Metabolome profiling of stratified seeds provides insight into the regulation of dormancy in Davidia involucrata

Dove tree (Davidia involucrata), a tertiary vestige species, is well-adapted to cool conditions. Dormancy in D. involucrata seed lasts for an extremely long period of time, typically between 3 and 4 years, and this characteristic makes the species an excellent model for studying the mechanisms of seed dormancy. The molecular mechanisms governing germination control in D. involucrata are still un-known. Seed stratification have been reported to enhance germination in recalcitrant seeds. We per-formed a widely targeted metabolome profiling to identify metabolites and associated pathways in D. involucrata seeds from six different moist sand stratification durations (0-30 months) using the ultra-high-performance liquid chromatography-Q Exactive Orbitrap-Mass spectrometry. There was an increasing germination rate with prolonged stratification durations (12-30 months). Furthermore, we detected 10,008 metabolites in the stratified seeds. We also detected 48 differentially accumulated metabolites (DAMs) between all stratification periods in the seeds, with 10 highly conserved metab-olites. Most of the differentially accumulated metabolites between unstratified and stratified seeds were enriched in purine metabolism, pyrimidine metabolism, flavone and flavonol biosynthesis, phenylpropanoid biosynthesis, and arginine biosynthesis pathways. Key phytohormones, abscisic acid, indole-3 acetic acid, and sinapic acid were differentially accumulated in the seeds and are predicted to regulate dormancy in D. involucrata. We have provided extensive metabolic information useful for future works on dove tree germination study.Copyright (c) 2021 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY -NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Dove tree seeds have a long dormancy period, and stratification treatment can enhance germination rate. The germination process involves various metabolites and pathways, with phytohormones playing a key role in seed dormancy regulation.