Search Results (813)

Polyvinyl chloride (PVC) is commonly employed as mulch in agriculture to boost crop yields. However, its toxicity is often overlooked. Due to its chemical stability, resistance to degradation, and the inadequacy of the recycling system, PVC tends to persist in farm environments, where it can decompose into microplastics (MPs) or nanoplastics (NPs). The radish (Raphanus sativus L.) was chosen as the model plant for this study to evaluate the underlying toxic mechanisms of PVC NPs on seedling growth through the integration of multi-omics approaches with oxidative stress evaluations. The results indicated that, compared with the control group, the shoot lengths in the 5 mg/L and 150 mg/L treatment groups decreased by 33.7% and 18.0%, respectively, and the root lengths decreased by 28.3% and 11.3%, respectively. However, there was no observable effect on seed germination rates. Except for the peroxidase (POD) activity in the 150 mg/L group, all antioxidant enzyme activities and malondialdehyde (MDA) levels were higher in the treated root tips than in the control group. Both transcriptome and metabolomic analysis profiles showed 2075 and 4635 differentially expressed genes (DEGs) in the high- and low-concentration groups, respectively, and 1961 metabolites under each treatment. PVC NPs predominantly influenced seedling growth by interfering with plant hormone signaling pathways and phenylpropanoid production. Notably, the reported toxicity was more evident at lower concentrations. This can be accounted for by the plant’s “growth-defense trade-off” strategy and the manner in which nanoparticles aggregate. By clarifying how PVC NPs coordinately regulate plant stress responses via hormone signaling and phenylpropanoid biosynthesis pathways, this research offers a scientific basis for assessing environmental concerns related to nanoplastics in agricultural systems. Full article

Zinc (Zn) deficiency poses a major global health challenge, and wheat grains generally contain low Zn concentrations. In this study, the wheat cultivar ‘Zhongmai 175’ was identified as zinc-efficient. Hydroponic experiments demonstrated that Zn deficiency induced the secretion of oxalic acid and malic acid in root exudates and significantly increased total root length in ‘Zhongmai 175’. To elucidate the underlying regulatory mechanisms, transcriptome profiling via RNA sequencing was conducted under Zn-deficient conditions. A total of 2287 and 1935 differentially expressed genes (DEGs) were identified in roots and shoots, respectively. Gene Ontology enrichment analysis revealed that these DEGs were primarily associated with Zn ion transport, homeostasis, transmembrane transport, and hormone signaling. Key DEGs belonged to gene families including VIT, NAS, DMAS, ZIP, tDT, HMA, and NAAT. KEGG pathway analysis indicated that phenylpropanoid biosynthesis, particularly lignin synthesis genes, was significantly downregulated in Zn-deficient roots. In shoots, cysteine and methionine metabolism, along with plant hormone signal transduction, were the most enriched pathways. Notably, most DEGs in shoots were associated with the biosynthesis of phytosiderophores (MAs, NA) and ethylene. Overall, genes involved in Zn ion transport, phytosiderophore biosynthesis, dicarboxylate transport, and ethylene biosynthesis appear to play central roles in wheat’s adaptive response to Zn deficiency. These findings provide a valuable foundation for understanding the molecular basis of Zn efficiency in wheat and for breeding Zn-enriched varieties. Full article

Global warming has resulted in an increase in the frequency of extreme high-temperature events. High temperatures can increase cell membrane permeability, elevate levels of osmotic adjustment substances, reduce photosynthetic capacity, impair plant growth and development, and even result in plant death. Under high-temperature stress, plants mitigate damage through physiological and biochemical adjustments, heat signal transduction, the regulation of transcription factors, and the synthesis of heat shock proteins. However, different plants exhibit varying regulatory abilities and temperature tolerances. Investigating the heat-resistance and regulatory mechanisms of plants can facilitate the development of heat-resistant varieties for plant genetic breeding and landscaping applications. This paper presents a systematic review of plant physiological and biochemical responses, regulatory substances, signal transduction pathways, molecular mechanisms—including the regulation of heat shock transcription factors and heat shock proteins—and the role of plant hormones under high-temperature stress. The study constructed a molecular regulatory network encompassing Ca²⁺ signaling, plant hormone pathways, and heat shock transcription factors, and it systematically elucidated the mechanisms underlying the enhancement of plant thermotolerance, thereby providing a scientific foundation for the development of heat-resistant plant varieties. 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

Gibberellins (GAs) are essential phytohormones that regulate seed dormancy release and germination. Lomatogonium rotatum (L.) Fries ex Nym is a traditional medicinal plant whose seed germination is often hindered by physiological dormancy. In this study, we systematically investigated the effects of exogenous GA₃ on the seed germination of L. rotatum and elucidated the underlying molecular regulatory mechanisms via transcriptomic analysis. GA₃ treatment (500 mg/L for 24 h) significantly improved the germination rate, vigor index, and other germination traits. RNA-seq analysis identified time-dependent transcriptional changes in GA₃-treated seeds across three developmental stages (24 h, 72 h, and 96 h). KEGG enrichment and K-means clustering revealed dynamic actiSvation of hormonal signaling, secondary metabolism, and DNA replication pathways. WGCNA uncovered two hormone-responsive co-expression modules (Red and Lightcyan) corresponding to early and late stages of germination, respectively. Key genes related to ABA and GA biosynthesis and signal transduction showed phase-specific expression, highlighting the coordinated hormonal regulation during seed germination. Our findings provide new insights into the molecular basis of GA₃-regulated seed germination and offer theoretical support for the cultivation and utilization of L. rotatum. Full article

Camellia azalea is an endemic species within the genus Camellia that exhibits the trait of summer flowering, which is of significant ornamental and research value. Nevertheless, research on the regulatory mechanisms of flower formation in C. azalea is still limited, so in this study, transcriptome sequencing and analysis of endogenous hormone contents were conducted at three distinct growth stages: floral induction, floral organ maturation, and anthesis. Illumina sequencing yielded a total of 20,643 high-quality unigenes. Comparative analyses of representative samples from the three growth stages identified 6681, 1925, and 8400 differentially expressed genes (DEGs), respectively. These DEGs were further analyzed for functional enrichment using the GO and KEGG databases. Additionally, core genes from each flowering pathway underwent expression pattern analysis and network diagram construction. This revealed that the flower development process in C. azalea is linked to the specific expression of the genes involved in the photoperiod, temperature, and autonomous pathways and is subject to comprehensive regulation by multiple pathways. Further analysis of the dynamic trends of five endogenous hormone contents and plant hormone signal transduction genes revealed significant differences in the requirements of endogenous hormones, such as gibberellins and indoleacetic acid, by C. azalea at distinct growth stages. Additionally, the majority of genes on the phytohormone signal transduction pathway demonstrated a high correlation with the changes in the contents of each hormone. The present study integrates physiological and molecular approaches to identify key genes and metabolic pathways that regulate the summer flowering of C. azalea, thereby laying a theoretical foundation for further investigations into its flowering mechanism and related functional genes. 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

Auxin (IAA), a key natural signaling molecule, plays a pivotal role in regulating plant growth, development, and stress responses. Understanding its signal transduction mechanisms is crucial for improving crop yields. In this study, we conducted a comparative transcriptome analysis of wheat leaf and root tissues treated with different concentrations of IAA (0, 1, and 50 μM). Functional enrichment analysis revealed that differentially expressed genes (DEGs) exhibited tissue-specific regulatory patterns in response to auxin. Weighted Gene Co-expression Network Analysis (WGCNA) identified receptor-like kinase genes within the MEgreen module as highly correlated with auxin response, suggesting their involvement in both root and leaf regulation. Among them, TaPBL7-2B, a receptor-like kinase gene significantly upregulated under 50 μM IAA treatment, was selected for functional validation. Ectopic overexpression of TaPBL7-2B in Arabidopsis thaliana (Col-0) enhanced auxin sensitivity and inhibited plant growth by suppressing root development and leaf expansion. In contrast, knockout of the Arabidopsis homolog AtPBL7 reduced auxin sensitivity and promoted both root and leaf growth. Transcriptome analysis of Col-0, the TaPBL7-2B overexpression line, and the pbl7 mutant indicated that TaPBL7-2B primarily functions through the MAPK signaling pathway and plant hormone signal transduction pathway. Furthermore, qRT-PCR analysis of wheat varieties with differing auxin sensitivities confirmed a positive correlation between TaPBL7-2B expression and auxin response. In conclusion, TaPBL7-2B acts as a negative regulator of plant growth, affecting root development and leaf expansion in both Arabidopsis and wheat. These findings enhance our understanding of auxin signaling and provide new insights for optimizing crop architecture and productivity. Full article

Background/Objectives: Moso bamboo (Phyllostachys edulis), the most widely distributed bamboo species in China, is valued for both its shoots and timber. This species often faces challenges from high-temperature stress. To cope with this stress, Moso bamboo has evolved various adaptive mechanisms at the physiological and molecular levels. Although numerous studies have revealed that a large number of transcription factors (TFs) and genes play important roles in the regulatory network of plant heat stress responses, the regulatory network involved in heat responses remains incompletely understood. Methods: In this study, Moso bamboo was placed in a high-temperature environment of 42 °C for 1 h and 24 h, and transcriptome sequencing was carried out to accurately identify key molecules affected by high temperature and their related biological pathways. Results: Through a differential expression analysis, we successfully identified a series of key candidate genes and transcription factors involved in heat stress responses, including members of the ethylene response factor, HSF, WRKY, MYB, and bHLH families. Notably, in addition to traditional heat shock proteins/factors, multiple genes related to lipid metabolism, antioxidant enzymes, dehydration responses, and hormone signal transduction were found to play significant roles in heat stress responses. To further verify the changes in the expression of these genes, we used qRT-PCR technology for detection, and the results strongly supported their key roles in cellular physiological processes and heat stress responses. Conclusions: This study not only deepens our understanding of plant strategies for coping with and defending against extreme abiotic stresses but also provides valuable insights for future research on heat tolerance in Moso bamboo and other plants. Full article

As a globally significant economic crop, pepper (Capsicum annuum L.) plants display excessive plant height (etiolation) in greenhouse production under an undesirable environment, leading to lodging-prone plants with reduced stress resistance. In the present study, we provided supplementary ultraviolet-B (UV-B, 280–315 nm) light to pepper plants grown in a greenhouse to assess the influences of UV-B on pepper growth, with an emphasis on the molecular mechanisms mediated through the gibberellin (GA) signaling pathway. The results indicated that UV-B significantly decreased the plant height and the fresh weight of pepper plants. However, no significant differences were observed in the chlorophyll content of pepper plants grown under natural light and supplementary UV-B radiation. The results of the transcriptomic and metabolomic analyses indicated that differentially expressed genes (DEGs) were significantly enriched in plant hormone signal transduction and that UV radiation altered the gibberellin synthesis pathway of pepper plants. Specifically, the GA3 content of the pepper plants grown with UV-B radiation decreased by 39.1% compared with those grown without supplementary UV-B radiation; however, the opposite trend was observed in GA34, GA7, and GA51 contents. In conclusion, UV-B exposure significantly reduced plant height, a phenotypic response mechanistically linked to an alteration in GA homeostasis, which may be caused by a decrease in GA3 content. Our study elucidated the interplay between UV-B and gibberellin biosynthesis in pepper morphogenesis, offering a theoretical rationale for developing UV-B photoregulation technologies as alternatives to chemical growth inhibitors. Full article

Plant growth-promoting rhizobacteria (PGPR) are beneficial rhizosphere microorganisms for plants. They can promote plant absorption of nutrients, inhibit pathogenic microorganisms, enhance plant tolerance to abiotic and biotic stresses, and improve plant growth. Isolating new beneficial microbes and elucidating their promoting mechanisms can facilitate the development of microbial fertilizers. This study combined transcriptome sequencing and related experiments to analyze the mechanism by which the endophytic fungus ‘BF-F’ promotes the growth of Sesuvium portulacastrum. We inoculated the ‘BF-F’ fungus beside S. portulacastrum seedlings as the experimental group. Meanwhile, S. portulacastrum seedlings not inoculated with ‘BF-F’ were set as the control group. After inoculation for 0 d, 7 d, 14 d, 21 d, and 28 d, the plant height and the number of roots were measured. Furthermore, transcriptome sequencing on the roots and leaves of the S. portulacastrum was conducted. Differentially expressed genes were screened, and KEGG enrichment analysis was performed. Nitrogen metabolism-related genes were selected, and qRT-PCR was conducted on these genes. Furthermore, we analyzed the metabolomics of ‘BF-F’ and its hormone products. The results showed that inoculation of ‘BF-F’ significantly promoted the growth of S. portulacastrum. After ‘BF-F’ inoculation, a large number of genes in S. portulacastrum were differentially expressed. The KEGG pathway enrichment results indicated that the ‘BF-F’ treatment affected multiple metabolic pathways in S. portulacastrum, including hormone signal transduction and nitrogen metabolism. The auxin signaling pathway was enhanced because of a decrease in AUX expression and an increase in ARF expression. Contrary to the auxin signal transduction pathway, the zeatin (ZT) signaling pathway was suppressed after the ‘BF-F’ treatment. ‘BF-F’ increased the expression of genes related to nitrogen metabolism (NRT, AMT, NR, and GAGOT), thereby promoting the nitrogen content in S. portulacastrum. The metabolites of ‘BF-F’ were analyzed, and we found that ‘BF-F’ can synthesize IAA and ZT, which are important for plant growth. Overall, ‘BF-F’ can produce IAA and enhance the nitrogen use efficiency of plants, which could have the potential to be used for developing a microbial fertilizer. Full article

This research centers on the sand-fixing plant known as Stipagrostis pennata, from which the β-glucosidase gene SpBGLU25 was successfully cloned using the molecular cloning method. SpBGLU25 encodes a hydrophilic and stable protein made up of 193 amino acids, located in the cell membrane. qRT-PCR analysis indicated that the expression of the SpBGLU25 is closely linked to the drought stress tolerance of S. pennata. Following this, functional validation was performed using an Arabidopsis overexpression system. The overexpression of transgenic Arabidopsis lines showed significantly improved drought tolerance under PEG and mannitol treatments. Assessments of germination, root length, and physiological indicators such as proline, malondialdehyde content, soluble sugars, and relative leaf water content (RLWC) further confirmed the enhanced performance of the overexpressing plants. Additionally, the comparative transcriptomic analysis of SpBGLU25-OE Arabidopsis compared to the wild-type (WT) showed that differentially upregulated genes were primarily enriched in categories of “cellular process,” “cell,” and “catalytic activity.” KEGG pathway enrichment analysis indicated that the genes were mainly concentrated in the pathways of phenylpropanoid biosynthesis and plant hormone signal transduction. These findings provide a crucial foundation for further investigation into the function of the SpBGLU25 and its role in regulating plant tissue development and adaptation to stress. This research is anticipated to offer new theoretical insights and genetic resources for enhancing plant stress tolerance through genetic engineering. Full article

The ratooning capacity of sugarcane cultivars represents a crucial agronomic trait that significantly influences the sustainability of crop yields. This study elucidates the physiological and molecular mechanisms underlying the sugarcane ratooning ability observed in ratoon-competent GuiTang 29 (GT29) and ratoon-deficient Badila cultivars following stem excision. Through integrated hormonal profiling and transcriptome analysis, we identified significant differences in hormone levels and gene expression patterns. The quantification of 15 endogenous hormones via HPLC revealed marked reductions in zeatin (ZA) and zeatin riboside (ZR) in both cultivars. Additionally, GT29 exhibited notable reductions in gibberellins (GA3 and GA5) and strigolactone (5-DS) post-stem-excision, while Badila displayed stable or distinct hormonal changes. Additionally, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that hormone signal transduction, MAPK signaling pathways, phenylpropanoid biosynthesis, flavonoid biosynthesis, and other metabolic pathways were significantly enriched in both GT29 and Badila, with a particularly higher enrichment of plant hormone signal transduction in GT29. Furthermore, several differentially expressed genes (DEGs) had different expression patterns between GT29 and Badila, including the cytokinin receptor B-ARR and transcription factor A-ARR, gibberellin pathway components GID1 and DELLA, and AUX/IAA and SAUR in the auxin pathway. The real-time quantitative PCR (qRT-PCR) validation of 12 DEGs corroborated the RNA-seq data, further supporting the reliability of the transcriptomic analysis. This study delineates a clear molecular framework distinguishing ratoon competence, offers novel insights into the molecular basis of perennial regeneration and provides reliable candidate genes for functional marker development in sugarcane breeding. Full article

The tea tree root system is an important tissue for nutrient uptake, accumulation, and transport, and pH is an important environmental factor regulating the growth of tea tree (Camellia sinensis). However, the physiological and molecular mechanisms of how the tea tree root system responds to pH are unclear. In this study, Tieguanyin tea tree was used as the research object, and treated with different pH values to determine the morphological indexes of the tea plant root system and systematically study the physiological and molecular mechanisms of the effect of pH on the growth of the tea plant root system using transcriptomics in combination with metabolomics. The results showed that total root length, root surface area, root volume, total root tips, root fork number, and root crossing number of root crosses of the tea plant root system increased significantly (p < 0.05) with increasing pH. Transcriptome analysis showed that a total of 2654 characteristic genes were obtained in response to pH regulation in the root system of the tea plant, which were mainly enriched in six metabolic pathways. Metabolomics analysis showed that the metabolites with the highest contribution in differentiating tea plant responses to different pH regulations were mainly heterocyclic compounds, amino acids and derivatives, alkaloids, and flavonoids. Interaction network analysis showed that pH positively regulated the metabolic intensity of the MAPK signaling pathway (plant, plant hormone signal transduction, and RNA degradation pathway), positively regulated the content of the heterocyclic compound, amino acids and derivatives, and alkaloids, and positively regulated tea plant root growth. However, it negatively regulated ribosome, protein processing in the endoplasmic reticulum, and phenylpropanoid biosynthesis pathway intensity, and negatively regulated the flavonoid content. This study reveals the physiological and molecular mechanisms of the tea plant root system in response to pH changes and provides an important theoretical basis for the cultivation and management of tea plants in acidified tea plantations. Full article

The global expansion of soil salinization has intensified the need to understand plants’ salt tolerance mechanisms. This study investigates the molecular basis of salt stress responses in Melia azedarach L. and the modulating role of 24-epibrassinolide (EBR) through transcriptomic analysis. While salt stress significantly inhibited seedling growth, EBR application substantially mitigated these effects. Transcriptomic analysis identified 11,747 differentially expressed genes (DEGs) in the salt-treated versus control seedlings (SA vs. CK) comparison, 3786 DEGs in the Salt + EBR-treated versus control seedlings (E1 vs. CK) comparison, and 8019 DEGs in the Salt + EBR-treated versus salt-treated seedlings (E1 vs. SA) comparison. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis identified the pivotal pathways in salt stress adaptation, such as plant hormone signal transduction, phenylpropanoid biosynthesis, and ribosome pathways. Notably, key regulators such as AUX1, TIR1, IAA, SAUR, PYL, and ABF showed dynamic expression patterns under salt stress and EBR treatment, revealing their critical roles in stress mitigation. Our findings provide novel insights into EBR-mediated salt tolerance, highlighting its potential to modulate phytohormone signaling networks. This study advances both the fundamental knowledge of salt stress adaptation and practical strategies for enhancing plant resilience in saline environments. Full article