MYB107 and MYB9 Homologs Regulate Suberin Deposition in Angiosperms.
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 theArabidopsis thalianaseed coat. Seeds ofmyb107andmyb9Arabidopsis 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.
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.|Research and Innovation Centre, Foundation Edmund Mach, I-38010 San Michele all'Adige, Trento, Italy.|ARC Infruitec-Nietvoorbij, Stellenbosch 7599, South Africa.
Justin
http://orcid.org/0000-0003-4511-4215
J
Lashbrooke
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Hagai
H
Cohen
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Dorit
D
Levy-Samocha
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Oren
O
Tzfadia
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Irina
I
Panizel
Department of Ecophysiology, IZMB, University of Bonn, 53115 Bonn, Germany.
Viktoria
V
Zeisler
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Hassan
H
Massalha
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
Adi
A
Stern
Department of Biology, University of Padova, 35121 Padova, Italy.
Livio
http://orcid.org/0000-0002-8829-8205
L
Trainotti
Department of Ecophysiology, IZMB, University of Bonn, 53115 Bonn, Germany.
Lukas
http://orcid.org/0000-0001-7003-9929
L
Schreiber
Research and Innovation Centre, Foundation Edmund Mach, I-38010 San Michele all'Adige, Trento, Italy.
Fabrizio
http://orcid.org/0000-0003-1416-1078
F
Costa
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel asaph.aharoni@weizmann.ac.il.
Asaph
A
Aharoni