Differential impact of the temperature stress and soil drought on lipoxygenase activity in winter rye plants

Abstract

Lipoxygenase cascade is a source of physiologically active compounds, the presence of which is considered not only as a sign of damage but also as a trigger of adaptive responses to stress. The aim of the study was to determine the effects of short-term (2 h) heat (40°C) and cold (4°C) temperature stress and moderate soil drought on lipoxygenase (LOX) activity in 14-day-old winter rye (Secale cereale L. ‘Boguslavka’) plants. The shoots were found to have both membrane-bound 9-LOX1 and 9-LOX2 and soluble 13-LOX activity, the roots – membrane-bound 9-LOX activity. After heat stress, the activity of 9-LOX1 and 9-LOX2 in the shoots increased by 3 and 2 times, respectively, the activity of 9-LOX in the roots – by 2 times, and 13-LOX activity in the shoots decreased by 1.5 times. After the cold stress, the activity of 9-LOX1 and 9-LOX2 in the shoots raised by almost 1.5 times, the activity of 9-LOX in the roots – by 1.2 times. Moderate soil drought caused enhancement in the activity of both membrane-bound isoforms of 9-LOX in the shoots by 1.5–2 times and in the roots – by 3 times. The established fluctuations indicate that molecular forms of LOX with different localization are differentially involved in the winter rye response to temperature stress and moderate soil drought.

Keywords

• hyperthermia
• hypothermia
• lipoxygenase activity
• secale cereale
• water deficit