A Molecular Framework for Somatic Embryogenesis

Background

Somatic embryogenesis is a form of asexual reproduction in which embryos develop from vegetative tissues. Somatic embryogenesis is a natural form of reproduction for some plants, like citrus and mango, but can also be induced using plant hormones in a wide range of plants and plant tissues. However, somatic embryo induction can be very difficult in many plants or even in different tissues of an otherwise responsive plant. We are interested in understanding the molecular-genetic factors that determine whether a plant cell is responsive or recalcitrant for somatic embryo induction.

Aim of the Project

Somatic embryogenesis can be induced in the model plant Arabidopsis thaliana (arabidopsis) by treating in vitro cultured explants with the synthetic auxin 2,4-D. Many types of arabidopsis tissues can be induced to form embryos e.g., leaves, shoot meristems and ovules. There is a large amount of natural variation among arabidopsis ecotypes for the ability to undergo somatic embryogenesis. This variation provides an experimental platform for understanding the competence-recalcitrance spectrum of somatic embryo induction. In this project we will compare two ecotypes with contrasting responses to somatic embryo induction. These comparisons involve cellular, molecular and chromatin level studies. (Live) imaging of hormone and cell fate fluorescent reporters will be used to identify the key cellular events during the development of responsive and non-responsive ecotypes. RNA-seq will be used to define the transcriptional cascades associated with the in vitro culture response of each ecotype. Finally, chemical screening with epidrug libraries will be used to identify chromatin modifying proteins that mimic the response of the responsive and non-responsive ecotypes..