Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Record number 507292
Title Epigenetic inheritance in apomictic dandelions : stress-induced and heritable modifications in DNA methylation and small RNA
Author(s) Preite, V.
Source University. Promotor(en): Wim van der Putten, co-promotor(en): K.J.F. Verhoeven. - Wageningen : Wageningen University - ISBN 9789462578715 - 152
Department(s) Laboratory of Nematology
EPS
Publication type Dissertation, internally prepared
Publication year 2016
Keyword(s) taraxacum officinale - epigenetics - inheritance - apomixis - dna methylation - rna - heritability - stress - epigenetica - overerving - dna-methylering
Categories Genetics (General)
Abstract

Epigenetic variation, such as changes in DNA methylations, regulatory small RNAs (sRNAs) and chromatin modifications can be induced by environmental stress. There is increasing information that such induced epigenetic modifications can be transmitted to offspring, potentially mediating adaptive transgenerational responses to environmental changes. However, it is unclear if this phenomenon is common and relevant for adaptation under natural conditions. My thesis study aimed to examine epigenetic inheritance in common and widespread apomictic dandelions (Taraxacum officinale Wig.). Due to their asexual reproduction mode by producing clonal seeds offspring from seeds are genetically uniform and thus suitable to investigate epigenetic effects that are not confounded with genetic variation.

I exposed apomictic dandelion lineages to drought and salicylic acid (SA) stress, which induces plant defense responses following pathogen attack, and found effects on patterns of DNA methylation up to two stress-free offspring generations after exposure. However, a heritable stress signal was not present in all tests and was stress- and lineage-dependent. Drought stress triggered a weak and lineage-dependent signal that was lost again in the second offspring generation. SA treatment revealed a stress-related increased rate of DNA methylation changes in the two offspring generations, but no stress signal was found in the stressed generation itself. I also observed changes in small RNA production due the drought and SA stress experienced two generations ago. These transgenerational sRNA effects showed association with gene functions related to grandparental drought and SA stress, which suggests functional relevance of the transgenerational effects.

I used a reciprocal transplantation field experiment to investigate whether exposing dandelions to natural field stresses also triggers DNA methylation changes. The experiment revealed evidence of adaptive divergence between the populations, suggesting that non-native habitats are experienced as more stressful. However, under these field conditions no induction-based DNA methylation changes were found that persisted into offspring.

By using AFLP and MS-AFLP screening of natural apomictic dandelion populations across a north-south transect in Europe I examined if natural, heritable DNA methylation variation reflects underlying genetic variation, or if it shows patterns that are not predictable from underlying genetics. I found that a large part of heritable DNA methylation differentiation along the north-south transect was correlated with genetic differentiation. However, a fraction of differentiation in heritable DNA methylation was independent from genetic variation. This suggests a potential of epigenetics to play an evolutionary role independently, at least to some extent, from underlying genetics. Overall, I found indications of epigenetic inheritance in apomictic dandelions. Whether epigenetic variation would result in adaptive phenotypic variation in nature and whether it would persist long enough to play a relevant role in adaptation remains unclear and requires further study.

Comments
There are no comments yet. You can post the first one!
Post a comment
 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.