Stable Transgenerational Epimutants in Okra Induced by Sodium Butyrate: A Novel Pathway to Functional Breeding

Histone deacetylation chemicals such as sodium butyrate can induce phenotypic epigenetic variations in okra varieties. Some of these induced variations can be transmitted across multiple generations with uniformity and stability over locations. Epigenetic modifications act as an extraneous source of variations in organisms possessing them. Epigenetic marks are observed in natural plant populations; however, the chemical induction, identification and heritable transmission of visible epigenetic variations remain relatively rare. In our study, we have tried inducing phenotypic variations in two open pollinated okra varieties, namely, Arka Anamika and Arka Abhay using a histone deacetylase inhibitor, sodium butyrate. A wide spectrum of visible mutations for various traits was observed among the treated plants. One particular mutant plant lacking purple color pigmentation on the backside of the petals was identified and observed to be reappearing in successive generations. The trait was stably inherited across generations and locations following a non-Mendelian pattern of inheritance. The study showed that mutations can be artificially induced epigenetically in plants and some of these induced mutations can be stably inherited by subsequent generations, exhibiting stable and uniform performance.