http://paymanhassibi.persiangig.com/document/mittler%20oxidative.pdf

Oxidative stress, antioxidants and stress tolerance

Reactive oxygen species and antioxidant machinery in abiotic stress tolerance in crop plants

Antioxidants, Oxidative Damage and Oxygen Deprivation Stress: a Review

The discovery that there is a close relationship between ascorbate and glutathione dates from soon after the characterization of the chemical formulae of the two molecules ([Szent-Gyorgyi, 1931][1]; [Hopkins and Morgan, 1936][2]). Similarly, it has long been known that thylakoids can generate

Ascorbate and glutathione: the heart of the redox hub.

Zinc (Zn) is an essential component of thousands of proteins in plants, although it is toxic in excess. In this review, the dominant fluxes of Zn in the soil-root-shoot continuum are described, including Zn inputs to soils, the plant availability of soluble Zn(2+) at the root surface, and plant uptake and accumulation of Zn. Knowledge of these fluxes can inform agronomic and genetic strategies to address the widespread problem of Zn-limited crop growth. Substantial within-species genetic variation in Zn composition is being used to alleviate human dietary Zn deficiencies through biofortification. Intriguingly, a meta-analysis of data from an extensive literature survey indicates that a small proportion of the genetic variation in shoot Zn concentration can be attributed to evolutionary processes whose effects manifest above the family level. Remarkable insights into the evolutionary potential of plants to respond to elevated soil Zn have recently been made through detailed anatomical, physiological, chemical, genetic and molecular characterizations of the brassicaceous Zn hyperaccumulators Thlaspi caerulescens and Arabidopsis halleri.

Zinc in plants

http://directory.umm.ac.id/Data%20Elmu/jurnal/P/PlantScience/Plant%20Science_BioMedNet/041-060/052.pdf

Plant glutathione S-transferases: enzymes with multiple functions in sickness and in health.

The soluble glutathione transferases (GSTs, EC 2.5.1.18) are encoded by a large and diverse gene family in plants, which can be divided on the basis of sequence identity into the phi, tau, theta, zeta and lambda classes. The theta and zeta GSTs have counterparts in animals but the other classes are plant-specific and form the focus of this article. The genome of Arabidopsis thaliana contains 48 GST genes, with the tau and phi classes being the most numerous. The GST proteins have evolved by gene duplication to perform a range of functional roles using the tripeptide glutathione (GSH) as a cosubstrate or coenzyme. GSTs are predominantly expressed in the cytosol, where their GSH-dependent catalytic functions include the conjugation and resulting detoxification of herbicides, the reduction of organic hydroperoxides formed during oxidative stress and the isomerization of maleylacetoacetate to fumarylacetoacetate, a key step in the catabolism of tyrosine. GSTs also have non-catalytic roles, binding flavonoid natural products in the cytosol prior to their deposition in the vacuole. Recent studies have also implicated GSTs as components of ultraviolet-inducible cell signaling pathways and as potential regulators of apoptosis. Although sequence diversification has produced GSTs with multiple functions, the structure of these proteins has been highly conserved. The GSTs thus represent an excellent example of how protein families can diversify to fulfill multiple functions while conserving form and structure.

/pdf/plant-glutathione-transferases-3phf7bxg9l.pdf

Plant glutathione transferases

Glutathione S-transferases (GSTs) appear to be ubiquitous in plants and have defined roles in herbicide detoxification. In contrast, little is known about their roles in normal plant physiology and during responses to biotic and abiotic stress. Forty-seven members of the GST super-family were identified in the Arabidopsis genome, grouped into four classes, with amino acid sequence identity between classes being below 25%. The two small zeta (GSTZ) and theta (GSTT) classes have related GSTs in animals while the large phi (GSTF) and tau (GSTU) classes are plant specific. As a first step to functionally characterize this diverse super-family, 10 cDNAs representing all GST classes were cloned by RT-PCR and used to study AtGST expression in response to treatment with phytohormones, herbicides, oxidative stress and inoculation with virulent and avirulent strains of the downy mildew pathogen Peronospora parasitica. The abundance of transcripts encoding AtGSTF9, AtGSTF10, AtGSTU5, AtGSTU13 and AtGSTT1 were unaffected by any of the treatments. In contrast, AtGSTF6 was upregulated by all treatments while AtGSTF2, AtGSTF8, AtGSTU19 and AtGSTZ1 each showed a selective spectrum of inducibility to the different stresses indicating that regulation of gene expression in this super-family is controlled by multiple mechanisms. The respective cDNAs were over expressed in E. coli. All GSTs except AtGSTF10 formed soluble proteins which catalysed a specific range of glutathione conjugation or glutathione peroxidase activities. Our results give further insights into the complex regulation and enzymic functions of this plant gene super-family.

Probing the diversity of the Arabidopsis glutathione S-transferase gene family.

Roles for glutathione transferases in plant secondary metabolism

https://users.ox.ac.uk/~dplb0149/publication/JBC2002_DHAR.pdf

Functional divergence in the glutathione transferase superfamily in plants. Identification of two classes with putative functions in redox homeostasis in Arabidopsis thaliana.

David P. Dixon

Papers

Plant glutathione S-transferases: enzymes with multiple functions in sickness and in health.

Plant glutathione transferases

Probing the diversity of the Arabidopsis glutathione S-transferase gene family.

Roles for glutathione transferases in plant secondary metabolism

Functional divergence in the glutathione transferase superfamily in plants. Identification of two classes with putative functions in redox homeostasis in Arabidopsis thaliana.