Induced and Constitutive DNA Methylation in a Salinity-Tolerant Wheat Introgression Line

Abstract

Cytosine methylation is a well recognized epigenetic mark. Here, the methylation status of a salinity-tolerant wheat cultivar (cv. SR3, derived from a somatic hybridization event) and its progenitor parent (cv. JN177) was explored both globally and within a set of 24 genes responsive to salinity stress. A further comparison was made between DNA extracted from plants grown under control conditions and when challenged by salinity stress. The SR3 and JN177 genomes differed with respect to their global methylation level, and methylation levels were reduced by exposure to salinity stress. We found the genetic stress- (triggered by a combination of different genomes in somatic hybridization) induced methylation pattern of 13 loci in non-stressed SR3; the same 13 loci were found to undergo methylation in salinity-stressed JN177. For the salinity-responsive genes, SR3 and JN177 also showed different methylation modifications. C methylation polymorphisms induced by salinity stress were present in both the promoter and coding regions of some of the 24 selected genes, but only the former were associated with changes in transcript abundance. The expression of both TaFLS1 (encoding a flavonol synthase) and TaWRSI5 (encoding a Bowman-Birk-type protease inhibitor), which showed both a different expression and a different DNA methylation level between SR3 and JN177, enhanced the salinity tolerance of Arabidopsis thaliana. C methylation changes appear to be a common component of the plant response to stress, and methylation changes triggered by somatic hybridization may contribute to the superior salinity tolerance of SR3.

Salt Stress Induces Non-CG Methylation in Coding Regions of Barley Seedlings (Hordeum vulgare)

“…Although considered relatively tolerant to salinity [5], barley grown of the genome. Of the many methods available, Methylation Sensitive Amplification Polymorphism (MSAP) analysis has proved particularly popular to study stress-induced changes to genome-wide methylation patterns [25,27,32], in part because of the reproducible reputation of the technique [39][40][41]. However, the MSAP method only generates relatively small numbers of anonymous markers [42,43] and so has limited utility for studies aiming to establish links between changes in methylation and altered gene expression.…”

“…However, the MSAP method only generates relatively small numbers of anonymous markers [42,43] and so has limited utility for studies aiming to establish links between changes in methylation and altered gene expression. While some works have sought to overcome this limitation by targeted sequencing of MSAP amplicons [7,25,32,33], others have argued that this amendment of the method is still cumbersome, costly and time-consuming [44]. The ability of Next Generation Sequencing to analyse large numbers of loci in multiple methylomes in parallel provides the opportunity to overcome these limitations.…”

Immediate and Transgenerational Regulation of Plant Stress Response through DNA Methylation

“…Salt stress induced shift in DNA methylation in both the promoter and coding regions of some of the 24 selected genes, but only the former were associated with changes in transcript (Wang et al, 2014). Similarly, in another study where two cultivars with different level of salt tolerances were evaluated, dose dependent genome-wide DNA hypomethylation was observed in salt stress conditions (Zhong et al, 2009).…”

“…In wheat, shift in the DNA methylationdue to salinity stress, in salinity tolerant cultivar and its salinity sensitive progenitor, has been recently reported (Wang et al, 2014). Salt stress induced shift in DNA methylation in both the promoter and coding regions of some of the 24 selected genes, but only the former were associated with changes in transcript (Wang et al, 2014).…”

Transcript profiling of serine- and cysteine protease inhibitors inTriticum aestivumvarieties with different drought tolerance

“…A BBPI was shown to be involved in the tolerance to salt stress in wheat (Shan et al 2008) and Arabidopsis (Wang et al 2014). BBPI was up regulated by water deficit in peanut leaves (Dramé et al 2013).…”