Potential evidence for transgenerational epigenetic memory in Arabidopsis thaliana following spaceflight (Commun. Biol.)

Transgenerational memory can occur through epigenetic regulation of gene expression (for example through DNA methylation) when plants have been exposed to abiotic stresses. Transferring a specific biochemical adaption to the next generation of plants can help the plant counter stress. Here Xu et al. profiled DNA methylation pattern in Arabidopsis seedlings following spaceflight to determine possible transgenerational memory in the progeny. They found that phenotypic effects of stress of spaceflight was seen in the F1 generation, and the heritability declined as the generations progressed. Root length, flowering time and silique length was increased in the F1 generation of spaceflight treated plants as compared to the ground control F1. The distribution of methylation in the DNA changed due to spaceflight although there were no large-scale changes in the genomic DNA methylation pattern. The protein coding genes of the F1 generation were associated with the methylation pattern. There was evidence of modifications due to space flight in the methylation levels of transposable elements in the F1 generation. The authors found that hypomethylation of nitrate signaling genes TGA1 and TGA4 may contribute to increased efficiency of N absorption in the F1 generation after spaceflight. (Summary by Arun K. Shanker @arunshanker) Commun. Biol.  10.1038/s42003-021-02342-4