Molecular mechanistic model of plant heavy metal tolerance

Abstract

Plants being sessile are susceptible to heavy metals (HMs) toxicity and respond differentially to hostile environments. The toxicity of HM is governed by the type of ion and its concentration, plant physiology and stage of plant growth. Plants counteract the HMs stress by overexpressing numerous stress related proteins, glutathione mediated tolerance pathways and signaling proteins involving networks of various stress regulations. Though the response may vary and be specific in its stress networks regulation for each HM. The intricacy of HM tolerance response involves the set of molecular regulation, which demands to be understood to yield HM tolerant plant. Topical advancements in molecular biology and genomics have facilitated studies in transcriptomics and proteomics to identify regulatory genes implied in HM tolerance in plants. The integration of resources obtained through these studies will be of extreme significance, combining the diverse fields of plant biology to dissect the actual HM stress response network. In this review, we put an endeavor to describe the specific aspects of the molecular mechanisms of a plant response to HMs which may contribute to better understanding of the mode of HMs action and overlaps in metal sensing and signaling/crosstalk to other stresses.

Cross Talk between Nitric Oxide and Phytohormones Regulate Plant Development during Abiotic Stresses

“…It is well documented that exposure to HMs enhances the production of ET [59] due to increased 1-aminocyclopropane-1-carboxylic acid (ACC) synthase (ACS) activity in metal stressed plants [60]. Cross talk between ET and stress signaling molecules like NO is important to understand the mechanisms of plant adaptation to HM-induced oxidative stress [61][62][63]. More recently, Thao et al [51] suggested a possible link between NO and ET through MAPKs in plants exposed to HM stress.…”

Proteomic changes in maize as a response to heavy metal (lead) stress revealed by iTRAQ quantitative proteomics

“…Previous studies have indicated that a range of gene regulatory mechanisms control the accumulation capacity of Pb in plants, including transcription factors, transport proteins, and some critical genes, which were activated in response to both biotic and abiotic stresses and were involved in certain signal transduction and secondary metabolite pathways (Atkinson and Urwin, 2012;Thapa et al, 2012;Fan et al, 2013). In a previous study, we assayed Pb contents in the roots and aboveground parts of 19 inbred lines of maize seedlings.…”

Zinc-Finger Transcription Factor ZAT6 Positively Regulates Cadmium Tolerance through the Glutathione-Dependent Pathway in Arabidopsis

“…Plants have evolved a number of potential mechanisms to act in detoxification and, thus, in tolerance to heavy metal stress (Clemens, 2001;Hall, 2002;Lin and Aarts, 2012;Gallego et al, 2012;Thapa et al, 2012). The detoxification of heavy metals in plants includes heavy metals being pumped out at the plasma membrane, chelated, or bound to various thiol compounds in the cytosol and sequestered into vacuoles (Clemens, 2001;Hall, 2002;Kim et al, 2006;Gallego et al, 2012).…”