Cultivating Pharmaceutical Potential: Optimising Triacontanol Application to Enhance Linseed’s Attributes under Drought Stress

Background: Triacontanol (TRIA) has been identified as a potent plant growth regulator, demonstrating significant benefits under various stress conditions. However, its specific impact on Linum usitatissimum L. (flax) under drought stress conditions remains underexplored. This study investigates the effects of TRIA on the growth, physiology, and biochemistry of two flax genotypes subjected to drought stress, aiming to enhance our understanding of its potential as a biostimulant for improving crop resilience and productivity. Objective: The primary objective of this study was to evaluate the effects of different concentrations of TRIA on the growth, physiological, and biochemical responses of two flax genotypes under drought stress conditions. We aimed to determine whether TRIA application could mitigate the adverse effects of drought and enhance plant performance. Methods: This study was conducted using two flax genotypes, G-20888 and G-22186. Plants were grown under controlled conditions and subjected to drought stress by maintaining soil moisture at 50% field capacity. TRIA was applied in three concentrations: 0 M (control), 10^-6 M, and 10^-7 M. A completely randomized design was used with three replications for each treatment. Plant growth parameters, including root length, shoot length, plant height, and shoot fresh weight, were measured. Physiological parameters such as chlorophyll content, relative water content (RWC), and electrolyte leakage were assessed. Biochemical analyses included the estimation of antioxidant enzyme activities (superoxide dismutase, catalase, and peroxidase). Data were statistically analyzed using SPSS version 25.0. Results: TRIA application significantly improved root length, shoot length, plant height, and shoot fresh weight in both flax genotypes under drought stress. For genotype G-20888, root length increased from 5.1 cm (control) to 6.8 cm (TRIA 10^-7 M). Shoot length showed a similar trend, with increases from 8.3 cm (control) to 10.1 cm (TRIA 10^-7 M). In G-22186, plant height increased from 70 cm (control) to 82 cm (TRIA 10^-7 M). Chlorophyll content increased by 15%, and RWC by 18% in TRIA-treated plants compared to controls. Antioxidant enzyme activities were also enhanced, with catalase activity increasing by 25% and peroxidase by 30%. Conclusion: TRIA application significantly mitigated the adverse effects of drought stress on flax genotypes by enhancing growth, physiological, and biochemical parameters. The findings suggest that TRIA could be an effective biostimulant for improving drought tolerance in flax, potentially leading to better crop resilience and productivity.