Multi-omics analyses unveil the molecular mechanism involving significant bioactive substances of sea buckthorn at various growth years

The present work seeks to elucidate the source-sink coordination linking the shoots and berries of sea buckthorn ( Hippophae rhamnoides L.) growth for 4, 5 and 6 years (4 year, 5 year and 6 year) based on integrated phenotypic and multi-omics analyses. Results indicated that with the increasing of tree age, a significant “two-stage” functional remodeling was undergone by the branches (the source). During the 4 year − 5 year period, driven by PRKAA and PP2C , the branches were primarily dedicated to reserving energy and glycosyl donors while suppressing efflux activities. Subsequently, during the 5 year − 6 year period, facilitated by the activation of MYBP and PIP5K , a comprehensive shift toward the targeted transport of metabolites was executed. The potential of source-end transcriptional activities to regulate sink-end correlational evidence substantiated the metabolite enrichment between branch genes and fruit metabolites. Furthermore, the weight and redness of the fruits (the sink) were significantly enhanced, and their core flavonoid metabolic strategy evolved from monomer accumulation to the synthesis of highly stable glycosidic compounds. In conclusion, the critical role of the branches as a key factor driving fruit quality development was elucidated in this study, thereby providing a solid research foundation for the age-appropriate harvesting and source-sink theory-based directional cultivation of sea buckthorn.