The aerial parts of most plants are covered with cuticular wax which is
important for plants to avoid harmful factors. While the wax is an important
part of the plant, there is still no cloning study on the wax synthesis gene
of the alcohol-forming pathway in Brassica species. The team of Dongming Liu
from the Chinese Academy of Agricultural Sciences aimed to study the target
gene using a wax-deficient cabbage (Brassica oleracea) mutant, LD10GL.
The team used scanning electron microscopy to compare the leaves of the wild
type and the mutant. Compared with wild type, wax crystals are severely
reduced in both the adaxial and abaxial sides of leaves from the LD10GL
mutant. Analysis revealed that the glossy trait of LD10GL is controlled by a
single recessive gene, designated Bol013612 or Cgl2 (Cabbage Glossy 2). The
gene is also homologous to Arabidopsis CER4, which encodes fatty
acyl-coenzyme A reductase.
Sequencing identified a single nucleotide substitution that results in an
insertion of six nucleotides in the Bol013612 gene in LD10GL. The phenotypic
defect of LD10GL was confirmed by a functional complementation test with
Arabidopsis mutant cer4.
These results indicate that wax crystals of cabbage mutant LD10GL are
severely reduced and mutation of gene Bol013612 or Cgl2 causes a glossy
phenotype in the LD10GL mutant.