Title: Indole Glucosinolate Biosynthesis Limits Phenylpropanoid Accumulation in Arabidopsis thaliana

Abstract

Plants produce an array of metabolites (including lignin monomers and soluble UV-protective metabolites) from phenylalanine through the phenylpropanoid biosynthetic pathway. A subset of plants, including many related to Arabidopsis thaliana, synthesizes glucosinolates, nitrogen- and sulfur-containing secondary metabolites that serve as components of a plant defense system that deters herbivores and pathogens. Here, we report that the Arabidopsis thaliana reduced epidermal fluorescence5 (ref5-1) mutant, identified in a screen for plants with defects in soluble phenylpropanoid accumulation, has a missense mutation in CYP83B1 and displays defects in glucosinolate biosynthesis and in phenylpropanoid accumulation. CYP79B2 and CYP79B3 are responsible for the production of the CYP83B1 substrate indole-3-acetaldoxime (IAOx), and we found that the phenylpropanoid content of cyp79b2 cyp79b3 and ref5-1 cyp79b2 cyp79b3 plants is increased compared with the wild type. These data suggest that levels of IAOx or a subsequent metabolite negatively influence phenylpropanoid accumulation in ref5 and more importantly that this crosstalk is relevant in the wild type. Additional biochemical and genetic evidence indicates that this inhibition impacts the early steps of the phenylpropanoid biosynthetic pathway and restoration of phenylpropanoid accumulation in a ref5-1 med5a/b triple mutant suggests that the function of the Mediator complex is required for the crosstalk.

Authors:

Kim, Jeong Im  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-5618-3948"

Dolan, Whitney L.  ^[1];

• Search DOE PAGES for author "Dolan, Whitney L."
• Search DOE PAGES for ORCID "0000-0001-9069-9764"

Anderson, Nickolas A.  ^[1];

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• Search DOE PAGES for ORCID "0000-0002-6572-8954"

Chapple, Clint  ^[1]

• Search DOE PAGES for author "Chapple, Clint"
• Search DOE PAGES for ORCID "0000-0002-5195-562X"

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+ Show Author Affiliations

1. Purdue Univ., West Lafayette, IN (United States). Dept. of Biochemistry

Publication Date:

Fri May 01 00:00:00 EDT 2015

Research Org.:

Purdue Univ., West Lafayette, IN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1597755

Grant/Contract Number:  

FG02-07ER15905; SC000997

Resource Type:

Accepted Manuscript

Journal Name:

The Plant Cell

Additional Journal Information:

Journal Volume: 27; Journal Issue: 5; Journal ID: ISSN 1040-4651

Publisher:

American Society of Plant Biologists

Country of Publication:

United States

Language:

English

Subject:

59 BASIC BIOLOGICAL SCIENCES