Enhanced cuticle accumulation by employing MIXTA-like transcription factors

Abstract

The cuticle covers almost the entire aerial surface of terrestrial plants, and provides protection from abiotic and biotic stresses. Cuticles basically consist of wax and cutin, and are produced with variable structures and thicknesses depending on the plant and organ. The application of plant cuticles to improve stress tolerance and wax production requires the deposition of the cuticle at specific times to avoid undesirable side effects. We previously showed that the MYB106 and MYB16 MIXTA-like transcription factors regulate cuticle formation. However, MYB106 over-expression results in severe dwarfism. In this study, we identified genes downstream of these MYB transcription factors and used their promoters to express MYB106 and MYB16 fused to the strong transcriptional activation domain, VP16. Comparisons of plant growth and cuticle morphology revealed that MYB106 and MYB16 preferentially produced cuticles that are typically observed in petals and leaves, respectively. Additionally, the CYP77A6 and CYP86A4 promoters effectively induced cuticle accumulation in leaves and petals, respectively, without inhibiting plant growth. Our strategy may be useful for increasing or altering cuticles in agronomically important plants.