Search Results (340)

Ilex paraguariensis (yerba mate), a culturally and economically important South American species, faces significant challenges in vitro, including contamination, phenolic oxidation, and low regeneration rates. Nanoparticles have recently emerged as promising tools to overcome such limitations. This study evaluated silver (AgNPs) and chitosan nanoparticles (ChNPs) in eight experiments using nodal, leaf, and internodal explants. Surface disinfection with 1% colloidal silver solution 20 ppm significantly reduced contamination (17.2% and 15%) while maintaining viability (62.1%). However, supplementation of culture media with AgNPs (4–75 mg·L⁻¹) or ChNPs (5–120 mg·L⁻¹) did not improve nodal segment responses. In leaf explants, 4 mg·L⁻¹ AgNPs proved most effective, reducing contamination and markedly decreasing callus oxidation from 63.3% to 10.0%. Callogenesis was enhanced when AgNPs were combined with growth regulators, with the highest induction at 6 mg·L⁻¹ AgNPs + zeatin (38.1%) and 4 mg·L⁻¹ AgNPs + BAP (42.9%). Conversely, in internodal segments, AgNPs combined with BAP completely inhibiting callus formation. The resulting calli exhibited compact and friable morphologies but no signs of somatic embryogenesis. Overall, the effectiveness of AgNPs depends on their formulation, explant type, and interaction with cytokinins. Optimization of nanoparticle formulation and hormonal balance remains essential to maximize efficacy while minimizing toxicity. Full article

Biological control serves as a crucial strategy for crop disease management. The biocontrol potential and plant growth-promoting effects of the strain YTBTa14 were investigated. Genetic sequencing confirmed YTBTa14 as Pseudomonas chlororaphis, which exhibited broad-spectrum antifungal activity against multiple pathogens affecting grapevine, apple, cherry, and wheat. YTBTa14 significantly enhanced the growth of wheat and grapevine, specifically increasing wheat seed germination rates and improving root and coleoptile development. In grapevine plant, significant increases in root length, stem length, and fresh weight were observed. The strain demonstrated robust adaptability and stable antagonism under varying sodium chloride (NaCl) concentrations, pH levels, and temperatures. YTBTa14 modulated plant hormone levels, elevating the content of indole-3-acetic acid (IAA), gibberellins (GA), and cytokinins (CTK). Furthermore, it effectively stimulated the production of key plant defense enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). Pretreatment of grape leaves with YTBTa14 triggered plant cell defense response and upregulated the expression of defense-related genes PR1 (pathogenesis-related protein 1) and PAL1 (phenylalanine ammonia-lyase 1), thereby mitigating the severity of downy mildew disease and inducing systemic resistance. These findings demonstrate that YTBTa14 is a highly promising candidate for development as a multifunctional agricultural biocontrol agent. Full article

Rhododendron spp., valuable ornamental plants, frequently suffer from infestations of the azalea lace bug (Stephanitis pyrioides Scott, ALB). However, the hormonal regulatory mechanisms underlying Rhododendron defense against ALB are not well understood. In this study, integrated transcriptomic and metabolomic analyses were performed to investigate the phytohormone responses under ALB stress in two Rhododendron cultivars with distinct insect susceptibility: the resistant ‘Taile’ (TL), and the susceptible ‘Yanzhimi’ (YZM). Transcriptomic sequencing identified 10,052 and 3113 differentially expressed genes (DEGs) in ‘TL’ and ‘YZM’, respectively, after ALB infestation. KEGG pathway enrichment analysis revealed that the DEGs in ‘TL’ were significantly enriched in hormone signal transduction pathways, including gibberellin (GA), jasmonic acid (JA), salicylic acid (SA), and ethylene (ETH), with 21 out of 25 hormone-related DEGs being upregulated. In contrast, ‘YZM’ exhibited 18 upregulated and 13 downregulated DEGs and suppressed auxin and cytokinin signaling. Non-targeted metabolomic analysis detected increased indole-3-acetic acid (IAA), abscisic acid (ABA), and jasmonoyl–isoleucine (JA-Ile) levels in both cultivars. ‘TL’ also showed elevated levels of SA precursor (benzoic acid) and ethylene precursor (1-aminocyclopropane-1-carboxylate, ACC). These findings indicate that ALB infestation induces endogenous hormone signaling-related genes in Rhododendron leaves and regulates hormones such as SA and JA to counteract insect stress. This study provides theoretical insights into the molecular mechanisms of Rhododendron defense against insect herbivory and lays the foundation for breeding resistant cultivars. Full article

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. Full article

N, as plants’ most essential nutrient, profoundly shapes root system architecture (RSA), with LRs being preferentially regulated. This review synthesizes the intricate molecular mechanisms underpinning N sensing, signaling, and its integration into developmental pathways governing LR initiation, primordium formation, emergence, and elongation. We delve deeply into the roles of specific transporters (NRT1.1, nitrate transporter 2.1 (NRT2.1)), transcription factors (Arabidopsis nitrate regulated 1 (ANR1), NLP7, TGACG motif-binding factor (TGA), squamosa promoter-binding protein-like 9 (SPL9)) and intricate hormone signaling networks (auxin, abscisic acid, cytokinins, ethylene) modulated by varying N availability (deficiency, sufficiency, excess) and chemical forms (NO₃⁻, NH₄⁺, organic N). Emphasis is placed on the systemic signaling pathways, including peptide-mediated long-distance communication (CEP—C-terminally encoded peptide receptor 1 (CEPR1)) and the critical role of the shoot in modulating root responses. Furthermore, we explore the emerging significance of carbon–nitrogen (C/N) balance, post-translational modifications (ubiquitination, phosphorylation), epigenetic regulation, and the complex interplay with other nutrients (phosphorus (P), sulfur (S)) and environmental factors in shaping N-dependent LR plasticity. Recent advances utilizing single-cell transcriptomics and advanced imaging reveal unprecedented cellular heterogeneity in LR responses to N. Understanding this sophisticated regulatory network is paramount for developing strategies to enhance nitrogen use efficiency (NUE) in crops. This synthesis underscores how N acts as a master regulator, dynamically rewiring developmental programs through molecular hubs that synchronize nutrient sensing with root morphogenesis—a key adaptive strategy for resource acquisition in heterogeneous soils. Full article

Background/Objectives: Possessing red and white ecotypes, and utilized in traditional Guyanese medicine, Doliocarpus dentatus’ red ecotype is preferred locally for its purported superior therapeutic efficacy. Although therapeutic metabolites were detected in D. dentatus previously, phytohormones remain largely unexplored, until now. Cytokinins, phytohormones responsible for plant cell division, growth and differentiation, are gaining traction for their therapeutic potential in human health. This study screened and quantified endogenous cytokinins and correlated detected cytokinins with selected secondary metabolites. Methods: Liquid chromatography–mass spectrometry was used to acquire phytohormone and metabolite data. Bioinformatics tools were used to assess untargeted metabolomics datasets via statistical and pathway analyses, and chemical groupings of putative metabolites. Results: In total, 20 of the 35 phytohormones were detected and quantified in both ecotypes, with the red ecotype displaying higher free base and glucoside cytokinin concentrations and exhibited 6.2 times the total CK content when compared to the white ecotype. Pathway analysis revealed flavonoid and monoterpenoid biosynthesis in red and white ecotypes, respectively. Positive correlations between specific cytokinins and alkaloids, and between trans-Zeatin and isopentenyladenosine riboside with phenolic compounds were observed. Conclusions: These results suggest that the red ecotype’s elevated cytokinin levels coupled with flavonoid biosynthesis enrichment support its preference in Guyanese traditional medicine. Full article

Global climate change is causing increasing fluctuations in winter temperatures, including episodes of warm conditions above 9 °C. Such events disrupt cold acclimation in plants and can induce deacclimation, reducing frost tolerance and altering, among other things, hormonal regulation. This study investigated hormonal and molecular changes associated with cold acclimation and deacclimation in oilseed rape (Brassica napus L.) cultivars Kuga and Thure. Plants were grown under different conditions: non-acclimated (17 °C for three weeks), cold-acclimated (4 °C for three weeks), and deacclimated (16/9 °C day/night for one week). Detailed hormone analysis included auxins, gibberellins, cytokinins, stress-related hormones, and the expression of hormone-related genes (BnABF2, BnAOS, BnARF1, BnARR6, BnICS1, BnRGA, and BnWRKY57). Hormone concentrations in leaves changed dynamically in response to deacclimation with increased amounts of growth-promoting hormones and decreased amounts of stress hormones. Additionally, alterations in gene expression during deacclimation, such as in BnABF2 and BnICS1, may function as protective mechanisms to help maintain or regain frost tolerance during reacclimation when temperatures decline again after the warm period. These findings improve the understanding of hormonal and molecular responses involved in the deacclimation of oilseed rape. Full article

Corn cockle (Agrostemma githago L. (Lychnis githago (L.) Scop.)) is the main ingredient in some plant preparations for biostimulation in agriculture, and it elicits many positive responses. In our study, we attempted to determine if the fresh and dry plant material of A. githago contained auxin-like and cytokinin-like growth regulators (PGRs). Cucumis and mung bean bioassays were used to determine the presence of auxin-like PGRs and Cucumis and Triticum bioassays were used to determine the presence of cytokinin-like PGRs. A water solution derived from the crushed, homogenized and extracted seeds, fresh and dry seedlings, and fresh and dry young plants showed auxin-like activity in both bioassays. The activity in the Cucumis bioassay corresponded to 0.5 to 2 mg L⁻¹ of Indole-3-butyric acid (IBA), and in the mung bean bioassay, the activity corresponded to 0.5 to 4 mg L⁻¹ of IBA. While the same water solutions showed weak or no cytokinin-like activity in the Cucumis cotyledon expansion bioassay, and they showed an activity of approximately 0.5 to 1 mg L⁻¹ of 6-Benzylaminopurine (BAP) in the Triticum bioassay. An LC-MS analysis confirmed the presence of free auxins, low levels of or no auxin analogues, a small amount of free cytokinins and a higher level of their cytokinin analogues in the samples, seeds, dry seedlings and young plants of A. githago, which was likely related to the fine-tuning between the free and analogue forms of the PGRs in the water solutions used in the experiments. Full article

Trichomes are specialized epidermal structures that protect plants from environmental stresses, regulated by transcription factors integrating hormonal and environmental cues. This study investigates the roles of two C2H2 zinc finger proteins, GIS2 and ZFP8, in regulating trichome patterning in Arabidopsis thaliana. Using dexamethasone-inducible overexpression lines, transcriptomic profiling, and chromatin immunoprecipitation, we identified 142 GIS2- and 138 ZFP8-associated candidate genes involved in sterol metabolism, senescence, and stress responses. GIS2 positively and directly regulated the expression of SQE5, linked to sterol biosynthesis and drought tolerance, and repressed SEN1, a senescence marker associated with abscisic acid and phosphate signaling. ZFP8 modulated stress-related target genes, including PR-4 and SPL15, with partial functional overlap between GIS family members. Spatially, GIS2 functions in inflorescence trichomes via integrating gibberellin-cytokinin pathways, while ZFP8 influences leaf trichomes through cytokinin and abscisic acid signal. Gibberellin treatment stabilized GIS2 protein and induced SQE5 expression, whereas SEN1 repression was gibberellin-independent. Chromatin immunoprecipitation and DEX-CHX experiment confirmed GIS2 binding to SQE5 and SEN1 promoters at conserved C2H2 motifs. These findings highlight hormone-mediated transcriptional regulation of trichome development by GIS2 and ZFP8, offering mechanistic insight into signal integration. The results provide a foundation for future crop improvement strategies targeting trichome-associated stress resilience. Full article

The worldwide agriculture industry is facing increasing problems due to rapid population increase and increasingly unfavorable weather patterns. In order to reach the projected food production targets, which are essential for guaranteeing global food security, innovative and sustainable agricultural methods must be adopted. Conventional approaches, including traditional breeding procedures, often cannot handle the complex and simultaneous effects of biotic pressures such as pest infestations, disease attacks, and nutritional imbalances, as well as abiotic stresses including heat, salt, drought, and heavy metal toxicity. Applying phytohormonal approaches, particularly those involving hormonal crosstalk, presents a viable way to increase crop resilience in this context. Abscisic acid (ABA), gibberellins (GAs), auxin, cytokinins, salicylic acid (SA), jasmonic acid (JA), ethylene, and GA are among the plant hormones that control plant stress responses. In order to precisely respond to a range of environmental stimuli, these hormones allow plants to control gene expression, signal transduction, and physiological adaptation through intricate networks of antagonistic and constructive interactions. This review focuses on how the principal hormonal signaling pathways (in particular, ABA-ET, ABA-JA, JA-SA, and ABA-auxin) intricately interact and how they affect the plant stress response. For example, ABA-driven drought tolerance controls immunological responses and stomatal behavior through antagonistic interactions with ET and SA, while using SnRK2 kinases to activate genes that react to stress. Similarly, the transcription factor MYC2 is an essential node in ABA–JA crosstalk and mediates the integration of defense and drought signals. Plants’ complex hormonal crosstalk networks are an example of a precisely calibrated regulatory system that strikes a balance between growth and abiotic stress adaptation. ABA, JA, SA, ethylene, auxin, cytokinin, GA, and BR are examples of central nodes that interact dynamically and context-specifically to modify signal transduction, rewire gene expression, and change physiological outcomes. To engineer stress-resilient crops in the face of shifting environmental challenges, a systems-level view of these pathways is provided by a combination of enrichment analyses and STRING-based interaction mapping. These hormonal interactions are directly related to the United Nations Sustainable Development Goals (SDGs), particularly SDGs 2 (Zero Hunger), 12 (Responsible Consumption and Production), and 13 (Climate Action). This review emphasizes the potential of biotechnologies to use hormone signaling to improve agricultural performance and sustainability by uncovering the molecular foundations of hormonal crosstalk. Increasing our understanding of these pathways presents a strategic opportunity to increase crop resilience, reduce environmental degradation, and secure food systems in the face of increasing climate unpredictability. Full article

As sessile organisms, plants adapt to environmental challenges through flexible developmental and physiological programs. Hormones play a central role in this adaptability, integrating environmental signals into coordinated responses that regulate growth and stress tolerance. Comparative studies across photosynthetic lineages reveal that several core hormone functions are remarkably conserved, despite major evolutionary changes in hormone perception, biosynthesis, metabolism, and transport. This conservation suggests that plant hormones have played a pivotal evolutionary role—not only preserving essential biological functions but also enabling increased complexity in plant form and function. A similar dual role is observed in evolutionary endocrinology in animals, where hormones contribute to the emergence and regulation of complex traits. We propose that hormones such as cytokinins, auxins, brassinosteroids, strigolactones, and abscisic acid originated as metabolic derivatives closely tied to core physiological functions essential for survival and reproduction, including reproductive success, nutrient sensing, and dehydration tolerance. Over time, these compounds were progressively integrated into increasingly sophisticated regulatory networks, where they now serve as central coordinators and key targets of evolutionary selection. This model advances our understanding of hormone evolution by providing a structured framework to interpret the persistence, specialization, and integration of plant hormones across evolutionary timescales. Full article

The cytokinin response regulator (ARR) gene is essential for cytokinin signal transduction, which plays a crucial role in plant growth and development. However, the functional mechanism of ARR genes in cotton leaf abscission remains incompletely understood. In this study, a total of 86 ARR genes were identified within the genome of Gossypium hirsutum. These genes were categorized into four distinct groups based on their phylogenetic characteristics, supported by analyses of gene structures and conserved protein motifs. The GhARR genes exhibited an uneven distribution across 25 chromosomes, with three pairs of tandem duplication events observed. Both segmental and tandem duplication events significantly contributed to the expansion of the ARR gene family. Furthermore, numerous putative cis-elements were identified in the promoter regions, with hormone and stress-related elements being common among all 86 GhARRs. Transcriptome expression profiling screening results demonstrated that GhARRs may play a mediating role in cotton’s response to TDZ (thidiazuron). The functional validation of GhARR16, GhARR43, and GhARR85 using virus-induced gene silencing (VIGS) technology demonstrated that the silencing of these genes led to pronounced leaf wilting and chlorosis in plants, accompanied by a substantial decrease in petiole fracture force. Overall, our study represents a comprehensive analysis of the G. hirsutum ARR gene family, revealing their potential roles in leaf abscission regulation. Full article

Seed germination is a critical phase in the plant lifecycle of Camellia oleifera (oil tea), directly influencing seedling establishment and crop reproduction. In this study, we examined transcriptomic and physiological changes across five defined germination stages (G0–G4), from radicle dormancy to cotyledon emergence. Using RNA sequencing (RNA-seq), we assembled 169,652 unigenes and identified differentially expressed genes (DEGs) at each stage compared to G0, increasing from 1708 in G1 to 10,250 in G4. Functional enrichment analysis revealed upregulation of genes associated with cell wall organization, glucan metabolism, and Photosystem II assembly. Key genes involved in cell wall remodeling, including cellulose synthase (CESA), phenylalanine ammonia-lyase (PAL), 4-coumarate-CoA ligase (4CL), caffeoyl-CoA O-methyltransferase (COMT), and peroxidase (POD) showed progressive activation during germination. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed dynamic regulation of phenylpropanoid and flavonoid biosynthesis, photosynthesis, carbohydrate metabolism, and hormone signaling pathways. Transcription factors such as indole-3-acetic acid (IAA), ABA-responsive element binding factor (ABF), and basic helix–loop–helix (bHLH) were upregulated, suggesting hormone-mediated regulation of dormancy release and seedling development. Physiologically, cytokinin (CTK) and IAA levels peaked in G4, antioxidant enzyme activities were highest in G2, and starch content increased toward later stages. These findings provide new insights into the molecular mechanisms underlying seed germination in C. oleifera and identify candidate genes relevant to rootstock breeding and nursery propagation. Full article

Phosphorus deficiency poses a significant challenge to the growth and productivity of crops, particularly in nutrient-poor soils. This study investigates the effects of phosphorus deficiency on the growth, endogenous phytohormones, metabolome, and transcriptome of sweet potato (Ipomoea batatas L.) over a growth period from 30 to 120 days. We found that low phosphorus conditions significantly reduced both above- and below-ground biomass, while tuber number remained unchanged. Endogenous phytohormone analysis revealed altered levels of abscisic acid (ABA), indole-3-acetic acid (IAA), and cytokinins, indicating a complex hormonal response to phosphorus starvation. Transcriptomic analysis identified a total of 6324 differentially expressed genes (DEGs) at 60 days, with significant enrichment in pathways related to stress response and phosphorus utilization (PAPs and PHO1). Metabolomic profiling revealed notable shifts in key metabolites, with consistent downregulation of several phosphorous-related compounds. Our findings highlight the intricate interplay between growth, hormonal regulation, metabolic reprogramming, and gene expression in response to phosphorus deficiency in sweet potato. This research underscores the importance of understanding nutrient stress responses to enhance sweet potato resilience and inform sustainable agricultural practices. Future research should focus on exploring the potential for genetic and agronomic interventions to mitigate the effects of phosphorus deficiency and optimize sweet potato productivity in challenging environments. Full article

The response of plants to elevated atmospheric [CO₂] is highly dynamic and influenced by developmental stage, yet its role in photosynthetic acclimation remains underexplored. This study examines the physiological and molecular responses of wheat (Triticum durum, var. Amilcar) to elevated [CO₂] (700 ppm vs. 400 ppm) at two distinct developmental stages: the vegetative stage at the end of the elongation stage and the reproductive stage at the beginning of ear emergence (Z39 and Z51, respectively). Wheat plants at the developmental stage Z39, cultivated under elevated [CO₂], maintained photosynthetic rates despite a carbohydrate build-up. However, at Z51, photosynthetic acclimation became more evident as the decline in Rubisco carboxylation capacity (Vc_max) persisted, but also stomatal conductance and diffusion were decreased. This was accompanied by the up-regulation of the CA1 and CA2 genes, likely as a compensatory mechanism to maintain CO₂ supply. Additionally, hormonal adjustments under elevated [CO₂], including increased auxin and bioactive cytokinins (zeatin and isopentenyl adenine), may have contributed to delayed senescence and nitrogen remobilization, sustaining carbon assimilation despite biochemical constraints. These findings highlight the developmental regulation of photosynthetic acclimation, emphasizing the need for the stage-specific assessments of crop responses to future atmospheric conditions. Full article