Analysis of Cytosine Methylation in Genomic DNA of Solanum × michoacanum (+) S. tuberosum Somatic Hybrids

Paulina Smyda-Dajmund,Marta Janiszewska,Clizia Villano,Riccardo Aversano,Jadwiga Śliwka,Domenico Carputo,Ewa Zimnoch-Guzowska,Piotr Tomasz Bednarek

doi:10.3390/agronomy11050845

Abstract

Interspecific somatic hybridization is a noteworthy breeding strategy that allows the production of novel genetic variability when crossing barriers exist between two parental species. Although the genetic consequences of somatic hybridization have been well documented, little is known on its impact at the epigenetic level. The objective of our research was to investigate the epigenetic changes, in particular DNA methylation, occurring in a population of potato somatic hybrids. The analysis of 96 Solanum × michoacanum (+) S. tuberosum somatic hybrids from five fusion combinations and their parents was carried out by methylation-sensitive amplified polymorphism (MSAP) and high-performance liquid chromatography (HPLC) methods. Six MSAP primer combinations generated 622 unique bands, of which 295 were fully methylated. HPLC analysis showed from 15.5% to 16.9% total cytosine methylation within the parental forms. Overall, the MSAP and HPLC methods indicated an increase in DNA methylation in the somatic hybrids in comparison to their parents. Among the latter, a lower degree of DNA methylation in the wild S. × michoacanum species than S. tuberosum was found. Our findings indicated that somatic hybridization changed the level of cytosine methylation in the studied potato somatic hybrids.

Highlights

Somatic fusion is a useful tool in plant breeding to overcome crossing barriers and enable the transfer of important traits
The aim of this research was to determine the methylation levels of mch (+) tbr somatic hybrids and their parental forms based on methylation-sensitive amplified polymorphism (MSAP) and high-performance liquid chromatography (HPLC) methods
The selected diversity arrays technology (DArT) markers were located on various potato chromosomes (I, II, III, IV, V, VI, VII, VIII and X) (Table S1)

Summary

Introduction

Somatic fusion is a useful tool in plant breeding to overcome crossing barriers and enable the transfer of important traits. Somatic hybridization results in changes in the structure and sequence of DNA and affects the epigenetic regulation of gene expression [1,2]. The DNA methylation, histone modifications and RNA interference are epigenetic mechanisms that regulate the gene expression with no changes in the DNA sequence [3,4,5]. The methylation pattern can change during the growth and development of plants [25]. This aspect is important in polyploid crops, such as coffee, cotton, potato, peanut, sugarcane and wheat [21]. Little is known about such changes in methylation patterns in somatic hybrids

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