Begonia rex cv. DS-EYWA is an important plant for indoor and outdoor cultivation, and cv. DS-EYWA is a rare unique cultivar with curly, colorful leaves. Due to their importance, applying plant tissue culture techniques for mass and healthy production in a short period of time without seasonal limitation is of immense economic value. Applying several concentrations of silver nitrate (AgNO₃) in combination with varied concentrations of cytokinins including 6-benzylaminopurine (BAP), thidiazuron (TDZ) (0, 0.5, 1, 1.5 mgL⁻¹), and 1-naphthaleneacetic acid (NAA) auxin (0, 0.5, 1 mgL⁻¹) via focusing on transverse thin cell layer (tTCL) petiole explants for high-scale production was used to establish an efficient in vitro propagation protocol. Our results showed that even low concentrations (25 mgL⁻¹) can control internal bacterial infection and increase shoot direct regeneration efficiency. A combination of 1.5 mgL⁻¹ BAP, 0.5 mgL⁻¹ NAA, and 25 mgL⁻¹ AgNO₃ was the best treatment to increase the number of direct regenerated shoots, and a lower concentration of BAP (0.5 mgL⁻¹) can be suggested for shoot elongation. Elongated shoots were successfully rooted in MS basal medium and acclimatized in a 1:1 peat moss/perlite sterilized pot mixture.

The browning of fruit juices and nectars is a common issue in the beverage industry and is a particular problem in strawberry nectars, where it significantly reduces the shelf-life. Polyphenol oxidases (PPOs), which are multicopper enzymes responsible for the oxidation of a wide plethora of polyphenols in plants, have been widely assumed to be involved in the enzymatic browning of strawberry nectar. To investigate the possible involvement of PPOs, the substrate specificity of four recombinant PPOs and their gene expression pattern in 10 cultivars of Fragaria × ananassa at five ripening stages were determined. This allowed us to obtain adequate amounts of enzymes to study them independently and without interfering matrix effects. All four PPOs possess monophenolase activity, which was particularly high for PPO4. PPO3 did not show sufficient stability for the kinetic studies. The other three showed a high preference for the flavan 3-ol catechin with a 2-fold higher catalytic efficiency compared to dopamine for PPO1 and PPO2. At a neutral pH, they also showed activity with cyanidin but not with pelargonidin, which is the prevalent anthocyanidin type in strawberry. The enzymes showed a high affinity but only low turnover rates for the dihydrochalcone phloretin, resulting in an inhibitory effect that was strong enough to extend the shelf-life of the strawberry nectar by one week if phloretin was added in high concentrations (600 µM). PPO1 and PPO2 were prevalently expressed in all fruit stages. The gene expression of the four PPOs did not correlate with the color stability of the nectars of the 10 varieties and also showed a random expression pattern during fruit development. The limited activity in acidic conditions and the low substrate specificity for pelargonidin does not point to a crucial role for PPOs in the browning of strawberry nectar, but the high catalytic efficiency with catechin as a substrate could contribute to anthocyanin degradation via mechanisms such as copolymerization.

Rosa canina is one of the precious native rose rootstocks with a high reputation among plant producers, which has potential horticultural and pharmacological properties related to the cosmetic values and the production of secondary metabolites. Due to high horticultural consumption, applying the plant tissue culture technique as a major tool for healthy and massive-scale production of R. canina plants is not unexpected. However, the response of R. canina in vitro plantlets to various plant tissue culture ingredients is not well understood to tender an efficient applied protocol for qualitative and quantitative in vitro propagation. In this regard, the main objective of this study is to investigate the influence of several abiotic in vitro variants including six plant tissue culture media formulations (McCown’s Woody Plant Medium (WPM), Murashige and Skoog (MS), Van der Salm (VS), Schenk and Hildebrant (SH), Driver Kuniyuki Walnut (DKW), and Gamburg B5 (B5)) in combination with four concentrations (0, 1.5, 3, 4 mgL⁻¹) of two types of cytokinins (6-Benzyaminopurine (BAP) and Kinetin (Kin)) simultaneously. Notably, it is perceived that DKW culture medium containing 1.5 mgL⁻¹ BAP and 0.1 mgL⁻¹ NAA is the best treatment for both in vitro morphological and flowering properties.

In vitro regeneration and flowering systems provide valuable platforms for rose breeding and biotechnological applications. Although the effects of plant growth regulators (PGRs) on Rose regeneration have been extensively studied, the contribution of growth additives, either alone or in combination with PGRs, remains insufficiently understood in Rosa chinensis. This study investigated the effects of PGRs (6-Benzylaminopurine (BAP), 1-Naphthaleneacetic acid (NAA), and indole-butyric acid (IBA)) combined with three growth additives, putrescine (Put), phloroglucinol (PG), and casein hydrolysate (CH), at different concentrations on the vegetative and reproductive responses of R. chinensis in an in vitro system. No flowering occurred in media without PGRs, regardless of the growth additive treatment, highlighting the essential role of PGRs in floral induction. However, the integration of growth additives with PGRs significantly enhanced regeneration and flowering performance. Among the tested additives, Put showed the strongest stimulatory effect, increasing in vitro flower production and improving floral characteristics. PG promoted several morphological traits, including shoot regeneration and flower stem elongation, but was less effective than Put. CH exhibited limited effects on both vegetative growth and reproductive development. These findings indicate that Put supplementation in PGR-based media is an effective approach for improving regeneration and flowering efficiency in R. chinensis, with potential applications in rose biotechnology and breeding programs.

Plant regeneration demonstrates the remarkable developmental plasticity of plants, enabling tissue repair, organ formation, and adaptation to environmental challenges through cellular reprogramming and redifferentiation. This capacity underpins numerous horticultural and biotechnological applications, including grafting, micropropagation, somatic embryogenesis, organogenesis, and genetic transformation. While regeneration has traditionally been explained by the coordinated actions of auxin and cytokinin together with key developmental regulators such as WUSCHEL, BABY BOOM, and WUSCHEL-related homeobox genes, recent studies indicate that regeneration is also influenced by stress signaling, metabolic reprogramming, reactive oxygen species, and epigenetic regulation. Among these regulatory components, polyamines have emerged as important modulators of cell division, differentiation, stress responses, and morphogenic competence during in vitro regeneration. Likewise, autophagy, a conserved intracellular recycling pathway, has gained increasing attention for its role in maintaining cellular homeostasis, facilitating metabolic adaptation, and supporting developmental transitions under tissue culture conditions. This review summarizes current knowledge on the independent roles of polyamines and autophagy in plant cell reprogramming and in vitro regeneration, with particular emphasis on wound responses, somatic embryogenesis, and organogenesis. In addition, it highlights common physiological processes through which these pathways may influence regeneration and identifies the limited understanding of their potential relationship as an important direction for future research.