title: Excess boron responsive regulations of antioxidative mechanism at physio-biochemical and molecular levels in Arabidopsis thaliana.
abstract: This work was aimed to evaluate the effect of boron (B) toxicity on oxidative damage level, non-enzymatic antioxidant accumulation such as anthocyanin, flavonoid and proline and expression levels of antioxidant enzymes including superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione reductase (GR) and their respective activities as well as expression levels of miR398 and miR408 in Arabidopsis thaliana. Plants were germinated and grown on MS medium containing 1 mM B (1B) and 3 mM B (3B) for 14 d. Toxic B led to a decrease of photosynthetic pigments and an increase in accumulation of total soluble and insoluble sugars in accordance with phenotypically viewed chlorosis of seedlings through increasing level of B concentration. Along with these inhibitions, a corresponding increase in contents of flavonoid, anthocyanin and proline occurred that provoked oxidative stress tolerance. 3B caused a remarkable increase in total SOD activity whereas the activities of APX, GR and CAT remained unchanged as verified by expected increase in H2O2content. In contrast to GR, the coincidence was found between the expressions of SOD and APX genes and their respective activities. 1B induced mir398 expression, whereas 3B did not cause any significant change in expression of mir408 and mir398. Expression levels of GR genes were coordinately regulated with DHAR2 expression. Moreover, the changes in expression level of MDAR2 was in accordance with changes in APX6 expression and total APX activity, indicating fine-tuned regulation of ascorbate-glutathione cycle which might trigger antioxidative responses against B toxicity in Arabidopsis thaliana.
authors: Department of Molecular Biology and Genetics, Gebze Technical University, Kocaeli, Turkey.
authors: Doğa Selin
authors: DS
authors: Kayıhan
authors: Department of Molecular Biology and Genetics, Gebze Technical University, Kocaeli, Turkey.
authors: Ceyhun
authors: C
authors: Kayıhan
authors: Department of Molecular Biology and Genetics, Gebze Technical University, Kocaeli, Turkey. Electronic address: ozden@gtu.edu.tr.
authors: Yelda Özden
authors: YÖ
authors: Çiftçi
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D060387:Ascorbate Peroxidases / Q000235:genetics / Q000378:metabolism; D001895:Boron / Q000633:toxicity*; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D017343:Genes, Plant; D005980:Glutathione Reductase / Q000235:genetics / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism; D012989:Soil Pollutants / Q000633:toxicity; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism
chemical_list: D000975:Antioxidants; D029681:Arabidopsis Proteins; C543882:MIRN398 microRNA, Arabidopsis; C000602078:MIRN408 microRNA, Arabidopsis; D035683:MicroRNAs; D012989:Soil Pollutants; D006861:Hydrogen Peroxide; C000614665:DHAR2 protein, Arabidopsis; D010088:Oxidoreductases; D060387:Ascorbate Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; C544456:MDAR2 protein, Arabidopsis; D009247:NADH, NADPH Oxidoreductases; D005980:Glutathione Reductase; D001895:Boron
keywords: Antioxidant enzymes; Arabidopsis thaliana; Boron toxicity; Gene expression; Oxidative stress; Post-transcriptional regulation