Co-treatment Effect of Triadimefon and Salt Stress on Antioxidant Responses, NHX1 and LEA Expression in Two Alfalfa Cultivars (Medicago sativa L.) under in vitro Culture

Arab, Leila,Ehsanpour, Ali Akbar,Jwa, Nam Soo 한국응용생명화학회 2013 Applied Biological Chemistry (Appl Biol Chem) Vol.56 No.4

This study was carried out to investigate the possibility of using Triadimefon as a plant growth regulator and salt stress protectant in order to decrease the adverse effects of salt stress. Two Medicago cultivars including Hamedani and Yazdi were treated with 0, 2 mg/L triadimefon (TRD) and 0, 100, and 140 mM NaCl. Salt stress increased $Na^+$, ascorbic acid (AA), reduced glutathione (GSH), reactive oxygen species and phenol contents and activity of ascorbate peroxidase (APX), and glutathione reductase (GR), whereas decreased the $K^+$ content and the activity of polyphenol oxidase (PPO) in both cultivars. When plants were treated with TRD and NaCl, they accumulated less $Na^+$, $K^+$, and ROS. Co-treatment of NaCl and TRD in both cultivars increased AA, GSH, and phenol contents, and the activities of APX and GR, whereas reduced PPO activity. Our results also showed that LEA gene was up-regulated by salt stress. TRD treatment resulted in down-regulation of this gene. Sodium/hydrogen exchanger gene was not affected by either salt or TRD treatments.

Co-treatment Effect of Triadimefon and Salt Stress on Antioxidant Responses, NHX1 and LEA Expression in Two Alfalfa Cultivars (Medicago sativa L.) under in vitro Culture

Leila Arab,Ali Akbar Ehsanpour,좌남수 한국응용생명화학회 2013 Applied Biological Chemistry (Appl Biol Chem) Vol.56 No.4

This study was carried out to investigate the possibility of using Triadimefon as a plant growth regulator and salt stress protectant in order to decrease the adverse effects of salt stress. Two Medicago cultivars including Hamedani and Yazdi were treated with 0, 2 mg/L triadimefon (TRD) and 0, 100, and 140mM NaCl. Salt stress increased Na+, ascorbic acid (AA), reduced glutathione (GSH), reactive oxygen species and phenol contents and activity of ascorbate peroxidase (APX), and glutathione reductase (GR), whereas decreased the K+ content and the activity of polyphenol oxidase (PPO) in both cultivars. When plants were treated with TRD and NaCl, they accumulated less Na+, K+, and ROS. Co-treatment of NaCl and TRD in both cultivars increased AA, GSH, and phenol contents, and the activities of APX and GR,whereas reduced PPO activity. Our results also showed that LEA gene was up-regulated by salt stress. TRD treatment resulted in down-regulation of this gene. Sodium/hydrogen exchanger gene was not affected by either salt or TRD treatments.

Silver Nanoparticles and Silver Ions: Oxidative Stress Responses and Toxicity in Potato (Solanum tuberosum L) Grown in vitro

Mozafar Bagherzadeh Homaee,Ali Akbar Ehsanpour 한국원예학회 2016 Horticulture, Environment, and Biotechnology Vol.57 No.6

Under in vitro conditions, we examined the effects of silver nanoparticles (AgNPs) and silver (Ag) ions on potato (Solanum tuberosum L.) in terms of silver accumulation, production of reactive oxygen species (ROS), oxidative stress responses, and antioxidative defense systems. At all concentrations (except at 2 mg・L-1), the amount of Ag in the shoots and roots of Ag ion-treated plantlets was significantly higher than in plantlets treated with AgNPs. In both treatments, total ROS and superoxide anions were increased at concentrations greater than 2 mg・L-1. Damage caused by oxidative stress, such as ion leakage and cell death, was significantly higher in plantlets treated with AgNPs than those treated with Ag ions. Significant increases in the activities of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase (GR),were found in both AgNP-treated, and Ag ion-treated plantlets compared to the control. However, in AgNP-treated plantlets, GR activity was significantly decreased at 20 mg・L-1. A significant reduction in glutathione (GSH), ascorbate (ASA), and the ratios of GSH to oxidized glutathione (GSSG) and ASA to oxidized ascorbate (DHA)were observed in plantlets treated with both AgNPs and Ag ions at concentrations higher than 2 mg・L-1. Moreover, a greater decrease in GSH and ASA contents was seen in plantlets treated with AgNPs compared to those treated with Ag ions. The present study indicates that both AgNPs and Ag ion treatments impose oxidative stress on potato plantlets under in vitro conditions. Furthermore, based on plantlets’ responses to oxidative damage, the observed alteration in the activities of radical scavenging enzymes and the depletion of GSH and ASA, AgNPs seem to have higher toxicity than the equivalent mass of Ag ions.

Potential objectives for gibberellic acid and paclobutrazol under salt stress in sweet sorghum (Sorghum bicolor [L.] Moench cv. Sofra)

Amir Hossein Forghani,Abbas Almodares,Ali Akbar Ehsanpour 한국응용생명화학회 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1

The phytohormones are important in plant adaptation to abiotic and biotic stresses by facilitating a wide range of adaptive responses. Application of gibberellic acid (GA3) and paclobutrazol (PBZ) as GA3 inhibitors have been shown to affect salinity tolerance through modulating phytohormones. The aim of this study was to find out the potential objectives for GA3 and PBZ as affected by salinity through altering the phytohormones and biochemical parameters in sweet sorghum. Following seed germination, seedlings were cultured in Hoagland nutrient solution containing NaCl supplemented with GA3 and PBZ for 12 days. The results were analyzed by principal component analysis to identify the best target(s) for salinity, GA3, and PBZ in sweet sorghum. Paclobutrazol associated with salt improved root/shoot length, carotenoid, and total chlorophyll by modulating cytokinin (CK)/GA3, indole acetic acid (IAA)/GA3, and total polyamines/GA3 ratios. Gibberellic acid-treated plants not exposed to salinity treatments notably improved phytohormones content such as cytokinin, auxin, abscisic acid (ABA), and polyamines resulting in increased stem growth. Moreover, the main objectives of GA3 were ABA, spermidine, and ABA/GA3 ratio in response to salinity. Though GA3 and PBZ have different roles against salt stress, ABA/ GA3 ratio was a similar target of GA3 and PBZ. This work suggests that altered levels of GA3 resulting from PBZ- and GA3-treated plants cause different allocation patterns in sweet sorghum by regulation of CK/GA3, IAA/GA3, and total polyamines/GA3 ratio. Also, accumulation chlorophyll pigments, carotenoids, and water soluble carbohydrates of sorghum plants under salinity regulated by total polyamines/GA3 and ABA/GA3 ratios positively correlated with PBZ application.

Potential objectives for gibberellic acid and paclobutrazol under salt stress in sweet sorghum (Sorghum bicolor [L.] Moench cv. Sofra)

Forghani, Amir Hossein,Almodares, Abbas,Ehsanpour, Ali Akbar The Korean Society for Applied Biological Chemistr 2018 Applied Biological Chemistry (Appl Biol Chem) Vol.61 No.1

The phytohormones are important in plant adaptation to abiotic and biotic stresses by facilitating a wide range of adaptive responses. Application of gibberellic acid ($GA_3$) and paclobutrazol (PBZ) as $GA_3$ inhibitors have been shown to affect salinity tolerance through modulating phytohormones. The aim of this study was to find out the potential objectives for $GA_3$ and PBZ as affected by salinity through altering the phytohormones and biochemical parameters in sweet sorghum. Following seed germination, seedlings were cultured in Hoagland nutrient solution containing NaCl supplemented with $GA_3$ and PBZ for 12 days. The results were analyzed by principal component analysis to identify the best target(s) for salinity, $GA_3$, and PBZ in sweet sorghum. Paclobutrazol associated with salt improved root/shoot length, carotenoid, and total chlorophyll by modulating cytokinin $(CK)/GA_3$, indole acetic acid $(IAA)/GA_3$, and total polyamines/$GA_3$ ratios. Gibberellic acid-treated plants not exposed to salinity treatments notably improved phytohormones content such as cytokinin, auxin, abscisic acid (ABA), and polyamines resulting in increased stem growth. Moreover, the main objectives of $GA_3$ were ABA, spermidine, and $ABA/GA_3$ ratio in response to salinity. Though $GA_3$ and PBZ have different roles against salt stress, $ABA/GA_3$ ratio was a similar target of $GA_3$ and PBZ. This work suggests that altered levels of $GA_3$ resulting from PBZ- and $GA_3$-treated plants cause different allocation patterns in sweet sorghum by regulation of $CK/GA_3$, $IAA/GA_3$, and total polyamines/$GA_3$ ratio. Also, accumulation chlorophyll pigments, carotenoids, and water soluble carbohydrates of sorghum plants under salinity regulated by total polyamines/$GA_3$ and $ABA/GA_3$ ratios positively correlated with PBZ application.