Search Results (2,763)

In this study, nine strains of plant growth-promoting rhizobacteria (PGPR) with multiple growth-promoting functions were isolated and screened from the rhizosphere of plants (Phragmites communis, Triglochin maritimum, and Alhagi maurorum) in the arid and barren regions of Western China. These strains belong to five genera: Klebsiella, Bacillus, Serratia, Pseudomonas, and Flavobacterium. The growth-promoting characteristics of these nine strains (PAP4, PA35, AC12, ACP1, AC25, TP7, TP8, TP12, and TP14) were analyzed. Furthermore, the growth-promoting potential of these PGPR strains was comprehensively evaluated through plate and pot experiments using Arabidopsis thaliana and alfalfa. The results indicate that most strains possess the ability to fix nitrogen and secrete zeatin and extracellular polysaccharides (EPS). Some strains exhibited significant traits such as phosphate solubilization, siderophore secretion, and the production of 1-aminocyclopropane-1-carboxylate (ACC) deaminase and indole-3-acetic acid (IAA). All strains showed high salt tolerance (0–8% NaCl) and were induced to secrete more EPS under salt stress. Plate experiments demonstrated that volatile organic compounds (VOCs) from the nine strains significantly promoted the root development of Arabidopsis thaliana and optimized its root architecture. Pot experiments revealed that inoculation with single strains influenced the growth of alfalfa to varying degrees; among them, strain TP14 showed the best performance, increasing plant height and shoot dry weight by 44.7% and 51.2%, respectively. Regarding microbial consortia, the combinations BD (PAP4 + TP14), ABC (PA35 + PAP4 + AC25), and ABCD (PA35 + PAP4 + AC25 + TP14) significantly improved the biomass, plant height, and stem diameter of alfalfa. The superior strains and their combinations identified in this study effectively promote plant growth. These high-performing PGPR strains provide valuable microbial resources for the development of bio-fertilizers tailored for saline–alkali and barren regions in Western China. Full article

Alternative splicing (AS) coupled with nonsense-mediated decay (NMD) is an important post-transcriptional mechanism that regulates the expression of many genes, including serine/arginine-rich (SR) proteins across eukaryotes. In plants, SR proteins participate in diverse developmental processes and stress responses, particularly in abscisic acid (ABA) signaling. However, the functional differences among individual splice isoforms of SR proteins remain poorly understood. Here, we investigated SCL30a, a plant-specific SR protein in Arabidopsis thaliana. By integrating third-generation long-read transcriptome sequencing, NMD stability assays, and subcellular localization analyses, we identified five alternatively spliced SCL30a transcripts. Among them, SCL30a.2 and SCL30a.3 contain premature termination codons (PTCs), display nucleocytoplasmic localization, and are rapidly degraded through the NMD pathway. In contrast, the other three isoforms, SCL30a.1, SCL30a.4, and SCL30a.5, retain an intact RS domain and localize exclusively to the nucleus. Functional analyses showed that SCL30a acts as a positive regulator of ABA signaling. Loss-of-function mutants of SCL30a displayed reduced ABA sensitivity in both root growth and seed germination assays, whereas complementation or overexpression of three stable isoforms of SCL30a (SCL30a.1, SCL30a.4, and SCL30a.5) enhanced ABA responsiveness. Transcriptome analysis further showed that the expression of a subset of ABA-related genes, particularly SnRK2.6, was significantly altered in ABA-treated scl30a mutants and SCL30a.1-OE lines compared with WT plants. In addition, genetic evidence showed that overexpression of SnRK2.6 rescued the ABA-insensitive phenotype of the scl30a mutant. Together, these findings suggest that SnRK2.6 may function as a candidate downstream component associated with SCL30a-mediated ABA responses. Full article

Systemic regulation of photosynthesis is crucial for plant survival in variable environments, yet the hormonal mechanisms coordinating photosynthetic responses to local stimuli are not fully elucidated. This study investigates the interplay between jasmonates (JAs) and abscisic acid (ABA) in systemic photosynthetic responses induced by local heat stress in Arabidopsis thaliana. Using phytohormone quantification, chlorophyll fluorescence and gas exchange measurements in wild-type and transgenic plants impaired in JA biosynthesis, this study showed that local heating-induced variation potential propagation triggers JA biosynthesis in systemic unstimulated leaves, followed by changes in ABA content, stomatal conductance and photosynthetic activity. Rapid systemic increases in jasmonoyl-L-isoleucine (JA-Ile) levels are essential for the systemic decreases in stomatal conductance and the consequent reduction in carbon assimilation. Systemic increases in JA-Ile levels also contribute to systemic accumulation of ABA, likely to maintain reduced stomatal conductance. Thus, the data support a model in which JA-Ile acts as a mediator of early stages of the systemic photosynthetic response, whereas ABA likely contributes to late stages of this response. These results highlight the complex integration of hormonal signals in the regulation of photosynthesis under stress conditions. Full article

Water availability and light conditions are among the most important environmental factors affecting tree growth and development. The FAR1/FHY3 (FRS) gene family consists of transposase-derived transcription factors that are widely involved in light signaling and responses to environmental stresses. Although FRS genes have been characterized in several plant species, a comprehensive analysis in P. bournei is still lacking. In this study, we performed the first comprehensive genome-wide analysis of the FRS gene family in P. bournei, including physicochemical characterization, chromosomal localization, phylogenetic analysis, gene structure and conserved motif analysis, protein structure prediction, promoter cis-element analysis, organ/tissue expression profiling, and RT-qPCR analysis under PEG-induced osmotic stress, full-light, and shade treatments. A total of 21 PbFRS genes were identified and found to be unevenly distributed across 11 chromosomes. Phylogenetic analysis, together with Arabidopsis thaliana and Zea mays FRS proteins, clustered the family members into five clades, including one P. bournei-specific clade, suggesting lineage-specific expansion and possible functional diversification. Structural analyses revealed both conserved and divergent features among PbFRS members. Promoter analysis identified diverse cis-acting elements related to light, temperature, hormones, and stress responses, suggesting that PbFRS genes may have diverse regulatory potentials in response to environmental signals. Organ/tissue expression profiling further revealed clear differences in expression patterns among family members. In addition, RT-qPCR analysis showed that several genes, including PbFRS9, PbFRS10, PbFRS12, PbFRS13, PbFRS16, and PbFRS18, exhibited transcriptional responses to PEG-induced osmotic stress, full-light, and shade treatments. These results indicate that these genes may serve as candidates for future functional studies, although their direct roles in stress tolerance require further validation. Overall, these results provide the first systematic overview of the PbFRS gene family and identify transcriptionally responsive candidate genes for future functional studies in P. bournei. Full article

Peanut (Arachis hypogaea L.) is a globally vital oilseed and cash crop. The LONELY GUY (LOG) gene family acts as a core regulator of cytokinin activation, governing plant meristem maintenance, growth, development, and stress responses. However, the genome-wide characteristics, evolutionary dynamics, and biological functions remain largely uncharacterized in peanut. In this study, 24 AhLOG genes were identified from the cultivated peanut Tifrunner. Phylogenetic analysis, gene structure characterization, and conserved motifs validated the high evolutionary conservation of the AhLOG gene family, and subcellular localization prediction indicated most AhLOG proteins were distributed in the cytoplasm. Promoter cis-element analysis revealed abundant hormone-responsive and stress-responsive cis-elements in the promoter regions of the AhLOG genes. Synteny analysis uncovered highly conserved collinear relationships between cultivated peanut and its diploid progenitors (A. duranensis, A. ipaensis) as well as the wild tetraploid relative (A. monticola), while numerous conserved orthologous syntenic pairs were detected between peanut and the model plant Arabidopsis thaliana. Tissue expression profiles revealed remarkable functional divergence among members: AhLOG3 and AhLOG16 were widely involved in both vegetative and reproductive development, while several other AhLOG genes exhibited strict tissue-specific expression. Furthermore, qRT-PCR analysis demonstrated that AhLOG genes were significantly induced by abscisic acid (ABA), gibberellin (GA), indole-3-acetic acid (IAA), methyl jasmonate (MeJA), drought and salt treatments, with distinct expression patterns under these abiotic stress conditions. Collectively, this work provides a systematic understanding of the AhLOG gene family and offers key candidate genes along with theoretical support for further functional investigation and molecular breeding of stress-resistant peanut. Full article

Plants perceive light signals through photoreceptors such as CRY1 to regulate growth and development. It is well-known that Arabidopsis CRY1 is a nucleocytoplasmic protein that mediates light inhibition of hypocotyl elongation in the nucleus, but the mechanisms by which CRY1 regulates root growth and functions in the cytoplasm remain poorly understood. Here, we identified eIF3G1, a subunit of the eukaryotic translation initiation factor 3 (eIF3) complex, as a CRY1-interacting protein associated with light-regulated root development. Under blue light, eif3g1 mutants showed longer primary roots, whereas eIF3G1 overexpression reduced root elongation, accompanied by corresponding changes in root apical meristem size. Differential irradiation experiments indicated that shoot illumination is required for eIF3G1-dependent root phenotypes. Transcriptome analysis revealed changes in translation-related and light-responsive genes in response to eIF3G1 perturbation. Comparison with the cry1 transcriptome revealed overlapping differentially expressed genes, including BIC1 and BIC2, and the bic1 bic2 double mutant showed reduced root elongation. Together, these findings identify eIF3G1 as a CRY1-interacting factor that contributes to the shoot-dependent regulation of root growth under blue light, suggesting that eIF3G1 may be associated with the CRY1-dependent shoot-to-root regulation of root growth. Full article

PP2C (protein phosphatases 2C) are key regulators of abscisic acid (ABA) signaling that play a crucial role in plant stress responses. Our analysis identified 71 DlPP2C genes in Dimocarpus longan, which were classified into distinct subgroups based on phylogenetic relationships with Arabidopsis thaliana and Oryza sativa. Structural analysis demonstrated conserved motif composition and gene organization within subgroups, while chromosomal distribution and synteny analysis revealed that segmental duplication events contributed to the expansion of this gene family. Promoter analysis uncovered several cis-acting elements related to hormone and stress responsiveness, especially abscisic acid-responsive elements (ABREs), suggesting that DlPP2C genes may play a role in ABA signaling pathways. Furthermore, we examined the ABA-responsive expression profiles of DlPP2C genes under exogenous ABA treatments. The expression patterns were dynamic and dose- and time-dependent, with several genes showing peak expression at 10 μM ABA after 16 h. The DlPP2C1 in particular displayed a strong transcriptional response, indicating its potential role in ABA regulation. While overexpression and GUS staining assays revealed enhanced activity under ABA treatment, further supporting the involvement of PP2C in ABA-responsive regulation, further mechanistic studies are needed for a full characterization. Finally, RNA sequencing analysis revealed a total of 1799 differentially expressed genes in response to ABA, with a prevalence of downregulated genes, showing extensive transcriptional reprogramming. Functional enrichment analysis demonstrated that these genes were largely associated with plant hormone signaling, stress response, and metabolic pathways. Weighted gene co-expression network analysis revealed a total of 32 key gene modules associated with ABA signaling. Collectively, our findings propose that DlPP2C genes, especially DlPP2C1, play a key role in ABA-mediated regulatory networks and provide valuable insights into stress adaptation mechanisms, especially during early somatic embryogenesis in longan. Full article

M. micrantha is a highly destructive invasive weed causing severe ecological and economic damage in invaded regions. Conventional control methods remain insufficient, highlighting the need for targeted management strategies. NAC transcription factors, a plant-specific family, play key regulatory roles in growth, secondary metabolism, and stress responses. Here, we performed a genome-wide identification and characterization of the NAC gene family in M. micrantha using bioinformatic approaches based on Arabidopsis thaliana NAC sequences and the M. micrantha whole-genome assembly. A total of 76 MmNAC genes were identified from M. micrantha, and these members were classified into 13 subfamilies and one unclassified clade, with subdomains C and D being the most conserved. Five conserved motifs were identified; motifs 1 and 2 were present in over 94% of members. Chromosomal mapping showed 68 genes distributed unevenly across 18 of 19 chromosomes. Tissue expression analysis revealed that NAP and AtNAC3 subfamilies are highly expressed in seeds, while NAM and NAC2 subfamilies predominate in floral tissues, suggesting potential subfamily–tissue expression patterns. These findings provide a basis for understanding NAC functions in M. micrantha and identifying targets for its control. Full article

Tea plants (Camellia sinensis) suffer growth limitations under cold stress. Jasmonic acid (JA) and long non-coding RNAs (lncRNAs) are involved in stress responses, yet how lncRNAs regulate JA-mediated cold tolerance remains unclear. Here, we identified an lncRNA, lnc015013, whose silencing compromised cold tolerance in tea plants, a phenotype rescued by exogenous methyl jasmonate (MeJA). Silencing lnc015013 down-regulated CsMYB30 and CsJAZ4/6, while its overexpression had opposite effects. Heterologous expression in Arabidopsis thaliana showed that CsMYB30 enhanced cold resistance, whereas CsJAZ4/6 suppressed it. Mechanistically, CsMYB30 repressed CsJAZ4/6 promoter activity and physically interacted with CsJAZ4/6, with MeJA attenuating this interaction. These findings reveal that the lnc015013-CsMYB30-CsJAZ4/6 module regulates JA biosynthesis within the JA signaling pathway, providing a novel mechanism for cold adaptation in tea plants and a theoretical basis for molecular breeding. Full article

Verticillium wilt (VW), caused by the soil-borne fungus Verticillium dahliae, is a major disease that markedly compromises both the yield and fiber quality of cotton. In this study, we explored the function and underlying mechanism of the cotton expansin gene GhEXLB2 in response to VW infection. Expression profiling revealed that members of the GhEXL family exhibit distinct patterns across tissues and under various biotic and abiotic stresses. Notably, GhEXLB2, which encodes an extracellular protein, showed the strongest induction following V. dahliae challenge. Ectopic expression of GhEXLB2 in Arabidopsis thaliana promoted root elongation and root hair formation, and was associated with improved resistance to the pathogen. In contrast, silencing GhEXLB2 in cotton via virus-induced gene silencing (VIGS) led to pronounced vascular browning, increased pathogen recovery, and a lower level of disease resistance. In addition, RNA-seq profiling of GhEXLB2-silenced (VIGS) cotton plants revealed that most differentially expressed genes were enriched in pathways related to phytohormone signaling and plant–pathogen interactions, with salicylic acid (SA) signaling and WRKY transcription factors emerging as central regulatory components. Analysis of the GhEXLB2 promoter further identified multiple cis-acting elements associated with stress and hormone responsiveness. When integrated with protein–protein interaction (PPI) prediction data, these results suggest that GhEXLB2 may be modulated by a network of transcription factors and signaling pathways. Collectively, the evidence supports a positive association between GhEXLB2 and VW resistance. This study provides a framework for understanding expansin functions in cotton defense against VW. Full article

The GRAS transcription factor family plays a pivotal role in plant stress adaptation, yet its systematic characterization and the underlying drought-responsive mechanisms remain poorly elucidated in Populus deltoides. Here, a genome-wide identification and analysis of GRAS genes in P. deltoides was performed, and a total of 92 family members were identified and classified into 12 distinct subfamilies through phylogenetic analysis. Evolutionary analysis revealed a high degree of conservation between the GRAS proteins of P. deltoides and those of Arabidopsis thaliana, Oryza sativa, and Solanum lycopersicum. Genomic duplication events, including 90 segmental and 11 tandem duplications, were identified as the primary drivers of GRAS family expansion. Promoter cis-element analysis uncovered an enrichment of stress-responsive elements (MBS, ABRE) and phytohormone-related motifs (e.g., TATC-box). Transcriptomic profiling further revealed distinct drought-inducible expression patterns of GRAS genes: PdeGRAS49 exhibited rapid upregulation at the early stage of drought exposure (1–3 h), whereas DELLA subfamily members PdeGRAS51 and PdeGRAS59 reached their expression peaks at 6–9 h, and PdeGRAS34 and PdeGRAS77 maintained sustained activation throughout 12–24 h. Moreover, the drought-inducible expression patterns of five DELLA genes were confirmed by qRT-PCR validation. Collectively, this study provides crucial genomic insights into the GRAS family and valuable candidate gene resources, which lay a foundation for molecular breeding of drought-tolerant P. deltoides cultivars via manipulating GRAS-mediated regulatory mechanisms. Full article

Peanut (Arachis hypogaea L.) production faces persistent threats from various infectious diseases. Planting healthy varieties with robust botanical defense networks is critical for minimizing future costs. Non-expressor of pathogenesis-related (NPR) regulators are involved in immune activation and act as key targets for deeper stress adaptation, and are thus promising targets for genetic enhancement. In this study, we characterized the peanut NPR4B protein and demonstrated its local subcellular binding to the nucleus. Ectopic overexpression of AhNPR4B in Arabidopsis thaliana significantly enhanced resistance to the necrotrophic pathogen Botrytis cinerea and enhanced cold tolerance, as supported by quantitative and statistical analyses (p < 0.05). As regards underlying molecular events, Y2H (Yeast 2-Hybrid) analysis revealed a binding in vitro physical relation of AhPR2-like to AhNPR4B. This binding was demonstrated in vivo through BiFC (Bimolecular Fluorescence Complementation). These results suggest that the AhNPR4B-AhPR2-like complex may act as a key regulatory module associated with biotic and abiotic stress signaling, potentially contributing to broad-spectrum stress resistance. These findings provide foundational insights into the functional roles of AhNPR4B and its interaction with AhPR2-like in regulating stress resistance and support its potential as a candidate target for future genetic improvements to enhance stress resilience in peanuts. Full article

Iris sanguinea features upright, stiff leaves, making it an excellent cut-foliage material, with its tall leaf architecture greatly enhancing ornamental value in landscaping. However, during the leaf expansion phase, plants frequently exhibit loose foliage arrangement, excessive spreading, and compromised mechanical strength, culminating in lodging and a concomitant decline in ornamental quality. Plant height in I. sanguinea is strongly regulated by phytohormones. This study showed that exogenous GA at concentrations of 50 mg·L⁻¹, 100 mg·L⁻¹, and 200 mg·L⁻¹ increased seedling height by 5.7%, 8.8%, and 12.7%, respectively, through foliar spraying on I. sanguinea seedlings grown ex vitro in a greenhouse; conversely, PAC treatment at equivalent concentrations suppressed growth by 19.3%, 21.0%, and 22.2%, respectively. Two pivotal GA signaling components, GAI and GID1a, were isolated from I. sanguinea. Subcellular localization confirmed that both IsGAI and IsGID1a proteins localize to the nucleus. Overexpression vectors pCAMBIA1300-IsGAI-GFP and pCAMBIA1300-IsGID1a-GFP were constructed and expressed in Arabidopsis thaliana. Transgenic lines overexpressing IsGAI showed significantly reduced plant height, hypocotyl elongation, and bolting, whereas IsGID1a overexpression promoted these traits. Exogenous GA application partially reversed the dwarf phenotype induced by IsGAI overexpression and further potentiated the height enhancement observed in IsGID1a-overexpressing lines. This study identifies two key genes controlling plant height and provides a theoretical basis and genetic resources for precisely engineering plant architecture in I. sanguinea. This is especially important for developing dwarf varieties with enhanced ornamental and agronomic traits, offering significant potential in the landscaping and cut flower industries. Full article

Verticillium wilt, caused by Verticillium dahliae, is a devastating disease that severely threatens cotton production worldwide. The long-term survival of the pathogen in soil and the limited availability of resistant cultivars make effective control strategies challenging. Although the fungal cross-kingdom RNA VdsR-1 has been reported to delay floral transition and prolong vegetative growth, the underlying plant regulatory mechanisms remain largely unclear. Here, we show that the transcription factor AtTOE1, a target of ath-miR172b-3p, displays altered expression in response to changes in ath-miR172b-3p levels during V. dahliae inoculation, coinciding with coordinated changes in plant immune-related and developmental responses. Increased AtTOE1 expression is correlated with enhanced disease resistance, reduced pathogen colonization, and delayed floral transition. Furthermore, our results indicate that the VdsR-1/AtSPL13A module is associated with modulation of AtTOE1 expression via ath-miR172b-3p, suggesting the involvement of a cross-kingdom RNA-related regulatory framework linking plant immunity and development. Notably, this regulatory relationship is also observed in cotton, indicating evolutionary conservation across plant species. Together, our findings highlight TOE1 as a potential integrator of defense and growth-related processes during pathogen challenge and provide insights that may inform strategies to improve resistance to V. dahliae in cotton and other crops. Full article

Background: As a transcription factor superfamily unique to plants, WRKY plays broad roles in both secondary development and secondary metabolic processes. Robinia pseudoacacia is renowned for its durable and naturally durable heartwood, which holds significant commercial value. However, their potential association with heartwood formation remains largely unexplored. Results: Leveraging published genomic data from Robinia pseudoacacia, we conducted a comprehensive bioinformatics analysis that identified 85 WRKY transcription factors. An uneven distribution across 11 chromosomes was observed for the RpWRKY genes, which were systematically named RpWRKY1 to RpWRKY85 according to their genomic locations, as determined by chromosomal localization. By conducting a phylogenetic comparison between RpWRKY and AtWRKY (from Arabidopsis thaliana), the RpWRKY family was categorized into three primary clades (I, II, and III), wherein group II was additionally partitioned into subgroups designated IIa through IIe. Conserved structural features and motif patterns were observed among members of each subgroup. Purifying selection was suggested by collinearity analysis as the primary evolutionary driver of RpWRKY, leading to structural and functional diversification. Finally, four candidate genes (RpWRKY78, RpWRKY45, RpWRKY50, RpWRKY80) potentially involved in heartwood formation regulation were identified through analysis of xylem tissue-specific expression patterns. Conclusions: For this economically important tree species, the present study not only provides the first systematic characterization of RpWRKY but also identifies potential regulators of heartwood development. Thus, the present study lays the groundwork for subsequent research aimed at uncovering the molecular processes that regulate heartwood development. Full article