Using the gamma-glutamylcysteine synthetase inhibitor, L-buthionine-[S,R]-sulphoximine (BSO), the role for phytochelatins (PCs) was evaluated in Cu, Cd, Zn, As, Ni, and Co tolerance in non-metallicolous and metallicolous, hypertolerant populations of Silene vulgaris (Moench) Garcke, Thlaspi caerulescens J.&C. Presl., Holcus lanatus L., and Agrostis castellana Boiss. et Reuter. Based on plant-in...

A functional analysis of the role of glutathione in protecting plants from environmental stress was undertaken by studying Arabidopsis that had been genetically modified to have altered glutathione levels. The steady-state glutathione concentration in Arabidopsis plants was modified by expressing the cDNA for gamma-glutamyl-cysteine synthetase (GSH1) in both the sense and antisense orientation....

Plants respond to environmental pollutants such as heavy metal(s) by triggering the expression of genes that encode proteins involved in stress response. Toxic metal ions profoundly affect the cellular protein homeostasis by interfering with the folding process and aggregation of nascent or non-native proteins leading to decreased cell viability. However, plants possess a range of ubiquitous ce...

Cd from roots of maize was partitioned in seedlings exposed to 3 microM CdSO4 for 1 to 7 d. Most of the root Cd (92-94%) was buffer soluble and provided the classical metal-induced cysteine-rich, high-molecular-weight Cd-binding complex. This complex, however, bound only part of the Cd within the roots, from 19% after 1 d of exposure to 59% by d 7. Three families of peptides formed the Cd-bindi...

Plants experience oxidative stress upon exposure to heavy metals that leads to cellular damage. In addition, plants accumulate metal ions that disturb cellular ionic homeostasis. To minimize the detrimental effects of heavy metal exposure and their accumulation, plants have evolved detoxification mechanisms. Such mechanisms are mainly based on chelation and subcellular compartmentalization. Che...

The ascorbate (AsA)–glutathione (GSH) metabolism pathway is an important antioxidant system in cadmium (Cd) detoxification; the AsA–GSHpathway generally regulated by a specific set of functional genes. However, transcription factors involved AsA–GSH have yet to be identified. Herein, we transformed heat shock factor SpHsfA4c from Sedum plumbizincicola into Populus. × canescens. Under 100 μM CdC...

The effect of four soil-applied sulfur (100 mg S kg?1 soil (100S) and 200 (200S)) in different sources (elemental S, ammonium sulfate, gypsum or magnesium sulfate) protecting mustard (Brassica juncea L. (Czern & Coss.)) from cadmium effects was studied. Based on the observed reduction growth photosynthesis plants subjected to 100 Cd soil, B. cv. Giriraj selected as most Cd-tolerant among fi...

Phytochelatins are Cys-rich peptides enzymatically synthesized by γ-Glu-Cys dipeptidyl transpeptidase, generally known as phytochelatin synthase. In the present work the enzymes of phytochelatin synthesis and cadmium (Cd) accumulation were investigated during Cd stress. Young maize plants were treated with 0.1 mM Cd for 48 hours. Roots and leaves were used for the experiments. The Cd was accumu...

The overexpression of either gamma-glutamylcysteine synthetase (gamma-ECS) or glutathione synthetase (GS) in Brassica juncea transgenics was shown previously to result in higher accumulation of glutathione (GSH) and phytochelatins (PCs), as well as enhanced Cd tolerance and accumulation. The present study was aimed at analyzing the effects of gamma-ECS or GS overexpression on tolerance to and a...

Unprecedented bioaccumulation and biomagnification of heavy metals (HMs) in the environment have become a dilemma for all living organisms including plants. HMs at toxic levels have the capability to interact with several vital cellular biomolecules such as nuclear proteins and DNA, leading to excessive augmentation of reactive oxygen species (ROS). This would inflict serious morphological, met...