2-(3,4-Dichlorophenoxy) triethylamine (DCPTA) regulates plant development; however, the molecular basis of this regulation is poorly understood.In this study, RNA sequencing (RNA-seq) analysis and physiological indexes of maize seedlings (three-leaf stage) treated with 15% polyethylene glycol (PEG) with/without DCPTA were investigated to explore the possible mechanism of exogenous DCPTA-improved drought tolerance.In the library pair comparisons of DCPTA vs.
the control, PEG vs.the control, and PEG + DCPTA vs.PEG, totals of 19, 38 and 20 Cookbook differentially expressed genes (DEGs) were classified as being involved in metabolic processes, respectively; totals of 5, 11, and 6 DEGs were enriched in the nitrogen (N) metabolic pathway, respectively.
The genes encoding nicotinamide adenine dinucleotide-nitrate reductase (NADH-NR), ferredoxin-nitrite reductase (Fd-NiR), reduced ferredoxin- glutamate synthase (Fd-GOGAT), and chloroplastic glutamine synthetase (GS 2) were common in response to PEG-simulated drought stress with/without DCPTA treatment.Moreover, DCPTA maintained stable gene relative expression levels and protein abundances of NADH-NR, Fd-NiR, GS2, and Fd-GOGAT.Moreover, exogenous DCPTA partially mitigated PEG-simulated drought-induced reductions in the enzymatic activities of NR, nitrite reductase (NiR), glutamine synthase (GS), glutamine oxoglutarate aminotransferase EAR TONE (GOGAT), and transaminase, as well as in the contents of nitrate (NO3−), nitrite (NO2−) and soluble proteins and increases in the contents of ammonium (NH4+) and free amino acids.
Together, our results indicate that exogenous DCPTA improved plant growth and drought tolerance by regulating N-mechanism enzymatic activities involved in transcription and enzymatic protein synthesis.