Search Results (141)

Aluminum (Al) toxicity severely limits crop growth in acidic soils. Although 24-epibrassinolide (EBR), a bioactive brassinosteroid analog, is known to regulate plant stress responses, its role in Al tolerance in oriental melon remains unclear. Here, we investigated the effects of exogenous EBR application on Al stress tolerance in oriental melon seedlings, and the molecular regulatory mechanisms underlying the EBR-induced alleviation of aluminum stress were explored. Seedlings were pretreated with 0, 0.01, 0.1, and 1 μM EBR for 24 h prior to exposure to 100 μM AlCl₃. Our results showed that 0.01 μM EBR significantly alleviated Al toxicity by improving root vitality, promoting primary root elongation, reducing hematoxylin staining intensity in root tips, and notably increasing malate exudation. The transcriptional analysis revealed that EBR upregulated CmBES1-6, a core transcription factor in BR signaling, along with Al-responsive genes including CmALMT7, CmALMT8, CmALMT12, CmSTOP3, and CmSTOP5. Silencing of CmBES1-6 though virus-induced gene silencing (VIGS) compromised Al tolerance, as reflected by the reduced expression of these Al-responsive genes. Yeast two-hybrid (Y2H) assays confirmed that CmBES1-6 physically interacts with both CmSTOP3 and CmSTOP5. Furthermore, yeast one-hybrid (Y1H) assays demonstrated that CmBES1-6 directly binds to E-box cis-elements (CANNTG) in the promoters of CmSTOP3 and CmSTOP5. Together, our findings suggest that exogenous EBR promotes BR signaling through CmBES1-6, which is associated with the upregulation of CmSTOP3 and CmSTOP5 and enhanced malate exudation from roots, thereby potentially contributing to improved Al tolerance in oriental melon seedlings. This work implicates a CmBES1-6–CmSTOP3/5 transcriptional module in Al tolerance and provides candidate genes for the genetic improvement of Al resistance in melons cultivated in acidic soils. Full article

The DUF538 gene family, harboring unknown functional proteins, has been reported to take active roles in plant development and response to adversities, while few studies of genome-wide identification and functional verification have been performed in cotton. Hence, two ancestral diploid species, G. arboretum and G. raimondii, and two cultivated tetraploid ones, G. hirsutum and G. barbadense, were chosen in this study to investigate the cotton DUF538 gene family, resulting in 37, 37, 70, and 70 members identified, respectively. A phylogenetic tree was constructed on these cotton DUF538 genes, together with 22 A. thaliana ones, which were divided into seven groups unevenly distributed across nearly all chromosomes. High-degree conservatism, while rich in diversity, was separately observed in gene structure and conserved motif analyses between the same groups and different groups, and a great number of gene-replication events were detected from intraspecific and interspecific collinearity analyses, implying this was the driving force for DUF538 family expansion. Multiple cis-acting elements relevant to adversity-stress responses were found in the promoter region, which were consistent with the transcriptome expression analyses in response to low-temperature and drought stress and Verticillium wilt infection. Coincidentally, GhDUF538-7 showed the core position in the protein–protein interaction network and was identified in the overlapping region of the interval of four reported VW resistance-related QTLs. The gene function of GhDUF538-7 was verified via gene cloning, relative expression-pattern detection, and virus-induced gene silencing (VIGS) experiment. The TRV:DUF538-7 plants showed more serious VW symptoms, significantly severe disease indices, relatively higher fungal biomass, and increased brown vascular bundles compared with TRV:00 plants. Significantly lower expression levels of marker genes PR4 and MYC2 in jasmonate signaling pathways indicated GhDUF538-7 as a potentially positive regulatory factor in plant defense via hormone signal transduction. This study not only broadened the research perspective of evolution and functional differentiation of the cotton DUF538 gene family, but it also revealed the cooperative relationship between DUF538-7 and the JA pathway for further molecular mechanisms of cotton resistance to VW infection. Full article

Geranyl diphosphate synthase (GPPS) is a key enzyme in the plant isoprenoid metabolic pathway and regulates the biosynthesis of volatile monoterpenes. It plays an important role in the biosynthesis of floral volatile terpenoids (FVTs) and inter-cultivar variation in snapdragon. Despite its importance in floral scent formation, the GPPS/GGPPS gene family in snapdragon (Antirrhinum majus L.) has not been systematically characterized. In this study, nine GPPS/GGPPS family members were identified at genome-wide level. These include six AmGPPS and three AmGGPPS genes. Phylogenetic analysis grouped them into distinct subfamilies. We further analyzed their chromosomal locations, gene structures, conserved protein motifs, and promoter cis-acting elements. These results revealed both conservation and functional divergence within the gene family. To explore their functional roles, we compared gene expression profiles at the full flowering stage. This comparison was performed between strongly scented cultivar (Am3) and the weakly scented cultivar (Am5). Among all candidates, AmGPPS6 showed the most significant differential expression. Further, functional validation was conducted using transient overexpression and virus-induced gene silencing (VIGS). Overexpression of AmGPPS6 significantly increased terpenoid production. Total floral volatile terpenoids (FVTs) increased by 1.4 fold. Both monoterpene and sesquiterpene emissions were enhanced. In contrast, silencing of AmGPPS6 markedly reduced the emission of key monoterpenes such as ocimene and its isomers. Sequence analysis showed that AmGPPS6 shares 67.04% identity with canonical GPPS small subunit (GPPS.SSU). However, it lacks the conserved catalytic DDx2-D motif. This suggests that AmGGPPS2 is not catalytically active. Instead, it likely functions through heterodimer with AmGGPPS2. This interaction is supported by coordinated transcriptional expression patterns. Additionally, natural sequence polymorphisms were identified in GPPS.SSU. These variations, rather than those in GPPS.LSU, appear to drive differences in monoterpense emission between cultivars. In conclusion, AmGPPS6 in a key regulator of floral scent biosynthesis in snapdragon. This study provides new insights into functional roles of GPPS/GGPPS genes. It also offers valuable gene targets for the molecular breeding of aromatic traits in ornamental plants. Full article

Soil salinity limits ginger productivity, but the underlying molecular mechanisms remain largely unclear. The 14-3-3 proteins are conserved regulators in stress signaling. Here, we genome-wide characterized the 14-3-3 family in Zingiber officinale and examined the possible involvement of Zo14-3-3-03 in salt response. A total of 21 Zo14-3-3 genes were identified and classified into four groups with uneven chromosomal distribution. Among them, Zo14-3-3-03 was strongly salt-responsive: transcript levels increased 9.91- to 33.82-fold during 1–7 days of treatment and reached 62.47-fold in leaves at day 14. NaCl treatment elevated GUS expression driven by the Zo14-3-3-03 promoter. Virus-induced gene silencing (VIGS) of Zo14-3-3-03 resulted in silenced plants exhibiting higher malondialdehyde (up to 73.6%), lower antioxidant enzyme activities (SOD, POD, CAT, and APX: 18.9–31.9% reduction), reduced osmolytes (proline, soluble protein, sugars, and ascorbic acid: 23.2–36.2% reduction), excessive reactive oxygen species, and decreased relative water content. Several antioxidant-related genes were significantly downregulated. Protein interaction assays suggested a possible interaction with ZoSOS2, and the expression of SOS2 pathway genes was altered in silenced plants, indicating a potential link to calcium signaling and ion homeostasis. Taken together, these results suggest that Zo14-3-3-03 participates in ginger salt stress response possibly through redox balance, osmotic adjustment, and calcium-mediated pathways which would provide a basis for understanding 14-3-3-mediated stress responses and nominates Zo14-3-3-03 as a candidate requiring deeper validation for salt tolerance improvement in ginger. Nevertheless, due to limited functional validation, its role as a positive regulator and breeding target remains preliminary. Further genetic and mechanistic studies are needed to confirm causality and assess field-level applicability. Full article

Background/Objectives: Until now, there have been no suitable medicines to treat infections caused by the Ebola virus. Cistus incanus, a traditional medicinal plant, contains several phytocompounds exhibiting antioxidant and anti-inflammatory properties. Methods: In this research, the molecular level interactions of the phytocompounds of Cistus incanus were investigated for their antiviral potential against the active site of VP40 protein of Ebola virus using in silico molecular docking. Further, the potential compounds were assessed for their stability in the protein using molecular dynamics (MD) simulations. Results: Methyl gallate, catechin, and quercetin showed excellent docking scores of −9.8, −8.8, and −7.7 kcal/mol, respectively, and favorable interactions with the target protein. These complexes showed good stability over the 100 ns MD simulation time. In addition, the phytocompounds displayed favorable pharmacokinetics and drug-like properties. Conclusions: Our study offers the antiviral potential of phytocompounds (methyl gallate, catechin, and quercetin) of Cistus incanus, suggesting their suitability as lead candidates for the treatment of Ebola viral infection. Full article

RipP1 is a well-characterized avirulence effector that induces a hypersensitive response (HR) in three tobacco species. However, the molecular mechanisms by which host proteins recognize RipP1 to activate a defense response and modulate host–pathogen interactions remain largely unknown. In this study, we screened a Nicotiana benthamiana cDNA library via yeast two-hybrid assay and identified FRIGIDA-like protein 4a (FRL4a) as a host protein interacting with RipP1. Secondary structure analysis of FRL4a and construction of serial mutants revealed that the ClyA-like domain of FRL4a is the key region mediating its interaction with RipP1. Using virus-induced gene silencing (VIGS) and quantitative real-time PCR (qPCR) analysis, we found that the ability of RipP1 to induce HR was significantly attenuated in FRL4a-silenced plants, and RipP1 no longer suppressed the ethylene signaling pathway. Pathogenicity tests by inoculating R. solanacearum on N. benthamiana with different FRL4a expression levels showed enhanced bacterial wilt resistance in FRL4a-silenced plants but increased susceptibility in FRL4a-overexpressing plants. Collectively, these findings demonstrate that RipP1 suppresses the ethylene pathway through its interaction with FRL4a, and FRL4a acts as a negative regulator of tobacco resistance to bacterial wilt. Full article

Salt stress severely inhibits plant growth and agricultural production by disrupting the balance of water and ions. To counteract this abiotic challenge, plants have evolved sophisticated mechanisms to modulate carbon allocation, prominently through the transcriptional regulation of sucrose metabolism-related genes (SMGs). This study focuses on the globally important horticultural crop, the rose (Rosa chinensis ‘Old Blush’), and provides the first systematic analysis of the RcSMG gene family. Using bioinformatics, 25 RcSMGs were identified, including 4 sucrose phosphate synthase (SPS), 6 sucrose synthase (SUS) and 15 invertase (INV) members. Phylogenetic analysis classified these SMGs into four distinct clades (SUS, SPS, CWINV, and NINV), with the INV family being the largest and the SPS family showing striking conservation across all four species. Evolutionary and collinearity analyses revealed that the SPS family is highly conserved, whereas the INV subfamily has undergone lineage-specific expansion. Protein analysis showed that all RcSMGs are hydrophilic. SPS proteins were found to be relatively unstable, while SUS and most INV members were stable. Further analysis of a protein–protein interaction (PPI) network showed that SPS proteins interact with enzymes in the metabolic pathway both upstream and downstream, forming a tightly regulated sucrose metabolism network. Transcriptome and promoter analyses revealed that RcSMGs exhibit tissue-specific expression patterns. The enrichment of diverse stress-responsive cis-regulatory elements in their promoter regions strongly implies a broad functional role in abiotic-stress adaptation, a hypothesis corroborated by transcriptome profiling under various stress conditions. Crucially, virus-induced gene silencing (VIGS) assays demonstrated that RcSUS3 and RcSPS1 positively regulate salt tolerance, while RcCWINV1 and RcVINV3 may act as negative regulators. In summary, this work provides the foundational framework for understanding the evolution, structure, and transcriptional regulation of the RcSMG family in roses. These findings highlight the important role of sucrose metabolism in stress resilience and provide a valuable basis for future molecular breeding to enhance stress resistance in horticultural crops. Full article

Potato virus Y (PVY), widely regarded as one of the world’s most important plant viruses, seriously threatens global potato production and food security. PVY deploys its proteins to interact with key host factors, thereby enabling viral replication, accumulation, and systemic infection. PVY also exhibits high genetic diversity and frequent recombination, which promote host adaptation and immune evasion. In response, potato plants perceive viral effectors through intracellular immune receptors and activate antiviral defenses. Over the past decade, significant progress has been made in elucidating PVY–host defense and counter-defense mechanisms. Here, we summarize the molecular basis of PVY pathogenicity and highlight recent advances in PVY resistance genes (e.g., Ry_sto and Ry_chc). Finally, we integrate emerging insights from plant virology and nucleotide-binding leucine-rich repeat (NLR) biology to discuss prospective, multi-pronged strategies for PVY management. Full article

Alfalfa mosaic virus (AMV) is a devastating plant pathogen with an extensive host range, yet effective control strategies remain limited. This study investigated the prophylactic efficacy and molecular mechanisms of two plant immune inducers, the Paecilomyces variotii extract DYDS and the antiviral agent Dufulin, against AMV infection in cowpea (Vigna unguiculata). Our results demonstrate that both agents possess potent antiviral activity, with inactivation, protective, and therapeutic efficacies all exceeding 21.00%. Notably, DYDS exhibited superior overall performance. RT-qPCR and immunofluorescence assays confirmed a significant downregulation of AMV coat protein (CP) expression in treated plants. Furthermore, exogenous application of these inducers mitigated chlorophyll loss and markedly augmented the activities of key defense enzymes’ activity, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), polyphenol oxidase (PPO), and L-phenylalanine ammonia-lyase (PAL), peaking at 5 days post-inoculation. In silico molecular docking simulations further revealed that DYDS and Dufulin interact spontaneously with the AMV-CP, yielding binding free energies of −6.5 and −5.8 kcal/mol, respectively. Gene expression analysis indicated that these inducers trigger a robust immune response through the integrated activation of the salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) signaling pathways. Collectively, these findings suggest that DYDS and Dufulin provide a dual mode of action—direct viral inhibition and host immune priming—offering a promising and sustainable approach for the management of AMV in leguminous crops. Full article

The circadian clock genes in tomato are key regulators of cold stress adaptation. However, the low-temperature regulatory mechanism of the circadian clock gene SlPCL1 remains unclear. In this study, we evaluated the role of SlPCL1 in cold tolerance through low-temperature treatment of transgenic plants. Downstream target genes were identified using RNA-seq, RT-qPCR, yeast-one-hybrid (Y1H), dual-luciferase assays, and electrophoretic mobility shift assay (EMSA), while interacting proteins were characterized using yeast-two-hybrid (Y2H), luciferase complementation imaging (LCI), and pull-down assays, thereby elucidating the molecular mechanism underlying SlPCL1-mediated low-temperature regulation. We identified SlPCL1 as a nuclear-localized circadian clock gene with transcriptional repressor activity. Overexpression of SlPCL1 resulted in a cold-sensitive phenotype, whereas virus-induced gene silencing (VIGS)-mediated silencing of SlPCL1 enhanced cold tolerance. SlNPF4.6 functions as an abscisic acid (ABA) transporter involved in ABA transport. RNA-seq and RT-qPCR identified the ABA transporter SlNPF4.6 as a downstream target. Functional assays confirmed that SlPCL1 binds to the MYB element in the SlNPF4.6 promoter to repress its expression. Meanwhile, VIGS-mediated silencing of SlNPF4.6 decreased cold tolerance. Furthermore, the expression levels of the ABA receptor SlPYLs in the silenced lines were significantly reduced, confirming the decrease in intracellular ABA content. SlSUMO1, a ubiquitin-like protein, can influence gene transcription through noncovalent interactions. In addition, SlSUMO1 was found to interact with the SlPCL1 protein, attenuating SlPCL1 transcriptional repression activity. Together, these findings establish an SlSUMO1-mediated fine control mechanism of the SlPCL1-SlNPF4.6 regulatory module. This integration of circadian clock regulation uncovers new molecular mechanisms of cold tolerance and supports the development of cold-resistant breeding materials. Full article

Wheat dwarf virus (WDV) is a major constraint to global wheat production, causing severe yield losses and economic disruption. Understanding the molecular basis of wheat–WDV interactions is essential for developing resistant cultivars. Non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are key regulators of gene expression and defence. This study identified ncRNAs involved in wheat responses to WDV, including host lncRNAs, miRNAs, and viral small interfering RNAs (siRNAs) targeting WDV genomic regions. High-throughput sequencing revealed extensive ncRNA reprogramming under WDV infection. A total of 437 differentially expressed lncRNAs (DElncRNAs) and 58 miRNAs (DEmiRNAs) were detected. Resistant genotypes displayed more DElncRNAs (204 in Svitava; 163 in Fengyou 3) than the susceptible Akteur (141). In Akteur, 66.7% of DElncRNAs were downregulated, whereas in Svitava, 56.9% were upregulated. Akteur also exhibited more DEmiRNAs (28) than resistant genotypes (15), with predominant downregulation. A co-expression network analysis revealed 391 significant DElncRNA–mRNA interactions mediated by 16 miRNAs. The lncRNA XLOC_058282 was linked to 298 transcripts in resistant genotypes, suggesting a central role in the host defence. Functional annotation showed enrichment in signalling, metabolic, and defence-related pathways. Small RNA profiling identified 1166 differentially expressed sRNAs targeting WDV, including conserved hotspots and 408 genotype-specific sites in Akteur versus Fengyou 3. Infected plants displayed longer sRNAs, a sense-strand bias, and a 5′ uridine preference, but lacked typical 21–24 nt phasing. These findings highlight the central roles of ncRNAs in orchestrating wheat antiviral defence and provide a molecular framework for breeding virus-resistant wheat. Full article

The tea plant (Camellia sinensis (L.) O. Kuntze) is a globally important crop, yet its cultivation is continually challenged by a range of viral pathogens that can compromise plant health and product quality. In this study, eighteen symptomatic leaves were collected from the Hubei Province Tea Germplasm Resources Nursery, China, representing multiple cultivars and diverse genetic backgrounds. The samples were pooled into three groups and subjected to ribodepleted transcriptome sequencing. Analyses revealed a complex virome, with Tea plant necrotic ring blotch virus (TPNRBV) dominating Pools A and B, whereas Badnavirus betacolocalasiae was the most prevalent in Pool C. Functional enrichment of viral genes indicated involvement in multiple biological processes, including replication, host interaction, and metabolism. Notably, two previously uncharacterized viruses were identified: Tea plant-associated ourmia-like virus 1 (TeaOLV1) and Tea plant-associated rhabdo-like virus 1 (TeaRLV1). Phylogenetic reconstruction positioned TeaOLV1 within the Penoulivirus genus, while TeaRLV1 formed a distinct clade among plant-associated rhabdoviruses. Conserved motif analysis revealed typical viral domains, accompanied by lineage-specific variations in tea plants. Collectively, these findings enhance our understanding of the viral diversity in tea plants, provide refined taxonomic placement for newly identified viruses, and offer molecular insights into their evolutionary relationships and potential functional roles. Full article

Oropouche virus (OROV), an emerging orthobunyavirus of increasing public health concern in the Americas, currently lacks approved antiviral therapies. In this study, we employed a structure-based in silico approach to identify natural antiviral scaffolds capable of targeting the Gc glycoprotein, a class II fusion protein essential for host membrane fusion and viral entry. A library of 537 plant-derived compounds was screened against the Gc head domain (PDB ID: 6H3X) through molecular docking and redocking, followed by 100-nanosecond molecular dynamics simulations, MM-PBSA free energy calculations, and ADMET profiling. Curcumin and Berberine emerged as standout candidates. Curcumin demonstrated a balanced profile, with stable binding (−38.14 kcal/mol), low backbone RMSD (1.82 Å), and consistent radius of gyration (Rg ~ 18.8 Å), suggesting strong conformational stability and compactness of the protein–ligand complex. Berberine exhibited the most favorable binding energy (−13.10 kcal/mol) and retained dynamic stability (RMSD 1.86 Å; Rg ~ 19.0 Å), though accompanied by predicted cytotoxicity that may require structural refinement. Both compounds induced reduced residue-level fluctuations (RMSF < 2.5 Å) in functionally critical regions of the Gc protein, consistent with a mechanism of action that involves stabilization of the prefusion conformation and interference with the structural transitions required for viral entry. These findings identify curcumin and berberine as promising scaffolds for anti-OROV drug development and offer a rational foundation for future experimental validation targeting viral fusion mechanisms. Full article

Chloroplasts, which are essential for plant defense and phytohormone signaling, contain ribosomal proteins that play key roles in viral infection processes. Plastid-specific ribosomal proteins (PSRPs), unique to chloroplasts, remain unexplored in their mechanistic roles during plant-virus interactions. In this study, we identified two PSRPs from non-heading Chinese cabbage (Brassica campestris ssp. chinensis) as interacting with turnip mosaic virus (TuMV, Potyvirus rapae). Subcellular localization revealed that BcPSRP2/4 is targeted to chloroplasts, while BiFC, Y2H, and LCAs confirmed their interaction with TuMV VPg (virus protein, genome-linked). Intriguingly, VPg altered the subcellular localization of BcPSRP2/4, suggesting an important role for BcPSRP2/4 in TuMV infection. Strikingly, overexpression of BcPSRP2/4 enhanced TuMV cell-to-cell movement, while psrp2 knockdown mutants in Arabidopsis exhibited a significant reduction in viral accumulation, highlighting their proviral roles. Furthermore, virus-induced gene silencing (VIGS)-mediated suppression of BcPSRP2/4 in non-heading Chinese cabbage resulted in milder symptoms upon TuMV infection without compromising plant growth: a distinct advantage over conventional resistance genes that incur fitness costs. These findings highlight PSRP2/4 as pivotal molecular hinges in chloroplast-virus interplay, offering novel targets for engineering sustainable antiviral strategies in cruciferous crops. Full article

Global climate change is the impact of combined abiotic and biotic stresses negatively affecting plant health and productivity. This study investigated the molecular and cellular responses of Nicotiana benthamiana L. plants to wild-type tomato bushy stunt virus (wtTBSV) infection under conditions of pre-existing heat stress. The experiments were conducted under controlled temperature regimes of 30 °C and 37 °C in combination with virus challenge. Morphological and biochemical analyses in plants under the influence of combined stress showed the alleviation of disease symptoms, reduction in virus content and reduced expression levels of viral proteins P19 and P33. Under conditions of combined stress, accumulation of hydrogen peroxide and malondialdehyde, as well as activation of the antioxidant enzyme catalase, especially in root tissues, were observed. Notably, at 37 °C, virus infection was suppressed despite high levels of oxidative stress, whereas at 30 °C, a marked decrease in the expression of host factors was observed. The results indicate that thermal stress modulates virus–host interactions and activates defense mechanisms, including antioxidant and RNA interference pathways. Therefore, temperature adaptation can be considered as a promising strategy for enhancing plant resistance to viral pathogens under climate changes. Full article