Effects of plant-derived smoke, karrikin, and salinity stress on Prunus armeniaca cv. Şalak seeds and seedlings: A morphological, biochemical, and molecular approach

Abstract

There is great interest in developing strategies to reduce the detrimental effects of salinity stress to improve plant growth and yield. The effects of plant-derived smoke on seed germination and plant growth, depending on concentration and time, are widely known. Although it has been suggested that plant-derived smoke and Karrikin (KAR1) tolerate the harmful effects of abiotic stress in plants, there is a lack of comprehensive information on biochemical and molecular changes related to KAR1 and smoke water (SW) in plants. Here we extensively compared the effects of SW and KAR1 on seed germination and morphology. Here we comprehensively compared the effects of SW and KAR1 on seed germination and morphological, biochemical, and molecular changes observable in the examined seeds. Moreover, we also showed that it regulated the expression of some genes encoding antioxidant enzymes in apricot seedlings (Prunus armeniaca L.) exposed to salinity stress (100 mM NaCl). Morphologically, we observed more adverse effects with decreased concentration in the SW treatment and increased concentration in the KAR1 treatment. The data revealed that SW (1:1000 v/v) and KAR1 (1µM) increased the expression levels of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) genes in the samples taken from the apricot seedlings treated with salt at hours 3, 6 and 9. This increase varies in SW and KAR1 depending on time. When the biochemical results were examined, it was seen that the application of SW and KAR1 to the seedlings under salinity stress led to a significant decrease in the thiobarbituric acid reactive substances (TBARS) content. We can assert that SW is more effective than KAR1 on TBARS content. Morphological, molecular, and biochemical results revealed enhanced germination, growth, gene expression, and TBARS content in apricot seeds and seedlings exposed to SW and KAR1. This data may be applicable to more comprehensive trials.