Physiological and molecular investigation of the effect of trehalose on drought stress tolerance in wheat (Triticum turgidum ssp. durum L.)

Factors such as the increase in the world population and the decrease in agricultural land are causing yield and quality losses in agricultural production. To cope with these challenges, it is necessary to protect crops from various stress factors. Drought stress can negatively affect the growth and productivity of plants; therefore, it is important to prepare plants against such stress conditions. Trehalose stands out as an osmolyte that helps plants cope with drought stress. Seed-priming treatments improve the germination rate and seedling development of plants by ensuring that seeds undergo certain preparatory processes before germination. Seed-priming with Trehalose can increase plant resilience to drought stress and improve productivity, thus supporting sustainability in agricultural production. Our study was conducted with two different techniques using cigar-roll and pot methods. In the cigar-roll method, plants were seed-primed with 5 and 10 mM Trehalose or distilled water for 40 h and drought-stressed with PEG 8000 when they reached a certain size. The results showed that Trehalose treatments resulted in a statistically significant improvement in plant growth parameters against drought stress. In the pot method, plants seed-primed with 5 and 10 mM Trehalose or distilled water for 40 hours were exposed to drought stress at 50% of the field capacity when they reached a certain size. As a result of this treatment, it was observed that Trehalose provided statistically significant improvement in plant growth parameters against drought stress. Trehalose seed primed plants showed an increase in chlorophyll pigments under drought stress. Furthermore, exogenous Trehalose increased antioxidant activity by DPPH method under both stressed and control conditions. To understand the molecular effects of Trehalose seed priming treatments on drought stress, plant samples were taken from both cigar-roll and pot studies and transcriptional changes of some important genes for plant immunity (WRKY75, ERF1, MYB3, SOD1, CAT1 and DREB1) were examined. The qRT-PCR results showed that expression levels of all genes except CAT1 increased in the petri group in the pot method and a significant increase in gene expression was observed in the 5 mM Trehalose-normal water and 10 mM Trehalose-10% PEG groups in the cigar-roll method. The findings of our study suggest that Trehalose seed priming applications will make important contributions to the existing literature and may have positive results in the field of stress tolerance in plants. The potential of Trehalose to enhance stress tolerance and increase productivity in plants offers a new perspective for research in this field.