BODYGUARD is required for the biosynthesis of cutin in Arabidopsis

Abstract

SummaryThe cuticle plays a critical role in plant survival during extreme drought conditions. There are, however, surprisingly, many gaps in our understanding of cuticle biosynthesis.An Arabidopsis thaliana T-DNA mutant library was screened for mutants with enhanced transpiration using a simple condensation spot method. Five mutants, named cool breath (cb), were isolated.The cb5 mutant was found to be allelic to bodyguard (bdg), which is affected in an a/bhydrolase fold protein important for cuticle structure. The analysis of cuticle components in cb5 (renamed as bdg-6) and another T-DNA mutant allele (bdg-7) revealed no impairment in wax synthesis, but a strong decrease in total cutin monomer load in young leaves and flowers. Root suberin content was also reduced. Overexpression of BDG increased total leaf cutin monomer content nearly four times by affecting preferentially C18 polyunsaturated x-OH fatty acids and dicarboxylic acids. Whole-plant gas exchange analysis showed that bdg-6 had higher cuticular conductance and rate of transpiration; however, plant lines overexpressing BDG resembled the wild-type with regard to these characteristics. This study identifies BDG as an important component of the cutin biosynthesis machinery in Arabidopsis. We also show that, using BDG, cutin can be greatly modified without altering the cuticular water barrier properties and transpiration.

Peroxidase-Generated Apoplastic ROS Impair Cuticle Integrity and Contribute to DAMP-Elicited Defenses

“…Our data is supported by previous studies using the bdg and lacs2.3 cuticular mutants (Schnurr et al, 2004; Bessire et al, 2007; L’Haridon et al, 2011; Jakobson et al, 2016), in which the permeability of the cuticle, the accumulation of ROS and cuticular waxes and the resistance to B. cinerea were enhanced in comparison to that observed in wild-type plants. The above findings, when taken together, indicate that in plants, cuticle integrity is influenced by a feedback mechanism.…”

The karrikin receptor KAI2 promotes drought resistance in Arabidopsis thaliana

“…Additionally, loss of KAI2 also downregulated the expression of cutin biosynthesis-related genes ( S5 Fig ). For example, CED1 / At1g64670 [ 37 , 38 ], which minimizes water loss through not only by enhancing cuticle structure but also by mediating ABA and osmotic stress signaling [ 39 ], was downregulated in kai2 versus WT after 4 h dehydration ( S5 Fig ). These findings support the positive role of KAI2 in mediating drought resistance, and the link among cuticle formation, KAI2 signaling, ABA signaling and osmotic stress responses in plants.…”

MdMyb93 is a regulator of suberin deposition in russeted apple fruit skins

“…The a, b-fold protein hydrolases, regulated by MdMYB93, might also participate in this process. Indeed, in A. thaliana, an a,b-fold protein hydrolase called BODYGUARD is a crucial actor of the polymerization of carboxylic esters of cutin and might be implicated in the attachment of suberin to the cell wall (Kurdyukov et al, 2006;Jakobson et al, 2016). However, the functions of these proteins is broad and caution should be taken regarding their function in suberization, as they might also participate generally in the hydroxylation of fatty acids (Bl ee & Schuber, 1993).…”