Exogenous application of limonene alleviates drought-induced oxidative stress in tobacco plants

Drought is a major ecologically hazardous factor limiting global crop productivity. High temperatures and stress caused by drought are major environmental stress factors on tobacco growth and productivity due to escalating global climate change. The present pot study was designed to investigate the impacts of foliar application of limonene on morphological, biochemical and qualitative traits of tobacco under drought stress. The experimental treatments were comprised of two factors, i.e., three drought severity levels (WW: well-watered, MDS: moderate drought stress with 60 ± 5 % field capacity, and SDS: severe drought stress with 35 ± 5 % field capacity of soil), and four levels of foliar-application of limonene (0.0, 0.1, 0.3, and 0.5 mg mL −1 ) in tobacco plants. The findings demonstrated that drought stress significantly affected plants growth, productivity and qualitative response of tobacco plants. The foliar application of limonene (0.3 mg mL −1 ) significantly enhanced growth traits, biomass attributes, total chlorophyll level (30.11 %) and carotenoid levels (43.41 %) as compared to control (0.0 mg mL −1 ). These findings further suggest that the intensity of the drought levels triggered an over production of proline and lipid peroxidation. The optimal level of limonene application enhanced soluble sugars (20.49 %), increased soluble protein (29.20 %), and reduced proline accumulation (10.23 %) as well as lipid peroxidation malonaldehyde (MDA) level (17.39 %) under severe drought conditions. Moreover, the limonene application enhanced leaf potassium levels (20.14 %) by restricting chloride ions (29.14 %) under severe drought conditions. Altogether, an optimal application of limonene (0.3 mg mL −1 ) holds significant potential as an effective approach to increase the drought tolerance of tobacco plants. This study distinctly emphasized the potential of foliar application of limonene as an environmentally sustainable approach to augment plant resistance under drought stress, providing novel insights into viable agriculture practices. • Drought stress significantly impacted the proline accumulation and lipid peroxidation. • Optimal level of limonene enhanced growth, biomass, and photosynthetic traits. • Limonene application increased soluble sugar (27.91 %, soluble protein (35.81 %), and decreased proline (16.50 %) and MDA (32.67 %). • Optimal level of limonene enhanced leaf potassium (38.64 %) and restricted chloride ions (55.21 %) under drought.