Handroanthus chrysanthus (Jacq.) S.O. Grose is a Neotropical tree species highly valued for its ornamental beauty, durable timber, and medicinal properties. However, overexploitation and the recalcitrant nature of its seeds have constrained propagation and conservation efforts, and the species has been listed as Vulnerable on the IUCN Red List since 2020. In this study, a direct adventitious shoot regeneration system was developed for H. chrysanthus by systematically evaluating explant type, basal medium, plant growth regulator combination, and light quality. Hypocotyls were identified as the most responsive explants for shoot induction, and the highest adventitious shoot induction frequency, 51.79%, was obtained on Murashige and Skoog medium (MS) supplemented with 5 mg·L-1 6-benzylaminopurine, 0.5 mg·L-1 indole-3-butyric acid, and 0.2 mg·L-1 thidiazuron under white fluorescent light. The highest shoot multiplication coefficient, 3.27, was obtained on MS medium containing 4 mg·L-1 6-benzylaminopurine and 0.3 mg·L-1 gibberellic acid. The maximum rooting frequency, 80%, was obtained on R14 medium after 30 days of culture. After acclimatization, 95% of the regenerated plantlets survived and grew vigorously under greenhouse conditions. To our knowledge, no direct adventitious shoot regeneration system has been reported for the Tabebuia alliance. This efficient regeneration protocol provides a practical platform for clonal propagation, germplasm conservation, and genetic improvement of H. chrysanthus and may also support regeneration and conservation in related endangered taxa within the Tabebuia alliance.

Vegetative propagation is widely used in forest plantations to propagate elite genotypes with traits of economic or ecological interest. However, the loss of the ability to form adventitious roots is a dramatic effect of tree age and maturation and represents a major limitation for the clonal propagation of high-quality genotypes. This review describes the evolution of our understanding-from the traditional role of plant growth regulators to current findings on cellular signaling-regarding the maturation-related decline of adventitious rooting in forest species. Evidence suggests that interactions between the cell wall, plasma membrane, and cytoskeleton play a key role in this process. Specific and dynamic modifications of the interactions between the cell wall and cytoskeleton could be possible targets for hormonal, developmental, environmental, and epigenetic regulation associated with the maturation-related decline in adventitious root formation.

Gabiroba (Campomanesia adamantium (Cambess.) O. Berg) is a native fruit tree of the Brazilian Cerrado biome with notable economic potential and phytotherapeutic properties. However, commercial seedling production is limited by the recalcitrant nature of its seeds and vegetative propagation is further constrained by phenolic compound oxidation. Therefore, this study evaluated the effects of antioxidant treatments on sprouting, cutting survival, callus formation and attempted adventitious rooting of C. adamantium cuttings collected in different seasons. The experiment was conducted in a greenhouse at the Federal University of Jataí using cuttings collected from an experimental orchard. Eleven treatments were evaluated: a control and different concentrations of ascorbic acid (AA; 10, 20, and 40 mg L-1), phloroglucinol (FLO; 50, 100, and 200 mg L-1), and polyvinylpyrrolidone (PVP; 100, 200, 400, and 600 mg L-1). After 60 days, sprouting, cutting survival, callus formation, rooting, and the number of old and new leaves were assessed. Data were subjected to analysis of variance, and means were compared using the Scott-Knott test. Antioxidant treatments did not promote rhizogenesis in C. adamantium cuttings. Nevertheless, the season influenced sprouting, survival, and callus formation, especially during summer and autumn. These results indicate that antioxidant application alone is insufficient to overcome rooting recalcitrance in this species, although it may affect early developmental responses of the cuttings under specific seasonal conditions.

Bioreactor technology for medicinal plants provides a controllable platform for the conservation of rare and endangered resources, the production of high-value-added active ingredients, and green manufacturing of traditional Chinese medicine. Focusing on in vitro culture systems of medicinal plants, this article systematically reviews the application progress of stirred-tank, airlift, bubble column, wave-mixed, spray-type, temporary immersion, and photobioreactors in the culture of suspension cells, adventitious roots, hairy roots, shoots, and somatic embryos. Different from existing studies that mainly list reactor types, this review further provides a comprehensive analysis from the perspectives of physiological characteristics of the cultured objects, mass transfer and shear environment, medium and elicitor regulation, inoculation density, culture cycle, representative cases, and industrialization limitations. The results indicate that bioreactors can shorten production cycles, improve environmental controllability, and enhance product quality consistency; however, their large-scale application remains constrained by scale-up stability, metabolic fluctuations, downstream processing costs, GMP quality control, and commercial feasibility. Future research should shift from merely pursuing increased yield to integrated process development that is scalable, verifiable, low-cost, and quality-controllable.

Enzootic calcinosis caused by Nierembergia spp. (Solanaceae) poisoning causes important economic losses for sheep and cattle production in South America. This study aims to provide a comprehensive description of N. rivularis Miers, focusing on its morphological characteristics, biomass distribution, dry matter content, phenological cycle, floral biology, environmental growth preferences, and the presence of potentially toxic compounds. The results revealed that N. rivularis is a perennial, small-sized plant whose stems are modified into underground rhizomes. These subterranean structures feature nodes from which adventitious roots emerge, functioning as the primary mechanism for clonal asexual reproduction. Its white, pentamerous flowers display capitate trichomes in the corolla throat and a long, firm corolla tube that positions the corolla semi-parallel to the soil. Two insect species were observed interacting with flowers of N. rivularis, both during the spring season: Astylus quadrilineatus (Melyridae) and a small bee from the family Apidae, subfamily Apinae, tribe Tapinotaspidini. The plant exhibited a belowground biomass (rhizomes and roots) up to 15 times greater (dry weight based) than its aerial structures (leaves and flowers). The greater presence of N. rivularis in the fields was associated with high soil humidity, direct sunlight exposure, mixed soil texture, and low competition from rhizomatous species for underground space. Hydroxylated vitamin D derivatives were detected by HPLC in all structures of N. rivularis, suggesting this species' capacity to accumulate calcinogenic substances. Knowledge about the toxic compounds, morphology, biology, and phenology of N. rivularis will contribute towards the prevention and control of poisoning by this plant.

Rootstocks critically influence apple growth, development, and stress tolerance, a process likely mediated by key transcriptional regulators. Among these, NAC transcription factors are pivotal for stress responses, yet their roles in the differential drought resistance of apple rootstock varieties remain unclear. This study identified NAC transcription factor 17 (NAC17), which exhibits contrasting drought-responsive expression: it is strongly induced in drought-resistant wild apple (Malus sieversii) but remains unresponsive in drought-sensitive M26 (Malus domestica). Functional analysis demonstrated that MsNAC17 acts as a positive regulator of drought tolerance. Transgenic M26 plants overexpressing MsNAC17 showed enhanced drought resistance and promoted adventitious root development, whereas silencing MsNAC17 increased drought susceptibility. MsNAC17 directly activated the expression of LATERAL ORGAN BOUNDARIES DOMAIN 64 (MdLBD64), a key root development regulator, and MdYUCCA11, a crucial auxin biosynthesis gene. Furthermore, the E3 ubiquitin ligase Plant U-box 30 (MdPUB30) negatively regulated MsNAC17 protein stability by promoting its degradation via the ubiquitin-proteasome pathway. The differential drought responses between rootstocks were attributed to distinct upstream regulation: in M. sieversii, the transcription factor MYB47 activated MsNAC17 expression, whereas in M26, bZIP46 upregulated MdPUB30 under drought stress. These results establish the NAC17-PUB30 regulatory module as a central hub controlling drought tolerance by coordinating root architecture and auxin homeostasis, providing molecular targets for breeding drought-resistant apple rootstocks.

Development of adventitious roots is crucial for successful tea propagation, yet it is often inhibited by low temperatures in winter. To enhance tea rooting efficiency during winter, we investigated the effects of different shade treatments (different colors and shade levels) on the root development of Camellia sinensis cv. Longjing 43. Blue and red nets with 95% shade percentage achieved the highest rooting rates (> 95%) and longer roots, followed by silvery and black nets at 55% shading, while the 95% black net showed the poorest performance. The underlying mechanisms were investigated using transcriptome and phytohormone profiles through weighted gene co-expression network analysis (WGCNA) and KEGG analysis. The results showed blue net shading primarily affected zeatin metabolism, and red net shading promoted indole-3-acetic acid (IAA) metabolism, both of which regulated hormone signaling and hormone composition. Relevant key genes significantly correlated with zeatin and IAA levels were identified using Mantel tests. These findings provide a practical and cost-effective strategy to improve the winter rooting efficiency of tea cuttings under cold conditions by optimizing field growth environments.

In February 2025, we detected highly pathogenic avian influenza virus A(H5N1) clade 2.3.4.4b virus in a fetal bovine serum lot during routine adventitious agent testing. Sequencing confirmed H5N1 genotype B3.13 virus. We found low viral loads in additional samples from the same lot. Heating at 56°C for 30 minutes completely inactivated the virus.

Strigolactones (SLs) modulate multiple aspects of plant development and stress physiology. This study investigated their role in maize response to abiotic stress by comparing an SL-biosynthesis mutant (zmccd8) with wild-type (WT) seedlings grown for 4 weeks in vermiculite under nutrient and water limitation. Plant growth, time-course pigment accumulation, targeted gene expression, and root transcriptomic profiles were analyzed. Our results showed that zmccd8 plants were largely unable to induce leaf senescence and efficient nutrient remobilization toward younger tissues under nitrogen (N) deficiency, a response previously associated with maize adaptation to low N availability. In parallel, the mutant developed a smaller root system, mainly due to limited adventitious root formation, particularly under N shortage. Root transcriptomic profiling revealed that N deficiency strongly affected WT plants, inducing extensive regulation of pathways involved in nitrogen metabolism and transport, secondary metabolism, ethylene and MAPK signaling, oxidative stress responses, and major transcription factor families. These responses were largely absent in the zmccd8 mutant, suggesting reduced transcriptional plasticity and compromised capacity to cope with stress-associated oxidative imbalance. Conversely, despite inducing substantial physiological and molecular responses, water stress elicited only modest SL-dependent regulation, with limited and heterogeneous changes between genotypes. Overall, our findings demonstrate that in maize, SLs act in a stress-specific manner, playing a predominant role in acclimatisation to nitrogen deficiency through coordinated regulation of senescence, nutrient remobilization, root architecture, and gene expression, while contributing more marginally to water-stress acclimatisation. These results provide new insights into SLs' role in shaping maize physiological plasticity under abiotic stress conditions.

As a globally significant dual-purpose crop, sweet potato yield is regulated by the node number of vine cuttings and the planting method. Elucidating the effects of stem segment number and soil-entry method on endogenous hormones within sweet potato nodes and storage root formation holds significant scientific value, providing theoretical basis and technical support for optimizing planting techniques and enhancing yields. A two-factor split-plot design was implemented from 2022 to 2023 using the Yuhongxinshu 98 cultivar. Main plots tested vine cuttings with 6 (A1), 8 (A2), or 10 nodes (A3). Subplots compared slanted planting with exposed tip (B1), flat planting with exposed tip (B2), and flat planting without exposed tip (B3). The study investigated the effects of these treatments on growth hormone content at nodes, root morphology, and yield. Results indicated that increasing vine cutting node number to 8 and 10 significantly enhanced early adventitious root development, including root length, root diameter, and root tip number, and increased aboveground branching. Compared with 6-node cuttings, 8- and 10-node cuttings increased storage root yield by 23.43% and 30.03%, respectively. Compared with slanting planting with exposed tip, flat planting with exposed tip and flat planting without exposed tip increased storage root yield by 20.11% and 18.10%, respectively. At 70 DAT, corresponding to the early storage root enlargement stage, ABA and IAA contents in buried nodes increased with vine cutting node number. IAA content showed a node-dependent pattern and peaked at the fourth buried node, whereas ABA content was highest at the second buried node. Correlation analysis showed that ABA and IAA contents were associated with storage root yield, storage root number, and root morphological traits. Nodal analysis indicated that storage root formation was mainly concentrated in the upper buried nodes, especially the second buried node, while flat planting increased the contribution of multiple buried nodes to storage root formation. Overall, 8-node vine cuttings combined with flat planting, especially A2B2 and A2B3, showed better performance in coordinating early root establishment, nodal storage root formation, and yield improvement. These findings provide a practical basis for optimizing sweet potato planting techniques through improved vine cutting node number and planting method.

Virus safety for biopharmaceutical products has been a well-established concern for several decades. While various virus reduction steps have been identified and implemented for traditional plasma-derived and monoclonal antibody products, there are various challenges to achieving the same virus safety in emerging gene therapy products. Virus removal filtration, or nanofiltration, has proven difficult to implement for larger gene therapy modalities, though there is a regulatory expectation to incorporate this step for smaller modalities such as adeno-associated virus (AAV) vector products. Here, we demonstrate the applicability of a virus removal filter with a 35 nm mean pore size distribution for AAV processes based on filtrations with porcine parvovirus (PPV) as a model for AAV vector and simian virus 40 (SV40) as a model contaminant virus. Filtration runs were performed at low pressure and included a defined process pause, two manufacturing conditions known to potentially impact viral clearance. All filtrations demonstrated SV40 reduction to below the limit of detection and no detectable reduction in PPV, indicating robust removal of large contaminating viruses without impacting product yields for AAV products. Thus, virus removal filtration is appropriate for the removal of adventitious viruses in gene therapy product manufacturing. Virus removal filters have an established history of improving patient safety and should be included in the manufacture of advanced gene therapy products whenever possible.

In extant literature, the bryozoan genus Chaperia Jullien, 1881 comprises 22 named species, seven of them solely fossil, with the two earliest temporal records dating from the New Zealand Oligocene. All but four of the putative extant species are confined to the Southern Hemisphere. A 2009 New Zealand checklist accepted three named indigenous Chaperia species (one of them misidentified), plus two yet-to-be named species and one other of uncertain identity. Restudy of this material, plus examination of Chaperia in new collections from throughout New Zealand's Exclusive Economic Zone (EEZ) and the Norfolk Ridge, has yielded additional new species, such that 17 species of Chaperia are now recognised in the EEZ at the present day, 15 of them new to science. Vestigial ooecia have been found in all of the species and small, sparsely distributed adventitious avicularia have also been discovered in two of them. The taxonomic usefulness of the available morphological characters of Chaperia species is discussed, as is the status of all other putative extant species and their relationship to the Zealandian species. It is hypothesized that Chaperia evolved from an austral Chaperiopsis ancestor in the late Paleocene or Eocene.

Emergence of adventitious roots (ARs) in partially submerged plants is a crucial morphological adaptation to flooding stress, although the underlying molecular mechanisms are not well understood. In the present research, we investigated the role of CsRBOHB-mediated reactive oxygen species (ROS) production in cucumber (Cucumis sativus L.). ROS specifically accumulated in the vascular tissues of partially submerged hypocotyls. Respiratory burst oxidase homologs (RBOHs) are enzymes that generate ROS. We found that a cucumber RBOH gene, CsRBOHB, was specifically induced in vascular cells by partial submergence. Knockout of CsRBOHB inhibited AR emergence, while overexpression of CsRBOHB enhanced it. Downregulation of an RBOHB homolog SlRBOHB in partially submerged tomato also inhibited AR emergence. Additionally, cucumber calcium-dependent protein kinase 2 (CsCDPK2) directly activated CsRBOHB in cucumber hypocotyls during AR emergence, and silencing it inhibited AR emergence under partially submerged conditions. These findings indicate that AR emergence in partially submerged cucumber is regulated by a CsCDPK-CsRBOHB pathway.

Phytosulfokines (PSKs) are disulfated plant peptide hormones regulating diverse growth and developmental processes, but their roles in trees remain largely unexplored. Here, we performed a genome-wide characterization of the PSK gene family in the model tree Populus trichocarpa, identifying eight PtrPSK genes that encode the PSK-α precursors. Phylogenetic analysis grouped PtrPSKs into two clades, with PtrPSK7 and PtrPSK8 forming a distinct paralogous pair. Expression profiling showed that PtrPSK7 and PtrPSK8 were highly and widely expressed but were significantly down-regulated during adventitious root (AR) formation in stem cuttings. Exogenous application of PSK-α peptide inhibited AR formation in a dose-dependent manner, primarily by suppressing primordium initiation. Conversely, PSK-α treatment promoted the elongation of newly emerged ARs, and heterologous overexpression of PtrPSK7 or PtrPSK8 in Arabidopsis significantly enhanced root growth. Mechanistically, PSK-α peptide suppressed the expression of key auxin-responsive genes, including several PtrARFs and downstream transcription factors (PtrWOX11/12a, PtrLBDs, PtrSCRs), during AR induction and initiation. Our findings demonstrate that PSK-α signaling plays a dual role in poplar root development: negatively regulating AR formation likely through antagonizing auxin-mediated transcriptional programs, while positively promoting root elongation via a conserved mechanism. This study elucidates the functions of PSK-α peptide and its encoding genes in poplar root architecture and provides new insights for improving clonal propagation in woody plants.