As a plant-specific gene family, class III peroxidases (PODs) play an important role in plant growth, development, and stress responses. However, the POD gene family has not been systematically studied in Paeonia ostii. In this study, a total of 57 PoPOD genes were identified in the P. ostii genome. Subsequently, phylogenetic analysis and chromosome mapping revealed that PoPODs were classified into six subgroups and were unevenly distributed across five chromosomes. The gene structure and conserved motifs indicated the potential for functional divergence among the different subgroups. Meanwhile, four PoPODs were identified as tandem duplicated genes, with no evidence of segmental duplication. Using RNA-seq data from eight different tissues, multiple PoPODs exhibited enhanced expression in apical and adventitious roots (ARs). Next, RNA-seq data from AR development combined with trend analysis showed that PoPOD30/34/43/46/47/57 are implicated in the formation of ARs in tree peony. Through WGCNA based on RNA-seq, two key genes, PoPOD5/15, might be involved in heat tolerance via ABA and MeJA signaling. In addition, real-time quantitative PCR (qRT-PCR) analysis indicated that PoPOD23 may play an important role in flower senescence. These findings deepened our understanding of POD-mediated AR development, heat tolerance, and petal senescence in tree peony.

The phosphatidylethanolamine-binding protein (PEBP) gene family, known for its pivotal role in controlling floral transition, regulates flowering time, and, thus, shapes the continuous-flowering trait in ornamental plants. In this study, we conducted the first genome-wide identification and bioinformatics analysis of the PEBP gene family in Begonia semperflorens ‘Super Olympia’, a variety that exhibits year-round flowering. Via phylogenetic analysis, a total of 10 BsPEBP genes were identified and categorized into four subfamilies: the FT-like (two members), TFL1-like (three members), PEBP-like (three members), and MFT-like (two members) subfamilies. Gene structure analysis revealed highly conserved motif compositions among family members, and protein tertiary structure prediction indicated the dominance of random coils in their structures. Promoter cis-acting element analysis revealed light-responsive, hormone-responsive (ABA, GA, and JA), and abiotic stress-responsive elements in the BsPEBP genes, suggesting their potential integration into multiple regulatory pathways. The tissue-specific expression profiles revealed that BsPEBP6 was significantly upregulated in floral organs, whereas TFL1-like subfamily members were predominantly expressed in vegetative tissues. These findings imply that the FT-like and TFL1-like genes antagonistically regulate the continuous-flowering trait of B. semperflorens ‘Super Olympia’ through their respective roles in promoting and repressing flowering. Our findings provide a preliminary theoretical foundation for elucidating the molecular mechanisms by which the PEBP gene family regulates flowering time in ornamental plants and offer valuable insights for developing breeding strategies aimed at flowering time modulation.

Tree peony (Paeonia ostii T. Hong et J. X. Zhang) is an important medicinal and ornamental plant. It would be useful to propagate this plant in tissue culture, but it is difficult to induce root formation. Auxin plays a pivotal role in adventitious root formation, and ABCB transporter proteins are involved in auxin transport. To elucidate the function of the ABCB transporter family in P. ostii, we identified members of the ABCB gene family in the P. ostii genome and analyzed the functional characteristics of the putative proteins. In total, 29 ABCB genes were identified in P.ostii, distributed on five chromosomes. In a phylogenetic analysis, the PoABCBs were grouped into four subfamilies, with the largest being Subfamily I, characterized by their MDR structure. PoABCB genes in the same subfamily exhibited similar intron/exon arrangements and motif composition. The promoters of PoABCBs contained cis-acting elements associated with the photoresponse and hormone signaling. qRT-PCR analyses showed that, after treatment of tissue-cultured P. ostii seedlings with auxin, five PoABCB gene family members (PoABCB6, PoABCB10, PoABCB11, PoABCB12, and PoABCB16) were significantly upregulated during adventitious root development. These genes may play roles in the auxin response and adventitious root development of P. ostii in vitro.

Light quality plays a critical role in regulating plant growth during both in vitro culture and hydroponic stages, attracting increasing research attention. However, comprehensive studies incorporating far-red LED light throughout the entire growth cycle of Spathiphyllum floribundum (Linden & André) N.E.Br. ‘Tianjiao’ remain limited. To investigate the effects of red, blue, and far-red light ratios on proliferation, rooting, and hydroponic acclimatization, six LED treatments were established with red: blue ratios of 80:20, 70:30, and 60:40, each with or without far-red light supplementation. Fluorescent light was used as the control. At each stage, morphological traits, photosynthetic pigments, osmotic compounds, antioxidant enzyme activities, and photosynthetic parameters were measured. The results identified distinct optimal light combinations for each growth phase. The optimal treatment for proliferation was 80%R + 20%B + Fr, which produced significant proliferation coefficients and enhanced chlorophyll b and soluble protein content. For rooting, 60%R + 40%B + Fr was most effective, resulting in the highest total chlorophyll content (0.109 mg·g⁻¹) and improved carotenoid accumulation and CAT activity. During hydroponic acclimatization, 60%R + 40%B without far-red light yielded the best performance, achieving the highest plant height (15.28 cm) and net photosynthetic rate (4.77 μmol·m⁻²·s⁻¹), along with improved water-use efficiency. These results provide potential LED light strategies for the complete process from tissue culture to hydroponics, offering a theoretical basis for designing specialized LED lighting systems for plant tissue culture and hydroponic production.

This study aimed to investigate the effects of different light-emitting diode (LED) light-quality combinations on the growth and development of Chrysanthemum morifolium tissue-cultured plantlets and to identify the optimal light-quality combinations for adventitious shoot induction and rooting. Six LED light-quality combinations consisting of red (R), blue (B), and far-red (Fr) light (80%R + 20%B, 70%R + 30%B, 60%R + 40%B, 80%R + 20%B + Fr, 70%R + 30%B + Fr, and 60%R + 40%B + Fr) were evaluated, with a fluorescent lamp serving as the control (CK). The responses to different light-quality combinations varied markedly between the adventitious shoot induction and rooting stages. During adventitious shoot induction, the carotenoid content, soluble protein content, and POD activity were highest under the 70%R + 30%B treatment, whereas chlorophyll a, chlorophyll b, total chlorophyll, and CAT activity reached their highest levels under the 70%R + 30%B + Fr treatment. The highest soluble sugar content and SOD activity were observed under the 60%R + 40%B + Fr treatment. These results suggest that the incorporation of far-red light into red–blue light combinations promoted photosynthetic pigment synthesis, photosynthate accumulation, and antioxidant capacity, thereby facilitating adventitious shoot induction. During the rooting stage, the greatest leaf number and SOD activity were observed under the 70%R + 30%B treatment, while the highest chlorophyll a, chlorophyll b, and total chlorophyll contents were obtained under the 60%R + 40%B + Fr treatment. Plant height, leaf length, root length, fresh mass, dry mass, carotenoid content, soluble protein content, and CAT activity were highest under the 60%R + 40%B treatment. These findings indicate that red–blue mixed light effectively promoted leaf and root development, photosynthetic pigment synthesis, biomass accumulation, and maintenance of antioxidant capacity. Therefore, the 70%R + 30%B + Fr and 60%R + 40%B + Fr treatments were identified as the most suitable light-quality combinations for adventitious shoot induction, whereas the 60%R + 40%B treatment was the most suitable for rooting of C. morifolium tissue-cultured plantlets.