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Abstract: Epigenetics is a study of heritable changes in gene expression and function that do not change the DNA sequence itself. One of the commonly described epigenetic modifications is DNA methylation where a methyl group is added to the fifth carbon of the cytosine (Lim & Maher, 2010). This may lead to gene silencing, regulation of gene expression and allows for plant plasticity to changing environment (Verhoeven et al., 2010). Epigenetic variation is often studied in species with asexual reproduction, due to the absence of genetic variation between individuals and because clonal species do not go through a germline and meiosis between generations which epigenetic resetting occurs. Lemna minor, also known as common duckweed, is the smallest flowering macrophyte that consist of modified leaf structures (fronds) and one hanging root. It is known for its rapid asexual reproduction (Ziegler et al., 2015). Daughter fronds are genetically identical to the mother plant and are produced without involvement of male or female germlines. Fast asexual reproduction makes Lemna minor a perfect candidate to study epigenetic effects of de novo gene regulatory evolution. The aim of this project is to screen divergence of environmentally-induced DNA methylation between different experimental treatments over multiple generations. The aim of this project is to screen divergence of temperature-induced DNA methylation between different experimental treatments over multiple generations. Results show that, temperature stress has a strong influence on L. minor growth and reproduction, and induces significant change in the DNA methylation in the CG and CHG methylation context. Temperature-induced DNA methylation was inherited over multiple clonal generation of L. minor in the CHG contexts, although since we did not detect any performance difference the functional consequences of this DNA methylation are unclear. This study contributes to the knowledge of environmentally-induced DNA methylation changes, which is essential regarding the increasing frequency of global climate changes.
Keywords: DNA methylation, duckweed, epigenetics, epiGBS, abiotic stress, transgenerational inheritance, asexual reproduction
Published in DKUM: 29.01.2019; Views: 1731; Downloads: 139
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