Institutional Repository | Satya Wacana Christian University: Respon Antioksidatif Tanaman Sorgum (Sorghum Bicolor (L.) Moench) pada Cekaman Cr(III) dan Cr(VI)

Abstract
Chromium (Cr) is the seve th ost a u da t etal i the earth’s rust a d a
important contaminant in environment. On Cr stress, ROS (reactive oxygen
species) is produced in many plants, generating oxidative stress leading to cells
damage. In response to oxidative stress, plants have developed defense system to
scavenge the ROS by enzymatic and non-enzymatic antioxidants. The aim of study
to analyzed antioxidative responses of Sorghum bicolor in Indonesia under Cr(III)
and Cr(VI) stresses. Experiments used FCRD (factorial completely randomized
designs) with three factors (Cr forms, Cr concentrations, and cultivars of Sorghum
bicolor). On Cr(VI) stress, ascorbic acid concentration of S. bicolor cv. Badik and
SOD (superoksida dismutase) activities increased, APX (ascorbate peroxidase)
activities increased in low concentration (1,8 mg/kg) but decreased in high
concentration (4,5 mg/kg), and carotenoid concentrations decreased. On Cr(III)
stress, SOD activity and antioxidant reducing power of S. bicolor cv. Badik and
APX activity of S. bicolor cv. UPCA increased, but APX activity of S. bicolor cv. Badik
decreased. Cr(VI) stress induced antioxidative responses of S. bicolor higher than
Cr(III) stress. Both cultivar of S. bicolor has similar antioxidative responses under
Cr(VI) dan Cr(III) stresses. Overall, antioxidative enzymes stronger than
antioxidant compounds in the detoxification of Cr toxicity. The interaction of
treatment factors on antioxidative enzymes and antioxidant compounds exert
significant influence.

Key words : Chromium, Sorghum bicolor, antioxidantive responses, antioxidant