Search Results (356)

Polyscias fruticosa (L.) Harms, a Southeast Asian medicinal plant of the Araliaceae family, has gained increasing attention due to its rich phytochemical profile and potential pharmacological applications. This review provides an up-to-date synthesis of biotechnological strategies and chemical investigations related to this species. In vitro propagation methods, including somatic embryogenesis, adventitious root, and cell suspension cultures, are discussed with emphasis on elicitation and bioreactor systems to enhance the production of secondary metabolites. Phytochemical analyses using gas chromatography–mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) have identified over 120 metabolites, including triterpenoid saponins, polyphenols, sterols, volatile terpenoids, polyacetylenes, and fatty acids. Several compounds, such as tocopherols, conjugated linoleic acids, and alismol, were identified for the first time in the genus. These constituents exhibit antioxidant, anti-inflammatory, antimicrobial, antidiabetic, anticancer, and neuroprotective activities, with selected saponins (e.g., chikusetsusaponin IVa, Polyscias fruticosa saponin [PFS], zingibroside R1) showing confirmed molecular mechanisms of action. The combination of biotechnological tools with phytochemical and pharmacological evaluation supports P. fruticosa as a promising candidate for further functional, therapeutic, and nutraceutical development. This review also identifies knowledge gaps related to compound characterization and mechanistic studies, suggesting future directions for interdisciplinary research. Full article

Mulberry trees are not only economically significant forest trees with substantial added value but also serve as exceptional candidates for environmental management and ecological enhancement. However, in the widely applied cutting propagation of mulberry, the intensity of adventitious root formation in cuttings has long remained a key challenge in the cutting process. Our research group previously found that 800 mg/L Rooting Powder No. 1 (ABT1) has an obvious promoting effect on the development of adventitious roots in mulberry cuttings, but its molecular mechanism has not yet been studied. In this research, transcriptome sequencing (RNA-seq) technology was employed to sequence the ‘Yueshenda 10’ mulberry during four distinct cutting stages. Through Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analysis, shifts in gene expression and metabolic pathways were scrutinized, pinpointing the pivotal role of plant hormones in this context. Furthermore, using Weighted Gene Co-Expression Network Analysis (WGCNA), the study analyzed gene expression across all samples, identifying two modules, “black” and “blue”. These modules were predominantly expressed in the treatment group during the rooting phase and minimally expressed in the control group. Critical genes such as gene21267 and gene16291 from the black module, alongside gene18291 and gene20028 from the blue module, were identified as key to the rooting success of the ‘Yueshenda 10’ cuttings. This investigation not only supports the nutrient propagation and effective use of mulberry trees but also clarifies the molecular basis of adventitious root formation in these plants, extending the research to other related species. This work fosters the diversification and enhancement of the mulberry industry chain. Full article

Eurasian aspen (Populus tremula L.) is a tree species with recognised ecological and economic importance for both natural and plantation forests. For the fast cloning of selected aspen genotypes, the method of plant propagation through in vitro culture (micropropagation) is often recommended. The efficiency of this method is related to the use of shoot-inducing chemical growth regulators, among which cytokinins, a type of plant hormone, dominate. Although cytokinins can inhibit rooting, this effect is avoided by using cytokinin-free media. This study sought to identify concentrations and combinations of growth regulators that would stimulate one type of P. tremula organogenesis (either shoot or root formation) without inhibiting the other. The investigated growth regulators included cytokinin 6-benzylaminopurine (BAP), auxin transport inhibitor 2,3,5-triiodobenzoic acid (TIBA), auxins indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA), gibberellin biosynthesis inhibitor paclobutrazol (PBZ), and a gibberellin mixture (GA₄/₇). Both BAP and TIBA increased shoot number per P. tremula explant and decreased the number of adventitious roots, but TIBA, in contrast to BAP, did not inhibit lateral root formation. However, for the maintenance of both adventitious shoot and root formation above the control level, the combination of PBZ and GA_4/7 was shown to be especially promising. Full article

Cutting propagation is a commonly employed technology for vegetative reproduction in agricultural, forestry, and horticultural practice. The success of cutting propagation depends on adventitious root (AR) formation—a process whereby roots regenerate from stem cuttings or leaf cuttings. In this review, we summarize the distinct stages of cutting-induced AR formation and highlight the pivotal roles of plant hormones and age in this process. Jasmonic acid (JA) acts as a master trigger for promoting AR formation, while auxin serves as the core regulator, driving AR formation. Furthermore, plant age is a crucial factor determining the regenerative competence of cuttings. Notably, age and JA collaboratively modulate auxin synthesis in cutting-induced AR formation. Overall, this review not only elucidates the molecular mechanisms underlying AR formation but also provides valuable insights for improving efficiency of cutting propagation in various plant species. Full article

Cinnamomum camphora is an ecologically and economically significant species, highly valued for its essential oil production and environmental benefits. Although a tissue culture system has been established for C. camphora, large-scale propagation remains limited due to the inconsistent formation of adventitious roots (ARs). This study investigated AR formation from callus tissue, focusing on associated physiological changes and gene expression dynamics. During AR induction, contents of soluble sugars and proteins decreased, alongside reduced activities of antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and polyphenol oxidase (PPO). Levels of indole-3-acetic acid (IAA) and abscisic acid (ABA) decreased significantly throughout AR formation. Zeatin riboside (ZR) levels initially declined and then rose, whereas gibberellic acid (GA) levels displayed the opposite trend. Comparative transcriptomic and temporal expression analyses identified differentially expressed genes (DEGs), which were grouped into four distinct expression patterns. KEGG pathway enrichment indicated that 67 DEGs are involved in plant hormone signaling pathways and that 38 DEGs are involved in the starch and sucrose metabolism pathway. Additionally, protein–protein interaction network (PPI) analysis revealed ten key regulatory genes, which are mainly involved in auxin, cytokinin, GA, ABA, and ethylene signaling pathways. The reliability of the transcriptome data was further validated by quantitative real-time PCR. Overall, this study provides new insights into the physiological and molecular mechanisms underlying AR formation in C. camphora and offers valuable guidance for optimizing tissue culture systems. Full article

Melastoma dodecandrum is primarily propagated through stem cuttings, which limits genetic variation and constrains breeding efforts. To overcome this limitation and facilitate molecular breeding, the establishment of a reliable and efficient regeneration system is essential. This study investigated the effects of plant growth regulators (PGRs) and culture media on the in vitro regeneration system of M. dodecandrum. The highest rate of callus induction (96.67%) was achieved when sterile leaf explants were cultured on Murashige and Skoog (MS) basal medium supplemented with 2.00 mg·L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.50 mg·L⁻¹ 6-benzylaminopurine (6-BA). For callus differentiation, the optimal formulation of MS + 2.0 mg·L⁻¹ 6-BA + 0.5 mg·L⁻¹ naphthylacetic acid (NAA) resulted in a differentiation frequency of 83.33%. The optimal PGR combinations for shoot proliferation were 1.5 mg·L⁻¹ 6-BA + 0.1 mg·L⁻¹ NAA and 0.5 mg·L⁻¹ 6-BA + 0.2 mg·L⁻¹ NAA. The optimal rooting media were MS medium supplemented with 0.1, 0.2, or 0.5 mg·L⁻¹ indole-3-butyric acid (IBA) or 1/2MS medium supplemented with 0.1 mg·L⁻¹ IBA. Additionally, this study investigated the dynamic changes in endogenous hormones during the regeneration process. The levels and ratios of hormones, including gibberellin (GA₃), abscisic acid (ABA), indole-3-acetic acid (IAA), and zeatin (ZT), collectively regulated the regeneration process. Elevated levels of ABA and GA₃ may promote callus initiation as well as the growth and development of adventitious roots during the early induction stage. Reduced levels of ABA and IAA favored callus differentiation into shoots, whereas elevated GA₃ levels facilitated proliferation of adventitious shoots. Throughout the regeneration process, fluctuations in ZT levels remained relatively stable. This study successfully established an in vitro regeneration system for M. dodecandrum using leaf explants, providing theoretical guidance and technical support for further molecular breeding efforts, genetic transformation, and industrial development. Full article

Azospirillum is a well-studied genus of plant growth-promoting rhizobacteria (PGPR) and one of the most extensively researched diazotrophs. This genus can colonize rhizosphere soil and enhance plant growth and productivity by supplying essential nutrients to the host. Azospirillum–plant interactions involve multiple mechanisms, including nitrogen fixation, the production of phytohormones (auxins, cytokinins, indole acetic acid (IAA), and gibberellins), plant growth regulators, siderophore production, phosphate solubilization, and the synthesis of various bioactive molecules, such as flavonoids, hydrogen cyanide (HCN), and catalase. Thus, Azospirillum is involved in plant growth and development. The genus Azospirillum also enhances membrane activity by modifying the composition of membrane phospholipids and fatty acids, thereby ensuring membrane fluidity under water deficiency. It promotes the development of adventitious root systems, increases mineral and water uptake, mitigates environmental stressors (both biotic and abiotic), and exhibits antipathogenic activity. Biological nitrogen fixation (BNF) is the primary mechanism of Azospirillum, which is governed by structural nif genes present in all diazotrophic species. Globally, Azospirillum spp. are widely used as inoculants for commercial crop production. It is considered a non-pathogenic bacterium that can be utilized as a biofertilizer for a variety of crops, particularly cereals and grasses such as rice and wheat, which are economically significant for agriculture. Furthermore, Azospirillum spp. influence gene expression pathways in plants, enhancing their resistance to biotic and abiotic stressors. Advances in genomics and transcriptomics have provided new insights into plant-microbe interactions. This review explored the molecular mechanisms underlying the role of Azospirillum spp. in plant growth. Additionally, BNF phytohormone synthesis, root architecture modification for nutrient uptake and stress tolerance, and immobilization for enhanced crop production are also important. A deeper understanding of the molecular basis of Azospirillum in biofertilizer and biostimulant development, as well as genetically engineered and immobilized strains for improved phosphate solubilization and nitrogen fixation, will contribute to sustainable agricultural practices and help to meet global food security demands. Full article

Efficient adventitious root formation is crucial for Lavandula angustifolia Mill. propagation. This study evaluated the effects of continuous and short-duration pulse applications (1 min, 1 h, and 1 day) of the auxin dichlorprop (DCP) and its prodrug dichlorprop-2-ethylhexyl ester (DCPE) at varying concentrations on adventitious rooting and callus formation. DCPE generally proved more effective than DCP in promoting rooting, especially at lower concentrations, with continuous application of 0.1 µM DCPE yielding the highest number of adventitious roots. Notably, a brief 1 min pulse of 2.5 µM DCPE induced superior rooting, including high root number and weight, while minimizing callus formation compared to longer exposures. In contrast, 1 h pulse treatments showed a positive correlation between auxin concentration and root number but led to substantial callus development. These findings highlight DCPE’s potential as an efficient auxin source for lavender propagation, likely due to its rapid hydrolysis to active DCP within plant tissues, facilitating systemic distribution. The enhanced rooting achieved with short pulse treatments offers significant implications for optimizing commercial propagation for this economically important aromatic plant. Full article

Arbuscular mycorrhizal fungi (AMF) symbiosis has great potential in improving grapevine performance and reducing external input dependency in viticulture. However, the precise, strain-specific impacts of different AMF species on ‘Summer Black’ grapevine cuttings across multiple physiological and morphological dimensions remain underexplored. To address this, we conducted a controlled greenhouse pot experiment, systematically evaluating four different AMF species (Diversispora versiformis, Diversispora spurca, Funneliformis mosseae, and Paraglomus occultum) on ‘Summer Black’ grapevine cuttings. All AMF treatments successfully established root colonization, with F. mosseae achieving the highest infection rate. In detail, F. mosseae notably enhanced total root length, root surface area, and volume, while D. versiformis specifically improved primary adventitious and 2nd-order lateral root numbers. Phosphorus (P) uptake in both leaves and roots was significantly elevated across all AMF treatments, with F. mosseae leading to a 42% increase in leaf P content. Furthermore, AMF inoculation generally enhanced the activities of catalase, superoxide dismutase, and peroxidase, along with soluble protein and soluble sugar contents in leaves and roots. Photosynthetic parameters, including net photosynthetic rate (Pn), stomatal conductance (Gs), and transpiration rate (Tr), were dramatically increased in AMF-colonized cutting seedlings. Whereas, P. occultum exhibited inhibitory effects on several growth metrics, such as shoot length, leaf and root biomass, and adventitious lateral root numbers, and decreased the contents of Nitrogen (N), potassium (K), magnesium (Mg), and iron (Fe) in both leaves and roots. These findings conclusively demonstrate that AMF symbiosis optimizes root morphology, enhances nutrient acquisition, and boosts photosynthetic efficiency and stress resilience, thus providing valuable insights for developing targeted bio-fertilization strategies in sustainable viticulture. Full article

Knowledge of propagation methods is crucial for conserving endangered plant species. Cycads are highly threatened, and propagation protocols using seeds and stem cuttings are well-understood. No air layer technique has been developed for cycad propagation, so the objective of this study was to develop a working protocol for adding this technique for cycad conservation. We opened wounds on mature Cycas edentata de Laub. stems to expose cortex and vascular tissue then installed an air layer medium to determine if adventitious roots would form. In one experiment, the peripheral vascular cylinder was exposed from 90° to 360°; in a second experiment, the use of auxin-promoting root stimulants was compared with a control group with no stimulants; and in a third experiment, the interior vascular cylinders were exposed in addition to the peripheral vascular cylinder. Every replication in every experiment developed adventitious roots beginning about 8 weeks and were ready to harvest with 10 cm roots by 14 weeks. The robust roots were about 1 cm in diameter, geotropic, and restricted to the outermost vascular cylinder exposed on the upper surface of the wounds. The number of roots and total root length per propagule increased by more than 300% as the percentage of exposed vascular tissue increased from 90° to 360°. Air layer techniques can be added to the cycad conservation toolbox, and its use may aid in conserving this threatened group of plants. Full article

Bombax ceiba is an important medicinal and ornamental tree widely distributed in tropical and subtropical areas. However, its seeds lose viability rapidly after harvest, which has created hurdles in large-scale propagation. Here, we describe the development of a rapid and efficient de novo organogenesis system for Bombax ceiba, incorporating both indirect and direct regeneration pathways. The optimal basal medium used throughout the protocol was ½ MS supplemented with 30 g/L glucose, with all cultures maintained at 26–28 °C. For the indirect pathway, callus was induced from both ends of each hypocotyl on basal medium supplemented with 0.2 mg·L⁻¹ 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg·L⁻¹ 6-Benzylaminopurine (6-BA) under dark conditions. The induced calluses were subsequently differentiated into adventitious shoots on basal media containing 0.5 mg·L⁻¹ Indole-3-butyric acid (IBA), 0.15 mg·L⁻¹ Kinetin (KIN), and 1 mg·L⁻¹ 6-BA under a 16 h photoperiod, resulting in a callus induction rate of 140% and a differentiation rate of 51%. For the direct regeneration pathway, shoot buds cultured on medium with 0.5 mg·L⁻¹ IBA and 1 mg·L⁻¹ 6-BA achieved a 100% sprouting rate with a regeneration coefficient of approximately 3.2. The regenerated adventitious shoots rooted successfully on medium supplemented with 0.5 mg·L⁻¹ Naphthylacetic acid (NAA) and were acclimatized under greenhouse conditions to produce viable plantlets. This regeneration system efficiently utilizes sterile seedling explants, is not limited by seasonal or environmental factors, and significantly improves the propagation efficiency of Bombax ceiba. These optimized micropropagation methods also provide a robust platform for future genetic transformation studies using hypocotyls and shoot buds as explants. Full article

Cinnamomum parthenoxylon (Jack) Meisner is an important spice tree species in southern China. In in vitro cultures of C. parthenoxylon, the young stem explants can differentiate into adventitious buds and roots under different exogenous growth regulator conditions. However, the underlying regulatory mechanisms governing this differentiation process remain unclear. In this study, physiological and biochemical characteristics were measured, and transcriptomic sequencing was performed in different differentiation processes. Significant changes in physiological and biochemical parameters were observed during the differentiation of the young stems. Soluble sugars, soluble proteins, malondialdehyde (MDA), zeatin riboside (ZR), abscisic acid (ABA), gibberellin (GA) content, the (IAA + GA + ZR)/ABA ratio, and polyphenol oxidase (PPO) activity displayed contrasting expression patterns during the formation of adventitious buds and roots. The RNA-seq result revealed that the differentiation direction of young stems is regulated by the synthesis of endogenous hormones and associated signaling pathways. At the same time, phenylpropanoid metabolism and glucose metabolism pathways acted as auxiliary pathways, facilitating the formation of adventitious buds and roots. Furthermore, quantitative real-time PCR (qRT-PCR) results were highly consistent with transcriptome sequencing results. This study lays the foundation for exploring the directional differentiation of young stems in C. parthenoxylon. Full article

Poplar (Populus spp.) is an economically and ecologically important temperate tree species known for its rapid growth. Clonal propagation has facilitated genetic advancements, but it remains challenging due to substantial variations in rooting capacity among poplar species and clones. Poplar clones were divided into two groups based on their rooting ability (high or low), and their transcriptome was analyzed for 3 weeks following stem-cutting propagation to investigate the rooting mechanisms of a hybrid of two fast-growing poplar species (Populus alba × P. tomentiglandulosa). The root length and area of the high-rooting group were 668.7% and 198.4% greater than those of the low-rooting ability group, respectively (maximum p < 0.001). Compared to week 0, genes involved in auxin signaling, cell wall organization, and secondary metabolite biosynthesis were consistently upregulated at 1, 2, and 3 weeks after planting, respectively. The expression of genes associated with cell wall differentiation and flavonoid biosynthesis was greater in the high- than in the low-rooting group at week 2. MYB and AP2/ERF transcription factors, which regulate flavonoid biosynthesis, as well as chalcone isomerase, a key enzyme in early flavonoid biosynthesis and root formation, were upregulated in the high-rooting group. The flavonoid biosynthesis pathway is important in rooting after stem cutting of Populus alba × P. tomentiglandulosa hybrids. Full article

The rhizome of Atractylodes lancea (Thunb.) DC. is a traditional Chinese medicine used extensively owing to its antimicrobial properties. It is utilized to treat nyctalopia and problems related to the gastrointestinal tract. However, its yield is limited because of its endangered status, long growth period, and restricted reproductive ability. Ancillary approaches have not been established to ensure sustainable resource utilization by applying efficient plant regeneration technologies and producing bioactive metabolites via genome editing. This study reports the effects of explants, hormones, and culture conditions on embryogenic callus induction, plant regeneration, adventitious and hairy root cultivation, and essential oil production. Embryogenic calli were successfully induced in MS and 2.0 mg/L 2,4-D and 1.0 mg/L NAA and 1/2MS medium supplemented with 4.0 mg/L 6-BA and 0.4 mg/L NAA, which were optimal for callus differentiation. Maximum proliferation (12-fold) of cluster buds was observed with a select combination of hormones [NAA (0.2 mg/L) and 6-BA (2.0 mg/L)]. “Efficient plant regeneration and bioactive metabolite production” can provide technical support for the protection and sustainable utilization of A. lancea germplasm resources in terms of resource preservation and new variety breeding, natural product production, and industrial breeding of medicinal plants. Full article