Effect of sucrose on Apx mRNA levels upon heavy metal stress

Abstract

Aim. In order to clarify molecular mechanisms of heavy metal stress response in plants expression of eight genes coding for ascorbate peroxidase (APX) isoenzymes induced by iron and copper ions in leaf tissues of Arabidopsis thaliana was evaluated. Methods. Changes of mRNA levels were estimated using quantitative real-time RT-PCR. Results. It was found that mRNA levels of several genes (especially that of Apx1 and sApx) were increased after 12 hours of treatment. Comparison of our novel and recently obtained results showed that after incubation of leaves in the buffer, which contains sucrose, the mRNA levels were the same or higher than after application of buffer without sucrose. Conclusions. The data indicate that the presence of sucrose in incubation buffer enhances Apx mRNA levels. We speculate that sucrose may serve as a source of energy required for effective transcription of Apx genes upon stressful conditions.  

Key words: Arabidopsis thaliana, copper, iron, sucrose, abiotic stress, Apx, gene expression.