Publications by authors named "Jeff W Denault"

Recent research has significantly advanced our understanding of the phenylpropanoid pathway but has left in doubt the pathway by which sinapic acid is synthesized in plants. The reduced epidermal fluorescence1 (ref1) mutant of Arabidopsis thaliana accumulates only 10 to 30% of the sinapate esters found in wild-type plants. Positional cloning of the REF1 gene revealed that it encodes an aldehyde dehydrogenase, a member of a large class of NADP(+)-dependent enzymes that catalyze the oxidation of aldehydes to their corresponding carboxylic acids.

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Branching ratios have been measured as a function of collision energy for the dissociation of mass-selected chloride-bound salt cluster ions, [Rb-35Cl-Mi]+, where Mi = Na, K, Cs. The extended version of the kinetic method was used to determine the heterolytic bond dissociation energy (HBDE) of Rb-Cl. The measured value of 480.

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The end products of the phenylpropanoid pathway play important roles in plant structure and development, as well as in plant defense mechanisms against biotic and abiotic stresses. From a human perspective, phenylpropanoid pathway-derived metabolites influence both human health and the potential utility of plants in agricultural contexts. The last known enzyme of the phenylpropanoid pathway that has not been characterized is p-coumarate 3-hydroxylase (C3H).

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Article Synopsis
  • The enzyme p-coumarate 3-hydroxylase (C3H) is crucial for making lignin and other compounds in plants, but methods to study it have been unsuccessful so far.
  • Researchers found Arabidopsis mutants with low levels of certain metabolites that revealed a mutant (ref8) unable to produce caffeic acid, indicating a problem with C3H activity.
  • The REF8 gene was isolated and identified as encoding C3H, which is actually a cytochrome P450-dependent monooxygenase, challenging previous beliefs about its function and suggesting the current understanding of lignin biosynthesis may need to be revised.
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