Chaetocin enhances callus induction by decreasing the expression of major leaf polarity genes in Nicotiana tabacum

Abstract

Using chemicals known as inhibitors of chromatin remodeling enzymes is a useful approach in understanding the regulation machinery that contributes to the maintenance of or conversion to a pluri- and totipotent states of the cells in multicellular organisms. They can serve as tools to reveal the molecular and cellular mechanisms required for reprogramming. A deeper understanding of reprogramming pathways that drive the cell into a dedifferentiated state might help us enhance plant micropropagation and green biotechnology applications. Chaetocin is one of the histone methyltransferase inhibitors known as key drivers in several cellular processes. It was shown that chaetocin enhanced the reprogramming of human fibroblasts. Here, by using an analogy approach, we tested the effects of chaetocin on the postgermination growth and callus induction in Nicotiana tabacum for the first time. We found that chaetocin retarded the leaf development in N. tabacum seedlings but increased the callus formation when applied in the post-germination growth phase (1.4 fold). The expression of AS1, KAN1, YAB3, FIL, major leaf polarity genes, significantly decreased when seeds were treated with Ch during the post-germination growth phase by 69, 45, 46, 68%, respectively. We also observed that chaetocin could not replace 2,4-Dichlorophenoxyacetic acid as a callus inducing modulator. The present study is a pioneer, exhibiting valuable data to understand the molecular mechanisms underlying the effects of chaetocin and the unknown properties of histone-modifying enzymes. Hence, novel approaches can be developed by using high throughput methods to elucidate epigenetic mechanisms of cellular differentiation/dedifferentiation processes in plant systems.