Transgenerational changes in plant physiology and in transposon expression in response to UV-C stress in Arabidopsis thaliana

Abstract

Abbreviations: (¡), grown under normal conditions; (C), grown under stressed conditions; C 1 , the progeny of plants grown under normal conditions in F 0 ; C 1 S 1 , the progeny of plants grown under normal conditions in F 0 and exposed to stress in F 1 ; C 2 , the progeny of plants grown under normal conditions for 2 generations; DCL, a Dicer-like protein; dpg, days post germination; ONSEN, a copia-type retrotransposon; S 1 , the progeny of plants exposed to stress in F 0 ; S 1 C 1 , the progeny of plants exposed to stress in F 0 and grown under normal conditions in F 1 ; S 2 , the progeny of plants exposed to stress for 2 generations; TEs, transposable elements; TSI, transcriptionally silent information; UV-C, ultraviolet radiation C.Stress has a negative impact on crop yield by altering a gain in biomass and affecting seed set. Recent reports suggest that exposure to stress also influences the response of the progeny. In this paper, we analyzed seed size, leaf size, bolting time and transposon expression in 2 consecutive generations of Arabidopsis thaliana plants exposed to moderate UV-C stress. Since previous reports suggested a potential role of Dicer-like (DCL) proteins in the establishment of transgenerational response, we used dcl2, dcl3 and dcl4 mutants in parallel with wild-type plants. These studies revealed that leaf number decreased in the progeny of UV-C stressed plants, and bolting occurred later. Transposons were also re-activated in the progeny of stressed plants. Changes in the dcl mutants were less prominent than in wild-type plants. DCL2 and DCL3 appeared to be more important in the transgenerational stress memory than DCL4 because transgenerational changes were less profound in the dcl2 and dcl3 mutants.

Digest: Transgenerational stress memory mechanisms in Arabidopsis thaliana *

“…However, contrary to the hypothesis that phenotypes would dissipate in the third generation without refamiliarization of the stressor in the second, the researchers found some accessions retained their phenotype, some exhibited stronger phenotypes than the previous generation, and some accessions even showed phenotypic plasticity in the opposite direction. These results were consistent with studies that showed reversible phenotypic plasticity in the third generation for some traits (Migicovsky and Kovalchuk 2014). In conclusion, the induction, temporal persistence, and environmental stability of the transgenerational environmental effects were not found to be correlated, indicating that independent genes regulate the three components of transgenerational stress memory and supporting the idea of a reversible epigenetic mechanism.…”

“…Severe heat stress has been shown to cause global DNA hypomethylation in the same generation and altered histone regulation in the offspring (Migicovsky and Kovalchuk 2013). In heat-stressed offspring, permissive histone marks were positively correlated with gene expression, whereas repressive histone marks were negatively correlated .…”

Rapid Increase in Genome Size as a Consequence of Transposable Element Hyperactivity in Wood-White (Leptidea) Butterflies

“…Notably, differences in TE proliferation rates might even be exacerbated under environmental stress ( Kim etal. 2014 ; Migicovsky and Kovalchuk 2014 ), indicating that variation in environmental conditions during population isolation—for example, under allopatric separation during glacial periods—may also contribute to genome size evolution.…”

Small DNA Methylation, Big Player in Plant Abiotic Stress Responses and Memory

“…Cold stress and harsh UV-B treatment-induced release of TGS remain limitedly detectable for two non-stressed progeny generations ( Lang-Mladek et al, 2010 ). The UV-C-mediated activation of some transposons can also be maintained for two generations without the presence of stress, which requires the roles of DCL proteins ( Migicovsky and Kovalchuk, 2014 ). Upon exposure to heavy metal stress, the 5mC state of a Tos17 retrotransposon is altered and shows transgenerational inheritance in rice ( Cong et al, 2019 ).…”