Regulation of boron toxicity responses via glutathione-dependent detoxification pathways at biochemical and molecular levels in Arabidopsis thaliana

Authors : Doğa Selin KAYIHAN, Ceyhun KAYIHAN, Yelda Özden ÇİFTÇİ

Pages : 749-757

View : 14 | Download : 6

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :The fine-tuned regulation of the Halliwell-Asada cycle insert ignore into journalissuearticles values(ascorbate-glutathione pathway); in Arabidopsis thaliana under boron insert ignore into journalissuearticles values(B); toxicity was shown in our previous report. In this study, we investigated the expression levels of some members of the glutathione S-transferase insert ignore into journalissuearticles values(GST); superfamily, such as phi insert ignore into journalissuearticles values(GSTF2, GSTF6, GSTF7, and GSTF8);, tau insert ignore into journalissuearticles values(GSTU19);, and zeta insert ignore into journalissuearticles values(GSTZ1); classes in Arabidopsis thaliana that were exposed to 1 mM boric acid insert ignore into journalissuearticles values(1B); and 3 mM boric acid insert ignore into journalissuearticles values(3B);. Additionally, the expression levels of genes for glutathione insert ignore into journalissuearticles values(GSH); and phytochelatin biosynthesis as well as miR169 and miR156 were evaluated in Arabidopsis thaliana exposed to 1B and 3B. Moreover, changes in the levels of total GST activity; GSH; and total, protein-bound, and nonprotein thiols were spectrophotometrically determined. GSH levels and nonprotein thiol content did not change significantly following both B-toxicity conditions. Expression levels of GSH1 and GSH2 stayed stable under 1B toxicity; however, GSH1 expression increased significantly under 3B conditions in Arabidopsis thaliana. The expression levels of four genes from phi class members of GST were not dramatically changed under B-toxicity conditions. However, the transcript levels of miR169, ATGSTU19, and ATGSTZ1 were significantly increased after 1B and 3B exposure. These GST genes may have a role in the dramatic increase of total GST activity under toxic B. To the best of our knowledge, this is the first report displaying an integrative view of high-B-induced regulation of GSH-dependent enzymatic machinery at different biological organization levels in Arabidopsis thaliana.
Keywords : Gene expression, glutathione S transferase, miRNA, plant, posttranscriptional regulation, toxic boron