PHYTOPLASMA-ASSOCIATED REVERSE METAMORPHOSIS: A COMPARATIVE DNA METHYLOME ANALYSIS IN SESAMUM INDICUM

Abstract

Phytoplasma infection in Sesamum indicum induces severe morphological abnormalities such as phyllody, characterized by the transformation of floral organs into leaf-like structures. This phenomenon represents retrograde metamorphosis, where reproductive organs revert to vegetative identity. The present study investigates genome-wide DNA methylation changes associated with phytoplasma infection using Whole Genome Bisulfite Sequencing (WGBS) and methylation-sensitive PCR approaches. Comparative methylome profiling between healthy and infected plants revealed global hypomethylation, particularly in the CHH context, along with locus-specific hypermethylation in genes associated with development and Défense. Differentially methylated cytosines (DMCs) were predominantly located in intergenic and promoter regions, suggesting epigenetic regulation of gene expression. The findings highlight the critical role of DNA methylation in phytoplasma-induced phenotypic plasticity and provide insights into molecular mechanisms underlying retrograde metamorphosis.