An Epigenetic Approach of Somaclonal Variation in the Oil Palm

Epigenetics is the study of heritable changes in gene function that occur without a change in the DNA sequence. In recent years, this field has attracted much attention as more epigenetic controls of gene activities are being discovered. Such controls involve a complex interplay of DNA methylation, histone modifications, and RNA-mediated pathways from non-coding RNAs. Although epigenetic processes are essential for development and differentiation, they can become misdirected as a consequence of environmental changes.

In plants, epigenetic phenomena have economic relevance in the case of somaclonal variation: a genetic and phenotypic variation among clonally propagated plants from a single donor genotype. In oil palm (Elaeis guineensis Jacq), approximately 5% of somatic embryo-derived palms show abnormalities in their floral development due to the feminization of male parts in flowers from both sexes.

The “mantled” variant phenotype provides an original model because somaclonal variation alters the expression of genes coding - directly or indirectly - for the flower structure and DNA hypomethylation has already been clearly demonstrated in somaclonal variants.

Recently launched NGS projects are providing new insights into both the oil palm genome and transcriptome for the identification and characterization of putative target genes with altered expression linked to somaclonal variation.