Analysis of the energy source at the early stage of poplar seed germination: verification of Perl’s pathway

Abstract

Adenosine triphosphate (ATP) is produced at the early stage of seed germination and provides the energy for metabolism. The source of ATP in seeds may be Perl's pathway, but this has not yet been confirmed. In this study, using germinating seeds of poplar as the experimental materials, the transcript levels of genes related to Perl's pathway were determined by real-time PCR. The activities of enzymes in Perl's pathway were also determined. The results were verified by comparison with RNA-Seq and metabolomics data. The results showed that there were high transcript levels of some genes encoding malate dehydrogenase (MDH), phosphoenolpyruvate carboxykinase (PEPCK), pyruvate decarboxylase (PDC), alcohol dehydrogenase (ADH), and pyruvate kinase (PK) at the early stage of germination (0.75 h). The enzymes MDH, PEPCK, PK, PDC, and ADH showed peaks in activity at around 0.75 h and 6 h during germination. The oxaloacetate concentration was high in poplar seeds at the early stage of germination. This study provides experimental data showing that Perl's pathway participates in supplying energy during the early stages of poplar seed germination, and lays the foundation for further studies on the complex metabolic processes that function during seed germination.

Hydro-Electro Hybrid Priming Promotes Carrot (Daucus carota L.) Seed Germination by Activating Lipid Utilization and Respiratory Metabolism

“…In addition, both in the Perl's pathway and the last step of glycolysis, pyruvate produced by PK is mainly metabolized by anaerobic respiration in the early stage of germination. Acetaldehyde is produced under the catalysis of PDC, and ultimately ethanol is produced under the action of ADH to release ATP [51]. This pathway is also vital for the energy supply in the early stage of germination under anoxic conditions [52,53].…”

Molecular dynamics of seed priming at the crossroads between basic and applied research

“…The fermentative pathway is less effective in ATP production and excess accumulation of the related products (e.g., acetaldehyde and ethanol) compromises seed germination (Zhang et al 1995 ). ATP is required to support high germination rates (Ching 1973 ; Lunn and Madsen 1981 ; Kibinza et al 2006 ; He et al 2019 ; Qu et al 2020 ), to help seeds withstand deterioration (Anderson 1977 ), and to accomplish successful seed priming (Corbineau et al 2000 ) although reports are underlining how high ATP content (Perl 1986 ; Corbineau et al 2002 ), as well as extracellular ATP levels (Wang et al 2022 ), can affect germination. Despite contrasting reports, energy metabolism—measured, e.g., in terms of energy charge and ATP:ADP ratio—could be an informative target to explore the impact of priming treatments on seed physiology (Corbineau et al 2002 ; Marthandan et al 2020 ) (Fig.…”