Plant Process and Function

en Enhancing the safflower performance and quality by brassinosteroids and salicylic acid foliar application under water stress conditions Enhancing the safflower performance and quality by brassinosteroids and salicylic acid foliar application under water stress conditions تنش خشكي Droughts Stress پژوهشي Research <div style="text-align: left;">World-over, under biotic stress conditions, plant growth regulators are used to increase the growth and production of crops. To evaluate the effect of salicylic acid (SA; 0 and 1 mM) and Brassinosteroids (BRs; 0, 0.75 and 1 μM) foliar application on seed and oil yield and physiological and biochemical responses of safflower under water deficit (100 and 50% F.C., I100, and I50), an experiment was carried out in a factorial on a randomized complete block design with four replicates in the research greenhouse of Agriculture Faculty, Shahid Bahonar University of Kerman during 2023. Grain yield per plant and its components, as well as seed oil content and oil yield of safflower, were reduced under I50 treatment. Moreover, I50 stress, increased the concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) as well as osmolyte accumulation (soluble sugars and proline) and anti-oxidant enzymes activity of safflower leaves. In addition, SA and BRs application significantly increased the anti-oxidant enzyme activity and the osmolyte contents and, in contrast, decreased the concentrations of MDA and H2O2 as well as EL, however, the positive effect of SA on these parameters was highest when applied simultaneously with BRs. Also, SA, and BRs applied increased the seed oil content and oil yield of safflower, but the effect of BRs and SA together was greater than that of SA or BRs applied separately. Overall, water-stress alleviation and yield improvement in safflower by BRs and SA application was attributable to partly improved osmotic adjustment (accumulation of osmolytes), cell membrane stability and antioxidant activity under stress conditions. Foliar applications of SA and BRs had great potential in improving growth and seed and oil yield of safflower under water stress conditions.</div> World-over, under biotic stress conditions, plant growth regulators are used to increase the growth and production of crops. To evaluate the effect of salicylic acid (SA; 0 and 1 mM) and Brassinosteroids (BRs; 0, 0.75 and 1 μM) foliar application on seed and oil yield and physiological and biochemical responses of safflower under water deficit (100 and 50% F.C., I100, and I50), an experiment was carried out in a factorial on a randomized complete block design with four replicates in the research greenhouse of Agriculture Faculty, Shahid Bahonar University of Kerman during 2023. Grain yield per plant and its components, as well as seed oil content and oil yield of safflower, were reduced under I50 treatment. Moreover, I50 stress, increased the concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) as well as osmolyte accumulation (soluble sugars and proline) and anti-oxidant enzymes activity of safflower leaves. In addition, SA and BRs application significantly increased the anti-oxidant enzyme activity and the osmolyte contents and, in contrast, decreased the concentrations of MDA and H2O2 as well as EL, however, the positive effect of SA on these parameters was highest when applied simultaneously with BRs. Also, SA, and BRs applied increased the seed oil content and oil yield of safflower, but the effect of BRs and SA together was greater than that of SA or BRs applied separately. Overall, water-stress alleviation and yield improvement in safflower by BRs and SA application was attributable to partly improved osmotic adjustment (accumulation of osmolytes), cell membrane stability and antioxidant activity under stress conditions. Foliar applications of SA and BRs had great potential in improving growth and seed and oil yield of safflower under water stress conditions. World-over, under biotic stress conditions, plant growth regulators are used to increase the growth and production of crops. To evaluate the effect of salicylic acid (SA; 0 and 1 mM) and Brassinosteroids (BRs; 0, 0.75 and 1 μM) foliar application on seed and oil yield and physiological and biochemical responses of safflower under water deficit (100 and 50% F.C., I100, and I50), an experiment was carried out in a factorial on a randomized complete block design with four replicates in the research greenhouse of Agriculture Faculty, Shahid Bahonar University of Kerman during 2023. Grain yield per plant and its components, as well as seed oil content and oil yield of safflower, were reduced under I50 treatment. Moreover, I50 stress, increased the concentrations of malondialdehyde (MDA), hydrogen peroxide (H2O2), and electrolyte leakage (EL) as well as osmolyte accumulation (soluble sugars and proline) and anti-oxidant enzymes activity of safflower leaves. In addition, SA and BRs application significantly increased the anti-oxidant enzyme activity and the osmolyte contents and, in contrast, decreased the concentrations of MDA and H2O2 as well as EL, however, the positive effect of SA on these parameters was highest when applied simultaneously with BRs. Also, SA, and BRs applied increased the seed oil content and oil yield of safflower, but the effect of BRs and SA together was greater than that of SA or BRs applied separately. Overall, water-stress alleviation and yield improvement in safflower by BRs and SA application was attributable to partly improved osmotic adjustment (accumulation of osmolytes), cell membrane stability and antioxidant activity under stress conditions. Foliar applications of SA and BRs had great potential in improving growth and seed and oil yield of safflower under water stress conditions. Cell membrane stability, Plant growth regulators, Oil yield Cell membrane stability, Plant growth regulators, Oil yield 95 106 http://jispp.iut.ac.ir/browse.php?a_code=A-10-1815-1&slc_lang=en&sid=1 Mehdi Naghizadeh Mehdi Naghizadeh naghizadeh@uk.ac.ir 0000-0001-9815-7062 Yes Department of Plant Productions, Agricultural Faculty of Bardsir, Shahid Bahonar University of Kerman, Kerman, Iran Department of Plant Productions, Agricultural Faculty of Bardsir, Shahid Bahonar University of Kerman, Kerman, Iran Kobra Maghsoudi Kobra Maghsoudi k_maghsoudi1982@yahoo.com 0000-0002-2273-4238 No Graduate University of Advanced Technology, Kerman, Iran Graduate University of Advanced Technology, Kerman, Iran