Over-expression of chickpea metallothionein 1 gene confers tolerance against major toxic heavy metal stress in Arabidopsis

Arvind Kumar Dubey, Anil Kumar, Navin Kumar, Sanoj Kumar, Meenakshi, Ambedkar Gautam, Mohd Akram Ansari, N. Manika, Swati Lal, Soumit Kumar Behera, Shekhar Mallick, Indraneel Sanyal

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Heavy metals are ubiquitously present in nature, including soil, water, and thus in plants, thereby causing a potential health risk. This study has investigated the role and efficiency of the chickpea metallothionein 1 (MT1) gene against the major toxic heavy metals, i.e., As [As(III) and As(V)], Cr(VI), and Cd toxicity. MT1 over-expressing transgenic lines had reduced As(V) and Cr(VI) accumulation, whereas Cd accumulation was enhanced in the L3 line. The physiological responses (WUE, A, Gs, E, ETR, and qP) were noted to be enhanced in transgenic plants, whereas qN was decreased. Similarly, the antioxidant molecules and enzymatic activities (GSH/GSSG, Asc/DHA, APX, GPX, and GRX) were higher in the transgenic plants. The activity of antioxidant enzymes, i.e., SOD, APX, GPX, and POD, were highest in the Cd-treated lines, whereas higher CAT activity was observed in As(V)-L1 and GRX in Cr-L3 line. The stress markers TBARS, H2O2, and electrolyte leakage were lower in transgenic lines in comparison to WT, while RWC was enhanced in the transgenic lines, and the transcript of MT1 gene was accumulated in the transgenic lines. Similarly, the level of stress-responsive amino acid cysteine was higher in transgenic plants as compared to WT plants. Among all the heavy metals, MT1 over-expressing lines showed a highly increased accumulation of Cd, whereas a non-significant effect was observed with As(III) treatment. Overall, the results demonstrate that Arabidopsis thaliana transformed with the MT1 gene mitigates heavy metal stress by regulating the defense mechanisms in plants.

Original languageEnglish
Pages (from-to)2665-2678
Number of pages14
JournalPhysiology and Molecular Biology of Plants
Volume27
Issue number12
DOIs
StatePublished - 1 Dec 2021
Externally publishedYes

Keywords

  • Arabidopsis thaliana
  • Chickpea
  • Heavy metals
  • Metallothionein
  • Oxidative stress
  • Transgenics

ASJC Scopus subject areas

  • Molecular Biology
  • Physiology
  • Plant Science

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