| Title: | A MYB Triad Controls Primary and Phenylpropanoid Metabolites for Pollen Coat Patterning |
| Author(s): | Battat M; Eitan A; Rogachev I; Hanhineva K; Fernie A; Tohge T; Beekwilder J; Aharoni A; |
| Address: | "Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel. Institute of Public Health and Clinical Nutrition, University of Eastern Finland, FI-70211 Kuopio, Finland. Max Planck Institute of Molecular Plant Physiology, D-14476 Potsdam-Golm, Germany. Plant Research International, 6700 AA Wageningen, The Netherlands. Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel asaph.aharoni@weizmann.ac.il" |
| ISSN/ISBN: | 1532-2548 (Electronic) 0032-0889 (Print) 0032-0889 (Linking) |
| Abstract: | "The pollen wall is a complex, durable structure essential for plant reproduction. A substantial portion of phenylpropanoids (e.g. flavonols) produced by pollen grain tapetal cells are deposited in the pollen wall. Transcriptional regulation of pollen wall formation has been studied extensively, and a specific regulatory mechanism for Arabidopsis (Arabidopsis thaliana) pollen flavonol biosynthesis has been postulated. Here, metabolome and transcriptome analyses of anthers from mutant and overexpression genotypes revealed that Arabidopsis MYB99, a putative ortholog of the petunia (Petunia hybrida) floral scent regulator ODORANT1 (ODO1), controls the exclusive production of tapetum diglycosylated flavonols and hydroxycinnamic acid amides. We discovered that MYB99 acts in a regulatory triad with MYB21 and MYB24, orthologs of emission of benzenoids I and II, which together with ODO1 coregulate petunia scent biosynthesis genes. Furthermore, promoter-activation assays showed that MYB99 directs precursor supply from the Calvin cycle and oxidative pentose-phosphate pathway in primary metabolism to phenylpropanoid biosynthesis by controlling TRANSKETOLASE2 expression. We provide a model depicting the relationship between the Arabidopsis MYB triad and structural genes from primary and phenylpropanoid metabolism and compare this mechanism with petunia scent control. The discovery of orthologous protein triads producing related secondary metabolites suggests that analogous regulatory modules exist in other plants and act to regulate various branches of the intricate phenylpropanoid pathway" |
| Keywords: | "Arabidopsis/metabolism/*physiology/ultrastructure Arabidopsis Proteins/genetics/metabolism/*physiology Coumaric Acids/metabolism Flavonols/metabolism Gene Expression Regulation, Plant Plant Leaves/metabolism Pollen/metabolism/*ultrastructure Transcription;" |
| Notes: | "MedlineBattat, Maor Eitan, Asa Rogachev, Ilana Hanhineva, Kati Fernie, Alisdair Tohge, Takayuki Beekwilder, Jules Aharoni, Asaph eng 2019/02/14 Plant Physiol. 2019 May; 180(1):87-108. doi: 10.1104/pp.19.00009. Epub 2019 Feb 12" |
