Search Results (545)

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

In this study, the effect of growth regulators on shoot proliferation and rooting were evaluated to develop an efficient micropropagation protocol for the Cannabis sativa L. cultivars ‘Cherry Soda’ and ‘Purple’. Apical meristems were isolated from actively growing shoots of stock plants and transferred to Driver and Kuniyuki Walnut (DKW) culture medium containing either 0.0, 0.5, 1.0, 2.0, or 5.0 μM meta-Topolin to study their shoot proliferation response. Resulting shoot cultures were transferred to medium containing varying levels of Indole Acetic Acid (IAA), Indole Butyric Acid (IBA), or Naphthalene Acetic Acid (NAA), solely or in combination, and were subjected to a 10-day dark incubation followed by a 16 h/8 h light/dark period to identify the best treatment for root production. Among the different shoot proliferation treatments studied, the maximum number of shoots was produced on the control medium that was devoid of any meta-Topolin. Cultures grown on medium containing 5.0 μM meta-Topolin exhibited hyperhydricity, where shoots appeared translucent and pale green in color; were characterized by water-soaked lesions; and leaves appeared curled and brittle in contrast to healthy looking cultures. Among the various rooting treatments studied, shoots grown in the dark for 10 days exhibited the highest frequency of rooting on medium containing 4.0 μM NAA or 6.0 μM IBA + 1.0 μM NAA. Full developed plants with a robust shoot and root system were transferred to soil, acclimatized under conditions for high humidity, and then transferred to ambient conditions in 4 weeks. The micropropagation protocol developed here allows for rapid multiplication of disease-free plants in C. sativa cultivars. Full article

Pinus yunnanensis is an essential tree species in southwest China. However, its genetic degeneration problem urgently needs to be addressed. Decapitation promotes seedling propagation primarily by disrupting apical dominance, triggering hormonal changes that stimulate lateral bud growth. To investigate the response of hormones and photosynthetic pigments in P. yunnanensis to decapitation at different seedling ages, seedlings aged 6, 10, 14, 18, and 30 months were used as materials to carry out unified decapitation treatment, and the dynamics of photosynthetic pigments, changes in endogenous hormones, and their relationship with tillering ability were analyzed. The results showed that the photosynthetic pigments were higher in younger decapitated seedlings than in older ones, and carotenoids showed an upward trend with time. Additionally, decapitation significantly altered the balance of endogenous hormones, including the contents of GAs, ABA, SA, JA, JA-Ile, and ACC. The GA₃ and ABA contents in the middle-aged decapitated seedlings of P. yunnanensis were higher. The seedlings with older decapitation ages showed higher contents of IAA, SA, and JA. Overall, seedlings with different decapitation ages exhibit significant differences in their responses to decapitation, as indicated by variations in photosynthetic pigments and hormones. This research elucidated the optimal decapitation age for P. yunnanensis, providing a theoretical foundation for establishing efficient decapitation nurseries and promoting near-natural propagation. Full article

(1) Background: This study used the cold-tolerant cultivar “Daye No. 3” (DY) and the cold-sensitive cultivar “Longdong” (LD) as plant materials to study the metabolic changes in plant hormones in alfalfa (Medicago sativa L.) under cold stress. (2) Methods: The targeted quantitative detection of phytohormones in alfalfa was carried out by liquid chromatography–tandem mass spectrometry (LC-MS/MS) technology. Principal component analysis (PCA), orthogonal signal correction, and partial least squares discriminant analysis (OPLS-DA) were used to investigate sample classification and screen differential metabolites. (3) Results: The results showed that 17 differential metabolites were detected. Seven metabolites showed common changes in the two cultivars after low-temperature stress induction. The levels of tryptamine, N-jasmonoylisoleucine, trans-zeatin riboside, isopentenyladenine riboside, cis-zeatin riboside, and gibberellin A7 were decreased, while N6-isopentenyladenine levels increased. In addition, compared with the LD variety, DY had more metabolite changes in response to low-temperature stress. Abscisic acid and trans-zeatin were elevated, whereas IAA-alanine, dihydrozeatin riboside, and indole-3-carboxaldehyde showed reduced concentrations. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that differential plant hormones were more active in plant hormone signal transduction, zeatin biosynthesis, and tryptophan metabolism pathways. In addition, a total of 12 metabolites in these three pathways showed common changes under cold stress. (4) This study identified significant metabolomic differences between two alfalfa genotypes under stress. It highlighted key pathways and provided new insights into the metabolic changes of alfalfa under cold-stress conditions. Full article

Cerium oxide nanoparticles (CeO₂NPs) can boost crops’ salt tolerance, yet their regulatory mechanisms in rice cultivars with contrasting salt tolerance remain unclear. This study investigated the regulatory differences in poly (acrylic acid)-coated nanoceria (PNC)-primed in salt-sensitive (Huanghuazhan, H) and salt-tolerant (Xiangliangyou900, X) rice. The results showed that PNC priming improved salt tolerance in two cultivars, but the underlying mechanisms differed. In the H cultivar, the enhanced tolerance was primarily attributed to enhanced photosynthesis (net photosynthesis and transpiration rates were 53.27% and 20.52% higher than the X cultivar); increased abscisic acid (ABA) content (up by 18.80% compared to the X cultivar), and activated stress-responsive signaling. Metabolomics further revealed that the differential metabolites were enriched in galactose metabolism, ascorbate, and aldarate metabolism, synergistically maintaining intracellular redox balance. In the X cultivar, PNC boosted reactive oxygen species’ (ROS) scavenging capacity (catalase (CAT) increased 36.07%, H₂O₂ and malondialdehyde (MDA) decreased 27.31% and 48.61% compared to H); elevated endogenous indole-3-acetic acid (IAA) and gibberellic acid3 (GA3) levels by 9.55% and 9.08%; and specifically activated cellular defense response and glutathione metabolism. Transcriptome analysis further revealed that the expression of IAA/GA3 signal-responsive genes (OsARGOS/OsGASR2) and antioxidant genes (OsCatA, OsAPX1) were significantly higher in the X cultivar than the H cultivar (p < 0.05), whereas the H cultivar showed higher expression of GST and ABA-related genes. This study provides a new perspective for the mechanism of PNC-enhanced salt tolerance in rice. Full article

To investigate how far-red (FR) light affects tobacco leaf growth, we established different light conditions, namely, CK: white (WL), T1: red (R), T2: red–white (R+WL) combination, T3: white–far-red (WL+FR) combination, and T4: white–red–far-red (WL+R+FR) combination; conducted supplemental light experiments on tobacco; and evaluated the growth of tobacco leaves by determining the biomass, size of the leaves, etc. In addition, the auxin (IAA) content and expression of leaf growth-related genes were examined to further reveal the mechanism of the FR regulation of tobacco leaf growth. The results show a maximum reduction in leaf area size of more than 90% and in fresh dry mass of more than 85%, while the chlorophyll content increased by more than 28%. in tobacco leaves exposed to FR compared with those exposed to white light. Meanwhile, levels of auxin IAA were increased by 113% (T3) and 17% (T4) under far-red light treatment. The anatomical structure of the tobacco leaves showed that FR reduced the number of epidermal cells in the leaves but increased the cell size. Subsequent findings revealed that FR’s impact on leaf growth was mediated through the PHYB–PIF7–IAA signaling pathway, wherein it regulated cell division and growth-related genes. This substantiates that FR diminishes the tobacco leaf area by impeding cell division rather than inhibiting cell growth. In this study, we explored the effects of far-red (FR) light on tobacco leaf growth changes and constructed a model of the related signaling pathways. Our results reveal a novel mechanism by which far-red light regulates the growth of tobacco leaves, elucidating how far-red light affects their growth and response to shading conditions. This finding not only provides a scientific basis for the optimization of high-density tobacco planting but also helps to improve photosynthetic efficiency and yield, providing strong support for the sustainable development of tobacco farming. Full article

MicroRNA319 (miR319) and its targets TEOSINTE-BRANCHED1/CYCLOIDEA/PCF (TCP) transcription factors are well-characterized regulators of leaf and flower development, yet their role in root development remains elusive. Here, we demonstrated that overexpression of miR319a led to a decrease in the number and density of lateral roots in poplar, while repressing miR319a by short tandem target mimics (STTM) promoted lateral root (LR) development. The auxin signaling repressors IAA3.1 and IAA3.2 were upregulated in miR319a-OE plants but downregulated in miR319a-STTM plants. After exogenous applications of naphthaleneacetic acid (NAA), which exhibited the characteristics and physiological functions of the endogenous auxin indole-3-acetic acid, the number and density of LR in WT increased by 30% and 44%, respectively. In miR319a-OE plants, the LR number increased by 23% and 48%, and the LR density increased by 10% and 26%. NAA treatment can partially compensate for the phenotype of inhibited LR development caused by the overexpression of miR319a. After N-1-naphthylphthalamic acid (NPA) treatment, which is a key inhibitor of the directional (polar) transport of the auxin hormone in plants, the LR number in WT decreased by 70%. In the overexpression plants, the number of lateral roots decreased by 85–87%, and in the STTM plants, the number of lateral roots decreased by about 83%. It was proved that NPA treatment could reverse the phenotype of increased LR number in miR319a-STTM plants. Expression analysis revealed that miR319a significantly inhibited the expression of the key auxin-regulated genes IAA3.1 and IAA3.2, suggesting that auxin signaling might mediate its effects on lateral root formation. Additionally, we compared the fluorescence signal in the reporter line with GFP expression driven by the auxin-responsive DR5 promoter within the genetic backgrounds of WT, miR319a-OE, and miR319a-STTM plants, which revealed that auxin signaling was stronger in the epidermal cells and elongation zone cells in the LR of miR319a-OE plants, whereas in LR of WT and miR319a-STTM plants, auxin signaling was more pronounced in the root tip meristematic cells. Furthermore, transactivation assays and expression analysis indicated that IAA3.2 was a downstream target of TCP19. Chromatin immunoprecipitation coupled with quantitative PCR (ChIP-qPCR) confirmed that TCP19 directly bound to the promoter region of IAA3.2. These findings establish that miR319a targeted and cleaved TCP19, and TCP19 further directly and negatively regulates the expression of IAA3.2, thereby controlling LR development in Populus tomentosa (P. tomentosa). The formation of LR can expand the plant root system, which is of great significance for the vegetative propagation of plants and the in-vitro regeneration of explants. Moreover, the formation of LR is an important strategy for plants to cope with environmental stresses. This study provides a theoretical basis for breeding poplars more suitable for vegetative propagation. Full article

The AP2/ERF (APETALA2/ethylene-responsive element binding factor) family represents one of the largest transcription factor families in plants, playing pivotal roles in abiotic stress responses and hormone signaling pathways. Through genome-wide analysis, we identified 163 AnAP2/ERF genes in Adiantum nelumboides. Transcriptome data revealed that 12 AnAP2/ERF genes were significantly upregulated under either drought or flooding stress, with 8 genes responding to both conditions. qRT-PCR validation confirmed that all 12 selected AnAP2/ERF genes exhibited differential expression under both stress types. Notably, these genes also showed significant induction by abscisic acid (ABA), auxin (IAA), and gibberellin (GA), suggesting their potential involvement in stress responses through hormone crosstalk. This study establishes a foundation for investigating AnAP2/ERF gene functions and their molecular mechanisms in abiotic stress adaptation in A. nelumboides. Full article

Fruit shape is an important quality and yield trait of pear, and the fruit shape of ‘Laiyang Cili’ presents a spindle shape which seriously affects its commercial value. Calyx excision treatment could change the fruit shape, while the underlying genes and their regulatory mechanism remain poorly understood. In this study, we constructed RNA-seq libraries of pear treated with calyx excision to explore underlying regulatory mechanisms. At the early stage of the calyx excision treatment, the numbers of differentially expressed genes (DEGs) between each comparison group were relatively high and gradually decreased along with fruit development. The expression pattern of the DEGs ranked in the top 30 of the six groups had obvious divergence, and DEGs were mainly distributed in the “after calyx excision treatment (0 days)” (AC0d) and AC2d groups. The DEGs were mainly enriched in plant hormone signal transduction and plant defense response. We identified 17 candidate genes related to fruit shape and tested their expression patterns along with fruit development. Among them, nine candidate genes expression trends were consistent with fragments per kilobase of exon model per million mapped fragment (FPKM) values, including MYB62, outer envelope pore protein 62 (OEP62), auxin response factor 3 (ARF3), auxin-responsive protein 50 (SAUR50), protein phosphatase 2C 51 (PP2C 51), major allergen Pyr c 1 (PYRC1), aquaporin TIP1-3 (TIP1-3), transcription factor TGA4 (TGA4) and auxin-responsive protein 17 (IAA17). And then, weighted gene co-expression network analysis (WGCNA) analysis revealed that the OVATE family protein (OFP) and SUN domain-containing protein (SUN) were divided into the MEblue model, which had a positive correlation with calyx excision treatment, and the expression trend of LOC103960706 (OFP8) appeared cohesive with FPKM values. Pbr014104.1 and Pbr016952.1, which were the ortholog genes of LOC103960706, were further identified from the pear genome, and were found to be highly expressed in pear fruit through RT-PCR analysis. Taken together, the key stage determining the development of fruit shape was in the early stage after calyx excision treatment, and fruit shape regulation and development were co-regulated by multiple genes. Full article

Grafting serves as a crucial propagation technique for superior Camellia oleifera varieties, where rootstock–scion compatibility significantly determines survival and growth performance. To systematically evaluate grafting compatibility in this economically important woody oil crop, we examined 15 rootstock–scion combinations using ‘Xianglin 210’ as the scion, assessing growth traits and conducting physiological assays (enzymatic activities of SOD and POD and levels of ROS and IAA) at multiple timepoints (0–32 days post-grafting). The results demonstrated that Comb. 4 (Xianglin 27 rootstock) exhibited superior compatibility, characterized by systemic antioxidant activation (peaking at 4–8 DPG), rapid auxin accumulation (4 DPG), and efficient sugar allocation. Transcriptome sequencing and WGCNA analysis identified 3781 differentially expressed genes, with notable enrichment in stress response pathways (Hsp70, DnaJ) and auxin biosynthesis (YUCCA), while also revealing key hub genes (FKBP19) associated with graft-healing efficiency. These findings establish that successful grafting in C. oleifera depends on coordinated rapid redox regulation, auxin-mediated cell proliferation, and metabolic reprogramming, with Comb. 4 emerging as the optimal rootstock choice. The identified molecular markers not only advance our understanding of grafting mechanisms in woody plants but also provide valuable targets for future breeding programs aimed at improving grafting success rates in this important oil crop. Full article

This study aimed to evaluate and optimize the effects of three auxin types—indole-3-butyric acid (IBA), naphthaleneacetic acid (NAA), and indole-3-acetic acid (IAA)—applied at four concentrations (1000, 3000, 5000, and 8000 ppm) on the rooting performance of Photinia × fraseri Dress. stem cuttings. The experiment was conducted under controlled greenhouse conditions using a sterile perlite medium. Rooting trays were placed on bottom-heated propagation benches maintained at a set temperature of 25 ± 2 °C to stimulate root formation. However, the actual rooting medium temperature—measured manually every four days from the perlite zone using a calibrated thermometer—ranged between 18 °C and 22 °C, with an overall average of approximately 20 ± 2 °C. The average values of these root-zone temperatures were used in the statistical analyses. Rooting percentage, root number, root length, callus formation, and mortality rate were recorded after 120 days. In addition to classical one-way ANOVA, response surface methodology (RSM) was employed to model and optimize the interactions between auxin type, concentration, and temperature. The results revealed that 5000 ppm IBA significantly enhanced rooting performance, yielding the highest rooting percentage (85%), average root number (5.80), and root length (6.30 cm). RSM-based regression models demonstrated strong predictive power, with the model for rooting percentage explaining up to 92.79% of the total variance. Temperature and auxin concentration were identified as the most influential linear factors, while second-order and interaction terms—particularly T·ppm—contributed substantially to root length variation. These findings validate IBA as the most effective exogenous auxin for the vegetative propagation of Photinia × fraseri Dress. and provide practical recommendations for optimizing hormone treatments. Moreover, the study offers a robust statistical modeling framework that can be applied to similar propagation systems in woody ornamental plants. Full article

Cyanobacteria are a prolific source of bioactive metabolites with expanding applications in sustainable agriculture and biotechnology. This work explores, for the first time in thermotolerant Colombian isolates, the impact of light spectrum, photoperiod, and irradiance on the co-production of exopolysaccharides (EPS) and indole-3-acetic acid (IAA). Six strains from hot-spring environments were screened under varying blue:red (B:R) LED ratios and full-spectrum illumination. Hapalosiphon sp. UFPS_002 outperformed all others, reaching ~290 mg L⁻¹ EPS and 28 µg mL⁻¹ IAA in the initial screen. Response-surface methodology was then used to optimize light intensity and photoperiod. EPS peaked at 281.4 mg L⁻¹ under a B:R ratio of 1:5 LED, 85 µmol m⁻² s⁻¹, and a 14.5 h light cycle, whereas IAA was maximized at 34.4 µg mL⁻¹ under cool-white LEDs at a similar irradiance. The quadratic models exhibited excellent predictive power (R² > 0.98) and a non-significant lack of fit, confirming the light regime as the dominant driver of metabolite yield. These results demonstrate that precise photonic tuning can selectively steer carbon flux toward either EPS or IAA, providing an energy-efficient strategy to upscale thermotolerant cyanobacteria for climate-resilient biofertilizers, bioplastics precursors, and other high-value bioproducts. Full article

Xyloglucan endotransglucosylase/hydrolases (XTHs) are a class of cell wall-associated enzymes involved in the construction and remodeling of cellulose/xyloglucan crosslinks. However, knowledge of this gene family in the model monocot Brachypodium distachyon is limited. A total of 29 BdXTH genes were identified from the whole genome, and these were further divided into three subgroups (Group I/II, Group III, and the Ancestral Group) through evolutionary analysis. Gene structure and protein motif analyses indicate that closely clustered BdXTH genes are relatively conserved within each group. A highly conserved amino acid domain (DEIDFEFLG) responsible for catalytic activity was identified in all BdXTH proteins. We detected three pairs of segmentally duplicated BdXTH genes and five groups of tandemly duplicated BdXTH genes, which played vital roles in the expansion of the BdXTH gene family. Cis-elements related to hormones, growth, and abiotic stress responses were identified in the promoters of each BdXTH gene, and when roots were treated with two abiotic stresses (salinity and drought) and four plant hormones (IAA, auxin; GA3, gibberellin; ABA, abscisic acid; and BR, brassinolide), the expression levels of many BdXTH genes changed significantly. Transcriptional analyses of the BdXTH genes in 38 tissue samples from the publicly available RNA-seq data indicated that most BdXTH genes have distinct expression patterns in different tissues and at different growth stages. Overexpressing the BdXTH27 gene in Brachypodium led to reduced root length in transgenic plants, which exhibited higher cellulose levels but lower hemicellulose levels compared to wild-type plants. Our results provide valuable information for further elucidation of the biological functions of BdXTH genes in the model grass B. distachyon. 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