BACKGROUND:The most prevalent subtype of renal cell carcinoma is clear cell renal cell carcinoma (ccRCC). Approximately 20-30 % of ccRCC patients develop metastatic clear cell renal cell carcinoma (mccRCC), characterized by aggressive tumor behavior and resistance to conventional therapies. Identification of critical hub genes involved in mccRCC progression is essential for advancing clinical management. METHODS:Differentially expressed genes (DEGs) about ccRCC were identified by integrated analysis of four public datasets. Protein-protein interaction (PPI) network and topological analyses were executed to pinpoint hub genes. Functional assays, including quantitative real-time PCR, proliferation, Western blotting, transwell assays, and Seahorse metabolic flux analysis, were performed in ccRCC cell lines. RESULTS:Albumin (ALB) was recognized as a hub gene consistently downregulated in ccRCC and mccRCC cell lines. ALB expression proved a strong correlation with tumor stage, metastasis, and histological grade. Functional experiments demonstrated that ALB suppressed proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in primary and metastatic ccRCC. Mechanistically, ALB showed a negative association with SPARC, which could potentially influence EMT progression. Metabolomic and glycolytic flux analyses revealed that ALB overexpression reprogrammed glycolysis by reducing glycolytic intermediates, glucose uptake, and lactate production. Silencing ALB enhanced glycolysis and malignant phenotypes, which were reversed by glycolysis inhibition or SPARC knockdown. CONCLUSION:ALB is associated with reduced proliferation, EMT, and glycolytic activity in mccRCC, potentially through its negative association with SPARC. This study provides novel insights into mccRCC pathogenesis and identifies ALB as a potential diagnostic biomarker and therapeutic target.

In plants, the diverse enzymes known as BAHD acyltransferases use acyl coenzyme A (acyl-CoA) as their substrate and fulfill crucial biological functions. In this study, 94 NtBAHD genes were identified in the tobacco (Nicotiana tabacum) genome. These genes displayed considerable diversity in their physicochemical properties, phylogenetic relationships, gene structures, and conserved motifs. Chlorogenic acid (CGA), which is the predominant polyphenol found in tobacco leaves, is mainly synthesized via the hydroxycinnamoyl-CoA: quinate hydroxycinnamoyl transferase (HQT) pathway. Four HQT genes (NtHQT1–NtHQT4) were identified in the BAHD gene family of N. tabacum. Of these, NtHQT1 and NtHQT2 were highly expressed in leaves, while NtHQT3 and NtHQT4 were root-specific. Following heterologous expression in vitro, three of the four HQT proteins (NtHQT2, NtHQT3, and NtHQT4) were obtained in soluble form; however, only NtHQT2 and NtHQT3 exhibited enzymatic activity. Downregulation of NtHQT1, NtHQT2, NtHQT3, and NtHQT4 significantly reduced both total polyphenol and chlorogenic acid (CGA) content, whereas the levels of rutin, scopoletin, and lignin remained unchanged. Furthermore, the expression of NtHQT genes was differentially induced under abiotic and biotic stresses, including drought, cold, and Phytophthora nicotianae infection. This study provides an integrated genome wide analysis of the BAHD family coupled with in vivo functional validation via gene silencing, revealing that all four NtHQT isoforms contribute to CGA biosynthesis and stress adaptation, despite their divergent enzymatic activities and expression patterns. This study does not involve clinical trials or human participants and, as such, does not require clinical trial registration.

Urban forest construction is widely regarded as a key strategy for improving air quality and mitigating urban heat island effects. However, the interactions between the urban thermal environment and air quality are influenced by a range of biophysical and meteorological factors, including canopy structure, air pollutant dispersion, and temperature-dependent chemical reactions, making them highly dynamic and complex. Thus, this study conducted field measurements at 10 m (within urban forests) and 20 m (outside the forests) to record concentrations of PM2.5, PM10, CO, NO2, SO2 and O3, as well as wind speed, wind direction, air temperature, relative humidity, and atmospheric pressure on polluted, heat-stressed, and control days. The 10 m level captures conditions within the canopy, where temperature, humidity, and pollutant levels are influenced by shading, transpiration, and leaf deposition. In contrast, the 20 m level reflects ambient conditions above the canopy, where atmospheric mixing and external sources dominate. Comparing these two heights helps reveal how urban forests regulate air quality and thermal environments, clarifying the mechanisms underlying their interactions. The study further assessed the influence of urban forests on air pollutant concentrations, air temperature, physiological equivalent temperature (PET), linear regression relationships, and trade-offs between air quality and thermal environments. The results showed that urban forests reduced PM2.5, PM10 and O3 concentrations while increasing CO, NO and NO2 concentrations. The concentration of PM2.5 within the urban forest was more than 20

PM2.5 and ozone (O3) are the primary air pollutants in Chinese cities, and their coordinated management is crucial for the sustained improvement of air quality. However, how urban characteristics influence their concentrations remains unclear. This study integrates multi-source data with the XGBoost-SHAP model to analyze the combined effects and nonlinear mechanisms of urban forests and built-up area characteristics on PM2.5 and O3 across different seasons. Our findings reveal that the average winter PM2.5 concentration (107.37 mu g center dot m-3) is approximately four times that of summer (26.97 mu g center dot m-3). The average summer O3 concentration (160.20 mu g center dot m-3) was approximately 2.5 times that of winter (63.26 mu g center dot m-3), indicating pronounced seasonal variations in air pollution characteristics. The prediction based on the XGBoost model (R2: 0.83-0.92) demonstrates that the three-dimensional urban structure features have a more significant impact on air pollution. In the Shenyang region, urban forest aboveground biomass ranged from 35.87 to 57.30, with NDVI values exceeding 0.70, correlating with lower PM2.5 and O3 concentrations. Additionally, a correlation was observed between higher PM2.5 and O3 concentrations and building height standard deviations exceeding 1.95. Therefore, urban planning should focus on increasing forest biomass and optimizing tree species composition to enhance air purification capacity, while also improving building layout and reducing height disparities. These measures aim to achieve seasonal coordination in pollution control and promote sustainable improvement of the urban environment.

Urban forests are highly multifunctional and provide numerous ecological functions. Plant functional traits individually or jointly influence the ecological multifunctionality of tree species (TS-EMF) and can also modify TS-EMF in response to environmental changes. However, there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF. Here, for 10 dominant tree species in urban forests of Northeast China, 14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons. Ecological functions and TS-EMF differed significantly throughout the seasons (P < 0.05). Synergistic relationships were found between carbon sequestration and oxygen release, between cooling and humidification, and between organic carbon accumulation and nutrient cycling. Notably, aboveground multifunctionality played a leading role in TS-EMF. With seasonal changes, resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF. The combination of traits that predicted TS-EMF varied by type, accounting for up to 66.45

The traditional Chinese medicinal plant Prunella vulgaris contains numerous triterpene saponin metabolites, notably ursolic and oleanolic acid saponins, which have significant pharmacological values. Despite their importance, the genes responsible for synthesizing these triterpene saponins in P. vulgaris remain unidentified. This study used a comprehensive screening methodology, combining phylogenetic analysis, gene expression assessment, metabolome-transcriptome correlation and co-expression analysis, to identify candidate genes involved in triterpene saponins biosynthesis. Nine candidate genes - two OSCs, three CYP716s and four UGT73s - were precisely identified from large gene families comprising hundreds of members. These genes were subjected to heterologous expression and functional characterization, with enzymatic activity assays confirming their roles in the biosynthetic pathway, aligning with bioinformatics predictions. Analysis revealed that these genes originated from a whole-genome duplication (WGD) event in P. vulgaris, highlighting the potential importance of WGD for plant metabolism. This study addresses the knowledge gap in the biosynthesis of triterpene saponins in P. vulgaris, establishing a theoretical foundation for industrial production via synthetic biology. Additionally, we present an efficient methodological protocol that integrates evolutionary principles and bioinformatics techniques in metabolite biosynthesis research. This approach holds significant value for studies focused on unraveling various biosynthetic pathways.

Trait-based functional diversity (FD) is an important predictor of tree species ecological multifunctionality (TS-EMF), but its relationship may be mediated by environmental factors. Currently, the study of threshold-dependent relationship between FD and TS-EMF along urban and suburban gradients and their environmental regulatory mechanisms is still quite limited. In this study, 12 typical tree species from urban and suburban forests in Shenyang were used to calculate TS-EMF by combining the multithreshold and averaging method, and to assess community FD, aiming to reveal the role of FD on TS-EMF and how environmental factors regulate TS-EMF through FD and community-weighted mean (CWM) traits. The results showed that urban TS-EMF was generally higher than suburban (P < 0.05). There were differences in the driving mechanisms of TS-EMF at different threshold levels, with air humidity (total effect: 0.435) and CWM P-n (net photosynthetic rate, relative importance: 24.42%) being the key drivers at high threshold levels. At low threshold levels, functional evenness (FEve) played a dominant role, but the extent to which influenced TS-EMF depended on the type and number of tree species within the TS-EMF threshold range. Notably, the effects of CWM P-n and FEve on TS-EMF showed threshold dependence, with thresholds of 61.18% and 64.47%, respectively. Additionally, the urban-suburban gradient could significantly influence the driving mechanism: the direct effect of environmental factors and CWM traits prevailed in urban forests, while suburban forests showed a multifactorial cascade effect. The study showed that the formation of TS-EMF in urban forests is the result of multifactorial coupling of traits, FD and environmental factors, and this finding provides a new theoretical perspective for understanding the ecosystem service drivers of urban forests.

Galantamine is an important secondary metabolite in plants that possesses a wide range of biological activities. The reduction of narwedine to form galantamine in planta has been proven to be catalyzed by enzymes in the aldo-keto reductase (AKR) gene family. In this study, ten homologous AKR unigenes were screened from the transcriptome data of Lycoris species, and two AKR homologs (LauAKR1 and LauAKR2) were cloned from Lycoris aurea. Both LauAKR1 and LauAKR2 belong to the AKR4B subfamily and share similarities with known plant AKRs. They have retained most of the conserved active-site residues found in the AKR superfamily of enzymes. LauAKR1 and LauAKR2 were ubiquitously expressed in different tissues of L. aurea, and they were expressed at relatively higher levels in the leaves, seeds, and bulbs. In addition, the transcripts of LauAKR1 and LauAKR2 were induced by treatment with sodium chloride but were unaffected by treatments with methyl jasmonate and mannitol. Additionally, LauAKR1 and LauAKR2 tagged with green fluorescent protein were subjected to agroinfiltration for transient expression in Nicotiana benthamiana, which showed that both LauAKR1 and LauAKR2 are localized to the cytoplasm. LauAKR1 and LauAKR2 facilitated the NADPH-dependent reduction of the substrates demethylnarwedine and narwedine. This study provides direct evidence that LauAKR catalyzes the crucial reduction reactions involved in the formation of galantamine.

Litter chemical traits critically regulate decomposition dynamics and are highly responsive to atmospheric nitrogen (N) deposition, yet the magnitude of their responses and their mechanistic roles in decomposition under N enrichment remain uncertain. Here, we synthesized data from 80 studies to quantify the effects of N addition on litter chemistry and decomposition rates. Our analysis reveals that N addition significantly increases litter N (+34.6 %) and phosphorus (P, +18.5 %) concentrations, while reducing lignin (-2.2 %), cellulose (-2.2 %), and hemicellulose (-2.7 %). Moreover, key stoichiometric ratios-C/N (-23.8 %) and lignin/N (-25.4 %)-decreased, thereby enhancing litter quality. These shifts were more pronounced in herbaceous plants and grassland ecosystems compared to woody plants and forests. Nitrogen enrichment accelerated decomposition of herbaceous plant litter in both common-site and in-situ experiments but had no significant effect on woody plant litter. Decomposition rates (k) in herbaceous plant litter correlated strongly with initial traits-including N, phosphorus (P), calcium (Ca), cellulose, and stoichiometric ratios-whereas woody litter decomposition depended primarily on Ca. Our findings reveal that plant functional types and ecosystems govern decomposition responses to N deposition: grasslands exhibit accelerated decomposition via improved litter quality, while forests exhibit attenuated or even negative decomposition responses due to microbial suppression and inhibition of lignin degradation under. Integrating these trait-mediated mechanisms into biogeochemical models will refine predictions of carbon and nutrient cycling under global N enrichment, particularly in contrasting grassland and forest ecosystems.

Jasmonates (JAs) are among the main phytohormones, regulating plant growth and development, stress responses, and secondary metabolism. As the major regulator of the JA signaling pathway, MYC2 also plays an important role in plant secondary metabolite synthesis and accumulation. In this study, we performed a comparative transcriptome analysis of Lycoris aurea seedlings subjected to methyl jasmonate (MeJA) at different treatment times. A total of 31,193 differentially expressed genes (DEGs) were identified by RNA sequencing. Among them, 732 differentially expressed transcription factors (TFs) comprising 51 TF families were characterized. The most abundant TF family was WRKY proteins (80), followed by AP2/ERF-EFR (67), MYB (59), bHLH (52), and NAC protein (49) families. Subsequently, by calculating the Pearson's correlation coefficient (PCC) between the expression level of TF DEGs and the lycorine contents, 41 potential TF genes (|PCC| >0.8) involved in lycorine accumulation were identified, including 36 positive regulators and 5 negative regulators. Moreover, a MeJA-inducible MYC2 gene (namely LaMYC2) was cloned on the basis of transcriptome sequencing. Bioinformatic analyses revealed that LaMYC2 proteins contain the bHLH-MYC_N domain and bHLH-AtAIB_like motif. LaMYC2 protein is localized in the cell nucleus, and can partly rescue the MYC2 mutant in Arabidopsis thaliana. LaMYC2 protein could interact with most LaJAZs (especially LaJAZ3 and LaJAZ4) identified previously. Transient overexpression of LaMYC2 increased lycorine contents in L. aurea petals, which might be associated with the activation of the transcript levels of tyrosine decarboxylase (TYDC) and phenylalanine ammonia lyase (PAL) genes. By isolating the 887-bp-length promoter fragment upstream of the start codon (ATG) of LaTYDC, we found several different types of E-box motifs (CANNTG) in the promoter of LaTYDC. Further study demonstrated that LaMYC2 was indeed able to bind the E-box (CACATG) present in the LaTYDC promoter, verifying that the pathway genes involved in lycorine biosynthesis could be regulated by LaMYC2, and that LaMYC2 has positive roles in the regulation of lycorine biosynthesis. These findings demonstrate that LaMYC2 is a positive regulator of lycorine biosynthesis and may facilitate further functional research of the LaMYC2 gene, especially its potential regulatory roles in Amaryllidaceae alkaloid accumulation in L. aurea.

The increasing concentrations of ground-level ozone (O3) resulting from industrialisation and anthropogenic activities present a substantial environmental threat to agricultural productivity, particularly affecting O3-sensitive crops such as soybeans. The effects of acute O3 exposure on soybean yield attributes and seed quality and whether soybean showed different detoxification mechanisms in response to moderate and severe O3 stress are not extensively explored. In this study, soybean seedlings were exposed to moderate (80 nmol mol-1) and acute severe (200 nmol mol-1) O3 stress, and then growth parameters, yield attributes, reactive oxygen species (ROS) levels, enzymatic and non-enzymatic antioxidant properties and associated gene expression in the leaves were assessed. The results revealed that moderate O3 exposure enhanced growth parameters but reduced the 100-grain weight, while acute severe exposure sharply depressed growth parameters, yield attributes and the 100-grain weight. Moderate O3 fumigation significantly increased hydrogen peroxide (H2O2) levels and catalase (CAT) activity from 4 to 32 h. Acute severe O3 stress induced the overproduction of superoxide anions (O2.-) and H2O2 during nearly the whole experiment period, but only enhanced superoxide dismutase (SOD) activity at 32 h, and showed no stimulatory effects on CAT activity. Additionally, the relative expression levels of the SOD and CAT gene family in soybean leaves exposed to elevated O3 were upregulated, peaking at 8 h. Moderate O3 treatment enhanced reduced glutathione (GSH) and ascorbate (AsA) levels and increased the activities of AsA-GSH cycle-related enzymes. In contrast, acute severe O3 exposure inhibited GSH and AsA contents and markedly suppressed AsA-GSH cycle-related enzymes, particularly from 8 to 32 h. Redundancy analysis indicated that CAT and AsA play crucial roles in scavenging O3-induced ROS under moderate stress, while ascorbate peroxidase (APX) and GSH were more effective under acute severe stress conditions. These findings provide insights into the differential impacts of acute O3 stress on soybeans, emphasising the importance of considering both crop yield and grain quality in assessing O3 risks to crops.

C-glycosides are a predominant class of flavonoids that demonstrate diverse medical properties and plant physiological functions. The chemical stability, structural diversity, and differential aboveground distribution of these compounds in plants make them ideal protectants. However, little is known about the transcriptional regulatory mechanisms that play these diverse roles in plant physiology. In this study, chard was selected from 69 families for its significantly different flavonoid C-glycosides distributions between the aboveground and underground parts to investigate the role and regulatory mechanism of flavonoid C-glycosides in plants. Our results indicate that flavonoid C-glycosides are affected by various stressors, especially UV-B. Through cloning and validation of key biosynthetic genes of flavonoid C-glycosides in chard (BvCGT1), we observed significant effects induced by UV-B radiation. This finding was further confirmed by resistance testing in BvCGT1 silenced chard lines and in Arabidopsis plants with BvCGT1 overexpression. Yeast one-hybrid and dual-luciferase assays were employed to determine the underlying regulatory mechanisms of BvCGT1 in withstanding UV-B stress. These results indicate a potential regulatory role of BvDof8 and BvDof13 in modulating flavonoid C-glycosides content, through their influence on BvCGT1. In conclusion, we have effectively demonstrated the regulation of BvCGT1 by BvDof8 and BvDof13, highlighting their crucial role in plant adaptation to UV-B radiation. Additionally, we have outlined a comprehensive transcriptional regulatory network involving BvDof8 and BvDof13 in response to UV-B radiation.

Agrobacterium transformation is widely used for plant genome manipulation, which is completed by integration of transfer DNA (T-DNA) into the plant genome. Application of new biotechnology such as genome editing in many horticultural crops is mediated by Agrobacterium transformation. Currently, our knowledge on the chromatin environment around the T-DNA integration sites is limited. In this study, we mapped the genomic locations of T-DNA integrations in woodland strawberry (Fragaria vesca) to the telomere-to-telomere genome, and found that T-DNA integrations recovered under antibiotic selections were biased towards TE-poor euchromatic sequences. We further performed bisulfite sequencing and chromatin immunoprecipitation to analyze DNA methylation and histone modifications of the integration sites. T-DNA integration sites had low levels of DNA methylation, as well as low levels of 24-nt small RNAs which were associated with RNA-dependent DNA methylation. In addition, the sequences flanking T-DNA integration sites had low levels of a silent mark histone 3 lysine 27 trimethylation, and high levels of an active mark histone 3 lysine 9/lysine 14 acetylation. Such structure indicates an open chromatin environment favored by T-DNA integration and/or antibiotic selection in strawberries. This study provides clues for increasing the transformation efficiency for molecular breeding in Rosaceae species in the future.

Although geoscience of natural hydrogen (H2), hydrogen-producing soil bacteria, and especially plant-based H2, has been observed, it is not clear whether or how above H2 resources influence root gravitropic responses. Here, pharmacological, genetic, molecular, and cell biological tools were applied to investigate how plant-based H2 coordinates gravity responses in Arabidopsis roots. Since roots show higher H2 production than shoots, exogenous H2 supply was used to mimic this function. After H2 supplementation, the asymmetric expression of the auxin-response reporter DR5 driven by auxin influx and efflux carriers, and thereafter positive root gravitropism were observed. These positive responses in root gravitropism were sensitive to auxin polar transport inhibitors, and importantly, the defective phenotypes observed in aux1-7, pin1, and pin2 mutants were not significantly altered by exogenous H2. The observed starch accumulation was matched with the reprogramming gene expression linked to starch synthesis and degradation. Transgenic plants expressing hydrogenase1 (CrHYD1) from Chlamydomonas reinhardtii not only displayed higher endogenous H2 concentrations, the inducible AUX1 gene expression and starch accumulation, but also showed pronounced root gravitropism. Collectively, above evidence preliminarily provides a framework for understanding the molecular basis of the possible functions of both plant/soil-based and nature H2 in root architecture.

Hydroxynitrile lyases (HNLs) are a class of hydrolytic enzymes from a wide range of sources, which play crucial roles in the catalysis of the reversible conversion of carbonyl compounds derived from cyanide and free cyanide in cyanogenic plant species. HNLs were also discovered in non-cyanogenic plants, such as Arabidopsis thaliana, and their roles remain unclear even during plant growth and reproduction. The pattern of expression of the HNL in A. thaliana (AtHNL) in different tissues, as well as under abiotic stresses and hormone treatments, was examined by real-time quantitative reverse transcription PCR (qRT-PCR) and an AtHNL promoter-driven histochemical β-glucuronidase (GUS) assay. AtHNL is highly expressed in flowers and siliques, and the expression of AtHNL was dramatically affected by abiotic stresses and hormone treatments. The overexpression of AtHNL resulted in transgenic A. thaliana seedlings that were more tolerance to mannitol and salinity. Moreover, transgenic lines of A. thaliana that overexpressed this gene were less sensitive to abscisic acid (ABA). Altered expression of ABA/stress responsive genes was also observed in hnl mutant and AtHNL-overexpressing plants, suggesting AtHNL may play functional roles on regulating Arabidopsis resistance to ABA and abiotic stresses by affecting ABA/stress responsive gene expression. In addition, the overexpression of AtHNL resulted in earlier flowering, whereas the AtHNL mutant flowered later than the wild type (WT) plants. The expression of the floral stimulators CONSTANS (CO), SUPPRESSOR OF OVER EXPRESSION OF CO 1 (SOC1) and FLOWERING LOCUS T (FT) was upregulated in plants that overexpressed AtHNL when compared with the WT plants. In contrast, expression of the floral repressor FLOWERING LOCUS C (FLC) was upregulated in AtHNL mutants and downregulated in plants that overexpressed AtHNL compared to the WT plants. This study revealed that AtHNL can be induced under abiotic stresses and ABA treatment, and genetic analysis showed that AtHNL could also act as a positive regulator of abiotic stress and ABA tolerance, as well as flowering time.

Lycoris radiata is the main source of galanthamine, a clinical drug used in Alzheimer’s disease; however, the galanthamine content in L. radiata is low. Lycoris aurea is another Lycoris species with high galanthamine content. Fungal endophytes can enhance plant secondary metabolite accumulation; thus, we compared the fungal communities in these two Lycoris species to identify certain fungal taxa in L. aurea capable of enhancing galanthamine accumulation. Several fungal endophytes, which were enriched in, exclusively isolated from L. aurea, or showed significant correlations with galanthamine, were demonstrated to enhance the accumulation of only galanthamine but no other Amaryllidaceae alkaloids (AAs) in L. radiata. These fungal endophytes mainly upregulated the downstream genes in the biosynthesis pathways of AAs in L. radiata, suggesting that they may allocate more precursors for galanthamine biosynthesis. This study demonstrated that fungal endophytes from L. aurea with higher galanthamine content can specifically enhance the accumulation of this medicinal alkaloid in other Lycoris species, thereby increasing the galanthamine source and reducing galanthamine separation and purification costs. This study broadens our understanding of the complex interactions between plant secondary metabolites and fungal endophytes.

Pyran- and furanocoumarins are key representatives of tetrahydropyrans and tetrahydrofurans, respectively, exhibiting diverse physiological and medical bioactivities. However, the biosynthetic mechanisms for their core structures remain poorly understood. Here we combined multiomics analyses of biosynthetic enzymes in Peucedanum praeruptorum and in vitro functional verification and identified two types of key enzymes critical for pyran and furan ring biosynthesis in plants. These included three distinct P. praeruptorum prenyltransferases (PpPT1-3) responsible for the prenylation of the simple coumarin skeleton 7 into linear or angular precursors, and two novel CYP450 cyclases (PpDC and PpOC) crucial for the cyclization of the linear/angular precursors into either tetrahydropyran or tetrahydrofuran scaffolds. Biochemical analyses of cyclases indicated that acid/base-assisted epoxide ring opening contributed to the enzyme -catalyzed tetrahydropyran and tetrahydrofuran ring refactoring. The possible acid/base-assisted catalytic mechanisms of the identified cyclases were theoretically investigated and assessed using site -specific mutagenesis. We identified two possible acidic amino acids Glu303 in PpDC and Asp301 in PpOC as vital in the catalytic process. This study provides new enzymatic tools in the epoxide formation/epoxide-opening mediated cascade reaction and exemplifies how plants become chem- ically diverse in terms of enzyme function and catalytic process. 2024 The Authors. Published by Elsevier B.V. on behalf of Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. This is an open access article under the CC BY -NC - ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

A reliable and stable hydrogen gas (H-2) supply will benefit agricultural laboratory and field trials. Here, we assessed ammonia borane (AB), an efficient hydrogen storage material used in the energy industry, and determined its effect on plant physiology and the corresponding mechanism. Through hydroponics and pot experiments, we discovered that AB increases tomato (Solanum lycopersicum) lateral root (LR) branching and this function depended on the increased endogenous H-2 level caused by the sustainable H-2 supply. In particular, AB might trigger LR primordia initiation. Transgenic tomato and Arabidopsis (Arabidopsis thaliana) expressing hydrogenase1 (CrHYD1) from Chlamydomonas reinhardtii not only accumulated higher endogenous H-2 and phytomelatonin levels but also displayed pronounced LR branching. These endogenous H-2 responses achieved by AB or genetic manipulation were sensitive to the pharmacological removal of phytomelatonin, indicating the downstream role of phytomelatonin in endogenous H-2 control of LR formation. Consistently, extra H-2 supply failed to influence the LR defective phenotypes in phytomelatonin synthetic mutants. Molecular evidence showed that the phytomelatonin-regulated auxin signaling network and cell-cycle regulation were associated with the AB/H-2 control of LR branching. Also, AB and melatonin had little effect on LR branching in the presence of auxin synthetic inhibitors. Collectively, our integrated approaches show that supplying H-2 via AB increases LR branching via phytomelatonin signaling. This finding might open the way for applying hydrogen storage materials to horticultural production.

Caffeic acid O-methyltransferase (COMT) catalyzes key steps in the biosynthesis of lignin. It can also act as an N-acetylserotonin O-methyltransferase (ASMT), which participates in the last step of melatonin biosynthesis. Melatonin has been demonstrated to play vital roles in the regulation of plant processes and stress responses. However, the ASMT activity of COMT has not yet been characterized in the non-model plant golden spider lily (Lycoris aurea [L’Hér.] Herb), which is an ornamental that is medicinally important. A previous transcriptome analysis identified the COMT gene (LaCOMT) in this plant. The recombinant LaCOMT protein from E. coli was highly active toward ASMT, and this activity was significantly inhibited by caffeic acid in a dose-dependent manner. LaCOMT-GFP was localized to the cytoplasm and nucleus. Considering that the bulbs of L. aurea can tolerate extreme environmental conditions, such as drought stress, waterlogging and poor soil conditions, the pattern of expression of LaCOMT in different tissues and after exposure to mercuric chloride (HgCl2) was analyzed. The results revealed that LaCOMT is ubiquitously expressed in all the tissues studied and can be induced by HgCl2. Moreover, the heterologous overexpression of LaCOMT led to mercury tolerance in transgenic Arabidopsis thaliana plants. This could be attributed to the accumulation of scavenged reactive oxygen species (ROS) by elevating antioxidant enzymes and augmenting antioxidants in the transgenic A. thaliana plants that overexpressed LaCOMT. Our results suggest that LaCOMT participates in the alleviation of Hg toxicity by modulating ROS homeostasis in plants.

Cinnamyl alcohol dehydrogenase (CAD) plays a crucial role in lignin biosynthesis, and the gene family encoding various CAD isozymes has been cloned and characterized in numerous plant species. However, limited information regarding the CAD gene family in tobacco is currently available. In this study, we identified 10 CAD genes in Nicotiana tabacum, four in N. tomentosiformis, and six in N. sylvestris. The nucleotide and amino acid sequences of these tobacco CADs demonstrate high levels of similarity, whereas the putative protein sequences conservatively possessed two Zn2+ binding motifs and an NADP(H) cofactor binding motif. Both NtCAD1 and NtCAD2 had conservative substrate binding sites, similar to those possessed by bona fide CADs, and evidence from phylogenetic analysis as well as expression profiling supported their role as bona fide CADs involved in lignin biosynthesis. NtCAD1 has two paralogous genes, NtCAD1–1 and NtCAD1–2. Enzyme activity analysis revealed that NtCAD1–1 and NtCAD1–2 had a high affinity to coniferyl aldehyde, p-coumaryl aldehyde, and sinapyl aldehyde, whereas NtCAD2 preferred coniferyl aldehyde and p-coumaryl aldehyde as substrates. The kinetic parameter assay revealed that NtCAD1–2 functions as the most efficient enzyme. Downregulation of both NtCAD1–1 and NtCAD1–2 resulted in reddish-brown stems without significant changes in lignin content. Furthermore, NtCAD1–1, NtCAD1–2, and NtCAD2 showed distinct expression patterns in response to biotic and abiotic stresses, as well as different phytohormones. Our findings suggest that NtCAD1–1 and NtCAD1–2 are involved in lignin biosynthesis, with NtCAD1–2 also participating in both biological and abiotic stresses, whereas NtCAD2 plays a distinct role mainly in responding to biological and abiotic stresses in tobacco.