Glutathione S-transferase and aluminum toxicity in maize

Abstract

Aluminum (Al) toxicity induces changes in the expression of several genes, some of which are involved in plant responses to oxidative stress. Using mRNA differential display, we identified a maize Al-inducible cDNA encoding a glutathione S-transferase (GST). The gene was named GST27.2 owing to its homology to the maize gene GST27, which is known to be induced by xenobiotics. GST27.2 is present in the maize genome as a single copy and analysis of its expression pattern revealed that the gene is expressed mainly in the root tip. Expression was up-regulated in response to various Al and Cd concentrations in both Al-tolerant and Al-sensitive maize lines. Consistent with its role in plants, phylogenetic analysis of theta-type GSTs revealed that GST27.2 belongs to a group of proteins that respond to different stresses. Finally, structural analysis of the polypeptide chain indicates that the two amino acids that differ between GST27.2 and GST27 (E102K and P123L) could be responsible for alterations in activity and / or specificity. Together, these results suggest that GST27.2 may play an important part in plant defenses against Al toxicity.

Identification and characterization of low temperature stress responsive genes in Poncirus trifoliata by suppression subtractive hybridization

“…It is also known to catalyze conjugation of GSH (reduced glutathione) to a wide range of electrophilic metabolites of xenobiotics, leading to the reduction of organic hydroperoxides (Armstrong, 1997;Hu et al, 2009). GST and its encoding gene have been shown to be involved in abiotic stress response in earlier studies (Cançado et al, 2005;Dixit et al, 2011;Hu et al, 2011). In this work, a gene (F2E8) encoding GST was overpresented in the forward library and the expression of F2E8 was induced by 3.5 folds under low temperature.…”

Transcriptional profiling of aluminum toxicity and tolerance responses in maize roots

“…Al stress has been shown to elicit the production of reactive oxygen species (Yamamoto et al ., 2002), although the possible role of oxidative stress in Al toxicity is not clear. The up‐regulation by Al of oxidative stress‐responsive genes has been shown in a number of plant species, including maize (Cançado et al ., 2005), Arabidopsis (Richards et al ., 1998), tobacco ( Nicotiana tabacum ; Ezaki et al ., 1995) and rye ( Secale cereale ; Milla et al ., 2002). In this study, a number of genes related to oxidative stress were shown to be up‐regulated by Al stress.…”

Gene expression profiling in maize roots under aluminum stress

“…These studies have been restricted to wheat and Arabidopsis. In maize, a crop with a wide range of Al tolerant germplasms, little is known about the Al stressregulated gene expression, except for a gene encoding a glutathione S-transferase recently identified (Cançado et al 2005).…”