Universität zu Köln

Frerigmann, Henning ORCID: 0000-0002-7067-2721 and Gigolashvili, Tamara ORCID: 0000-0002-0416-4796 (2014). Update on the role of R2R3-MYBs in the regulation of glucosinolates upon sulfur deficiency. Front. Plant Sci., 5. LAUSANNE: FRONTIERS MEDIA SA. ISSN 1664-462X

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Abstract

To balance the flux of sulfur (S) into glucosinolates (GSL) and primary metabolites plants exploit various regulatory mechanisms particularly important upon S deficiency (S). The role of MYB34, MYB51 and MYB122 controlling the production of indolic glucosinolates (IGs) and MYB28, MYB29, and MYB76 regulating the biosynthesis of aliphatic glucosinolates (AGs) in Arabidopsis thaliana has not been fully addressed at S conditions yet. We show that the decline in the concentrations of GSL during S depletion does not coincide with the globally decreased transcription of R2R3-MYBs. Whereas the levels of GSL are diminished, the expression of MYB34, MYB51, MYB122, and MYB28 is hardly changed in early phase of S limitation. Furthermore, the mRNA levels of these MYBs start to raise under prolonged S starvation. In parallel, we found that SLIM1 can downregulate the MYBs in vitro as demonstrated in trans-activation assays in cultured Arabidopsis cells with SLIM1 as effector and ProMYB51:uidA as a reporter construct. However, in vivo, only the mRNA of MYB29 and MYB76 correlated with the levels of GSL at S. We propose that the negative effect of SLIM1 on GSL regulatory genes can be overridden by a low GSL signal inducing the transcription of MYBs in a feedback regulatory loop. In accordance with this hypothesis, the expression of MYB34, MYB51, MYB122, and CYP83B1 was further induced in cyp79b2 cyp79b3 mutant exposed to S conditions vs. cyp79b2 cyp79b3 plants grown on control medium. In addition, the possible role of MYBs in the regulation of essential S assimilation enzymes, in the regulation of GSL biosynthesis upon accelerated termination of life cycles, in the mobilization of auxin and lateral root formation at S deficiency is discussed.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Frerigmann, Henning UNSPECIFIED orcid.org/0000-0002-7067-2721 UNSPECIFIED Gigolashvili, Tamara UNSPECIFIED orcid.org/0000-0002-0416-4796 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-423542
DOI:	10.3389/fpls.2014.00626
Journal or Publication Title:	Front. Plant Sci.
Volume:	5
Date:	2014
Publisher:	FRONTIERS MEDIA SA
Place of Publication:	LAUSANNE
ISSN:	1664-462X
Language:	English
Faculty:	Faculty of Mathematics and Natural Sciences
Divisions:	Faculty of Mathematics and Natural Sciences > Department of Biology > Botanical Institute
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language TRANSCRIPTIONAL REGULATOR; SULFATE ASSIMILATION; ARABIDOPSIS; GENE; BIOSYNTHESIS; METABOLOMICS; INTEGRATION; METABOLISM; MYROSINASE; EVOLUTION Multiple languages Plant Sciences Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/42354