Congratulations Emma!
Wednesday 12 January. DynaMo member Emma Sofie Timm Aller defended her PhD thesis and was awarded the PhD degree.
The thesis is entitled: Epigenetic Impact on Plant Plasticity
Emma warming up for the defence!
Summary
Emma investigated how environmental perceptions of plants can lead to alterations and responses that potentially cross generations.
She assessed the impact of the major epigenetic regulator, DNA methylations, on the defence compounds glucosinolates. This was facilitated by the availability of epigenetic Recombinant Inbred Lines, an Arabidopsis thaliana population that varies in DNA methylations and little in DNA. Methylation of specific genomic regions correlated with the mean abundance of different glucosinolate compounds and furthermore, methylations affected the variance of glucosinolates. This suggests that variance of the defence compounds is a controlled trait. By comparing her data to glucosinolate studies in populations with genetic variation, she could assess the relative contribution of epigenetics verses genetics on these compounds. Emma shows an epigenetic impact on glucosinolates, yet not as big as genetic impact. As such, genetic variation must be the major driver of the evolution of glucosinolates.
Emma investigated one glucosinolate outlier which she hypothesized to have genetic causality for its compound levels rather than epigenetic. By testing for Mendelian segregation and genome sequencing, she identified the movement of a transposable element into the gene of a glucosinolate transporter. RNA sequencing revealed a tissue specific transcriptomic profiles, likely explained by feedback to the impaired transport.
In her last chapter, Emma assessed strategies for propagation of stress responses in Arabidopsis thaliana wild type by assessing 22 traits in offspring upon parental exposure to spider mites at different developmental stages. Emma showed that progeny varied for many traits in relation to the specific silique position on parent and this variation is differentially affected by herbivore stress. Furthermore, herbivore stress in the parental generation correlated with increased resistance to both abiotic and biotic stress in following generation. Increased resistance to relatively abiotic and biotic stress propagated to different silique positions.
Emma a BSc and MSc in Biology- Biotechnology from University of Copenhagen in 2016 and has been part of the DynaMo centre since 2011.
Emmas project was part of a Villum Young Investigator grant by DynaMo partner Professor Meike Burow and her PhD supervisors were Meike Burow and DynaMo partner Daniel Kliebenstein from UC Davis, California.
Emma will continue as Postdoc at the DynaMo Center working on a Novo Nordisk Foundation grant on de novo assembly of the kale genome.