Enabling the Spaceflight Methylome: DNA Isolated from Plant Tissues Preserved in RNAlater® Is Suitable for Bisulfite PCR Assay of Genome Methylation

Spaceflight has a unique set of abiotic conditions to which plants respond by orchestrating genome-wide alterations to their transcriptome. The methods for preserving plants for RNA analysis are well-established and proven over multiple missions, but, methods for investigating the possible epigenetic mechanisms that may contribute to the transcriptome alteration are not well-developed for the confining limitations of the International Space Station (ISS). Currently, the methods used to isolate genomic DNA and to perform epigenetic analyses are ideal for frozen plants, as opposed to plants stored in RNAlater®—a high salt solution that chemically suspends all cellular activity and is typically used on the ISS. Therefore, we developed a method for extracting high-quality genomic DNA suitable for epigenetic analysis from Arabidopsis thaliana (Arabidopsis) plants that were preserved with the current preservation system aboard the ISS—fixation in RNAlater® using Kennedy Space Center Fixation Tubes (KFTs).