Oxidative and genotoxic damages in plants in response to heavy metal stress and maintenance of genome stability

Abstract

Plants, being sessile in nature, are constantly exposed to various environmental stresses, such as solar UV radiations, soil salinity, drought and desiccation, rehydration, low and high temperatures and other vast array of air and soil borne chemicals, industrial waste products, metals and metalloids. These agents, either directly or indirectly via the induction of oxidative stress and overproduction of reactive oxygen species (ROS), frequently perturb the chemical or physical structures of DNA and induce both cytotoxic or genotoxic stresses. Such condition, in turn, leads to genome instability and thus eventually severely affecting plant health and crop yield. With the growing industrialization process and non-judicious use of chemical fertilizers, the heavy metal mediated chemical toxicity has become one of the major environmental threats for the plants around the globe. The heavy metal ions cause damage to the structural, enzymatic and non-enzymatic components of plant cell, often resulting in loss of cell viability, thus negatively impacting plant growth and development. Plants have also evolved with an extensive and highly efficient mechanism to respond and adapt under such heavy metal toxicity mediated stress conditions. In addition to morpho-anatomical, hormonal and biochemical responses, at the molecular level, plants respond to heavy metal stress induced oxidative and genotoxic damage via the rapid change in the expression of the responsive genes at the transcriptional level. Various families of transcription factors play crucial role in triggering such responses. Apart from transcriptional response, epigenetic modifications have also been found to be essential for maintenance of plant genome stability under genotoxic stress. This review represents a comprehensive survey of recent advances in our understanding of plant responses to heavy metal mediated toxicity in general with particular emphasis on the transcriptional and epigenetic responses and highlights the importance of understanding the potential targets in the associated pathways for improved stress tolerance in crops.

Effects of Biogenic Zinc Oxide Nanoparticles on Growth and Oxidative Stress Response in Flax Seedlings vs. In Vitro Cultures: A Comparative Analysis

“…Protein-level oxidative damage has been suggested to hinder the detoxification process and reduce the plant tolerance to stress [ 57 , 59 ]. The exposure to NPs induced DNA damage [ 60 ], indicating possible genotoxic effects that could lead to cell death [ 53 , 54 ]. Here, we have observed that this oxidative stress could also lead to the formation of 8-oxo-guanine, one of the major mutagenic DNA damages that could significantly impair gene expression and function.…”

“…The antioxidant response to ROS scavenging is a means of avoiding potential oxidative damage caused by the application of NPs. To do so, plants developed a set of antioxidant defense systems that rely on enzymatic and/or non-enzymatic mechanisms [ 53 , 54 ]. Since ROS was often used by plants as a second messenger for the signal transduction of multiple physiological reactions, ROS cannot be completely scavenged.…”

In silico identification and expression analysis of Metal-nicotianamine transporter (YSL3) and Oligopeptide transporter 3 (OPT3) under Cd stress in Brassica oleracea var. acephala

“…Nouairi et al (2006) reported that the accumulation of Cd suppresses the growth of root and shoot in B. juncea and B. napus under cadmium stress. Further, Dutta et al (2018b) reported also reduced root growth and shoot lengths in B. juncea under different heavy metals, including cadmium. Similar results were reported by Pandey & Ripathi (2011) where Cd treatment has an inhibitory effect on the growth of Albizia proceraas roots.…”

“…The key mechanism in the protection and survival of plants under heavy metal stress is regulation of its gene expression (Dutta et al 2018b). YSL3 belongs to Oligopeptide transporter family (OPT), known to be involved in different processes nitrogen mobilization (Koh et al 2002, Stacey et al 2008, glutathione transport (Cagnac et al 2004, heavy metal sequestration (Vasconcelos et al 2008), and long-distance metal distribution (Stacey et al 2008).…”

Glycine Betaine Accumulation, Significance and Interests for Heavy Metal Tolerance in Plants

“…Transduction of heavy metal stress signaling is started by ion channels/receptors through awareness of stress signals and also through non-protein messengers like hydrogen ions, calcium and cyclic nucleotides as given in ( Figure 1 ). Several studies reported the importance of these signaling molecules and responsive genes in plants against the stress induced by HMs [ 56 , 57 , 58 , 59 , 60 ].…”