental Botany
|February 8, 2008
Summary
Plant hormone ethylene influences benzoyl CoA:benzyl alcohol/phenylethanol benzoyltransferase (PhBPBT) gene expression in petunia. This ethylene-induced PhBPBT regulation is crucial for defense mechanisms in flowers and vegetative tissues.
Area of Science:
- Plant molecular biology
- Plant hormone signaling
- Biochemistry
Background:
- Ethylene is a key gaseous plant hormone regulating senescence, fruit ripening, and defense.
- Benzoyl CoA:benzyl alcohol/phenylethanol benzoyltransferase (PhBPBT) synthesizes benzyl benzoate and phenylethyl benzoate in petunia.
Purpose of the Study:
- To investigate the effects of pollination and wound-induced ethylene signals on PhBPBT transcript accumulation in Petuniaxhybrida.
- To elucidate the role of PhBPBT in plant defense mechanisms.
Main Methods:
- RNA interference (RNAi) to silence PhBPBT transcript levels.
- Detailed expression analysis of PhBPBT under various conditions (light, circadian rhythm, ethylene treatment).
- Analysis of ethylene-insensitive transgenic petunia plants.
Main Results:
- RNAi-silenced lines showed reduced benzyl benzoate emission and increased benzyl alcohol.
- PhBPBT expression is regulated by light, circadian rhythm, and ethylene in a tissue-specific manner.
- Pollination decreased PhBPBT in corolla and increased it in the ovary, mediated by ethylene.
Conclusions:
- Ethylene differentially regulates PhBPBT expression in floral and vegetative tissues.
- PhBPBT and benzyl benzoate production are hypothesized to be involved in defense responses.
- Ethylene signaling is critical for wound-induced PhBPBT expression in vegetative tissues.
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