Abstract
Maize (Zea mays L.), an important agricultural crop, suffers from drought stress frequently during its growth period, thus leading to a decline in yield. 2-(3,4-Dichlorophenoxy) triethylamine (DCPTA) regulates many aspects of plant development; however, its effects on crop stress tolerance are poorly understood. We pre-treated maize seedlings by adding DCPTA to a hydroponic solution and then subjected the seedlings to a drought condition [15% polyethylene glycol (PEG)-6000 treatment]. The activities of superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and glutathione reductase (GR) were enhanced under drought stress and further enhanced by the DCPTA application. The activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and catalase (CAT) declined continuously under drought stress; however, the activities partially recovered with DCPTA application. Up-regulation of the activities and transcript levels of APX, GR, MDHAR and DHAR in the DCPTA treatments contributed to the increases in ascorbate (AsA) and glutathione (GSH) levels and inhibited the increased generation rate of superoxide anion radicals (O2·−), the contents of hydrogen peroxide (H2O2) and malondialdehyde (MDA), and the electrolyte leakage (EL) induced by drought. These results suggest that the enhanced antioxidant capacity induced by DCPTA application may represent an efficient mechanism for increasing the drought stress tolerance of maize seedlings.
Highlights
Reactive oxygen species (ROS), the by-products of aerobic metabolism, are continuously produced in plants and efficiently eliminated by plant antioxidant defence mechanisms under non-stress conditions [1]
We investigated the effects of DCPTA on the growth parameters of seedlings and the generation rate of O2Á−; H2O2 and malondialdehyde (MDA) contents; electrolyte leakage (EL); non-enzymatic and enzymatic antioxidants; and the relative expression of genes encoding the isoenzymes of ascorbate peroxidase (APX), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) in the leaves of seedlings exposed to 15% polyethylene glycol (PEG)-6000 treatment to explore the modulation of the AsA-GSH cycle by DCPTA under drought stress
Compared with that of the control, the relative growth rate (RGR) of the shoots and roots decreased by 35.26% and 27.99% in response to 15% PEG-6000 treatment and by 21.60% and 16.28% in response to PEG + DCPTA treatment, but increased by 9.54% and 8.22% in response to DCPTA treatment, respectively
Summary
Reactive oxygen species (ROS), the by-products of aerobic metabolism, are continuously produced in plants and efficiently eliminated by plant antioxidant defence mechanisms under non-stress conditions [1]. Drought stress inevitably alters the critical balance between the generation and scavenging of ROS, resulting in excessive levels of ROS [2]. These levels can damage biological membrane systems and macromolecules, resulting in the interruption of normal metabolism and thereby leading to the inhibition of plant growth [3]. Modulating the antioxidant system by DCPTA in maize seedlings exposed to PEG-simulated drought stress
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
