Role of Metallothionein
and Phytochelatin in Combating Abiotic
Stress Imparted by Copper-Induced
Toxicity in Brinjal (Solanum melongena)
Pratik Talukder
Abstract Plants, though sessile, have various enzymatic and nonenzymatic antioxidant systems which help them in combating the heavy metal-induced oxidative stress
and various other abiotic stresses. Metallothioneins (MTs) and Phytochelatins (PCs)
are the two best characterized heavy metal-binding ligands in plants. In the present
investigation, we made a comparative study on the role of metallothionein and PCs
in combating copper-induced oxidative stress in brinjal (Solanum melongena), an
important vegetable plant with immense nutritional value. Seedlings were exposed
to various sublethal doses of copper and grew them for a period of 1 month. We
studied the relative expression of these genes by reverse transcription PCR and realtime PCR techniques and the relative content of the major secondary metabolites and
phytochelatins by High-Performance Liquid Chromatographic (HPLC) technique. In
both cases, we find that 800 μM is the highest dose that the plants can withstand. On
further increasing the dose to 1000 μM, a sudden drop in the expression of the genes,
as well as polyphenolic and phytochelatin compound contents, was observed. This
observation proves that phytochelatin and metallothionein function in a coordinated
way to chelate, detoxify, and rendering the plant more tolerant to metal stress.
Keywords Abiotic Stress · Copper · Brinjal · Solanum melongena · Secondary
metabolism · Polyphenols · Metallothionein · Phytochelatin
1 Introduction
Heavy metals are defined as those metals and metalloids which have atomic density
5 g cm
−3 and above (i.e., greater than water) and atomic number >20, and should
possess properties of metals. A concentration >0.1% in soil becomes toxic to the
plants. There are both essential and nonessential heavy metals present in the soil. Fe,
Mn, Cu, Zn, Co, Mo are few important essential heavy metals, whereas Cd, Pb, Ur, Tl,
Cr, Ag, Hg are considered as nonessential heavy metals (Wuana and Okieimen 2011).
P. Talukder (B)
Department of Biotechnology, University of Engineering and Management, Kolkata, India
e-mail: pratiktalukder@gmail.com
© Springer Nature Singapore Pte Ltd. 2021
D. Ramkrishna et al. (eds.), Advances in Bioprocess Engineering and Technology,
Lecture Notes in Bioengineering,
https://doi.org/10.1007/978-981-15-7409-2_35
349
and Phytochelatin in Combating Abiotic
Stress Imparted by Copper-Induced
Toxicity in Brinjal (Solanum melongena)
Pratik Talukder
Abstract Plants, though sessile, have various enzymatic and nonenzymatic antioxidant systems which help them in combating the heavy metal-induced oxidative stress
and various other abiotic stresses. Metallothioneins (MTs) and Phytochelatins (PCs)
are the two best characterized heavy metal-binding ligands in plants. In the present
investigation, we made a comparative study on the role of metallothionein and PCs
in combating copper-induced oxidative stress in brinjal (Solanum melongena), an
important vegetable plant with immense nutritional value. Seedlings were exposed
to various sublethal doses of copper and grew them for a period of 1 month. We
studied the relative expression of these genes by reverse transcription PCR and realtime PCR techniques and the relative content of the major secondary metabolites and
phytochelatins by High-Performance Liquid Chromatographic (HPLC) technique. In
both cases, we find that 800 μM is the highest dose that the plants can withstand. On
further increasing the dose to 1000 μM, a sudden drop in the expression of the genes,
as well as polyphenolic and phytochelatin compound contents, was observed. This
observation proves that phytochelatin and metallothionein function in a coordinated
way to chelate, detoxify, and rendering the plant more tolerant to metal stress.
Keywords Abiotic Stress · Copper · Brinjal · Solanum melongena · Secondary
metabolism · Polyphenols · Metallothionein · Phytochelatin
1 Introduction
Heavy metals are defined as those metals and metalloids which have atomic density
5 g cm
−3 and above (i.e., greater than water) and atomic number >20, and should
possess properties of metals. A concentration >0.1% in soil becomes toxic to the
plants. There are both essential and nonessential heavy metals present in the soil. Fe,
Mn, Cu, Zn, Co, Mo are few important essential heavy metals, whereas Cd, Pb, Ur, Tl,
Cr, Ag, Hg are considered as nonessential heavy metals (Wuana and Okieimen 2011).
P. Talukder (B)
Department of Biotechnology, University of Engineering and Management, Kolkata, India
e-mail: pratiktalukder@gmail.com
© Springer Nature Singapore Pte Ltd. 2021
D. Ramkrishna et al. (eds.), Advances in Bioprocess Engineering and Technology,
Lecture Notes in Bioengineering,
https://doi.org/10.1007/978-981-15-7409-2_35
349