MYB107 and MYB9 Homologs Regulate Suberin Deposition in Angiosperms

Justin Lashbrooke, Hagai Cohen, Dorit Levy-Samocha, Oren Tzfadia, Irina Panizel, Viktoria Zeisler, Hassan Massalha, Adi Stern, Livio Trainotti, Lukas Schreiber, Fabrizio Costa, Asaph Aharoni

Research output: Contribution to journalArticle

Abstract

Suberin, a polymer composed of both aliphatic and aromatic domains, is deposited as a rough matrix upon plant surface damage and during normal growth in the root endodermis, bark, specialized organs (e.g., potato [Solanum tuberosum] tubers), and seed coats. To identify genes associated with the developmental control of suberin deposition, we investigated the chemical composition and transcriptomes of suberized tomato (Solanum lycopersicum) and russet apple (Malus x domestica) fruit surfaces. Consequently, a gene expression signature for suberin polymer assembly was revealed that is highly conserved in angiosperms. Seed permeability assays of knockout mutants corresponding to signature genes revealed regulatory proteins (i.e., AtMYB9 and AtMYB107) required for suberin assembly in the Arabidopsis thaliana seed coat. Seeds of myb107 and myb9 Arabidopsis mutants displayed a significant reduction in suberin monomers and altered levels of other seed coat-associated metabolites. They also exhibited increased permeability, and lower germination capacities under osmotic and salt stress. AtMYB9 and AtMYB107 appear to synchronize the transcriptional induction of aliphatic and aromatic monomer biosynthesis and transport and suberin polymerization in the seed outer integument layer. Collectively, our findings establish a regulatory system controlling developmentally deposited suberin, which likely differs from the one of stress-induced polymer assembly recognized to date.

Original languageEnglish
JournalPlant Cell
Volume28
Issue number9
Pages (from-to)2097-2116
Number of pages20
ISSN1040-4651
DOIs
Publication statusPublished - Sep-2016

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