Search Results (229)

The living roots of woody plants in forests play a crucial role in sustaining the soil temperature equilibrium. However, there is limited research investigating the effects of soil temperature balance disruption, influenced by living roots, on soil microarthropods, especially in the context of global climate change. To address this knowledge gap, we conducted a three-year in situ simulation experiment involving either experimental warming or root trenching treatments to mimic environmental changes and their impacts on soil microarthropod communities in a temperate forest ecosystem in Northeast China. Statistical analysis focused on assessing the abundance and family richness of Collembola and Acari. Warming increased soil temperature, while root trenching had contrasting effects. In the absence of root trenching, warming positively influenced Collembola but negatively affected Acari. Conversely, when combined with root trenching, warming had a diminished impact on both Collembola and Acari. Our findings demonstrate that the interactive effects of warming on soil microarthropod communities vary depending on the presence or absence of root trenching. Specifically, within the context of root trenching treatment compared to no-root trenching treatment, warming exhibited a comparatively attenuated influence on soil microarthropod communities. Overall, living roots play a pivotal role in mediating soil temperature conditions, which significantly impact soil microarthropod communities in the context of global climate change. Full article

The bZIP gene family play a crucial role in plant growth, development, and stress responses, functioning as transcription factors. While this gene family has been studied in several plant species, its roles in the endangered woody plant Phoebe bournei remain largely unclear. This study comprehensively analyzed the PbbZIP gene family in P. bournei, identifying 71 PbbZIP genes distributed across all 12 chromosomes. The amino acid count in these genes ranged from 74 to 839, with molecular weights varying from 8813.28 Da to 88,864.94 Da. Phylogenetic analysis categorized the PbbZIP genes into 12 subfamilies (A-K, S). Interspecific collinearity analysis revealed homologous PbbZIP genes between P. bournei and Arabidopsis thaliana. A promoter cis-acting element analysis indicated that PbbZIP genes contain various elements responsive to plant hormones, stress signals, and light. Additionally, expression analysis of public RNA-seq data showed that PbbZIP genes are distributed across multiple tissues, exhibiting distinct expression patterns specific to root bark, root xylem, stem bark, stem xylem, and leaves. We also performed qRT-PCR analysis on five representative PbbZIP genes (PbbZIP14, PbbZIP26, PbbZIP32, PbbZIP67, and PbbZIP69). The results demonstrated significant differences in the expression of PbbZIP genes under various abiotic stress conditions, including salt stress, heat, and drought. Notably, PbbZIP67 and PbbZIP69 exhibited robust responses under salt or heat stress conditions. This study confirmed the roles of the PbbZIP gene family in responding to various abiotic stresses, thereby providing insights into its functions in plant growth, development, and stress adaptation. The findings lay a foundation for future research on breeding and enhancing stress resistance in P. bournei. Full article

Malania oleifera Chun & S.K. Lee, an endemic monotypic species that belongs to the family Olacaceae, is under continuous pressure of decline owing to several ecological and physiological factors. The present study aimed to establish an efficient in vitro protocol for callus-mediated indirect somatic embryogenesis in M. oleifera by alleviating tissue browning. Internodes and leaves obtained from seedlings were used as explants. Antioxidant pre-treatment (ascorbic acid, AA) followed by different carbon sources (sucrose, maltose, glucose, and fructose) and plant growth regulators in various concentrations and combinations were employed in Woody Plant Medium (WPM) to alleviate explant browning and induce callus formation from the explants. AA pre-treatment and subsequent culture on maltose at a concentration of 116.8 mM were optimal for controlling phenolic exudation on >90% of both explants. The highest responses of 53.77% and 57.43% for embryogenic calli were induced from internode and leaf explants, respectively. The highest responses, 85.22% and 93.80%, were observed for somatic embryos that matured into the globular, heart-shaped and torpedo stages at different percentages on NAA 2.5 mg/L in combination with BA 1.0 mg/L for both explants. The matured somatic embryos were finally germinated at a maximum concentration of GA₃, 2.0 mg/L. All plantlets were successfully hardened and acclimatized under culture room conditions and then transferred to the greenhouse. The current study suggests an efficient protocol for indirect somatic embryogenesis by alleviating phenolic exudation from the explants of M. oleifera. This first successful report of in vitro culture establishment in M. oleifera may offer an effective alternative measure to conserve this species and provide a system for analyzing bioactive chemicals and for use in the oil industry. Full article

Stephanopodium engleri Baill. is an endangered tree species from the Dichapetalaceae family and endemic to the Iron Quadrangle region of Brazil. Recalcitrance and low seed viability limit conventional seedling production, making vegetative propagation a crucial alternative for conservation efforts. This study evaluated the rooting and sprouting potential of different cutting types (apical, middle, and basal segments from the main stem, as well as the tip and the herbaceous and woody segments from the lateral branches) treated with Indole-3-Butyric Acid (IBA) at varying concentrations (0, 1, 2, 3, and 4 g L⁻¹) and immersion durations (5 s to 10 min). Cuttings were collected from 12-month-old plants grown under controlled conditions and planted in Carolina Soil^® substrate after treatment. Sprouting and rooting rates varied significantly between cutting types, with basal main stem cuttings showing the highest rooting success, particularly at 3 g L⁻¹ of IBA. These cuttings also exhibited more and longer roots and enhanced sprouting-related biometric traits. Shorter immersion times (15 s and 1 min) were the most effective, promoting root formation while avoiding the potential inhibitory effects of prolonged exposure. Our findings provide a practical protocol for large-scale seedling production of S. engleri while minimizing impacts on wild populations. The effective use of vegetative propagation could facilitate the expansion of S. engleri populations in their natural habitats, enhancing conservation efforts and ensuring sustainable species management. Full article

Abscisic acid (ABA), a pivotal phytohormone regulating plant growth and stress adaptation, orchestrates abiotic stress responses through the ABA-responsive element-binding factors ABF/AREB/ABI5. Nevertheless, the functional characterization of ABF/AREB/ABI5 homologs in Z. jujuba cv. Dongzao remains unexplored. In this study, we identified seven ZjABF genes distributed across five chromosomes. Domain analyses revealed high structural conservation, particularly within the basic leucine zipper (bZIP) DNA-binding domain. Subcellular localization confirmed nuclear targeting of all seven ZjABF proteins. Phylogenetic classification resolved these factors into three clades (A–C). Cis-regulatory element profiling implicated the involvement of the ZjABFs in hormone signaling, abiotic stress transduction, and photoregulatory pathways. Synteny analyses identified three segmental duplication events within the gene family. Tissue-specific expression patterns indicated critical roles for ZjABF2 and ZjABF3 in fruit maturation, and most of the ABF/AREB/ABI5 genes were highly expressed in the root. Under drought stress, four ZjABF genes exhibited differential expression, with ZjABF2 demonstrating pronounced sensitivity. These findings establish a molecular framework for understanding ZjABF-mediated abiotic stress responses in non-model woody perennials. Full article

Background: The peony (Paeonia suffruticosa Andr.), a globally valued woody ornamental species, suffers severe heat-induced floral damage that compromises its horticultural value. While the HSP20 proteins are critical for plant thermotolerance, their genomic organization and regulatory dynamics remain uncharacterized in the peony. This study aims to systematically identify the PsHSP20 genes, resolve their molecular features, and elucidate their heat-responsive expression patterns to enable targeted thermotolerance breeding. Methods: The genome-wide identification employed HMMER and BLASTP searches against the peony genome. The physicochemical properties and protein structures of the gene family were analyzed using online websites, such as Expasy, Plant-mPLoc, and SOPMA. The cis-regulatory elements were predicted using PlantCARE. Expression profiles under different times of 40 °C heat stress were validated by qRT-PCR (p < 0.05). Results: We identified 58 PsHSP20 genes, classified into 11 subfamilies. All members retain the conserved α-crystallin domain, and exhibit predominant nuclear/cytoplasmic localization. Chromosomal mapping revealed uneven distribution without lineage-specific duplications. The promoters were enriched in stress-responsive elements (e.g., HSE, ABRE) and in 24 TF families. The protein networks linked 13 PsHSP20s to co-expressed partners in heat response (GO:0009408) and ER protein processing (KEGG:04141). Transcriptomics demonstrated rapid upregulation of 48 PsHSP20s within 2 h of heat exposure, with PsHSP20-12, -34, and -51 showing the highest induction (>15-fold) at 6 h/24 h. Conclusions: This first genome-wide study resolves the architecture and heat-responsive dynamics of the PsHSP20 family. The discovery of early-induced genes (PsHSP20-12/-34/-51) provides candidates for thermotolerance enhancement. These findings establish a foundation for molecular breeding in the peony. Full article

The aromatic C₁₃ apocarotenoid β-ionone is a high-value natural-flavor and -fragrance compound derived from the oxidative cleavage of carotenoids. Carotenoid cleavage dioxygenases (CCDs) play a pivotal role in the biosynthesis of volatile apocarotenoids, particularly β-ionone. In this study, we report the identification, cloning, and functional characterization of two CCD1 homologs: OeCCD1 from Olea europaea and InCCD1 from Ipomoea nil. These two species, which, respectively, represent a woody perennial and a herbaceous annual, were selected to explore the potential functional divergence of CCD1 enzymes across different plant growth forms. These CCD1 genes were synthesized using codon optimization for Escherichia coli expression, followed by heterologous expression and purification using a GST-fusion system. In vitro assays confirmed that both enzymes cleave β-carotene at the 9,10 (9′,10′) double bond to yield β-ionone, but only OeCCD1 exhibits detectable activity on zeaxanthin; InCCD1 shows no in vitro cleavage of zeaxanthin. Kinetic characterization using β-apo-8′-carotenal as substrate revealed, for OeCCD1, a K_m of 0.82 mM, V_max of 2.30 U/mg (k_cat = 3.35 s⁻¹), and k_cat/K_m of 4.09 mM⁻¹·s⁻¹, whereas InCCD1 displayed K_m = 0.69 mM, V_max = 1.22 U/mg (k_cat = 1.82 s⁻¹), and k_cat/K_m = 2.64 mM⁻¹·s⁻¹. The optimization of expression parameters, as well as the systematic evaluation of temperature, pH, solvent, and metal ion effects, provided further insights into the stability and functional diversity within the plant CCD1 family. Overall, these findings offer promising enzymatic tools for the sustainable production of β-ionone and related apocarotenoids in engineered microbial cell factories. Full article

Aspartic proteases (APs) are among the four primary families of proteolytic enzymes found in plants, and they are essential for both stress response mechanisms and developmental activities. While the AP gene family has been studied in model plants like Arabidopsis, its characterization in woody species-particularly in extremophytes like Populus euphratica, remains limited. Moreover, the potential involvement of APs in salt tolerance mechanisms in trees is yet to be explored. In this research, 55 PeAPs were discovered and categorized into three distinct classes based on their conserved protein structures. The phylogenetic analysis revealed potential functions of AP genes derived from Arabidopsis thaliana, V. vinifera, and P. euphratica. Our findings indicate that PeAP possesses a well-conserved evolutionary background and contains numerous highly variable regions, making it an excellent candidate for the identification and systematic examination of woody trees. Additionally, motifs frequently found in aspartic proteases within the genome of P. euphratica may be linked to functional PeAPs. It appears that PeAPs are associated with specific gene functions. These genes are influenced by cis-elements, which may play a role in their responsiveness to phytohormone, stress adaptation maybe changed to these genes are regulated by cis-elements that may mediate their responsiveness to phytohormones, abiotic stress, and developmental cues. Our research offers the initial comprehensive analysis of the AP family in P. euphratica, emphasizing its potential functions in adapting to salt conditions. The findings uncover candidate PeAPs for genetic engineering to enhance salinity tolerance in woody crops. Full article

Dirigent proteins (DIRs) are pivotal regulators of lignin/lignan biosynthesis and play multifaceted roles in plant development and stress adaptation. Despite their functional significance, DIR genes remain unexplored in Rosa chinensis, a globally important woody ornamental species. This study identified 33 RcDIRs through whole-genome analysis, including their chromosomal distribution, phylogenetic relationships, collinearity, protein and gene structure, conserved motifs, and cis-acting element distribution, and classified them into three phylogenetically independent subgroups (DIR-a, DIR-b/d, and DIR-e). Notably, the DIR-e subgroup includes an exclusive tandem cluster comprising RcDIR7-RcDIR12, representing the largest lineage-specific RcDIR expansion in R. chinensis. Structural characterization revealed that most RcDIRs exhibit a conserved single-exon architecture. Promoter cis-element analysis uncovered abundant stress-/hormone-responsive elements and three pollen-specific motifs (AAATGA, POLLEN1LELAT52, GTGANTG10), with RcDIR12 from the DIR-e cluster showing high pollen-specific regulatory potential. Experimental validation included cloning the RcDIR12 promoter from R. chinensis ‘Old Blush’, constructing proRcDIR12::GUS vectors, and conducting histochemical GUS assays with pollen viability/DAPI staining in transgenic Arabidopsis. Histochemical assays demonstrated GUS activity localization in mature trinucleate pollen grains, marking the first experimental evidence of pollen-specific DIRs in rose. Our findings not only elucidate the DIR family’s genomic organization and evolutionary innovations in R. chinensis but also establish proRcDIR12 as a molecular tool for manipulating pollen development in plants. Full article

Carbon dioxide (CO₂) is a predominant greenhouse gas significantly contributing to atmospheric heat retention, primarily driven by anthropogenic activities intensifying the greenhouse effect. This study aims to evaluate the diversity of plant species, above-ground biomass (AGB), and carbon stock within a dry dipterocarp forest, which is a vital local natural resource. This study presents a comprehensive evaluation of plant species diversity, AGB, and carbon stock capacity within a dry dipterocarp forest at the Nature Study Center, Mahasarakham University, located in the Kham Riang Subdistrict of Kantharawichai District, Maha Sarakham Province, spanning an area of 20.80 hectares. Ten sample plots, each measuring 40 × 40 m, were established and distributed across the study area. The diameter at breast height (DBH) and the height of the trees were meticulously recorded for all trees within these plots. Advanced statistical techniques were employed to calculate the relative dominance (RD), relative frequency (RF), and Importance Value Index (IVI), alongside a comprehensive assessment of plant species diversity. The AGB was assessed using precise allometric equations, with a focus on analyzing carbon storage within woody biomass. The findings revealed the presence of 52 tree species across 26 families within the forest. The total AGB was measured at 144.510 tons, with carbon stock reaching 67.920 tCO₂. These results offer critical insights into enhancing land management strategies to optimize carbon stock, thereby playing a vital role in mitigating greenhouse gas emissions, a significant factor in climate change dynamics. Full article

Toona sinensis (A. Juss.) Roem, classified under the Toona genus of the Meliaceae family, is a fast-growing, woody species endemic to China, valued as both a vegetable crop and medicinal plant. Its seeds achieve rapid germination through a cascade of interconnected physiological, metabolic, and hormonal adaptations. Initially, physiological hydration is driven and accelerated by only two distinct phases of water imbibition. This hydration surge triggers storage reserve mobilization, with soluble sugars, proteins, and lipids undergoing rapid degradation during imbibition, while starch catabolism proceeds gradually—a pattern mirrored by progressive increases in enzymatic activities (amylase, protease, and acid phosphodiesterase (ACP)) that correlate with reserve reallocation. Concurrently, a metabolic shift from glycolysis to the pentose phosphate pathway (PPP) optimizes energy utilization, supporting germination acceleration. These biochemical changes are orchestrated by hormonal coordination: elevated gibberellin A₃ (GA₃), zeatin riboside (ZR), and indole-3-acetic acid (IAA) levels, coupled with rising GA₃/ABA, IAA/ABA, and ZR/ABA ratios, temporally aligned with germination progression. Finally, structural evidence confirms successful germination completion, as cotyledon lipid droplet breakdown and starch granule synthesis directly correlate with embryonic elongation. Together, these mechanisms underscore T. sinensis’ adaptive strategy, integrating physiological plasticity, metabolic flexibility, and endocrine precision to ensure efficient germination. Full article

Basic helix–loop–helix (bHLH) transcription factors play significant roles in plant growth and organ development and diverse biochemical processes. However, the function of bHLH transcription factors in woody plants is not fully understood. In this study, the bHLH gene family in Rhododendron × pulchrum Sweet was identified and characterized using whole-genome data. A total of 109 bHLH family genes (RpbHLHs) were identified in R. pulchrum, and their expression levels were analyzed in flowers of different colors and developmental stages. The results showed that the RpbHLH family is divided into 24 subfamilies. Chromosomal localization and collinearity analyses revealed numerous duplication events during evolution, which is one of the main reasons for the diversification of gene functions. The bHLH domains showed relative conservation of RpbHLH proteins. In the promoter regions of the RpbHLHs, various cis-regulatory elements involved in light response, gibberellic acid (GA) response, and abscisic acid (ABA) response were identified. These elements may regulate flower development and pigment synthesis. A Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis of the target RpbHLHs revealed that 25 genes are enriched in the flavonoid biosynthetic pathway. Potential RpbHLHs related to flower development and pigment synthesis were identified through a transcriptome analysis and validated through quantitative reverse transcription PCR (qRT-PCR). This study will enhance our understanding of RpbHLH functions and provide a reference for the study of flower development and coloration in R. pulchrum. Full article

Fire is a natural disturbance in the Brazilian Cerrado that modulates the vegetation structure. Protium heptaphyllum, a woody species of the family Burseraceae, is common in this biome. The resin produced in secretory canals immersed in the phloem of the stem and leaves of this species plays important ecological and industrial roles. The aim of this study was to investigate the influence of fire on the development of resin canals in the leaves and stem of P. heptaphyllum and on the chemical profile of substances produced in the leaves. Young plants were subjected to controlled fire experiments. Leaf and stem portions were analyzed using light microscopy; the chemical compounds in the leaves were identified through gas chromatography–mass spectrometry. The percentage area occupied by secretory canals in the leaf midrib was higher in fire-treated plants than in control plants. Similarly, the density of secretory canals and their lumen area were higher in young stems (primary growth) of fire-treated plants. By contrast, although the canal density in the secondary phloem was lower in older stem portions (secondary growth) in fire-treated plants, their lumens were larger, resulting in similar data regarding the total lumen area of the secretory canals in fire-treated and control plants. The main chemical compounds identified in the leaves were vitamin E, sitosterol, α-amyrin, squalene, and β-amyrin. Three compounds showed significant increases in fire-treated plants, with vitamin E being the only one reduced by fire. Our findings reveal the plasticity of the secretory system and of the biochemical properties of the leaves of P. heptaphyllum in response to fire. These results are important when considering the current increase in fires caused by climate change and human activity in different ecosystems around the world. Full article

Xyloglucan endotransglucosylases/hydrolases (XTHs) are key enzymes involved in cell wall remodeling by modifying xyloglucan–cellulose networks, thereby influencing plant growth, development, and secondary cell wall formation. While the roles of XTHs have been extensively studied in primary and secondary growth, their functions in the formation and thickening of lignified nut shells remain largely unknown. Pecan (Carya illinoinensis), an economically important nut crop, develops a hard, lignified shell that protects the seed during fruit maturation. In this study, we performed a comprehensive genome-wide characterization of the XTH gene family in pecan and identified 38 XTH genes, which were categorized into four distinct phylogenetic groups. Structural analyses of the deduced proteins revealed conserved catalytic residues alongside divergent loop regions, suggesting functional diversification. Expression profiling across various tissues and among pecan cultivars with contrasting shell phenotypes indicated that specific XTH genes may play critical roles in shell structure formation. Moreover, gene regulatory networks in thin- and thick-shelled pecans provided new insights into the molecular mechanisms underlying shell development and thickness regulation. These findings lay a foundation for future genetic improvement strategies targeting nut shell traits in woody perennials. Full article

Phoebe bournei, a rare tree species native to China, holds considerable economic importance. The heat shock protein 70 (Hsp70) family is a group of molecular chaperones that is broadly distributed across living organisms and play a critical role in processes like growth, development, and stress response. While Hsp70 genes have been identified and studied in various plant species, their specific functions in the growth and development of P. bournei remain unexplored. We performed a comprehensive analysis of the Hsp70 gene family in P. bournei, identifying a total of 45 Hsp70 genes, which were classified into four groups (I–IV) through phylogenetic analysis. All Hsp70 proteins possessed conserved structural domains, including motif 7, and introns were present in 77.8% of the genes. Chromosomal localization and collinearity analyses of the Hsp70 genes revealed their evolutionary relationships and potential gene duplication events. Examination of the cis-acting elements within the Hsp70 promoter regions revealed that the predominant elements were associated with growth and development, followed by those responsive to hormones, and then elements linked to abiotic stress. Nine genes with high expression were selected for RT-qPCR analysis. Under high-temperature stress, all nine genes were differentially upregulated, and most of these genes belonged to subfamilies II and III, indicating that these two subfamilies have strong potential for heat resistance. In this study, we have elucidated the molecular characteristics and heat response properties of the Hsp70 gene family in P. bournei, revealing the mechanisms behind its heat stress response. Our work provides a reference for stress breeding in P. bournei and a theoretical basis for the exploration of heat tolerance in woody plants. Full article