Antioxidant activity and gene expression associated with cadmium toxicity in wheat affected by mycorrhizal fungus

In this study, the effects of Funelliformis mosseae and Piriformospora indica on wheat growth, enzyme activity and gene expression of catalase (CAT), ascorbate peroxidase (APX) and glutathione S-transferase (GST) in wheat leaves under different cadmium (Cd) toxicity were investigated. Cd exposure reduced plant dry mass and enzyme activities of CAT and APX, but it increased GST activity. The presence of F. mosseae and P. indica (alone or together) caused an increase in plant dry mass and activities of CAT, APX and GST. In response to Cd exposure, transcriptional level of CAT was decreased but, transcription of APX and GST was up-regulated. Although F. mosseae induced the expression of the antioxidant genes, P. indica was not detected to have such a strong induction in the genes expression. The results obtained from this study suggest that F. mosseae and P. indica can be used to alleviate Cd stress in wheat plants in contaminated soil. Also, no correlation was observed between mRNA and enzyme alterations in some cases, which indicate that post-transcriptional and post-translational regulations may play major roles.