AtMYB41 activates ectopic suberin synthesis and assembly in multiple plant species and cell types

Abstract

Suberin is a lipid and phenolic cell wall heteropolymer found in the roots and other organs of all vascular plants. Suberin plays a critical role in plant water relations and in protecting plants from biotic and abiotic stresses. Here we describe a transcription factor, AtMYB41 (At4g28110), that can activate the steps necessary for aliphatic suberin synthesis and deposition of cell wall-associated suberin-like lamellae in both Arabidopsis thaliana and Nicotiana benthamiana. Overexpression of AtMYB41 increased the abundance of suberin biosynthetic gene transcripts by orders of magnitude and resulted in the accumulation of up to 22 times more suberin-type than cutin-type aliphatic monomers in leaves. Overexpression of AtMYB41 also resulted in elevated amounts of monolignols in leaves and an increase in the accumulation of phenylpropanoid and lignin biosynthetic gene transcripts. Surprisingly, ultrastructural data indicated that overexpression led to the formation of suberin-like lamellae in both epidermal and mesophyll cells of leaves. We further implicate AtMYB41 in the production of aliphatic suberin under abiotic stress conditions. These results provide insight into the molecular-genetic mechanisms of the biosynthesis and deposition of a ubiquitous cell wall-associated plant structure and will serve as a basis for discovering the transcriptional network behind one of the most abundant lipid-based polymers in nature.

MYB107 and MYB9 Homologs Regulate Suberin Deposition in Angiosperms

“…Yet, suberization is one of the hallmarks of wound injury and is well known to occur in cases of abiotic and biotic stress conditions. This is highlighted by the recent discovery that ATMYB41 is involved in the ABA-mediated plant response and suberin formation (Cominelli et al, 2008;Lippold et al, 2009;Kosma et al, 2014). In potato tuber, native and wound periderms are similar in composition, although the wound periderm is enriched with wax alkyl ferulates and is more permeable to water .…”

“…It appears that this gene pair coordinates the production of aromatic monomers through the phenylpropanoid pathway, while at the same time activating aliphatic monomer production in fatty acid biosynthesis as well as the extracellular transport and polymerization of these monomers ( Figure 9). It is important to note that members of the neighboring clade of MYB transcription factors include (1) AtMYB16 and AtMYB106, both demonstrated previously to regulate cutin formation (Oshima et al, 2013); (2) AtMYB74 and AtMYB102, which have been found to be involved in the plant's response to wounding, salt, and osmotic stresses (Denekamp and Smeekens, 2003;Xu et al, 2015); and (3) AtMYB41, the recently identified stress suberin regulator (Kosma et al, 2014). Together with the classification of AtMYB107 and At-MYB9 as regulators of suberin, this clade appears to include plant surface regulators, with a particular association to osmotic stress.…”

“…The recently described MYB factor AtMYB41 was demonstrated to be a positive regulator of suberin biosynthesis in Arabidopsis thaliana under stress conditions. Its overexpression was shown to activate ectopic suberin synthesis in multiple tissues (Kosma et al, 2014). AtMYB41 expression was earlier found to be induced under drought, abscisic acid (ABA), and salt treatments, and it most likely plays a role in the plant's response to abiotic stresses (Cominelli et al, 2008).…”

A comparative transcriptomic approach to understanding the formation of cork

“…Although a set of transcription factors belonging to MYB and NAC families has very recently been related to suberin accumulation (Kosma et al 2014;Gou et al 2017;Lashbrooke et al 2016;Legay et al 2016;Verdaguer et al 2016), only MYB102 and MYB107 were highlighted as upregulated in cork oak tissue according to DEGseq. Nevertheless, we identified several genes that may be involved in regulating phellogen activity.…”

The Tomato MIXTA-like Transcription Factor Coordinates Fruit Epidermis Conical Cell Development and Cuticular Lipid Biosynthesis and Assembly

“…Two members of the SHN1/WIN1 clade of transcription factors from Arabidopsis and tomato (AtSHN1 and SlSHN3, respectively) have been shown to be required for both cutin biosynthesis as well as epidermal cell patterning (Aharoni et al, 2004;Broun et al, 2004;Shi et al, 2011Shi et al, , 2013. Finally, members of the R2R3 MYB transcription factor superfamily, AtMYB41 and AtMYB96, have also been shown to regulate wax deposition during abiotic stress (Cominelli et al, 2008;Seo et al, 2011), although more recent results suggest that AtMYB41 likely promotes suberin biosynthesis and deposition (Kosma et al, 2014).…”