Integrated physiological and biochemical, endogenous hormone, transcriptome, and metabolome analyses reveal changes in growth and development of Cibotium barometz (L.) J. Sm. tissue culture seedlings

Cibotium barometz (L.) J. Sm., a traditional Chinese medicinal plant belonging to the genus Cibotium (family Dicksoniaceae), was investigated to assess dynamic changes in physiological and biochemical indices (PBIs), endogenous plant hormones (EPHs), and differentially accumulated metabolites (DAMs). This study aimed to elucidate key regulatory pathways and genes involved in the growth and development of C. barometz in the tissue culture seedlings (TCSs). To preliminarily elucidate the mechanisms governing the growth and development of the TCSs, the PBIs, EPHs, transcriptome, and metabolome of filamentous (SZT), gametophytic (PZT), and sporophytic (BZT) were measured, and the dynamic changes in these indices were analyzed over various periods in this study. The results demonstrated that C. barometz exhibited stronger resistance to harsh external environmental conditions in the BZT compared to the PZT and SZT. Moreover, transplanting the TCSs proved more feasible under these conditions. The EPHs detected in TCSs were predominantly composed of auxin (IAA), cytokinins (CTK), and gibberellins (GA), along with minor quantities of salicylic acid (SA) and jasmonic acid (JA). In contrast, abscisic acid (ABA) was present at significantly lower levels. Metabolomics analysis revealed that amino sugar and nucleotide sugar metabolism served as the predominant metabolic pathways during growth and development, suggesting the prevalence of primary metabolites in C. barometz TCSs. Transcriptomic analysis revealed significant enrichment of the phytohormone signaling pathway, with a high number of differentially expressed genes (DEGs) identified across different developmental periods. These findings suggest that sugar metabolism and EPHs likely play crucial regulatory roles in the growth and development processes. The DEGs were found to predominantly regulate the biosynthesis of primary metabolites. This study systematically elucidated the dynamic changes in PBIs and EPHs, metabolite accumulation patterns, and transcriptional regulation networks during the growth and development of C. barometz TCSs. The results showed that the growth regularity of TCSs of C. barometz at different development stages could provide a scientific basis for the establishment of seedling control standards and optimization of TCSs technology. In this study, the PBIs, EPHs, transcriptome, and metabolome of filamentous (SZT), gametophytic (PZT), and sporophytic (BZT) were measured, and the dynamic changes of the indexes were analyzed in various periods.