It is now known that the DNA sequence of any given gene is not the only carrier of information that determines phenotype of an organism. Changes in gene expression that lead to novel phenotypes can occur through chemical modifications of the DNA (methylation) and the way the DNA is packaged (chromatin structure) within the nucleus of each cell. This type of gene regulation is known as “above gene” or “epigenetic”.
Due to their sessile nature, plants undergo widespread epigenetic modifications to allow them to adapt rapidly to a changing environment. A major environmental stress for plants is exposure to high salinity, which affects approximately half of the world’s crop production, yet the mechanism(s) that modulate resistance to high salinity remain elusive. My PhD project aims to identify the specific epigenetic changes induced by salt stress and studying their stability across generations . Using a range of state-of-the-art techniques I will identify the molecular mechanism(s) that regulate this adaptative process. Results from this project will benefit science and society by providing new strategies for improving crop productivity in an increasingly adverse environment and potentially increasing the percentage of cultivable agricultural land.
For my PhD project, Arabidopsis thaliana wild-type ecotype Columbia (Col) and various Arabidopsis epigenetic mutant lines were used. Arabidopsis plants are germinated and grown in MS medium containing various concentration of salt for five constitutive generations.The plants then transferred and grown on soil until maturity. In addition to evalaution of plant's tolerance level to salt stress, various molecular changes in response to salt stress, such as DNA methylation, gene expression, and long non-coding RNA expression were analyzed. To studying the inheritance of stress-induced epigenetic changes, I also analyzed the effect of multigenerational salt stress on sperm cell, egg cell and embryos epiegenetic landscape.
Dr. Jose Gutierrez-Marcos