Elevated indole-3-acetic acid peroxidase activity is involved in the cadmium-induced hydrogen peroxide production in barley root tip

• Published in: Plant growth regulation Vol. 62; no. 1; pp. 59 - 64
• Main Authors: Halušková, L'ubica, Valentovičová, Katarína, Huttová, Jana, Mistrík, Igor, Tamás, Ladislav
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.09.2010; Springer Netherlands; Springer Nature B.V
• Subjects: Acetic acid; Agriculture; Biomedical and Life Sciences; Cadmium; Heavy metals; Hydrogen peroxide; Indole-3-acetic acid peroxidase; Life Sciences; Original Research; Plant Anatomy/Development; Plant growth; Plant Physiology; Plant Sciences; reactive oxygen species; Root growth inhibition; Cadmium; Reactive oxygen species; Root growth inhibition; Indole-3-acetic acid peroxidase; Heavy metals
• ISSN: 0167-6903; 1573-5087
• DOI: 10.1007/s10725-010-9486-5

All of the analyzed heavy metals significantly inhibited root growth, but in addition to Cd exposure an elevated IAA-POD activity was detected under Co, Cu and Hg treatment, while Ni and Pb inhibited its activity. The Cd-induced IAA-POD activity increased from the root apex towards to the mature region of root tips. However similar or even more severe root growth inhibition was observed by exogenously applied IAA, IAA-POD activity was activated only at high IAA concentrations. Elevated Cd-induced H₂O₂ production was detected both in the absence or in the presence of IAA in the reaction mixture, but in the case of IAA as a possible substrate for PODs the production of H₂O₂ increased markedly just in the Cd-treated roots. Exogenously applied H₂O₂ also activated IAA-POD activity. Our results indicated that in the development of Cd toxicity syndrome the production of ROS during IAA degradation by elevated IAA-POD activity plays a crucial role, mainly under severe Cd stress.