Exogenous DCPTA Ameliorates Simulated Drought Conditions by Improving the Growth and Photosynthetic Capacity of Maize Seedlings

Abstract

Previous reports have indicated that 2-(3,4-dichlorophenoxy)triethylamine (DCPTA) can promote the growth and photosynthetic capacity of plants. However, only a small number of these studies have focused on crops, and few reports have focused on whether DCPTA affects stress tolerance. In this study, maize (Zea mays L.) seedlings were pretreated with or without DCPTA and then exposed to drought stress in a controlled growth room for 7 days, and the growth and photosynthesis indexes of the seedlings were investigated. The DCPTA treatment partly counteracted the observed decreases in biomass, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), effective photochemical efficiency of photosystem II (ΦPSII), maximum photochemical efficiency of PSII (Fv/Fm), non-photochemical quenching (NPQ), and photosynthetic pigment content and increased the minimal fluorescence (Fo) induced by drought stress. The DCPTA treatment also alleviated the damage induced by drought stress in the photosynthetic apparatus. In addition, DCPTA pretreatment simultaneously increased the root size (e.g., the length, surface area, and volume) and root hydraulic conductivity, which promoted the maintenance of higher relative leaf water contents (RLWCs) under stress conditions. These results indicate that exogenous DCPTA ameliorates simulated drought conditions by improving the growth and photosynthetic capacity of maize seedlings.

Exogenous DCPTA Increases the Tolerance of Maize Seedlings to PEG-Simulated Drought by Regulating Nitrogen Metabolism-Related Enzymes

“…Stable AST and ALT activities were detected in the PEG + DCPTA treatment, accelerating the synthesis of aspartate and alanine; this was reflected by the suppressed PEG-simulated drought stress-induced decrease in alanine and aspartate contents ( Table 4). The energy and C skeletons required for the transamination process are generated by photosynthesis, so another reason for the stable alanine and aspartate contents under PEG-simulated drought stress may be related to the stable photosynthesis induced by exogenous DCPTA, which was proven in our previous study [26,28]. Glutamate is also the primary amino acid for the synthesis of many other amino acids.…”

“…In our previously reported results, DCPTA was proven to increase the drought tolerance of maize seedlings under hydroponic conditions [26,27]. However, the underlying molecular mechanisms remain poorly understood.…”

“…Our previous study demonstrated that DCPTA applications could increase the drought tolerance of maize by improving the photosynthetic capability [26], modulating the antioxidant system [27], and ameliorating the soil drought effects on N metabolism in maize during the pre-female inflorescence emergence stage [28]. To further investigate the possible mechanism of the exogenous DCPTA-promoted drought tolerance of maize seedlings, this work was designed to address the following questions: (1) How do transcripts change in maize seedlings in response to drought stress and/or exogenous DCPTA?…”

Modulating the antioxidant system by exogenous 2-(3,4-dichlorophenoxy) triethylamine in maize seedlings exposed to polyethylene glycol-simulated drought stress

“…The doses of DCPTA (15 mg l –1 ) and PEG-6000 (15%) were selected according to our previous work [19]. The experiment was repeated five times.…”

Improving water use efficiency by changing hydraulic and stomatal characteristics in soybean exposed to drought: the involvement of nitric oxide

“…Considering the extensive damage caused by WD in plants and the future prospects of increases in the frequency and intensity of drought events, several studies have explored the mechanisms underlying plant tolerance to water restriction (Jiang et al , Wani et al , Xie et al , Zargar et al ). To date, these mechanisms have been found to commonly include a reduction in g s , the control of damage caused by oxidative stress and molecular and structural adaptations of the photosynthetic apparatus.…”