Global Changes in DNA Methylation in Seeds and Seedlings of Pyrus communis after Seed Desiccation and Storage

Abstract

The effects of storage and deep desiccation on structural changes of DNA in orthodox seeds are poorly characterized. In this study we analyzed the 5-methylcytosine (m5C) global content of DNA isolated from seeds of common pear (Pyrus communis L.) that had been subjected to extreme desiccation, and the seedlings derived from these seeds. Germination and seedling emergence tests were applied to determine seed viability after their desiccation. In parallel, analysis of the global content of m5C in dried seeds and DNA of seedlings obtained from such seeds was performed with a 2D TLC method. Desiccation of fresh seeds to 5.3% moisture content (mc) resulted in a slight reduction of DNA methylation, whereas severe desiccation down to 2–3% mc increased DNA methylation. Strong desiccation of seeds resulted in the subsequent generation of seedlings of shorter height. A 1-year period of seed storage induced a significant increase in the level of DNA methylation in seeds. It is possible that alterations in the m5C content of DNA in strongly desiccated pear seeds reflect a reaction of desiccation-tolerant (orthodox) seeds to severe desiccation. Epigenetic changes were observed not only in severely desiccated seeds but also in 3-month old seedlings obtained from these seeds. With regard to seed storage practices, epigenetic assessment could be used by gene banks for early detection of structural changes in the DNA of stored seeds.

Transcriptomic Profiling Reveals Metabolic and Regulatory Pathways in the Desiccation Tolerance of Mungbean (Vigna radiata [L.] R. Wilczek)

“…Thus, the decrease of methylation at 3 and 6 h of imbibition might active the expression of some genes, which will be involved in DT. In common pear seeds during desiccation, a slight decrease in global DNA methylation from 8.2–8.8 to 4.8–5.3% were observed (Michalak et al, 2013). DNA methylation was also affected by desiccation in orthodox seeds of Acer platanoides and played a relevant role in DT in seeds (Plitta et al, 2014).…”

Effect of seed storage temperature on fine root development and mycorrhizal colonization of young Populus nigra seedlings

“…Currently, there is not sufficient information pertaining to how storage conditions induce biochemical changes in seeds that can influence subsequent seedling development (Sershen and Pammeneter 2010;Michalak et al 2013). Our previous studies on P. nigra showed, however, that temperatures of −196°C and −20°C did not cause disturbances in seed germination ).…”

“…Various seed storage temperatures have been reported for P. nigra, which have resulted in the ability to store the seeds for different lengths of time and still retain sufficient levels of seed viability (Stanton and Villar 1996;Tylkowski 2010;Michalak et al 2014;Suszka et al 2014). Thus far in the literature, optimal seed storage conditions have been assessed on the basis of seed germination (Popova et al 2012;Malik et al 2013;Suszka et al 2014) or seedling emergence (Michalak et al 2013;Popova et al 2013). These parameters do measure the impact of storage temperature on seed viability and initial emergence.…”

Genomics: A Hallmark to Monitor Molecular and Biochemical Processes Leading Toward a Better Perceptive of Seed Aging and ex-situ Conservation

“…In the seeds and seedlings of pear (Pyrus communis), DNA methylation has been reported to increase as the moisture level declined 2.3%, whereas DNA methylation was reduced when the moisture content increased to 5.3% (Michalak et al, 2013). Moreover, significantly increased DNA methylation has been reportedin seeds under storage period of one year (Singh et al, 2013).These results suggest the possibility of seed aging coupled with increased DNA methylation.…”

“…However, thin-layer chromatography is more feasible, since a smaller amount of DNA is needed to differentiate ribo-and deoxyribonucleotides under experimental analysis (Michalak et al, 2013).…”