Effects of plant-derived smoke water on germination and growth in stressed plants

Approximately 30 million additional people joined the vast number of people experiencing food insecurity in 2021 due to climate change. It is paramount to find ways to increase seed germination and plant growth under climate change-related stresses. Previous research has shown that smoke water, the chemical extract of all substances in smoke that is created when burning plants, can stimulate seed germination and plant growth. However, little research has been done on the effect of smoke water treatment on seed germination and plant growth when exposed to abiotic stresses. Thus, our goal was to examine the effect of plant-derived smoke waters on radish, buckwheat, barley, and pea plant germination and growth under heat stress, salinity stress, drought stress, and excessive water stress. We hypothesized that plant seeds germinated with plant-derived smoke water and exposed to abiotic stress would have higher germination and growth rates than those plant seeds not germinated with smoke water and exposed to stress. We derived smoke water from radish, buckwheat, barley, and pea plants, then we germinated and grew the plants with different smoke waters. We found that smoke water derived from certain plants—particularly buckwheat, pea, and radish—can positively influence plant germination and growth under certain environmental stress conditions. The plant-derived smoke water has the greatest influence on increased drought and excessive water stress followed by salinity stress but has little influence on increased temperature stress. Thus, our research provides evidence that smoke water can aid plants germinating and growing in stressed conditions.