Search Results (155)

The miRNA172–APETALA2 (AP2) regulatory module is a conserved mechanism governing floral development in plants. Disruption of the miR172 target sites in AP2 genes has been shown to be key to the domestication of double flowers in ornamental species. Camellia japonica, a woody ornamental plant with diverse floral forms, serves as an important model for studying double-flower formation. In this study, we characterized two AP2-like transcription factors, CjAP2-1 and CjAP2-2, which possess evolutionarily conserved miR172-binding sites and exhibit broad expression across floral tissues. To investigate the role of the miR172–AP2 module in C. japonica, we identified four members of the miR172 family and demonstrated that miR172 is directly involved in the cleavage of CjAP2-1 and CjAP2-2 transcripts. Through bulked amplicon sequencing of cultivars with diverse floral forms, we uncovered natural variations at the miR172-binding sites of CjAP2-1 and CjAP2-2, which can potentially disrupt miR172-mediated mRNA cleavage. We showed that two dinucleotide mutations (CjAP2-1-mut5 and CjAP2-1-mut9) significantly reduced the miR172-mediated repression of CjAP2-1 transcripts. Functional analysis in Arabidopsis revealed that overexpression of the CjAP2-1-mut5 variant caused significant floral abnormalities, including ectopic formation of reproductive organs, loss of floral determinacy, and fusion of floral organs. Further analysis of downstream genes indicated that key regulators of floral homeotic and meristem activity were markedly altered in the transgenic plants. Our findings demonstrate that perturbations in the miR172–AP2 regulatory relationship underlie the formation of double flowers in C. japonica by altering floral meristem determinacy and organ identity. Full article

Red clover (Trifolium pratense L.) is a crop used as a forage that possesses an exceptional nutritional profile and digestibility. Unfortunately, this crop has low seed yield. Within the framework of the “Legume Generation” EC-funded project, our team aimed to investigate the role of foliar boron application on pollen viability and pollen tube development, and to assess its overall effect on red clover cultivation. Plants of six commercial diploid red clover cultivars, Nika 11, Sofia 52, AberClaret, Milvus, Global, and S123, were field-grown and boron-treated by spraying with the commercial product “Lebasol”, 11% active water-soluble boron. To reach our purpose, the transcript levels of genes related to flower, pollen, and pollen tube development and boron transport were measured by qRT-PCR; pollen grain viability and count were assessed microscopically. For this research, eight genes were selected: Auxin Response factor (TprARF17); TprAPETALA3; Walls are thin (TprWAT1 and TprWAT2); NIPs genes (Nodulin Intrinsic Protein) TprNIP4;2, TprNIP7;1, TprNIP5;1, and TprNIP6;1. Additionally, total nitrogen content in leaves detached from field-grown boron-treated and untreated plants was assessed and compared with the expression levels of two TprNIP5;1 and TprNIP6;1 transporters. The fresh and dry biomass weight from the first and second cuts was evaluated, as well as the seed collected from the red clover plants. Seed germination percentage and vigor of seedlings were examined in vitro for both boron-treated and untreated groups of two specific cultivars. Collected data confirm that foliar application of boron affects pollen viability and plant development of red clover in the cultivation conditions of South East Europe. Full article

APETALA2/ethylene-responsive factor (AP2/ERF) transcription factors integrate phytohormone signalling with developmental programmes and specialised metabolism, yet their family-wide features and potential contributions to phenolic-acid biosynthesis remain to be systematically clarified in Salvia miltiorrhiza. In this study, we conducted a comprehensive genome-wide analysis and identified 169 SmAP2/ERF genes, which were classified into five subfamilies (AP2, ERF, DREB, RAV and Soloist). SmAP2/ERFs were unevenly distributed across chromosomes and expanded predominantly through tandem and segmental duplication, and Ka/Ks analysis indicated that tandem-duplicated pairs have mainly undergone purifying selection. Promoter analysis revealed abundant cis-acting elements related to light, phytohormones and stress responses, indicating extensive regulatory potential. Comparative phylogenetic analysis with Arabidopsis thaliana prioritised four candidates (SmAP2/ERF88, SmAP2/ERF110, SmAP2/ERF121 and SmAP2/ERF122) closely associated with specialised-metabolism regulators. These genes exhibited distinct tissue-preferential expression patterns and divergent hormone responsiveness: SmAP2/ERF88/110 were broadly inducible, whereas SmAP2/ERF121/122 responded mainly to abscisic acid and were repressed by brassinosteroids. Confocal imaging of GFP fusions confirmed nuclear localisation of all four proteins. Phytohormone treatments differentially regulated key phenolic-acid pathway genes (PAL, C4H, 4CL, TAT, HPPR, RAS and CYP98A14) and altered rosmarinic acid and salvianolic acid B accumulation. These results broaden the genome-wide understanding of the SmAP2/ERF family in Salvia miltiorrhiza. Hormone-responsive SmAP2/ERFs show expression patterns associated with hormone-dependent transcriptional changes in phenolic-acid pathway genes and with RA and SAB accumulation, providing candidates for future functional validation and metabolic engineering. Full article

The APETALA2/Ethylene Response Factor (AP2/ERF) family of transcription factors (TF) is characterized by their participation in various biological processes related to growth, development, and response to stress. ERFs are ideal candidates for crop improvement because they regulate defense genes like JERF1, JERF3, LeERF2, NtERF5, and Tsil which confer tolerance to drought, salinity, osmotic stress, and pathogen attack, respectively. The ERF subfamily includes the TF Pti4, whose activity is regulated by different signaling pathways, thus providing tolerance response to multiple factors such as drought, salinity, cold, and pathogen attack in tomato. In this work we evaluated the effect of overexpression of TF SlPti4 from Solanum lycopersicum in transgenic tobacco plants when subjected to saline, osmotic, and drought stress. Our results from this study demonstrated that transgenic lines overexpressing Pti4 tolerate abiotic stress during germination and in plants. The transgenic lines showed improvements in photoinhibition, electron transport rate, chlorophyll content, and biomass, as well as a reduction in malondialdehyde content. Full article

Longan (Dimocarpus longan Lour.) is a commercially valuable tropical fruit crop that contains two antagonistic FLOWERING LOCUS T (FT) homologs involved in regulating flowering time. However, how these FT genes interact with flowering regulators FLOWERING LOCUS D (FD) and APETALA1 (AP1) remains unknown. Four flowering-related genes in longan, DlFT1, DlFT2, DlAP1 and DlFD, were successfully isolated. Expression profiling revealed that all four genes were expressed in leaves and buds across different stages of natural and KClO₃-induced floral bud differentiation. Functional characterization through heterologous overexpression in Arabidopsis thaliana showed that DlAP1 significantly promotes early flowering under long-day conditions and induced morphological changes in floral organs and leaves. In contrast, DlFD overexpression had no effect on flowering time. Subcellular localization assays revealed that DlFT1 and DlFT2 localized to both the nucleus and the plasma membrane, while DlAP1 and DlFD localized exclusively to the nucleus. Yeast two-hybrid and bimolecular fluorescence complementation (BiFC) analyses revealed a novel regulatory node: DlFT1 directly interacts with DlAP1, a finding that expands the classical FT-FD-AP1 flowering model. Additionally, DlFD interacts more strongly with DlFT1 than with DlFT2, whereas DlFT1 only interacts with DlAP1, but not DlFT2. These results demonstrate that DlFT1 promotes flowering not only via the conserved FD-dependent pathway but also through direct association with AP1. These findings advance our understanding of the regulatory mechanisms of flowering in longan and provide valuable insights into flowering pathways of perennial woody species. Full article

The AP2/ERF (APETALA2/ethylene-responsive factor) superfamily is one of the largest transcription factor families in plants and is not only vital for plant growth and development but also participates in responding to various abiotic stresses. However, few studies have investigated the function of the AP2/ERF gene family in natural rubber (NR) biosynthesis in Hevea brasiliensis. Here, 174 HbAP2/ERF genes were identified genome-wide and classified into 18 subclades based on gene-conserved structure and phylogenetic analysis. Gene duplication analysis revealed that 7 tandem and 100 segmental duplication events were major drivers of this gene family. Cis-element analysis in HbAP2/ERF promoters identified light-, hormone-, stress-, and development-associated cis-elements. Tissue-specific expression profiles revealed that 160 HbAP2/ERFs were expressed in at least one tissue. The protein–protein interaction network identified 59 potential interactions among the HbAP2/ERFs. Critically, dual-luciferase reporter assays confirmed that two key regulators exhibit distinct regulatory modes on NR biosynthesis-related genes: HbAP2/ERF25 significantly repressed the transcriptional activities of HbMVD1, HbCPT7, and HbSRPP1, whereas HbAP2/ERF46 repressed HbMVD1 but activated HbHMGR1, HbFPS1, and HbSRPP1. These findings reveal the complex regulatory network of HbAP2/ERFs in NR biosynthesis, establish a comprehensive framework for understanding their evolution and functional diversification, and provide novel molecular targets for genetic improvement of NR yield in rubber tree breeding and metabolic engineering. Full article

Anthocyanins are important secondary metabolites that impart color to fruits, and their biosynthesis is regulated by light. AP2/ERF transcription factors represent one of the largest TF families in plants and play pivotal roles in regulating plant growth and development, secondary metabolism, and stress responses. However, their comprehensive profile in mango (Mangifera indica L.) and their role in mango anthocyanin biosynthesis remain largely unclear. In this study, genome-wide identification and analysis of the AP2/ERF gene family in mango were conducted. A total of 240 family members were identified and classified into five subfamilies. Phylogenetic tree, conserved motif, and gene structure analyses revealed high conservation within the same subfamily and significant divergence among different subfamilies. Synteny analysis indicated that segmental and tandem duplication events played a major role in the expansion of the MiAP2/ERF family. Organ-specific expression profiles based on RNA-seq data uncovered the expression patterns of MiAP2/ERF genes in different plant organs. Furthermore, RNA-seq analyses related to light-induced anthocyanin accumulation, including preharvest “bagging–debagging” treatment and postharvest UV-B/white light and blue light treatments, identified a subset of MiAP2/ERF genes with significant light-responsive trends. The expression patterns of six blue-light-induced MiAP2/ERF genes were validated by means of qPCR. In summary, this study provides a comprehensive theoretical characterization of the AP2/ERF family in mango and reveals its potential role in light-induced anthocyanin accumulation, thereby establishing a solid theoretical foundation for subsequent investigations into gene functions and molecular mechanisms. Full article

AP2/ERF (APETALA2/ethylene-responsive factor) is one of the largest plant transcription factor families, characterized by 1-2 AP2/ERF domains (≈60–70 amino acids) that regulate plant development and biotic/abiotic stress responses. This study presents the first genome-wide identification and characterization of the AP2/ERF family in the selenium (Se) hyperaccumulator Cardamine hupingshanensis via bioinformatics. A total of 230 AP2/ERF genes were identified, which were non-randomly distributed across 16 chromosomes. Their encoded proteins varied in length (126–623 aa), molecular mass (13.927–68.112 kDa), and isoelectric point (4.48–10.31). Phylogenetic analysis classified these genes into five conserved subfamilies (AP2, DREB, ERF, RAV, Soloist), consistent with other plant species. Intron distribution differed among subfamilies (42.17% of genes contained introns), and motif 1 was universally conserved. Promoter cis-element analysis revealed enrichment of hormone-, stress-, and growth-related elements, highlighting potential roles in abiotic stress responses (notably, light and abscisic acid signaling). Expression profiling under Se stress (100 μg Se/L and 80,000 μg Se/L) demonstrated tissue-specific, dose-dependent, and temporal dynamic patterns. This inaugural genome-wide investigation of C. hupingshanensis AP2/ERFs provides foundational datasets for deciphering regulatory networks governing growth and Se stress response in this Se hyperaccumulator plant. Full article

Mangrove ecosystems play a critical role in global carbon cycling, serving as significant carbon sinks by storing carbon in both aboveground biomass (ACG) and soil carbon stock (SOC). However, the temporal dynamics of ACG and SOC, as well as their spatial variations across different mangrove age stages, remain poorly understood, particularly under the influence of introduced species such as Sonneratia apetala Buch.-Ham. To address these gaps, our study used a long-term series of NDVI from Landsat (from 1990 to 2024) and the mangrove product of China (1990, 2000, 2010, and 2018) to estimate the mangrove age stage ($\mathrm{Stage}\mathrm{I}$ 10–24 years, $\mathrm{Stage}\mathrm{II}$ 24–34 years, and $\mathrm{Stage}\mathrm{III}$ > 34 years). UAV-LiDAR and in-situ surveys were applied to measure mangrove canopy height to calculate ACG and measure the belowground soil carbon stock, respectively. Combined with the mangrove age stage, ACG, and SOC, our results reveal that ACG accumulates rapidly in younger mangroves dominated by Sonneratia apetala, peaking early (<20 years) and then stabilizing as mangroves, indicating that the introduction of Sonneratia apetala changed the increase in ACG with age. In contrast, SOC increases more gradually over time, with only older mangroves (over 30 years) storing significantly higher SOC. Root structure, TN, and TP were sensitive to the SOC. The different root structures (pneumatophore, plank, pop, and knee root) had different SOC results, and the pneumatophore had the lowest SOC. Remote sensing data revealed that the introduction of Sonneratia apetala altered the species composition of younger mangroves, leading to its predominance within these ecosystems. This shift in species composition not only altered the temporal dynamics of aboveground carbon (ACG) but also favored pneumatophore-dominated root structures, which were associated with the lowest soil organic carbon (SOC). Consequently, younger stands may require more time to accumulate SOC to levels comparable to older mangrove forests. These results suggest that restoration targets for vegetation carbon and soil carbon should be set on different timelines, explicitly accounting for stand age, species composition, and root functional types. Full article

Rice (Oryza sativa), a crucial global staple, grapples with environmental stress and resource constraints, necessitating sustainable farming. This review explores the transformative role of transcription factors (TFs) in revolutionizing rice agriculture and their potential impact on global food security. It underscores TFs’ pivotal role in gene expression, particularly in responding to environmental stimuli, presenting a promising avenue for enhancing rice resilience. Delving into key TF families in rice, it highlights their multifaceted roles in abiotic stress responses, defense mechanisms, yield improvement, nutrient uptake, seed development, photosynthesis, and flowering regulation. Specific TFs, including DREB (Dehydration-Responsive Element-Binding), WRKY, NAC, MYB (Myeloblastosis), AP2/ERF (APETALA2/Ethylene Responsive Factor), and bHLH (basic Helix–Loop–Helix), are examined for their contributions to stress resilience, defense mechanisms, and yield enhancement. Concrete examples from cutting-edge research illustrate the tangible benefits of harnessing these molecular regulators. However, manipulating TFs presents challenges, necessitating innovative approaches such as predictive models, collaborative field testing, and transparent communication to navigate intricate regulatory networks and regulatory hurdles. Ultimately, a promising future emerges where manipulating rice TFs leads to the development of resilient, high-yielding, and nutritious varieties. Embracing research advancements and addressing existing challenges is imperative to unlock the full potential of these concealed regulators, ensuring sustainable food security for a growing global population. Full article

The APETALA2/Ethylene Responsive Factor (AP2/ERF transcription factor) family plays pivotal roles in plant growth, stress responses, and metabolic regulation. Here, we identified 118 AP2/ERF family members in the apricot (Prunus armeniaca L.) genome, which were classified into four major subfamilies (AP2, DREB, ERF, and RAV) and Soloists (few unclassified factors), through phylogenetic analysis. The ERF subfamily exhibited the largest expansion (55 members), driven predominantly by 10 tandem and 14 segmental duplication events. Gene structures and conserved motifs exhibited similar patterns within each subfamily. Chromosomal distribution was uneven, with chromosome 1 harboring the highest gene density. PaWRI1 was specifically expressed in apricot kernel and positively correlated with oil accumulation. A total of 47 lipid-related genes were predicted as potential targets of PaWRI1 through correlation analysis, which covers the entire three-stage process of plant oil synthesis. These results advance our understanding of how core AP2/ERF transcription factors modulate oil accumulation pathways in apricot, offering potential targets for metabolic engineering. 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

The APETALA2/ethylene response factor (AP2/ERF) is a class of plant-specific transcription factors, among which the dehydration-responsive element-binding protein (DREB) subfamily has been widely reported to enhance plant resistance to abiotic stresses. A high-temperature-related gene, Apium graveolens DREBA6b (AgDREBA6b; accession number: OR727346), was previously cloned from a heat-tolerant celery variety. In this study, we transformed this gene into Arabidopsis thaliana using an Agrobacterium rhizogenes-mediated method to explore its function. The results showed that overexpressing AgDREBA6b in Arabidopsis thaliana significantly improved plant growth under high-temperature stress (38 °C) compared to the dreb mutant and wild-type (WT) plants. The anatomical structure of the leaves revealed that the number and degree of stomatal openings in the overexpressed plants were significantly higher than those in the WT and dreb plants, suggesting that AgDREBA6b enhances stomatal opening. Additionally, the chlorophyll content, chlorophyll fluorescence properties, proline (Pro), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities were higher in the transgenic plants, indicating better stress tolerance. qPCR analysis showed that four heat tolerance-related genes (AtHSP98.7, AtHSP70-1, AtAPX1, and AtGOLS1) were upregulated in the transgenic plants, with higher expression levels than in WT and mutant plants. This study provides valuable genetic resources for understanding the molecular mechanisms of celery’s heat tolerance and offers insights for breeding heat-tolerant celery varieties. Full article

To understand the mechanisms underlying species assemblage along salt gradients in intertidal zones, we measured the xylem hydraulic vulnerability curves (HVCs), leaf water potential (ψ), stomatal conductance (g_s), specific leaf area (SLA), and wood density (WD) for six mangrove species of Avicennia marina, Bruguiera gymnorrhiza, Aegiceras corniculatum, Kandelia obovata, Sonneratia apetala, and Sonneratia caseolaris. We found the following: (1) A. marina and B. gymnorhiza had the most negative P₅₀ (water potential at which 50% of hydraulic conductivity was lost), while S. caseolaris and S. apetala had the least negative P₅₀, indicating different resistance to embolism in xylem; (2) P₅₀ and P₈₈ (water potential at which 88% of hydraulic conductivity was lost) declined with increasing salinity from the onshore to offshore species, as their water regulation strategy meanwhile transitioned from isohydry to anisohydry; (3) B. gymnorhiza had smaller SLA but larger hydraulic safety margin (HSM), implying potentially higher capacity of water retention in leaves and lower risk of hydraulic failure in xylem. These results suggest that hydraulic traits play an important role in shaping the salt-driven niche segregation of mangroves along intertidal zones. Our research contributes to a more comprehensive understanding of the hydraulic physiology of mangroves in salt adaption and may facilitate a general modeling framework for examining and predicting mangrove resilience to a changing climate. Full article

The head rice rate, defined as the proportion of milled grains retaining at least three-quarters of their original length, has become a limiting factor that restricts the improvement of rice quality in China in recent years. Here, we characterized the role of ETHYLENE RESPONSIVE FACTOR34 (OsERF34), an APETALA2 (AP2/ERF) family TF, in the grain morphology, physiochemical properties, and processing quality of rice. Through CRISPR/Cas9-mediated knockout (Oserf34) and overexpression (OsERF34-OE) in the japonica cultivar ZH11, we demonstrate that OsERF34 exerts dose-dependent effects on grain morphology and processing traits. Oserf34 mutants exhibited significantly elevated chalkiness levels, with a 52.0% increase in percentage of grains with chalkiness(PGWC) and a 65.4% enhancement in chalkiness degree, with disordered and enlarged starch granules, reduced amylose content and skewed chain-length distribution (A/B1 chains increased but B2/B3 chains decreased), and displayed heightened starch solubility and swelling power but diminished milling resistance (shear hardness having fallen by 12.7–16.1% and compression hardness having fallen by 11.2–16.4%), culminating in doubled breakage rates and lower head rice rate (decreased by 6.7–9.0%) during processing. Strikingly, both mutants and OE lines showed analogous grain narrowing, yet the processing quality diverged. Mutants suffered structural fragility, while the OE lines enhanced mechanical robustness (compression hardness increased by 11.4–12.1%). The OsERF34-OE lines achieved 6.5–7.1% higher head rice rates. Our work positions OsERF34 as a dual-function regulator that governs grain morphology, regulating appearance and processing quality. These insights suggest that an overexpression of OsERF34 could improve processing efficiency, potentially laying a foundation for precision breeding. Full article