The role of the Class I acyl-CoA-binding protein family function in Arabidopsis cuticle formation

Abstract

The Arabidopsis thaliana Class I acyl-CoA-binding protein family was shown here to functi on in cuti cle formati on. This was achieved using T-DNA inserti onal mutants in Arabidopsis. The acbp mutants showed fewer wax crystals on the stem/leaf surfaces and displayed disrupted cuti cle layers in scanning and transmission electron microscopy, respecti vely. Cuti cular wax and cuti n monomer compositi on was found to be reduced in the mutants in comparison to the wild type when analyzed with gas chromatography (GC) and GC-mass spectrometry (MS). Mutant ti ssue also had consistent reducti on in the expression of genes involved in the biosynthesis of cuti cular wax and cuti n. To further investi gate the spati al expression of AtACBP, AtACBP promoter::Y-glucuronidase gene fusions were generated. Resultant transgenic Arabidopsis plants demonstrated GUS expression on the surfaces supporti ng its role in cuti cle formati on. Our fi ndings imply that the Class I ACBP family parti cipates in Arabidopsis cuti cular wax accumulati on by traffi cking very-long-chain acyl-CoAs to which recombinant forms are known to bind.