Cuticle Biosynthesis in Tomato Leaves Is Developmentally Regulated by Abscisic Acid

Abstract

The expansion of aerial organs in plants is coupled with the synthesis and deposition of a hydrophobic cuticle, composed of cutin and waxes, which is critically important in limiting water loss. While the abiotic stress-related hormone abscisic acid (ABA) is known to up-regulate wax accumulation in response to drought, the hormonal regulation of cuticle biosynthesis during organ ontogeny is poorly understood. To address the hypothesis that ABA also mediates cuticle formation during organ development, we assessed the effect of ABA deficiency on cuticle formation in three ABA biosynthesis-impaired tomato mutants. The mutant leaf cuticles were thinner, had structural abnormalities, and had a substantial reduction in levels of cutin. ABA deficiency also consistently resulted in differences in the composition of leaf cutin and cuticular waxes. Exogenous application of ABA partially rescued these phenotypes, confirming that they were a consequence of reduced ABA levels. The ABA mutants also showed reduced expression of genes involved in cutin or wax formation. This difference was again countered by exogenous ABA, further indicating regulation of cuticle biosynthesis by ABA. The fruit cuticles were affected differently by the ABA-associated mutations, but in general were thicker. However, no structural abnormalities were observed, and the cutin and wax compositions were less affected than in leaf cuticles, suggesting that ABA action influences cuticle formation in an organdependent manner. These results suggest dual roles for ABA in regulating leaf cuticle formation: one that is fundamentally associated with leaf expansion, independent of abiotic stress, and another that is drought induced.

Manipulation of β‐carotene levels in tomato fruits results in increased ABA content and extended shelf life

“…LCYb‐ overexpressing fruits also had significantly higher amounts of cutin monomers and alicyclic wax components relative to WT , but unchanged levels of linear, very‐long‐chain wax compounds. Our results suggest a regulatory effect of ABA on cuticle deposition in fruits, consistent with previously published data in tomato (Curvers et al , ; Martin et al , ) and Arabidopsis (Seo et al , ; Zhang et al , ) leaves.…”

Effect of abscisic acid and methyl jasmonate preharvest applications on fruit quality and cracking tolerance of sweet cherry

“…The effect of these phytohormones on cracking susceptibility could be associated with several mechanisms. For example, it is known that ABA plays an active role in wax metabolism through the activation of genes related to biosynthesis and transport of cutin and waxes (Kosma et al, 2009;Martin et al, 2017). Indeed, in Arabidopsis it has been shown that ABA induces the expression of CER1 (Kosma et al, 2009), which encodes a regulation enzyme that promotes C29 alkane biosynthesis (Bourdenx et al, 2011).…”

“…It is known that ABA plays a decisive role in the regulation of cuticle and cell wall biosynthesis, which consequently affects the structure and composition of the outer surface layers. Although a direct effect of ABA application on the fruit CM biosynthesis has not been reported, exogenous ABA application in Arabidopsis increases cuticle lipids biosynthesis, reducing cuticle permeability (Martin et al, 2017).…”

Characterizing the involvement of FaMADS9 in the regulation of strawberry fruit receptacle development

“…In tomato fruits, it has been reported that cuticular wax composition is changed in ABA‐deficient mutants (Martin et al , ). Previous studies have shown that ABA plays an important role in the regulation of strawberry fruit ripening (Chai et al , ; Jia et al , ; Li et al , ).…”