Antioxidant enzymatic protection during tobacco leaf ageing is affected by cytokinin depletion

0365377 - ÚEB 2012 RIV NL eng J - Článek v odborném periodiku
Mýtinová, Zuzana - Motyka, Václav - Haisel, Daniel - Lubovská, Zuzana - Trávníčková, Alena - Dobrev, Petre - Holík, Josef - Wilhelmová, Naděžda
Antioxidant enzymatic protection during tobacco leaf ageing is affected by cytokinin depletion.
Plant Growth Regulation. Roč. 65, č. 1 (2011), s. 23-34. ISSN 0167-6903. E-ISSN 1573-5087
Grant CEP: GA ČR GA522/03/0312; GA AV ČR IAA600380701; GA MŠMT(CZ) LC06034
Výzkumný záměr: CEZ:AV0Z50380511
Klíčová slova: Ageing * Antioxidant enzymes * Cytokinins
Kód oboru RIV: CE - Biochemie
Impakt faktor: 1.604, rok: 2011

Plant ageing is associated with increased levels of ROS. Level of cytokinins is controlled by their irreversible degradation catalysed by CKX. The control and transgenic AtCKX2 plants differed substantially in their phenotypes. When the lowest leaves in controls became yellow all leaves in AtCKX2 tobacco still remained green. Activities of antioxidant enzymes decreased with leaf age in both tobacco plants except for APX in the old leaves and GR in young leaves. Enhancement of GR activity at all leaf stages, an increase of SOD and a decline of catalase in young leaves, as well as an increase of APX in the oldest leaves were observed in AtCKX2 plant compared to control. Similar changes were detected after determination of isoenzymes on zymograms. It is evident that AtCKX2 plants had postponed onset of senescence despite the significantly lowered level of cytokinins. Enhanced antioxidant protection, especially in the oldest leaves, could subsidise this phenomenon.
Trvalý link: http://hdl.handle.net/11104/0200632