Camphora officinarum (syn. Cinnamomum camphora) is an ecologically, medicinally, and economically important tree species widely known for its essential oils (EOs), timber, and long history of use in traditional medicine. In recent years, renewed interest in this species has been driven by taxonomic revision, the discovery of chemically distinct chemotypes, and advances in genomics, metabolomics, and biotechnological processing. This review summarizes current knowledge on the botany, distribution, phytochemistry, biological properties, agro-industrial value, and biotechnological potential of C. officinarum. Particular attention is given to the genetic and metabolic basis of terpene diversity, especially the role of terpene synthase (TPS) gene expansion in the formation of camphor-, linalool-, borneol-, cineole-, and citral-type profiles. We also discuss developments in essential oil extraction, the utilization of non-volatile constituents such as flavonoids and lignans, and the nutritional value of seed kernel oil rich in medium-chain fatty acids (MCFAs). In addition, recent progress in tissue culture, multi-omics analysis, metabolic engineering, and nano-enabled delivery systems is reviewed. The paper also considers important safety and ecological issues, including the dose-dependent toxicity of camphor and the contrasting status of the species as a protected native resource in East Asia and an invasive plant in some introduced regions. Overall, this review provides an updated and balanced overview of C. officinarum, identifies key knowledge gaps, and highlights future prospects for sustainable utilization, conservation of native genetic resources, and exploitative control of invasive populations.

Cadmium (Cd) pollution poses significant threats to ecosystems and human health, with agricultural soils in China particularly affected. Ilex verticillata, a popular ornamental plant, has not been extensively studied for its response to Cd stress. This study investigated the physiological and molecular mechanisms underlying Cd stress tolerance in I. verticillata, focusing on auxin signaling pathways. Under Cd stress (500 mmol/kg soil), I. verticillata exhibited inhibited stem growth, reduced photosynthetic capacity, and elevated oxidative stress markers such as malondialdehyde, H2O2, ·O2−, and antioxidant enzyme activities. Transcriptomic analysis revealed 3750 differentially expressed genes (DEGs) with significant enrichment in auxin signaling pathways. Six nucleus-localized IvIAA genes were identified and shown to interact with the transcription factor IvMYB77, suggesting a regulatory module in Cd stress responses. These findings highlight the role of auxin signaling in mediating Cd stress tolerance and provide insights into the molecular adaptation of I. verticillata to heavy metal pollution.

Drought stress imposes oxidative damage on plants, yet the tissue-specific roles of salicylic acid (SA) in modulating phenolic metabolism remain poorly understood in woody species. Using Ilex rotunda seedlings, we investigated whether exogenous SA (100 µM) mitigates drought-induced oxidative damage and reshapes phenolic profiles in different tissues. Drought alone increased leaf total phenolics by 32% but depleted root phenolics by 29%, whereas combined drought + SA (DSA) treatment partially restored root phenolic levels, coinciding with elevated malondialdehyde (MDA) (2.2-fold in leaves, 2.6-fold in roots) and H2O2. Leaf antioxidant capacity increased under drought (DPPH by 73%, •OH by 33%), whereas root DPPH declined by 27% despite a 26% rise in •OH scavenging. SA alone induced mild oxidative responses and selectively upregulated caffeoylquinic and galloyl derivatives, notably 1-Caffeoylquinic acid (log2FC = 6.38) in leaves. DSA treatment mitigated oxidative damage-reducing leaf MDA by 44% and root H2O2 by 38%. Metabolomics revealed tissue-specific reprogramming leaves accumulated dicaffeoylshikimic acid (log2FC = 10.66) and trilobatin D (log2FC = 11.18) under DSA, whereas roots showed contrasting patterns with up-accumulation of vanillate (log2FC = 5.77) and suppression of 3,5-dicaffeoylquinic acid (log2FC = -7.21) under drought, with stronger metabolic reprogramming in leaves than roots. Our findings indicate that SA-mediated drought tolerance is associated with tissue-specific phenolic reprogramming, identifying candidate indicators that advance the mechanistic understanding of woody plant resilience to drought. These results provide a framework for translating metabolomic signatures into practical strategies for stress mitigation in medicinal perennials facing climate change.

Drought stress severely compromises the physiological integrity and secondary metabolism of medicinal plants. This study integrated physiological, biochemical, and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analyses to investigate the effects of exogenous methyl jasmonate (MeJA) on drought-stressed Ilex rotunda seedlings. Drought reduced relative water content by 29% and chlorophyll by >50%, while elevating H2O2 (76%) and malondialdehyde (120%). MeJA application mitigated these impairments, reducing oxidative markers by 25% and enhancing non-enzymatic antioxidant capacity, as shown by a 74% increase in DPPH radical scavenging activity and a 141% rise in total phenolic content. Hierarchical clustering analysis (HCA), principal component analysis (PCA), and orthogonal partial least squares-discriminant analysis (OPLS-DA), and pathway mapping confirmed a significant reprogramming of the phenolic metabolome, particularly within phenylpropanoid and benzoate biosynthesis pathways. Drought + MeJA-treated plants exhibited a distinct and enriched profile compared to both well-watered control and drought-stressed groups. This reprogramming specifically elevated key hydroxycinnamates, including verbascoside and neochlorogenic acid (increased by 50% and 52%, respectively), while suppressing alternative phenolic branches. These findings demonstrate that MeJA orchestrates a shift from enzymatic scavenging to a potent metabolite-based antioxidant system, positioning it as an effective elicitor for enhancing drought resilience and enriching the high-value phytochemicals in I. rotunda.

Grafting is an important method for pecans, while the molecular mechanisms underlying graft union formation still need in-depth analysis. In the current investigation, we identified 22 BGLU genes in Carya illinoinensis (pecan) and demonstrated that CiBGLU21, a β-glucosidase-encoding gene, plays an important positive role in graft healing. The overexpression of CiBGLU21 enhanced graft survival rates and accelerated tissue regeneration, while biochemical assays confirmed its role in cell wall reinforcement and sugar metabolism. Additionally, we identified that CiWOX13 formed heterodimers with CiWOX14 to directly and synergistically activate the transcription of CiBGLU21. The current investigation revealed a CiWOX13/14-CiBGLU21 module as an important modulator of graft union formation, offering insights into improving grafting efficiency in perennial crops and advancing the understanding of cell wall dynamics during tissue regeneration.

Low temperature constitutes a major environmental constraint on the successful cultivation and survival of the giant freshwater prawn, Macrobrachium rosenbergii. However, the physiological mechanisms underlying low temperature-induced tissue damage and metabolic adjustments remain elusive. This study integrated transcriptomics, ultrastructural observation, enzyme activity assays and gene expression analysis to investigate the systemic response of M. rosenbergii muscle and hepatopancreas to low temperature stress. Transcriptomic profiling demonstrated that the identified differentially expressed genes were significantly enriched in several key biological processes, including cellular metabolism, glycolysis/gluconeogenesis, redox homeostasis, and cytochrome P450-mediated detoxification. Transmission electron microscopy revealed severe mitochondrial swelling and dissolution of cristae in the hepatopancreas, whereas muscle ultrastructure remained relatively intact, indicating that the hepatopancreas is the primary target of low-temperature-induced cellular injury. Metabolic analysis indicated muscle tissue significantly upregulated key glycolytic enzymes (Hexokinase, Phosphofructokinase, Lactate dehydrogenase) and Succinate dehydrogenase (p < 0.05), suggesting a compensatory shift toward anaerobic glycolysis and energy mobilization to maintain function. Conversely, the hepatopancreas exhibited suppressed metabolic enzyme activities and a significant downregulation of antioxidant genes (CAT, Se-GPx, SOD), despite the robust upregulation of stress markers (HSP70, P450), suggesting the activation of defense mechanisms in response to oxidative damage. These results are highly consistent with the transcriptomic data. Overall, short-term low temperature stress increases reliance on anaerobic metabolism through metabolic reprogramming and disrupts mitochondrial function, thereby inducing oxidative stress and activating the anti-stress response. This study elucidates the mechanisms of early low temperature adaptation and injury in M. rosenbergii from a metabolic perspective, providing a theoretical basis for developing low temperature aquaculture management strategies and screening physiological biomarkers for low temperature resistance.

Cryptomeria japonica var. sinensis Miquel (Chinese cedar) is an ecologically and economically vital evergreen conifer endemic to China. Renowned for its rapid growth and superior timber quality, the species has evolved from a traditional forestry resource into a multifaceted model species for phytochemistry and biotechnology. This review synthesizes recent advancements in its biology, chemical profiling, industrial utilization, and molecular breeding. Taxonomically and morphologically distinct from the Japanese variety, Chinese cedar exhibits robust physiological plasticity and complex transcriptomic responses to abiotic stresses. Phytochemically, the tree is a prolific reservoir of volatile essential oils, complex terpenoids, and flavonoids. These bioactive secondary metabolites demonstrate potent antimicrobial, antioxidant, and neuroprotective properties, driving broad applications in modern pharmacology and sustainable agrochemicals. Industrially, the timber is increasingly utilized in the fabrication of advanced engineered structural composites and circular bioenergy production. Concurrently, breakthrough biotechnological platforms including a chromosome-level reference genome assembly, multi-omics, somatic embryogenesis, and CRISPR/Cas9-mediated genome editing have advanced molecular breeding, accelerating the targeted development of climate-resilient and non-pollen-producing (hypoallergenic) elite cultivars. However, as global climate change and historical habitat fragmentation severely threaten ancient wild populations, this review advocates for integrated in situ and ex situ conservation strategies. By identifying critical research gaps in translational pharmacology, precision gene editing, and comparative genomics, this review provides a comprehensive foundation for understanding the biology, phytochemistry, biotechnology, and utilization of this invaluable botanical resource, offering a strategic roadmap for its sustainable management and commercial valorization.

Pumpkin (Cucurbita moschata Duchesne) is an economically important vegetable crop in the family Cucurbitaceae. However, existing genetic transformation systems for pumpkin are limited by cultivar dependence, low efficiency, lengthy regeneration, and poor stability. In this study, we developed and optimized an Agrobacterium rhizogenes-mediated hairy root induction system for pumpkin leaves under non-tissue culture conditions, using the cultivar ‘Jintian No. 1’ as the experimental material. Systematic comparisons were performed across multiple parameters, including infection method, duration, bacterial strain, bacterial concentration, seedling age, and leaf position. The optimized transformation conditions were as follows: the second fully expanded leaf of 30-day-old seedlings, A. rhizogenes strain K599 at an optical density (OD600) of 0.8, and direct immersion for 15 min. Under these optimized conditions, the positive hairy root induction rate reached 89.58%. Moreover, the system successfully induced positive hairy roots in all tested pumpkin cultivars. In summary, this study establishes a highly efficient and practical hairy root induction system for pumpkin leaves, providing a robust platform for root-specific gene functional analysis and rapid validation of candidate genes related to root development and stress responses in pumpkin.

The pulsatile fluctuations of the steroid hormone 20-hydroxyecdysone (20E) in crustaceans involve both its biosynthesis and subsequent inactivation. Although the regulatory mechanisms of 20E biosynthesis have been extensively studied, the physiological significance of its inactivation in crustaceans is far less clear. This study reports the identification of the cytochrome P450 enzyme gene Mn-CYP18A1 from Macrobrachium nipponense. Structural analysis confirmed the presence of conserved cytochrome P450 motifs in Mn-CYP18A1, notably the heme binding domain. Phylogenetic analysis indicates that CYP18A1 orthologs are widely distributed in most major groups of insects and crustaceans. Expression analysis revealed that Mn-CYP18A1 expression was highest in the eyestalk compared to other tissues and peaked during the postmolt stage. RNA interference mediated knockdown of Mn-CYP18A1 prompted the upregulation of 20E biosynthetic genes (CYP306A1, CYP307A1) and the nuclear receptor FTZ-F1, consequently elevating 20E titers. This consequently led to molting impairment and a significant reduction in the molting rate. Our study demonstrates that 20E inactivation, mediated by Mn-CYP18A1, is essential for normal molting in M. nipponense.

Plants face various abiotic stresses in their natural environments that trigger the production of reactive oxygen species (ROS), leading to oxidative stress and potential cellular damage. This comprehensive review examines the interplay between plant antioxidant defense systems and ROS under abiotic stress conditions. We discuss the major enzymatic antioxidants, including superoxide dismutase, catalase, reductases, and peroxidases, as well as non-enzymatic antioxidants, such as ascorbic acid, glutathione, polyphenols, and flavonoids, which play crucial roles in ROS detoxification. This review elaborates on different types of ROS, their production sites within plant cells, and their dual role as both damaging oxidants and key signaling molecules. We discuss how various abiotic stresses—including heat, cold, drought, flooding, salinity, and heavy metal toxicity—induce oxidative stress and trigger specific antioxidant responses in plants. Additionally, the mechanisms of ROS generation under these abiotic stress conditions and the corresponding activation of enzymatic and non-enzymatic scavenging systems are discussed in detail. This review also discusses recent advances in understanding ROS signaling networks and their integration with other stress-response pathways. This knowledge provides valuable insights into plant stress-tolerance mechanisms and suggests potential strategies for developing stress-resistant crops by enhancing antioxidant defense systems. Moreover, the strategic ROS modulation through priming, exogenous antioxidants, nanoparticles, or genetic tools can enhance plant resilience. Integrating these methods with agronomic practices (e.g., irrigation management) offers a sustainable path to climate-smart agriculture. Our review reveals that ROS accumulation can be detrimental; however, the coordinated action of various antioxidant systems helps plants maintain redox homeostasis and adapt to environmental stress.

Functional gene expression is closely linked to an organism’s physiology and can be quantified using Real-Time Quantitative Reverse Transcription PCR (RT-qPCR). However, the stability of reference gene expression is not absolute, which may impact the accuracy of RT-qPCR results. In this study, we evaluated the suitability of nine genes including receptor for activated protein kinase c1 (rack1), ribosomal protein L6 (rpl6), ribosomal protein L9 (rpl9), ribosomal protein S2 (rps2), ribosomal protein S18 (rps18), ribosomal protein lateral stalk subunit P0 (rplp0), eukaryotic translation elongation factor 1β (eef1b), eukaryotic translation initiation factor 4a (eif4a), eukaryotic translation initiation factor 5a (eif5a) analyzed from RNA sequencing (RNA-Seq) data in addition to three genes including eukaryotic elongation factor 1α (eef1a), β-actin (actb), and glyceraldehyde 3-phosphate dehydrogenase (gapdh) selected from the literature to obtain the best internal controls in the RT-qPCR analysis of M. rosenbergii under overmating stress and natural aging. RefFinder was used to comprehensively evaluate the stability of the candidate reference genes. The initial results showed that three genes (eif5a, rps18, and rplp0) from the RNA-Seq data had relatively stable expression levels, which were more stable than those of the three commonly used reference genes. Eif5a and rps18 were the best combination for the RT-qPCR analysis of M. rosenbergii under overmating stress and aging. Further analysis indicated that eif5a might be the best reference gene for the study of M. rosenbergii.

Macrobrachium rosenbergii is an economically important freshwater prawn species in China. The X-organ–sinus gland complex in crustacean eyestalks regulates reproduction through neurohormones, with ablation significantly promoting ovarian maturation. However, the miRNA mediated molecular mechanisms underlying this eyestalk ovary regulatory axis remain poorly characterized in M. rosenbergii. RNA sequencing of 9 ovarian samples produced 207 million paired-end reads (62.25 Gb total), averaging > 6 Gb per sample with Q30 scores exceeding 94.42

Ilex verticillata (winterberry) is a valuable ornamental shrub increasingly threatened by leaf blight, a disease that compromises its aesthetic and economic value. While fungal pathogens like Alternaria alternata are known to cause leaf blight in horticultural crops, their role in I. verticillata and the host’s defense mechanisms have not been fully characterized. Our study investigated the pathogen-host interaction by identifying the causal agent and examining the physiological and molecular defense mechanisms of I. verticillata. Through morphological and multi-locus molecular analyses (ITS, TEF1-α, G3PDH, RPB2), A. alternata was confirmed as the primary pathogen, fulfilling Koch’s postulates. Pathogenicity assays revealed distinct disease progression stages, from necrotic lesions to tissue degradation. Transcriptomic profiling uncovered dynamic host responses, with early upregulation of pattern recognition receptors (PRRs) and transcripts encoding antioxidant enzymes (SOD, CAT), followed by downregulation of metabolic pathway genes. Phytohormone analysis highlighted intricate crosstalk, with salicylic acid (SA) peaking during mid-infection and jasmonic acid (JA) rebounding later, reflecting a coordinated defense strategy. Additionally, the oxidative stress marker malondialdehyde (MDA), an indicator of membrane lipid peroxidation, surged early, indicating membrane damage, while sustained induction of antioxidant enzymes suggested adaptive responses. The key finding was distinct phytohormone crosstalk, characterized by a mid-infection SA peak followed by a late JA rebound, alongside an early oxidative burst marked by MDA accumulation and sustained antioxidant enzyme activity. These findings provide a framework for understanding I. verticillata’s defense mechanisms and offer insights for developing targeted disease management strategies, such as resistant cultivar breeding or hormone-mediated interventions.

Grafting involves complex hormonal interactions at graft interfaces that are not yet fully understood. In this study, we analyzed hormone fluctuations and gene expression during callus proliferation and vascular tissue differentiation in hickory (Carya cathayensis Sarg.) grafts. Cytokinin and ethylene precursor ACC levels steadily increased after grafting. The biosynthetic genes for these hormones (IPT3, ACS1, ACO1, and ACO5) exhibited heightened expression. Genes related to cytokinin signaling (RR3, ARR4, and ZFP5) and ethylene signaling (MKK9, ESE1, and ESE3) were similarly upregulated. Conversely, genes associated with jasmonic acid, abscisic acid, and strigolactone pathways were downregulated, including synthesis genes (AOC4 and AOS) and those involved in signal transduction (NAC3, WRKY51, and SMAX1). Correspondingly, JA-Ile and 5-deoxystrigol levels significantly decreased. Indole-3-acetic acid (IAA) levels also dropped during the early stages of graft union formation. These results suggest that low auxin concentrations may be essential in the initial stages after grafting to encourage callus proliferation, followed by an increase at later stages to facilitate vascular bundle differentiation. These findings imply that maintaining a balance between low auxin levels and elevated cytokinin and ethylene levels may be critical to support cell division and callus formation during the initial proliferation phase. Later, during the vascular differentiation phase, a gradual rise in auxin levels, accompanied by elevated ethylene, may facilitate the differentiation of vascular bundles in hickory grafts.

During the breeding process of Macrobrachium rosenbergii, a male-to-female ratio of 1:3 or higher is typically adopted, so as a result, the quality of the male broodstock significantly influences the quality of the offspring. We observed that overused males exhibited notable changes in body color, particularly in the tail fan region, which turned orange or red due to the excessive accumulation of astaxanthin in the muscles and exoskeleton. Frequent mating also led to a significant decrease in male body weight, with histological analysis revealing disorganized muscle fiber patterns and increased tissue damage. To investigate the molecular mechanisms underlying these physiological changes, we performed transcriptomic and metabolomic analyses of muscle tissues. A total of 1069 differentially expressed genes (DEGs), 540 differentially expressed proteins (DEPs), and 385 differentially expressed metabolites (DEMs) were identified. Pathway analysis revealed that the DEGs were significantly enriched in pathways related to energy metabolism and degenerative diseases, while the DEMs were notably associated with cancer metabolism, signal transduction, substance transport, energy metabolism, nucleic acid metabolism, neurotransmission, immune response, and metabolic diseases. Proteome analysis showed that proteins and lipids were involved in muscle energy supply. These findings suggest that male M. rosenbergii upregulate energy metabolism in muscles to cope with frequent mating stress, but this adaptation leads to physiological damage. This study provides valuable insights for optimizing male broodstock selection and mating frequency in M. rosenbergii breeding practices.

NPC intracellular cholesterol transporter 1 (NPC1) plays an important role in sterol metabolism and transport processes and has been studied in many vertebrates and some insects, but rarely in crustaceans. In this study, we characterized NPC1 from Macrobrachium nipponense (Mn-NPC1) and evaluated its functions. Its total cDNA length was 4283 bp, encoding for 1344 amino acids. It contained three conserved domains typical of the NPC family (NPC1_N, SSD, and PTC). In contrast to its role in insects, Mn-NPC1 was mainly expressed in the adult female hepatopancreas, with moderate expression in the ovary and heart. No expression was found in the embryo (stages CS–ZS) and only weak expression in the larval stages from hatching to the post-larval stage (L1–PL15). Mn-NPC1 expression was positively correlated with ovarian maturation. In situ hybridization showed that it was mainly located in the cytoplasmic membrane and nucleus of oocytes. A 25-day RNA interference experiment was employed to illustrate the Mn-NPC1 function in ovary maturation. Experimental knockdown of Mn-NPC1 using dsRNA resulted in a marked reduction in the gonadosomatic index and ecdysone content of M. nipponense females. The experimental group showed a significant delay in ovarian maturation and a reduction in the frequency of molting. These results expand our understanding of NPC1 in crustaceans and of the regulatory mechanism of ovarian maturation in M. nipponense.

Citrus species are widely cultivated across the globe and frequently encounter drought stress during their growth and development phases. Previous research has indicated that citrus species synthesize flavonoids as a response mechanism to drought stress. This study aimed to comprehensively quantify and analyze the presence of 85 distinct flavonoids in the leaf and root tissues of lemon (drought susceptible) and sour orange (drought tolerant). In drought-stressed sour orange roots, flavonoids, such as isosakuranin, mangiferin, trilobatin, liquiritigenin, avicularin, silibinin, and glabridin, were more elevated than control sour orange roots and drought-stressed lemon roots. Additionally, hydroxysafflor yellow A, cynaroside, tiliroside, and apigenin 7-glucoside were increased in drought-stressed sour orange leaves compared to drought-stressed lemon leaves. Under drought stress, flavonoids such as (-)-epigallocatechin, silibinin, benzylideneacetophenone, trilobatin, isorhamnetin, 3,7,4 '-trihydroxyflavone, and liquiritigenin were significantly increased, by 3.01-, 3.01-, 2.59-, 2.43-, 2.07-, 2.05-, and 2.01-fold, in sour orange roots compared to control sour orange roots. Moreover, the total flavonoid content and antioxidant capacity were significantly increased in drought-stressed sour orange leaves and root tissues compared to drought-stressed lemon leaves and root tissues. The expression levels of genes involved in flavonoid biosynthesis were highly expressed in sour orange leaves and roots, compared to lemon leaves and root tissues, post-drought stress. These findings indicate that lemons fail to synthesize protective flavonoids under drought conditions, whereas sour orange leaves and root tissues enhance flavonoid synthesis, with higher antioxidant activities to mitigate the adverse effects of reactive oxygen species generated during drought stress.

This study investigates the role of lysosomal acid lipase (LIPA) in sex hormone regulation and gonadal development in Macrobrachium nipponense. The full-length Mn-LIPA cDNA was cloned, and its expression patterns were analyzed using quantitative real-time PCR (qPCR) in various tissues and developmental stages. Higher expression levels were observed in the hepatopancreas, cerebral ganglion, and testes, indicating the potential involvement of Mn-LIPA in sex differentiation and gonadal development. In situ hybridization experiments revealed strong Mn-LIPA signaling in the spermatheca and hepatopancreas, suggesting their potential role in steroid synthesis (such as cholesterol, fatty acids, cholesteryl ester, and triglycerides) and sperm maturation. Increased expression levels of male-specific genes, such as insulin-like androgenic gland hormone (IAG), sperm gelatinase (SG), and mab-3-related transcription factor (Dmrt11E), were observed after dsMn-LIPA (double-stranded LIPA) injection, and significant inhibition of sperm development and maturation was observed histologically. Additionally, the relationship between Mn-LIPA and sex-related genes (IAG, SG, and Dmrt11E) and hormones (17β-estradiol and 17α-methyltestosterone) was explored by administering sex hormones to male prawns, indicating that Mn-LIPA does not directly control the production of sex hormones but rather utilizes the property of hydrolyzing triglycerides and cholesterol to provide energy while influencing the synthesis and secretion of self-sex hormones. These findings provide valuable insights into the function of Mn-LIPA in M. nipponense and its potential implications for understanding sex differentiation and gonadal development in crustaceans. It provides an important theoretical basis for the realization of a monosex culture of M. nipponense.

Background Macrobrachium nipponense is a freshwater prawn of economic importance in China. Its reproductive molt is crucial for seedling rearing and directly impacts the industry’s economic efficiency. 20-hydroxyecdysone (20E) controls various physiological behaviors in crustaceans, among which is the initiation of molt. Previous studies have shown that 20E plays a vital role in regulating molt and oviposition in M. nipponense . However, research on the molecular mechanisms underlying the reproductive molt and role of 20E in M. nipponense is still limited. Results A total of 240.24 Gb of data was obtained from 18 tissue samples by transcriptome sequencing, with > 6 Gb of clean reads per sample. The efficiency of comparison with the reference transcriptome ranged from 87.05 to 92.48%. A total of 2532 differentially expressed genes (DEGs) were identified. Eighty-seven DEGs associated with molt or 20E were screened in the transcriptomes of the different tissues sampled in both the experimental and control groups. The reliability of the RNA sequencing data was confirmed using Quantitative Real-Time PCR. The expression levels of the eight strong candidate genes showed significant variation at the different stages of molt. Conclusion This study established the first transcriptome library for the different tissues of M. nipponense in response to 20E and demonstrated the dominant role of 20E in the molting process of this species. The discovery of a large number of 20E-regulated strong candidate DEGs further confirms the extensive regulatory role of 20E and provides a foundation for the deeper understanding of its molecular regulatory mechanisms.

Manganese (Mn) is an essential element for plant growth but can be toxic at high levels. Pecan (Carya illinoensis), an important nut-producing species, has been observed to exhibit tolerance to high Mn levels. In this study, pecan seedlings were exposed to a nutrient solution containing either 2 μM (control) or 1000 μM (excess) MnSO4 to investigate the physiological mechanisms. Despite substantial increases in Mn concentration in all pecan tissues, the presence of excess Mn did not induce visible symptoms of Mn toxicity on pecan leaves, nor did it result in any changes in malondialdehyde (MDA) levels. Photosynthetic rate and chlorophyll fluorescence parameters also remained unchanged. Subsequent examination revealed more cell layers and greater cell numbers in leaf palisade mesophyll tissue of Mn-treated plants compared with the control group. Cell length, and cell area decreased significantly in response to excess Mn, but total chloroplast area was unchanged and chloroplast structure remained intact. Subcellular fractionation analysis demonstrated that the cell walls, and to a lesser extent the soluble fraction, contained the majority of the Mn in leaves. The presence of excess Mn caused a marked increase in leaf concentrations of malic acid and citric acid, potential chelators of Mn. Our results suggest that the majority of Mn was sequestered in the leaf cell walls and may have been present as less-toxic chelated organic acids, thereby safeguarding the primary Mn target, the chloroplast, and ultimately conferring robust Mn tolerance in pecan.