Mýtinová, Z., Motyka, V., Haisel, D., Gaudinová, A., Lubovská, Z., Wilhelmová, N.
BIOLOGIA PLANTARUM
54 (3):
461-470,
2010
Keywords:
abscisic acid, cytokinin, cytokinin oxidase/dehydrogenase, drought, salinity, zinc
Abstract:
The responses of antioxidant enzymes (AOE) ascorbate peroxidase (APX), glutathione reductase (GR), superoxide
dismutase (SOD), and catalase (CAT) in soluble protein extracts from leaves and roots of tobacco (Nicotiana tabacum
L. cv. Samsun NN) plants to the drought stress, salinity and enhanced zinc concentration were investigated. The studied
tobacco included wild-type (WT) and transgenic plants (AtCKX2) harbouring the cytokinin oxidase/dehydrogenase
gene under control of 35S promoter from Arabidopsis thaliana (AtCKX2). The transgenic plants exhibited highly
enhanced CKX activity and decreased contents of cytokinins and abscisic acid in both leaves and roots, altered
phenotype, retarded growth, and postponed senescence onset. Under control conditions, the AtCKX2 plants exhibited
noticeably higher activity of GR in leaves and APX and SOD in roots. CAT activity in leaves always decreased upon
stresses in WT while increased in AtCKX2 plants. On the contrary, the SOD activity was enhanced in WT but declined
in AtCKX2 leaves. In roots, the APX activity prevailingly increased in WT while mainly decreased in AtCKX2 in
response to the stresses. Both WT and AtCKX2 leaves as well as roots exhibited elevated abscisic acid content and
increased CKX activity under all stresses while endogenous CKs and IAA contents were not much affected by stress
treatments in either WT or transgenic plants.
Fulltext: contact IEB authors
IEB authors: Alena Gaudinová,
Daniel Haisel,
Zuzana Lubovská,
Václav Motyka,
Naďa Wilhelmová