Evaluation Of Photosynthetic Reactions and Antioxidant System Of Wheat Cultivar M7318 Using 6-Benzyladenine (6-BA) Under Water Deficit Stress Conditions
محورهای موضوعی : Research On Crop EcophysiologySeyed Ali Emami 1 , Ali Soleymani 2
1 - PhD Student of Islamic Azad University of Khorasgan, Iran.
2 - Department of Agronomy, Isfahan Branch, Islamic Azad University, Isfahn, Iran
کلید واژه: Keywords: Drought stress, Enzymatic characteristics, Photosynthetic traits, Wheat, 6-benzyladenine,
چکیده مقاله :
Evaluation Of Photosynthetic Reactions and Antioxidant System Of Wheat Cultivar M7318 Using 6-Benzyladenine (6-BA) Under Water Deficit Stress Conditions SAYED ALI EMAMI1*, ALI SOLEYMANI2 1-PhD Student of Islamic Azad University of Khorasgan, Iran. 2- Deprtment of Agronomy and Plant Breeding, Islamic Azad University of Khorasgan , Isfahan, Iran. *Corresponding author’s E-mail: dr.s.a.emami110@gmail.com Received: 25 March 2024 Accepted: 5 June 2024 ABSTRACT Drought is one of the most significant constraints on agricultural productivity worldwide, and its severity is predicted to increase in the future. To combat drought stress in plants, employing effective strategies such as foliar application of plant hormones is essential. Wheat, as a strategic crop, plays a vital role in global food security; however, drought stress severely impacts both its quantitative and qualitative yield. This study was conducted over two consecutive growing seasons (2016-2017 and 2017-2018) at a research farm located in Barsian village, Ziar, with the objective of investigating the effects of different drought stress levels (including normal, mild drought stress, and drought stress) and foliar application of the cytokinin hormone 6-BA at three concentrations (15, 30, and 45 ppm) on yield value, photosynthetic traits (chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll), and enzymatic traits (catalase, ascorbate peroxidase, and peroxidase) of wheat cultivar M7318. ANOVA confirmed significant moisture regime effects on all traits, and cytokinin 6-BA impacting all except Chla, and significant interactions only for GY, POX, and CAR. Results reveal a 39% GY reduction under drought stress, alongside significant declines in traits such as Chla, Chlb, and CAR, indicating disrupted photosynthesis due to oxidative damage and reduced stomatal conductance. Drought-induced enzymatic increases (POX, CAT, APX) reflect an adaptive ROS-scavenging response, while 6-BA at 30-45 ppm enhanced CAT and APX but reduced POX, suggesting dose-dependent regulation. The 45 ppm 6-BA treatment significantly boosted GY under normal conditions (758 g/m²) and improved Chlb, Tchl, and CAR. Interaction effects showed the highest POX under drought with 45 ppm (15.5 min⁻¹ mg⁻¹ protein) and lowest under normal conditions (8.5 min⁻¹ mg⁻¹ protein), indicating context-specific responses. These findings indicate the usefulness of foliar application of cytokinin 6-BA as a useful method for reducing the effects of drought in wheat, and the results of this study can be used to improve yield, chlorophyll, and enzyme properties in agriculture and future studies. Keywords: Drought stress, Enzymatic characteristics, Photosynthetic traits, Wheat, 6-benzyladenine
Evaluation Of Photosynthetic Reactions and Antioxidant System Of Wheat Cultivar M7318 Using 6-Benzyladenine (6-BA) Under Water Deficit Stress Conditions SAYED ALI EMAMI1*, ALI SOLEYMANI2 1-PhD Student of Islamic Azad University of Khorasgan, Iran. 2- Deprtment of Agronomy and Plant Breeding, Islamic Azad University of Khorasgan , Isfahan, Iran. *Corresponding author’s E-mail: dr.s.a.emami110@gmail.com Received: 25 March 2024 Accepted: 5 June 2024 ABSTRACT Drought is one of the most significant constraints on agricultural productivity worldwide, and its severity is predicted to increase in the future. To combat drought stress in plants, employing effective strategies such as foliar application of plant hormones is essential. Wheat, as a strategic crop, plays a vital role in global food security; however, drought stress severely impacts both its quantitative and qualitative yield. This study was conducted over two consecutive growing seasons (2016-2017 and 2017-2018) at a research farm located in Barsian village, Ziar, with the objective of investigating the effects of different drought stress levels (including normal, mild drought stress, and drought stress) and foliar application of the cytokinin hormone 6-BA at three concentrations (15, 30, and 45 ppm) on yield value, photosynthetic traits (chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll), and enzymatic traits (catalase, ascorbate peroxidase, and peroxidase) of wheat cultivar M7318. ANOVA confirmed significant moisture regime effects on all traits, and cytokinin 6-BA impacting all except Chla, and significant interactions only for GY, POX, and CAR. Results reveal a 39% GY reduction under drought stress, alongside significant declines in traits such as Chla, Chlb, and CAR, indicating disrupted photosynthesis due to oxidative damage and reduced stomatal conductance. Drought-induced enzymatic increases (POX, CAT, APX) reflect an adaptive ROS-scavenging response, while 6-BA at 30-45 ppm enhanced CAT and APX but reduced POX, suggesting dose-dependent regulation. The 45 ppm 6-BA treatment significantly boosted GY under normal conditions (758 g/m²) and improved Chlb, Tchl, and CAR. Interaction effects showed the highest POX under drought with 45 ppm (15.5 min⁻¹ mg⁻¹ protein) and lowest under normal conditions (8.5 min⁻¹ mg⁻¹ protein), indicating context-specific responses. These findings indicate the usefulness of foliar application of cytokinin 6-BA as a useful method for reducing the effects of drought in wheat, and the results of this study can be used to improve yield, chlorophyll, and enzyme properties in agriculture and future studies. Keywords: Drought stress, Enzymatic characteristics, Photosynthetic traits, Wheat, 6-benzyladenine
