DNA methylation and physio-biochemical analysis of chickpea in response to cold stress

Abstract

Cold stress (CS) signals are translated into physiological changes as products of direct and/or indirect of gene expression regulated by different factors like DNA methylation. In this study, some of these factors were comparatively studied in two chickpea (Cicer arietinum L.) genotypes (Sel96Th11439, cold-tolerant genotype, and ILC533, cold susceptible one) under control (23 °C) and days 1, 3, and 6 after exposing the seedlings to CS (4 °C). Under CS, tolerant genotype prevented H2O2 accumulation which led to a decrease in damage indices (malondialdehyde and electrolyte leakage index) compared to susceptible one. The significant activities of antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase, guaiacol peroxidase, and polyphenol oxidase) along with a significant proportion of change in DNA methylation/demethylation patterns were often effective factors in preserving cell against cold-induced oxidative stress. Chickpea cells in response to CS changed access to their genome as the number of bands without change from day 1 to day 6 of exposure to CS particularly in tolerant genotype was decreased. During CS, the methylation level was higher compared to demethylation (29.05 vs 19.79 %) in tolerant genotype and (27.92 vs 22.09 %) in susceptible one. However, for prolonged periods of CS, changes in demethylated bands in tolerant genotype were higher than that of in susceptible one (9.24 vs 4.13 %), indicating higher potential for activation of CS responsive genes. Such a status along with higher activity of antioxidants and less damage indices could be related to cold tolerance (CT) mechanisms in chickpea. Sequencing analysis confirmed the important role of some specific DNA sequences in creating CT with possible responsive components involved in CS. Thus, dynamic assessment using multi-dimensional approaches allows us to progressively fill in the gaps between physio-biochemical and molecular events in creating CT, to comprehend better the nature of the plant stress response and molecular mechanisms behind.

Effects of Temperature Treatments on Cytosine-Methylation Profiles of Diploid and Autotetraploid Plants of the Alpine Species Ranunculus kuepferi (Ranunculaceae)

“…Furthermore, DNA methylation in response to abiotic environmental stress could regulate gene expression (e.g. Steward et al, 2002;Shan et al, 2013;Rakei et al, 2016), mostly by global demethylation of genomic DNA, while DNA methylation is believed to play a role in the maintenance of cell stability under stress (Song et al, 2015). However, since the interpretation of our methylation profiles is not straightforward we can just confer a high dynamics from our experiments.…”

Developing Climate-Resilient Chickpea Involving Physiological and Molecular Approaches With a Focus on Temperature and Drought Stresses

“…There is also a study indicating that changes in methylation patterns may be associated with cold tolerance in chickpea. Prolonged cold stress in a cold-tolerant genotype increased demethylation, relative to a cold-susceptible genotype, suggesting a higher potential for activation of cold-stressresponsive genes (Rakei et al, 2016). Thus, WGS and its further exploitation has generated genomic resources and enhanced our understanding of mechanisms governing cold tolerance/susceptibility in chickpea.…”

DNA Methylation in Rehmannia glutinosa Roots Suffering from Replanting Disease

“…A number of environmental stresses have been suggested as being able to induce alterations in DNA methylation profiles (Dowen et al, 2012;Liang et al, 2014). In some cases, the stress lowers methylation -such as stress by drought in Lolium perenne and cold in Cicer arietinum L. Rakei et al, 2016). While in other cases, the stress increases the levels of cytosine methylation -such as stress by salinity in Jatropha curcas L., water in pea (Pisum sativum L.), and heavy metal in maize (Zea mays L.) (Labra et al, 2002;Mastan et al, 2012;Erturk et al, 2015).…”