Long-term copper (Cu2+) exposure impacts on auxin, nitric oxide (NO) metabolism and morphology of Arabidopsisthaliana L

• Published in: Plant growth regulation 2012, Vol.68 (2), p.151-159
• Main Authors: Kolbert, Zsuzsanna, Pető, Andrea, Lehotai, Nóra, Feigl, Gábor, Erdei, László
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Life Sciences; Original Paper; Plant Anatomy/Development; Plant Physiology; Plant Sciences
• ISSN: 0167-6903; 1573-5087
• DOI: 10.1007/s10725-012-9701-7

Plants are able to dynamically adapt to their environment by reprogramming of their growth and development. Copper (Cu 2+ ) excess modifies shoot and root architecture of plants by a lesser known mechanism, therefore the involvement of a major hormone component (auxin) and a signal molecule (nitric oxide) in Cu 2+ -induced morphological responses were studied in Arabidopsis using microscopic methods. Auxin-inducible gene expression was visualized in DR5::GUS Arabidopsis and nitric oxide (NO) levels were detected by DAF-FM fluorophore in the stem and root system. Copper excess caused the inhibition of stem and root growth of Arabidopsis , during which cell elongation, division and expansion were also affected. The symptoms of stress-induced morphogenic response were found in the root system of 25 μM Cu 2+ -treated plants. In both organs, the decrease of auxin-dependent gene expression was found, which can partly explain the growth inhibitions. Besides hormonal system, nitric oxide metabolism was also affected by Cu 2+ . In root tips, copper excess induced NO generation, while NO content in lateral roots was not affected by the treatments. Using nia1nia2 mutants, nitrate reductase enzyme as a putative source of Cu 2+ -induced NO was identified in Arabidopsis primary roots.