Epigenetic responses to drought stress in rice (Oryza sativa L.)

Abstract

Cytosine methylation polymorphism plays a key role in gene regulation, mainly in expression of genes in crop plants. The differential expression of cytosine methylation over drought stress response was analyzed in rice using drought susceptible but agronomically superior lines IR 20 and CO 43, and drought tolerant genotypes PL and PMK 3 and their F1 hybrids. The parents and hybrids were subjected to two moisture regimes viz., one under drought condition and another under control condition. The cytosine methylation polymorphism in genomic DNA was quantified under both the conditions at the reproductive stage of the plant using the Methylation Sensitive Amplified Polymorphism (MSAP) technique devised by Xiong et al. (261:439-446, 1999). The results depicted that under drought condition, hyper-methylation was predominant in the drought susceptible genotypes while drought tolerant genotypes presented hypo-methylation behavior. While imposing drought, spikelet sterility per cent was positively correlated to percentage of methylation whereas, panicle length, number of seed per panicle, panicle weight, 100 seed weight, and yield/plant were negatively correlated indicating the role of epigenetic regulation in yield attributing traits in response to drought. Thus, methylation can be considered as an important epigenetic regulatory mechanism in rice plants to adapt drought situation. From this study, we speculate that the hyper- methylation may be an indicator of drought susceptibility and the hypo-methylation for drought tolerance and this methylation polymorphism can be effectively used in drought screening program.

Transgenerational epimutations induced by multi-generation drought imposition mediate rice plant’s adaptation to drought condition

“…High-throughput analysis and single-base resolution allowed the investigation of epimutations in all contexts (CG, CHG and CHH) and in all forms (DMPs, SMPs and DMRs); previous studies have not considered this level of detail due to low resolution928. With respect to the genomic structures in Huhan3 and II-32B, the genome-wide methylation patterns were similar to other rice varieties2930.…”

“…The different distribution features possibly implied different functions between DMPs and SMPs in the stress response; however, most of the previous high-resolution studies focused on only one type of marker111231. Loci with different methylation statuses, when investigated in low-resolution studies using enzyme digestion methods, such as methylation-sensitive amplified polymorphism (MSAP), were determined to be SMPs, and the extent of DNA methylation could not be distinguished928. Therefore, SMPs and DMPs should be discriminated in future studies.…”

DNA hypomethylation concomitant with the overproduction of ROS induced by naphthoquinone juglone on tobacco BY-2 suspension cells

“…Both abiotic and biotic stress factors can lead to changes in DNA methylation. A number of studies have shown the ability of cold stress (Steward et al, 2000;Shan et al, 2013), drought (Labra et al, 2002;Wang et al, 2011a;Gayacharan and Joel, 2013;Tang et al, 2014), osmotic and salt stress (Tan, 2010;Wang et al, 2011b;Demirkiran et al, 2013), and heavy metals (Aina et al, 2004;Labra et al, 2004;Yang et al, 2007) to influence the level of DNA methylation. Moreover, a correlation between methylation of DNA and gene inactivity has been suggested (Ng and Adrian, 1999).…”

Flexible shift on gene body methylation and transcription of LpCYP72A161 exposed to temperature stress in perennial ryegrass

“…Abiotic stress's impact on DNA methylation has been widely reported in plants at the genome level (Ci et al, 2015;Gayacharan and Joel 2013;Tang et al, 2014b;Wang et al, 2015a), and on the promoter regions (Baek et al, 2011;Chinnusamy and Zhu 2009), but only a few studies focused on changes in DNA methylation on gene body regions. Currently, the relationship between gene body methylation and transcription remains unclear (Maunakea et al, 2010;Zemach et al, 2010).…”