Abstract

Drought stress is a highly pervasive and economically damaging abiotic stress that affects plant yield and productivity worldwide. Physiologically, drought stress in plants is associated with oxidative stress leading to tissue damage. Drought stress imposed over 72 h in 10 days old seedlings of Guizotia abyssinica Cass, niger (cv; RCR-18) under greenhouse conditions resulted in elevated levels of oxidative stress markers such as H₂O₂, malondialdehyde, proline, reduced glutathione and ascorbate in a time-dependent manner. Levels of antioxidant enzymes: peroxidases and glutathione reductase, and metabolic enzyme: amylase and acid phosphatase were moderately enhanced. The levels of stress markers, antioxidants, and recovery upon re-watering suggested that the antioxidant system in niger could withstand the drought stress for up to 48 h under greenhouse conditions.

Key words: Drought stress, antioxidants, antioxidant enzymes, malondialdehyde, abiotic stress.