LysM receptor-like kinases involved in immunity perceive lipo-chitooligosaccharides in mycotrophic plants.

Symbiotic microorganisms such as arbuscular mycorrhizal fungi (AMF) produce both conserved microbial molecules that activate plant defense and lipo-chitooligosaccharides (LCOs) that modulate plant defense. Beside a well-established role of LCOs in the activation of a signaling pathway required for AMF penetration in roots, LCO perception and defense modulation during arbuscular mycorrhiza is not well understood. Here we show that members of the LYRIIIA phylogenetic group from the multigenic Lysin Motif Receptor-Like Kinase family have a conserved role in dicotyledons as modulators of plant defense and regulate AMF colonization in the Solanaceae species Nicotiana benthamiana. Interestingly, these proteins have a high-affinity for LCOs in plant species able to form a symbiosis with AMF but have lost this property in species that have lost this ability. Our data support the hypothesis that LYRIIIA proteins modulate plant defense upon LCO perception to facilitate AMF colonization in mycotrophic plant species and that only their role in plant defense, but not their ability to be regulated by LCOs, has been conserved in non-mycotrophic plants.

LC-MS/MS based metabolomics and proteomics reveal candidate biomarkers and molecular mechanism of early IgA nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN), a globally common primary chronic glomerulopathy, is one of the leading causes of end-stage renal disease. However, the underlying mechanisms of IgAN have yet to be demonstrated. There were no adequate and reliable plasma biomarkers for clinical diagnosis, especially at the early stage. In the present study, integrative proteomics and metabolomics were aimed at exploring the mechanism of IgAN and identifying potential biomarkers. METHODS: Plasma from IgAN and healthy individuals were collected and analyzed in a randomized controlled manner. Data-independent acquisition quantification proteomics and mass spectrometry based untargeted metabolomics techniques were used to profile the differentially expressed proteins (DEPs) and differentially abundant metabolites (DAMs) between two groups and identify potential biomarkers for IgAN from health at the early stage. Disease-related pathways were screened out by clustering and function enrichment analyses of DEPs and DAMs. And the potential biomarkers for IgAN were identified through the machine learning approach. Additionally, an independent cohort was used to validate the priority candidates by enzyme-linked immunosorbent assay (ELISA). RESULTS: Proteomic and metabolomic analyses of IgAN plasma showed that the complement and the immune system were activated, while the energy and amino acid metabolism were disordered in the IgAN patients. PRKAR2A, IL6ST, SOS1, and palmitoleic acid have been identified as potential biomarkers. Based on the AUC value for the training and test sets, the classification performance was 0.994 and 0.977, respectively. The AUC of the external validation of the four biomarkers was 0.91. CONCLUSION: In this study, we combined proteomics and metabolomics techniques to analyze the plasma of IgAN patients and healthy individuals, constructing a biomarker panel, which could provide new insights and provide potential novel molecular diagnoses for IgAN.

The 16α-Hydroxylation of Progesterone by Cytochrome P450 107X1 from Streptomyces avermitilis.

Cytochrome P450 enzymes (CYPs or P450s) are ubiquitous heme-dependent enzymes that catalyze the monooxygenation of non-activated C-H bonds to modify the structure of the substrate. In this study, we heterologously expressed CYP107X1 from Streptomyces avermitilis and conducted in vitro substrate screening using the alternative redox partners putidaredoxin and putidaredoxin reductase. CYP107X1 catalyzed the 16α-hydroxylation of progesterone with regio- and stereoselectivity. The spectroscopic analyses showed that CYP107X1 bound progesterone with a relatively high Kd value of 65.3±38.9 µM. The Km and kcat values for progesterone were estimated to be 47.7±12.0 µM and 0.30 min-1 , respectively. Furthermore, a crystal structure was obtained of CYP107X1 bound with glycerol from the buffer solution. Interestingly, a conserved threonine was replaced with asparagine in CYP107X1, indicating that it may adopt an unnatural proton transfer process and play a crucial role in its catalytic activity.

Transcriptional regulation of Lonicera japonica Thunb. during flower development as revealed by comprehensive analysis of transcription factors.

BACKGROUND: Lonicera japonica Thunb. flower has been used for the treatment of various diseases for a long time and attracted many studies on its potential effects. Transcription factors (TFs) regulate extensive biological processes during plant development. As the restricted reports of L. japonica on TFs, our work was carried out to better understand the TFs' regulatory roles under different developmental stages in L. japonica. RESULTS: In this study, 1316 TFs belonging to 52 families were identified from the transcriptomic data, and corresponding expression profiles during the L. japonica flower development were comprehensively analyzed. 917 (69.68%) TFs were differentially expressed. TFs in bHLH, ERF, MYB, bZIP, and NAC families exhibited obviously altered expression during flower growth. Based on the analysis of differentially expressed TFs (DETFs), TFs in MYB, WRKY, NAC and LSD families that involved in phenylpropanoids biosynthesis, senescence processes and antioxidant activity were detected. The expression of MYB114 exhibited a positive correlation with the contents of luteoloside; Positive correlation was observed among the expression of MYC12, chalcone synthase (CHS) and flavonol synthase (FLS), while negative correlation was observed between the expression of MYB44 and the synthases; The expression of LSD1 was highly correlated with the expression of SOD and the total antioxidant capacity, while the expression of LOL1 and LOL2 exhibited a negative correlation with them; Many TFs in NAC and WRKY families may be potentially involved in the senescence process regulated by hormones and reactive oxygen species (ROS). The expression of NAC19, NAC29, and NAC53 exhibited a positive correlation with the contents of ABA and H2O2, while the expression of WRKY53, WRKY54, and WRKY70 exhibited a negative correlation with the contents of JA, SA and ABA. CONCLUSIONS: Our study provided a comprehensive characterization of the expression profiles of TFs during the developmental stages of L. japonica. In addition, we detected the key TFs that may play significant roles in controlling active components biosynthesis, antioxidant activity and flower senescence in L. japonica, thereby providing valuable insights into the molecular networks underlying L. japonica flower development.

A metabolomic strategy revealed the role of JA and SA balance in Clematis terniflora DC. Response to UVB radiation and dark.

Clematis terniflora DC. is a valuable resource with potential high pharmaceutical value. Proteomic, transcriptomic and metabolomic analyses of C. terniflora that has been exposed to high levels of UVB irradiation and dark conditions (HUVB + D) have revealed the mechanisms underlying its medicinal potential. However, the signal transduction pathways and the mechanisms of regulation for the accumulation of secondary metabolites remain unclear. In this study, we show that the jasmonic acid (JA) and salicylic acid (SA) signals were activated in C. terniflora in response to HUVB + D. Metabolomic analysis demonstrated that the perturbation in JA and SA balance led to additional reallocation of carbon and nitrogen resources. Evaluating the fold change ratios of differentially changed metabolites proved that JA signal enhanced the transformation of nitrogen to carbon through the 4-aminobutyric acid (GABA) shunt pathway, which increased the carbon reserve to be utilized in the production of secondary metabolites. However, SA signal induced the synthesis of proline, while avoiding the accumulation of secondary metabolites. Over all, the results indicate that the co-increase of JA and SA reconstructed the dynamic stability of transformation from nitrogen to carbon, which effectively enhanced the oxidative defense to HUVB + D in C. terniflora by increasing the secondary metabolites.

Organ-Specific Analysis of Morus alba Using a Gel-Free/Label-Free Proteomic Technique.

Morus alba is an important medicinal plant that is used to treat human diseases. The leaf, branch, and root of Morus can be applied as antidiabetic, antioxidant, and anti-inflammatory medicines, respectively. To explore the molecular mechanisms underlying the various pharmacological functions within different parts of Morus, organ-specific proteomics were performed. Protein profiles of the Morus leaf, branch, and root were determined using a gel-free/label-free proteomic technique. In the Morus leaf, branch, and root, a total of 492, 414, and 355 proteins were identified, respectively, including 84 common proteins. In leaf, the main function was related to protein degradation, photosynthesis, and redox ascorbate/glutathione metabolism. In branch, the main function was related to protein synthesis/degradation, stress, and redox ascorbate/glutathione metabolism. In root, the main function was related to protein synthesis/degradation, stress, and cell wall. Additionally, organ-specific metabolites and antioxidant activities were analyzed. These results revealed that flavonoids were highly accumulated in Morus root compared with the branch and leaf. Accordingly, two root-specific proteins named chalcone flavanone isomerase and flavonoid 3,5-hydroxylase were accumulated in the flavonoid pathway. Consistent with this finding, the content of the total flavonoids was higher in root compared to those detected in branch and leaf. These results suggest that the flavonoids in Morus root might be responsible for its biological activity and the root is the main part for flavonoid biosynthesis in Morus.

Molecular Characterization of a Geranyl Diphosphate-Specific Prenyltransferase Catalyzing Stilbenoid Prenylation from Morus alba.

Pharmaceutically active compounds from medical plants are attractive as a major source for new drug development. Prenylated stilbenoids with increased lipophilicity are valuable secondary metabolites which possess a wide range of biological activities. So far, many prenylated stilbenoids have been isolated from Morus alba but the enzyme responsible for the crucial prenyl modification remains unknown. In the present study, a stilbenoid-specific prenyltransferase (PT), termed Morus alba oxyresveratrol geranyltransferase (MaOGT), was identified and functionally characterized in vitro. MaOGT recognized oxyresveratrol and geranyl diphosphate (GPP) as natural substrates, and catalyzed oxyresveratrol prenylation. Our results indicated that MaOGT shared common features with other aromatic PTs, e.g. multiple transmembrane regions, conserved functional domains and targeting to plant plastids. This distinct PT represents the first stilbenoid-specific PT accepting GPP as a natural prenyl donor, and could help identify additional functionally varied PTs in moraceous plants. Furthermore, MaOGT might be applied for high-efficiency and large-scale prenylation of oxyresveratrol to produce bioactive compounds for potential therapeutic applications.

Comparative Proteomic Analysis Reveals Elevated Capacity for Photosynthesis in Polyphenol Oxidase Expression-Silenced Clematis terniflora DC. Leaves.

Polyphenol oxidase (PPO) catalyzes the o-hydroxylation of monophenols and oxidation of o-diphenols to quinones. Although the effects of PPO on plant physiology were recently proposed, little has been done to explore the inherent molecular mechanisms. To explore the in vivo physiological functions of PPO, a model with decreased PPO expression and enzymatic activity was constructed on Clematis terniflora DC. using virus-induced gene silencing (VIGS) technology. Proteomics was performed to identify the differentially expressed proteins (DEPs) in the model (VC) and empty vector-carrying plants (VV) untreated or exposed to high levels of UV-B and dark (HUV-B+D). Following integration, it was concluded that the DEPs mainly functioned in photosynthesis, glycolysis, and redox in the PPO silence plants. Mapman analysis showed that the DEPs were mainly involved in light reaction and Calvin cycle in photosynthesis. Further analysis illustrated that the expression level of adenosine triphosphate (ATP) synthase, the content of chlorophyll, and the photosynthesis rate were increased in VC plants compared to VV plants pre- and post HUV-B+D. These results indicate that the silence of PPO elevated the plant photosynthesis by activating the glycolysis process, regulating Calvin cycle and providing ATP for energy metabolism. This study provides a prospective approach for increasing crop yield in agricultural production.

Proteomic and Metabolomic Analyses of Leaf from Clematis terniflora DC. Exposed to High-Level Ultraviolet-B Irradiation with Dark Treatment.

Clematis terniflora DC. has potential pharmaceutical value; on the contrary, high-level UV-B irradiation with dark treatment led to the accumulation of secondary metabolites. Metabolomic and proteomic analyses of leaf of C. terniflora were performed to investigate the systematic response mechanisms to high-level UV-B irradiation with dark treatment. Metabolites related to carbohydrates, fatty acids, and amino acids and/or proteins related to stress, cell wall, and amino acid metabolism were gradually increased in response to high-level UV-B irradiation with dark treatment. On the basis of cluster analysis and mapping of proteins related to amino acid metabolism, the abundances of S-adenosylmethionine synthetase and cysteine synthase as well as 1,1-diphenyl-2-picrylhydrazyl scavenging activity were gradually increased in response to high-level UV-B irradiation with dark treatment. Furthermore, the abundance of dihydrolipoyl dehydrogenase/glutamate dehydrogenase and the content of γ-aminobutyric acid were also increased following high-level UV-B irradiation with dark treatment. Taken together, these results suggest that high-level UV-B irradiation with dark treatment induces the activation of reactive oxygen species scavenging system and γ-aminobutyric acid shunt pathway in leaf of C. terniflora.

Enhanced metabolic process to indole alkaloids in Clematis terniflora DC. after exposure to high level of UV-B irradiation followed by the dark.

BACKGROUND: Indole alkaloids, which characteristically contain an indole nucleus, have pharmaceutical potential in a diverse range of applications. UV-B can elicit the accumulation of indole alkaloids. The indole alkaloid (6-hydroxyl-1H-indol-3-yl) carboxylic acid methyl ester with cytotoxic activity was found to accumulate in Clematis terniflora DC. leaves after exposure to high level of UV-B irradiation and the dark. However, a more in-depth analysis of the process behind this response has not yet been performed. Therefore, an integrated approach involving metabolomic, proteomic, and transcriptomic analyses is essential to detail the biosynthetic mechanisms of the regulation of indole alkaloid under binary stress. RESULTS: Indole alkaloid (6-hydroxyl-1H-indol-3-yl) carboxylic acid methyl ester was found to increase 7-fold in C. terniflora leaves post-treatment with high level of UV-B irradiation followed by an incubation in the dark compared with pre-treatment. Analysis by proteomics and metabolomics indicates a decrease in photosynthesis and carbohydrate metabolism, respectively. By contrast, amino acid metabolism was activated by this binary stress, and, specifically, the genes involved in the metabolic pathway converting shikimate to L-tryptophan were concurrently upregulated. Metabolites involved in indole biosynthesis (shikimate metabolic) pathway were anthranilate, indole, and L-tryptophan, which increased 2-, 441-, and 1-fold, respectively. In addition, there was an increase of 2- and 9-fold in L-serine deaminase (L-SD) and L-tryptophan synthase activity in C. terniflora leaves after exposure to high level of UV-B irradiation and the dark. CONCLUSIONS: (6-hydroxyl-1H-indol-3-yl) carboxylic acid methyl ester was found to increase in response to high level of UV-B irradiation followed by an incubation in the dark, implying that indole alkaloid biosynthesis was activated in C. terniflora leaves. Analysis of perturbations in metabolism in these leaves demonstrated that amino acid metabolism was specifically activated by this binary stress. In addition, an enhancement in serine level and L-SD activity was noted, which likely leads to an accumulation of pyruvate that, in turn, supplies shikimate metabolic pathway. The genes, metabolites, and L-tryptophan synthase activity that are involved in the metabolic pathway leading from shikimate to L-tryptophan all increased under the experimental binary stress, resulting in an enhancement of indole biosynthesis (shikimate metabolic) pathway. Therefore, the metabolic process to indole alkaloids in C. terniflora was enhanced after exposure to high level of UV-B irradiation followed by the dark.

Aurantiamide acetate suppresses the growth of malignant gliomas in vitro and in vivo by inhibiting autophagic flux.

We aim to investigate the effect of aurantiamide acetate isolated from the aerial parts of Clematis terniflora DC against gliomas. Human malignant glioma U87 and U251 cells were incubated with different concentrations (0-100 µM) of aurantiamide acetate. Aurantiamide acetate greatly decreased the cell viability in a dose- and time-dependent manner. It induced moderate mitochondrial fragmentation and the loss of mitochondrial membrane potential. No significant difference was found in the alternation of other intracellular organelles, although F-actin structure was slightly disturbed. Apparent ultrastructure alternation with increased autophagosome and autolysosome accumulation was observed in aurantiamide acetate-treated cells. The expression of LC3-II was greatly up-regulated in cells exposed to aurantiamide acetate (P < 0.05 compared with control). The cytoplasmic accumulation of autophagosomes and autolysosomes induced by aurantiamide acetate treatment was confirmed by fluorescent reporter protein labelling. Administration of chloroquine (CQ), which inhibits the fusion step of autophagosomes, further increased the accumulation of autophagosomes in the cytoplasm of U87 cells. Autophagy inhibition by 3-methyladenine, Bafilomycin A1 or CQ had no influence on aurantiamide acetate-induced cytotoxicity, whereas autophagy stimulator rapamycin significantly suppressed aurantiamide acetate-induced cell death. The anti-tumour effects of aurantiamide acetate were further evaluated in tumour-bearing nude mice. Intratumoural injection of aurantiamide acetate obviously suppressed tumour growth, and increased number of autophagic vacuoles was observed in tumour tissues of animals receiving aurantiamide acetate. Our findings suggest that aurantiamide acetate may suppress the growth of malignant gliomas by blocking autophagic flux.

Transcriptomic Insights into Molecular Response of Butter Lettuce to Different Light Wavelengths.

Lettuce is a widely consumed leafy vegetable; it became popular due to its enhanced nutritional content. Recently, lettuce is also regarded as one of the model plants for vegetable production in plant factories. Light and nutrients are essential environmental factors that affect lettuce growth and morphology. To evaluate the impact of light spectra on lettuce, butter lettuce was grown under the light wavelengths of 460, 525, and 660 nm, along with white light as the control. Plant morphology, physiology, nutritional content, and transcriptomic analyses were performed to study the light response mechanisms. The results showed that the leaf fresh weight and length/width were higher when grown at 460 nm and lower when grown at 525 nm compared to the control treatment. When exposed to 460 nm light, the sugar, crude fiber, mineral, and vitamin concentrations were favorably altered; however, these levels decreased when exposed to light with a wavelength of 525 nm. The transcriptomic analysis showed that co-factor and vitamin metabolism- and secondary metabolism-related genes were specifically induced by 460 nm light exposure. Furthermore, the pathway enrichment analysis found that flavonoid biosynthesis- and vitamin B6 metabolism-related genes were significantly upregulated in response to 460 nm light exposure. Additional experiments demonstrated that the vitamin B6 and B2 content was significantly higher in leaves exposed to 460 nm light than those grown under the other conditions. Our findings suggested that the addition of 460 nm light could improve lettuce's biomass and nutritional value and help us to further understand how the light spectrum can be tuned as needed for lettuce production.

Lead toxicity regulation via protein degradation and tetrapyrrole biosynthesis pathways in Brassica species: A comparative quantitative analysis of proteomic study.

Understanding the heavy metals (HMs) tolerance mechanism is crucial for improving plant growth in metal-contaminated soil. In order to evaluate the lead (Pb) tolerance mechanism in Brassica species, a comparative proteomic study was used. Thirteen-day-old seedlings of B. juncea and B. napus were treated with different Pb(NO3)2 concentrations at 0, 3, 30, and 300 mg/L. Under 300 mg/L Pb(NO3)2 concentration, B. napus growth was significantly decreased, while B. juncea maintained normal growth similar to the control. The Pb accumulation was also higher in B. napus root and shoot compared to B. juncea. Gel-free proteomic analysis of roots revealed a total of 68 and 37 differentially abundant proteins (DAPs) in B. juncea and B. napus-specifically, after 300 mg/L Pb exposure. The majority of these proteins are associated with protein degradation, cellular respiration, and enzyme classification. The upregulated RPT2 and tetrapyrrole biosynthesis pathway-associated proteins maintain the cellular homeostasis and photosynthetic rate in B. juncea. Among the 55 common DAPs, S-adenosyl methionine and TCA cycle proteins were upregulated in B. juncea and down-regulated in B. napus after Pb exposure. Furthermore, higher oxidative stress also reduced the antioxidant enzyme activity in B. napus. The current finding suggests that B. juncea is more Pb tolerant than B. napus, possibly due to the upregulation of proteins involved in protein recycling, degradation, and tetrapyrrole biosynthesis pathway.

The role of reduced graphene oxide on mitigation of lead phytotoxicity in Triticum aestivum L.plants at morphological and physiological levels.

Rapid global industrialization and an increase in population have enhanced the risk of heavy metals accumulation in plant bodies to disrupt the morphological, biochemical, and physiological processes of plants. To cope with this situation, reduced graphene oxide (rGO) NPs were used first time to mitigate abiotic stresses caused in plant. In this study, rGO NPs were synthesized and reduced with Tecoma stans plant leave extract through modified Hummer's methods. The well prepared rGO NPs were characterized by ultra-violet visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Zeta potential, and scanning electron microscopy (SEM). However, pot experiment was conducted with four different concentrations (15, 30, 60, 120 mg/L) of rGO NPs and three different concentrations (300, 500,700 mg/L) of lead (Pb) stress were applied. To observe the mitigative effects of rGO NPs, 30 mg/L of rGO NPs and 700 mg/L of Pb were used in combination. Changes in morphological and biochemical characteristics of wheat plants were observed for both Pb stress and rGO NPs treatments. Pb was found to inhibit the morphological and biochemical characteristics of plants. rGO NPs alone as well as in combination with Pb was found to increase the chlorophyll content of wheat plants. Under Pb stress conditions and rGO NPs treatments, antioxidant enzyme activities like ascorbate peroxidases (APX), superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) were observed. Current findings revealed that greenly reduced graphene oxide NPs can effectively promote growth in wheat plants under Pb stress by elevating chlorophyll content of leaves, reducing the Pb uptake, and suppressing ROS produced due to Pb toxicity.

Integrative Proteomic and Phosphoproteomic Analyses Revealed the Regulatory Mechanism of the Response to Ultraviolet B Stress in Clematis terniflora DC.

Clematis terniflora DC. (C. terniflora) has been used as an ancient Chinese traditional herbal medicine. The active substances in C. terniflora have been confirmed to be effective in treating diseases such as prostatitis. UV light radiation is a common environmental factor that damages plants and influences primary and secondary metabolism. Previous studies showed that ultraviolet B (UV-B) radiation followed by dark stress resulted in the accumulation of secondary metabolites in C. terniflora leaves. An in-depth understanding of how C. terniflora leaves respond to UV-B stress is crucial for improving C. terniflora value. Here, we conducted label-free proteomic and phosphoproteomic analyses to explore the protein changes under UV-B and UV-B combined with dark treatment. A total of 2839 proteins and 1638 phosphorylated proteins were identified. Integrative omics revealed that the photosynthetic system and carbohydrate balance were modulated under both stresses. The phosphoproteomic data indicated that the mitogen-activated protein kinase signaling pathway was triggered, while the abundance of phosphorylated proteins related to osmotic stress was increased under UV-B stress. Differentially abundant phosphoproteins from UV-B followed by dark treatment were mainly enriched in response to stimulus including calcium-mediated proteins. This study provides new insight into the impact of UV-B stress on C. terniflora and plant molecular resistance mechanisms through proteomic and phosphoproteomic analyses.

Integrative Omic Analysis Reveals the Dynamic Change in Phenylpropanoid Metabolism in Morus alba under Different Stress.

Morus alba is used as a traditional Chinese medicine due to its various biological activities. Phenylpropanoid metabolism is one of the most important pathways in Morus alba to produce secondary metabolites and response to stress. From the general phenylpropanoid pathway, there are two metabolic branches in M. alba, including flavonoid and lignin biosynthesis, which also play roles in response to stress. However, the dynamic changes between flavonoid and lignin biosynthesis under Botrytis cinerea infection and UV-B stress in M. alba were unclear. To explore the different regulation mode of flavonoid and lignin biosynthesis in M. alba leaves' response to biotic and abiotic stress, a combined proteomic and metabolomic study of M. alba leaves under UV-B stress and B. cinerea infection was performed. The results showed that most of the proteins involved in the lignin and flavonoid biosynthesis pathway were increased under either UV-B stress or B. cinerea infection in M. alba. This was also confirmed by enzyme assays and metabolomics analysis. Additionally, the abundance of proteins involved in the biosynthesis of jasmonic acid was increased after B. cinerea infection. This suggests that both flavonoid and lignin biosynthesis participate in the responses to abiotic and biotic stress in M. alba, but they might be regulated by different hormone signaling.

The chloroplast GATA-motif of Mahonia bealei participates in alkaloid-mediated photosystem inhibition during dark to light transition.

Mahonia bealei and Mahonia fortunei are important plant resources in Traditional Chinese Medicine that are valued for their high levels of benzylisoquinoline alkaloids (BIAs). Although the phytotoxic activity of BIAs has been recognized, information is limited on the mechanism of action by which these compounds regulate photosynthetic activity. Here, we performed comparative chloroplast genome analysis to examine insertions and deletions in the two species. We found a GATA-motif located in the promoter region of the ndhF gene of only M. bealei. K-mer frequency-based diversity analysis illustrated the close correlation between the GATA-motif and leaf phenotype. We found that the GATA-motif significantly inhibits GUS gene expression in tobacco during the dark-light transition (DLT). The expression of ndhF was downregulated in M. bealei and upregulated in M. fortunei during the DLT. NDH-F activity was remarkably decreased and exhibited a significant negative correlation with BIA levels in M. bealei during the DLT. Furthermore, the NADPH produced through photosynthetic metabolism was found to decrease in M. bealei during the DLT. Taken together, our results indicate that this GATA-motif might act as the functional site by which BIAs inhibit photosynthetic metabolism through downregulating ndhF expression during the DLT.

Integrated multi-omic analysis reveals the cytokinin and sucrose metabolism-mediated regulation of flavone glycoside biosynthesis by MeJA exposure in Ficus pandurata Hance.

Ficus pandurata Hance (FPH) holds a rich history as a traditional Chinese botanical remedy, utilized both as a culinary condiment and a medicinal intervention for diverse ailments. This study focuses on enhancing FPH's therapeutic potential by subjecting it to exogenous methyl jasmonate (MeJA) treatment, a strategy aimed at elevating the levels of active constituents to align with clinical and commercial requirements. Employing metabolomics, the impact of MeJA treatment on the lipid and flavonoid profiles of FPH leaves was investigated, revealing a marked increase in flavone glycosides, a subset of flavonoids. Investigation into the regulatory mechanism governing flavone glycoside biosynthesis uncovered elevated expression of structural genes associated with flavonoid production in response to MeJA exposure. Global endogenous hormone analysis pinpointed the selective activation of JA and cytokinin biosynthesis following MeJA treatment. Through a comprehensive integration of transcriptomic and metabolomic data, the cooperative stimulation of glucosyltransferase activity, alongside the JA and cytokinin signaling pathways, orchestrated by MeJA were explored. Furthermore, genes linked to sucrose metabolism exhibited heightened expression, concomitant with a noteworthy surge in antioxidant activity subsequent to MeJA treatment. These findings validate the augmentation of FPH leaf antioxidant capacity through MeJA intervention, while also offering profound insights into the regulatory role of MeJA in flavone glycoside biosynthesis, mediated by the interplay between cytokinin and sucrose metabolism pathways.

Proteomics and metabolomics reveal the mechanism underlying differential antioxidant activity among the organs of two base plants of Shiliang tea (Chimonanthus salicifolius and Chimonanthus zhejiangensis).

The leaves and branches of Chimonanthus salicifolius and Chimonanthus zhejiangensis are the base ingredients of Shiliang tea. In this study, proteomics and metabolomics were performed to understand the molecular mechanisms underlying antioxidant activity (AA) in the leaves and branches of the two species. Stress and redox related proteins are differentially expressed among organs. The abundance of isoprenoid pathway-related proteins is higher in leaves while the abundance of phenylpropanoid and flavonoid pathway-related proteins is higher in branches in both species. Metabolomics revealed the flavonoid composition and demonstrated that procyanidins are more abundant in branches. Superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and AA are stronger in branches than leaves. Overall, branches might contribute to redox homeostasis through SOD/GSH-PX and flavonoids. Furthermore, the high level of AA of branches might be largely due to their increased accumulation of procyanidins.

Transcriptomic analysis unravels the molecular response of Lonicera japonica leaves to chilling stress.

Lonicera japonica is not only an important resource of traditional Chinese medicine, but also has very high horticultural value. Studies have been performed on the physiological responses of L. japonica leaves to chilling, however, the molecular mechanism underlying the low temperature-induced leaves morphological changes remains unclear. In this study, it has been demonstrated that the ratio of pigments content including anthocyanins, chlorophylls, and carotenoids was significantly altered in response to chilling condition, resulting in the color transformation of leaves from green to purple. Transcriptomic analysis showed there were 10,329 differentially expressed genes (DEGs) co-expressed during chilling stress. DEGs were mainly mapped to secondary metabolism, cell wall, and minor carbohydrate. The upregulated genes (UGs) were mainly enriched in protein metabolism, transport, and signaling, while UGs in secondary metabolism were mainly involved in phenylpropaoids-flavonoids pathway (PFP) and carotenoids pathway (CP). Protein-protein interaction analysis illustrated that 21 interacted genes including CAX3, NHX2, ACA8, and ACA9 were enriched in calcium transport/potassium ion transport. BR biosynthesis pathway related genes and BR insensitive (BRI) were collectively induced by chilling stress. Furthermore, the expression of genes involved in anthocyanins and CPs as well as the content of chlorogenic acid (CGA) and luteoloside were increased in leaves of L. japonica under stress. Taken together, these results indicate that the activation of PFP and CP in leaves of L. japonica under chilling stress, largely attributed to the elevation of calcium homeostasis and stimulation of BR signaling, which then regulated the PFP/CP related transcription factors.