Transgenerational inheritance of epigenetic response to cold in Arabidopsis thaliana

Exposure to stresses such as temperature fluctuations, drought and UV can cause physiological and epigenetic changes in plants. Such changes may be inherited by progeny of stressed plants and may alter their response to stress. To understand the ability of plants to inherit an epigenetic memory of exposure to cold stress and to analyze physiological manifestations of this memory, we propagated cold-stressed and control plants and compared their progeny under both normal and stress conditions. Our studies revealed that in the progeny of stressed plants, leaf number decreased and bolting occurred earlier. Transposons were also re-activated in the progeny of stressed plants. In addition to wild-type plants, we used the Dicer-like mutants dcl2, dcl3 and dcl4 because of the role of DCL2, 3 and 4 in siRNA biogenesis and their responses to stress. DCL2 and DCL3 appeared to be more important in the transgenerational stress memory than DCL4, and the changes observed in the progeny of dcl2 and dcl3 mutants were less profound or not evident at all Thus, this work has expanded our previous study and has shown physiological changes in the progeny of cold-stressed plants, it also has confirmed an important role of DCL2 and DCL3 in passing on the memory of stress exposure to the progeny. (C) 2014 Elsevier Ltd. All rights reserved.