Differential responses of antioxidative systems and photosynthetic pigments in the leaves of Quercus aucheri under drought stress condition.

Abstract

DIFFERENTIAL RESPONSES OF ANTIOXIDATIVE

SYSTEMS AND PHOTOSYNTHETIC PIGMENTS

IN THE LEAVES OF QUERCUS AUCHERI (BOZ

PIRNAL OAK) UNDER DROUGHT STRESS CONDITION

Hakan, Ö. - Gulriz, B.

Istanbul University

Drought is the most important stress factor determining plant

growth and productivity world-wide. The aim of the present study

was to investigate disturbances of antioxidative systems and

photosynthetic pigments in the leaves of Quercus aucheri which

are endemic for Turkey under drought stress condition. 6 months

old plants were treated with drought stress for 4 weeks. At the

end of the treatment period, contents of photosynthetic pigments,

levels of lipid peroxidation, levels of reduced glutathione (GSH)

and oxidized glutathione (GSSG) and activities of antioxidant

enzymes such as superoxide dismutase (SOD), glutathione reductase

(GR), ascorbate peroxidase (APX), guaicol peroxidase

(GPX) and catalase (CAT) were determined in the leaves of

Quercus aucheri. 4 weeks drought stress significantly decreased

contents of photosynthetic pigments while increased the levels

of lipid peroxidation in the leaves of Quercus aucheri. Levels

of GSH were significantly decreased while levels of GSSG were

significantly increased in the leaves of Quercus aucheri at the 4

weeks drought stress treatment. The activities of CAT, AP and

GR were significantly decreased while activities of SOD and

GPX were significantly increased in the leaves of Quercus aucheri

at the 4 weeks drought stress treatment. The results indicated

that 4 weeks drought stress may induce oxidative stress and

cause differential responses on the antioxidant enzymes in the

leaves of Quercus aucheri. The present study would contribute to

future studies on Quercus species which are endemic for Turkey

under drought stress conditions.