Abstract
Summary
Background
The cuticle is a hydrophobic polymeric assembly covering the surface of the aerial parts of plants. In the tomato fruit (
Solanum lycopersicum
), the cuticle is involved in many agronomically important traits, such as fruit brightness, resistance to cracking or shelf life. The development of a molecular tool targeting cuticle-associated genes in tomato fruit epidermis could considerably advance our understanding of the relationship between the structure of the cuticle and its functional properties.
Results
According to its expression profile, the
non-specific Lipid Transfer Protein 2
promoter (
pronsLTP
) was selected and its application as a molecular tool for targeting modifications in the epidermis of tomato fruit was validated. Indeed, fluorescence analysis confirmed that
pronsLTP
activity is associated with the fruit epidermis and coincides with cuticle accumulation. In addition, edition using a CRISPR tissue-specific knockout approach (CRISPR-TSKO) of the carotenoid
SlPSY1
gene via
pronsLTP
showed a high mutation frequency only in the fruit exocarp and mesocarp. Furthermore, overexpression of the flavonoid regulatory gene
SlMYB75
under the control of
pronsLTP
resulted in targeted accumulation of anthocyanins in the exocarp of growing fruit, associated with a change in cuticle composition and permeability.
Conclusions
Altogether, our results provide a new molecular tool essential for delineating the functional role of cuticle components and opens new perspectives for the targeted engineering of cuticle-related traits to improve fruit quality and agronomical properties.