Structural diversity, evolutionary origin, and metabolic engineering of plant specialized benzylisoquinoline alkaloids.

Covering: up to June 2024Benzylisoquinoline alkaloids (BIAs) represent a diverse class of plant specialized metabolites derived from L-tyrosine, exhibiting significant pharmacological properties such as anti-microbial, anti-spasmodic, anti-cancer, cardiovascular protection, and analgesic effects. The industrial production of valuable BIAs relies on extraction from plants; however, challenges concerning their low concentration and efficiency hinder drug development. Hence, alternative approaches, including biosynthesis and chemoenzymatic synthesis, have been explored. Model species like Papaver somniferum and Coptis japonica have played a key role in unraveling the biosynthetic pathways of BIAs; however, many aspects, particularly modified steps like oxidation and methylation, remain unclear. Critical enzymes, e.g., CYP450s and methyltransferases, play a substantial role in BIA backbone formation and modification, which is essential for understanding the origin and adaptive evolution of these plant specialized metabolites. This review comprehensively analyzes the structural diversity of reported BIAs and their distribution in plant lineages. In addition, the progress in understanding biosynthesis, evolution, and catalytic mechanisms underlying BIA biosynthesis is summarized. Finally, we discuss the progress and challenges in metabolic engineering, providing valuable insights into BIA drug development and the sustainable utilization of BIA-producing plants.

Multifunctional Super-Hydrophilic MXene/Biomass Composite Aerogel Evaporator for Efficient Solar-Driven Desalination and Wastewater Treatment.

Solar-driven interfacial evaporation is recognized as a sustainable and effective strategy for desalination to mitigate the freshwater scarcity issue. Nevertheless, the challenges of oil contamination, salt accumulation, and poor long-term stability of the solar desalination process limit its applications. Herein, a 3D biomass-based multifunctional solar aerogel evaporator is developed for water production with fabricated chitosan/lignin (CSL) aerogel as the skeleton, encapsulated with carbonized lignin (CL) particles and Ti3C2TiX (MXene) nanosheets as light-absorbing materials. Benefitting from its super-hydrophilic wettability, interconnected macropore structure, and high broadband light absorption (ca. 95.50%), the prepared CSL-C@MXene-20 mg evaporator exhibited a high and stable water evaporation flux of 2.351 kg m-2 h-1 with an energy conversion efficiency of 88.22% under 1 Sun (1 kW m-2) illumination. The CSL-C@MXene-20 mg evaporator performed excellent salt tolerance and long-term solar vapor generation in a 3.5 wt.% NaCl solution. Also, its super-hydrophilicity and oleophobicity resulted in superior salt resistance and anti-fouling performance in high salinity brine (20 wt.% NaCl) and oily wastewater. This work offers new insight into the manufacture of porous and eco-friendly biomass-based photothermal aerogels for advanced solar-powered seawater desalination and wastewater purification.

Photonic generation of dual-band triangular chirps utilizing a monolithic integrated mutual injection laser and application in radars.

We propose and demonstrate a dual-band microwave photonic radar scheme based on a monolithic integrated mutual injection laser. Based on the photon-photon resonance (PPR) and the gain switching effect of the integrated laser, the C-/X-band triangular chirp signals with high-quality and comparable power at 4.75-5.25 GHz and 9.5-10.5 GHz are generated. In the current proof-of-concept experiment, the range resolution of the dual-band chirp signals can reach 16.9 cm, compared with the single-band chirp signal that cannot distinguish the targets. Through the application of a single integrated device and a transceiver module sharing a set of antennas, the dual-band microwave photonic radar system scheme improves the system integration.

QTL mapping and omics analysis to identify genes controlling kernel dehydration in maize.

KEY MESSAGE: This study mapped and screened three candidate genes related to kernel dehydration in maize. The slow development rate of maize kernels during later stages leads to high kernel moisture content at harvest, posing a challenge for mechanized maize harvesting in China. This study utilized a recombinant inbred line population derived from Zheng 58 (slow dehydration) and PH6WC (fast dehydration) as parents. After four years of trait investigation and analysis, 25 quantitative trait loci (QTLs) associated with kernel dehydration rate and moisture content were identified, with six QTLs showing a significant contribution value exceeding 10% in the phenotype. Furthermore, a comparison was made between the QTLs identified in this study and those from previous research on maize kernel moisture content and dehydration rate, followed by screening through the omics analysis of the parental lines. Three candidate genes related to kernel dehydration rate were identified, primarily involving carbohydrate metabolism, energy metabolism processes (Zm00001d014030 and Zm00001d006476), and stimulus resistance (Zm00001d040113). These findings provide valuable insights to assist and guide future breeding efforts for mechanical harvesting of maize.

Transcriptomics Combined with Physiology and Metabolomics Reveals the Mechanism of Tolerance to Lead Toxicity in Maize Seedling.

Lead (Pb) exposure can induce molecular changes in plants, disrupt metabolites, and impact plant growth. Therefore, it is essential to comprehend the molecular mechanisms involved in Pb tolerance in plants to evaluate the long-term environmental consequences of Pb exposure. This research focused on maize as the test subject to study variations in biomass, root traits, genes, and metabolites under hydroponic conditions under Pb conditions. The findings indicate that high Pb stress significantly disrupts plant growth and development, leading to a reduction in catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) activities by 17.12, 5.78, and 19.38%, respectively. Conversely, Pb stress led to increase malondialdehyde (MDA) contents, ultimately impacting the growth of maize. The non-targeted metabolomics analysis identified 393 metabolites categorized into 12 groups, primarily consisting of organic acids and derivatives, organ heterocyclic compounds, lipids and lipid-like molecules and benzenoids. Further analysis indicated that Pb stress induced an accumulation of 174 metabolites mainly enriched in seven metabolic pathways, for example phenylpropanoid biosynthesis and flavonoid biosynthesis. Transcriptome analysis revealed 1933 shared differentially expressed genes (DEGs), with 1356 upregulated and 577 downregulated genes across all Pb treatments. Additionally, an integrated analysis identified several DEGs and differentially accumulated metabolites (DAMs), including peroxidase, alpha-trehalose, and D-glucose 6-phosphate, which were linked to cell wall biosynthesis. These findings imply the significance of this pathway in Pb detoxification. This comprehensive investigation, employing multiple methodologies, provides a detailed molecular-level insight into maize's response to Pb stress.

Functionalized magnetic particles coupled with LC-MS strategy facilitated discovery of trace thioalkaloids with potent immunosuppressive activity.

Trace natural products (TNPs) are still the vital source of drug development. However, the mining of novel TNPs is becoming increasingly challenging due to their low abundance and complex interference. A comprehensive strategy was proposed in which the functionalized magnetic particles integrated with LC-MS for TNPs discovery. Under the guidance of the approach, fifteen trace Nuphar alkaloids including seven new ones, cyanopumiline A sulfoxide (1), cyanopumiline C sulfoxide (8) and cyanopumilines A-E (4-5, 10, 12-13) featuring an undescribed nitrile-containing 6/6/5/6/6 pentacyclic ring system were isolated from the rhizomes of Nuphar pumila. Their structures and absolute configurations were determined on the basis of detailed spectroscopic data analysis and single-crystal X-ray diffraction analysis. Notably, a concise method based on 13C NMR spectroscopy was established to determine the relative configurations of spiroatoms. Biologically, compounds 1-12 exhibited potent immunosuppressive activities with IC50 values ranging from 0.1-12.1 µM against anti-CD3/CD28 induced human peripheral T cell proliferation. Mechanistic studies revealed that 4 could dose-dependently decrease pro-inflammatory cytokines and the expression levels of CD25 and CD71.

New caffeoyl derivatives with potent DPPH radical scavenging activity from Elephantopus tomentosus.

Eight new caffeoyl derivatives, elephantomentosides A-H (1 - 8), together with ten known ones (9 - 18), were isolated from the whole plant of Elephantopos tomentosus L. Their structures were elucidated using detailed spectroscopic analysis. Structurally, compounds 1 - 8 are composed of ß-D-glucopyranose, and almost all of the substituent positions are at the C-1' and C-4' of glucopyranose. The anti-inflammatory and antioxidant activities of all isolated compounds were evaluated in vitro. Compounds 9-10, 13-15, and 17-18 exhibited significant DPPH scavenging capacity with IC50 values in the range of 10.01-25.07 µM, in comparison with Vc (IC50, 17.98 µM).

The genome of Corydalis reveals the evolution of benzylisoquinoline alkaloid biosynthesis in Ranunculales.

Species belonging to the order Ranunculales have attracted much attention because of their phylogenetic position as a sister group to all other eudicot lineages and their ability to produce unique yet diverse benzylisoquinoline alkaloids (BIAs). The Papaveraceae family in Ranunculales is often used as a model system for studying BIA biosynthesis. Here, we report the chromosome-level genome assembly of Corydalis tomentella, a species of Fumarioideae, one of the two subfamilies of Papaveraceae. Based on comparisons of sequenced Ranunculalean species, we present clear evidence of a shared whole-genome duplication (WGD) event that has occurred before the divergence of Ranunculales but after its divergence from other eudicot lineages. The C. tomentella genome enabled us to integrate isotopic labeling and comparative genomics to reconstruct the BIA biosynthetic pathway for both sanguinarine biosynthesis shared by papaveraceous species and the cavidine biosynthesis that is specific to Corydalis. Also, our comparative analysis revealed that gene duplications, especially tandem gene duplications, underlie the diversification of BIA biosynthetic pathways in Ranunculales. In particular, tandemly duplicated berberine bridge enzyme-like genes appear to be involved in cavidine biosynthesis. In conclusion, our study of the C. tomentella genome provides important insights into the occurrence of WGDs during the early evolution of eudicots, as well as into the evolution of BIA biosynthesis in Ranunculales.

Chromatin architecture of two different strains of Artemisia annua reveals the alterations in interaction and gene expression.

MAIN CONCLUSION: The hierarchical architecture of chromatins affects the gene expression level of glandular secreting trichomes and the artemisinin biosynthetic pathway-related genes, consequently bringing on huge differences in the content of artemisinin and its derivatives of A. annua. The plant of traditional Chinese medicine "Qinghao" is called Artemisia annua L. in Chinese Pharmacopoeia. High content and the total amount of artemisinin is the main goal of A. annua breeding, nevertheless, the change of chromatin organization during the artemisinin synthesis process has not been discovered yet. This study intended to find the roles of chromatin structure in the production of artemisinin through bioinformatics and experimental validation. Chromosome conformation capture analysis was used to scrutinize the interactions among chromosomes and categorize various scales of chromatin during artemisinin synthesis in A. annua. To confirm the effect of the changes in chromatin structure, Hi-C and RNA-sequencing were performed on two different strains to find the correlation between chromatin structure and gene expression levels on artemisinin synthesis progress and regulation. Our results revealed that the frequency of intra-chromosomal interactions was higher in the inter-chromosomal interactions between the root and leaves on a high artemisinin production strain (HAP) compared to a low artemisinin production strain (LAP). We found that compartmental transition was connected with interactions among different chromatins. Interestingly, glandular secreting trichomes (GSTs) and the artemisinin biosynthetic pathway (ABP) related genes were enriched in the areas which have the compartmental transition, reflecting the regulation of artemisinin synthesis. Topologically associated domain boundaries were associated with various distributions of genes and expression levels. Genes associated with ABP and GST in the adjacent loop were highly expressed, suggesting that epigenetic regulation plays an important role during artemisinin synthesis and glandular secreting trichomes production process. Chromatin structure could show an important status in the mechanisms of artemisinin synthesis process in A. annua.

Manual correction of genome annotation improved alternative splicing identification of Artemisia annua.

Gene annotation is essential for genome-based studies. However, algorithm-based genome annotation is difficult to fully and correctly reveal genomic information, especially for species with complex genomes. Artemisia annua L. is the only commercial resource of artemisinin production though the content of artemisinin is still to be improved. Genome-based genetic modification and breeding are useful strategies to boost artemisinin content and therefore, ensure the supply of artemisinin and reduce costs, but better gene annotation is urgently needed. In this study, we manually corrected the newly released genome annotation of A. annua using second- and third-generation transcriptome data. We found that incorrect gene information may lead to differences in structural, functional, and expression levels compared to the original expectations. We also identified alternative splicing events and found that genome annotation information impacted identifying alternative splicing genes. We further demonstrated that genome annotation information and alternative splicing could affect gene expression estimation and gene function prediction. Finally, we provided a valuable version of A. annua genome annotation and demonstrated the importance of gene annotation in future research.

High-purity linearly frequency-modulated signal generation based on the integrated semiconductor laser subject to the dynamical optoelectrical feedback.

A novel photonic method of linearly frequency-modulated (LFM) signal generation with high purity based on the monolithically integrated semiconductor laser (MISL) subject to the dynamical optoelectrical feedback is proposed and demonstrated in this paper. In this approach, the MISL is firstly operated in period-one state. By introducing the dynamical optoelectrical feedback to modulate the MISL, the generated LFM signals would be constantly optimized as long as the delay of the feedback loop is matched with the repetition period of the LFM signal. In this system, no additional high-speed external modulator, high-frequency electrical LFM oscillator are required, highly simplifying the framework and reducing the power consumption. In the current proof-of-concept experiment, one LFM signal with the bandwidth as large as 5.6 GHz is generated and the corresponding frequency comb contrast can be drastically improved by 51 dB. Furthermore, the effect of the delay mismatch is also discussed in this paper.

A Tetratricopeptide Repeat Protein Regulates Carotenoid Biosynthesis and Chromoplast Development in Monkeyflowers (Mimulus).

Little is known about the factors regulating carotenoid biosynthesis in flowers. Here, we characterized the REDUCED CAROTENOID PIGMENTATION2 (RCP2) locus from two monkeyflower (Mimulus) species, the bumblebee-pollinated species Mimulus lewisii and the hummingbird-pollinated species Mimulus verbenaceus We show that loss-of-function mutations of RCP2 cause drastic down-regulation of the entire carotenoid biosynthetic pathway. The causal gene underlying RCP2 encodes a tetratricopeptide repeat protein that is closely related to the Arabidopsis (Arabidopsis thaliana) REDUCED CHLOROPLAST COVERAGE proteins. RCP2 appears to regulate carotenoid biosynthesis independently of RCP1, a previously identified R2R3-MYB master regulator of carotenoid biosynthesis. We show that RCP2 is necessary and sufficient for chromoplast development and carotenoid accumulation in floral tissues. Simultaneous down-regulation of RCP2 and two closely related paralogs, RCP2-L1 and RCP2-L2, yielded plants with pale leaves deficient in chlorophyll and carotenoids and with reduced chloroplast compartment size. Finally, we demonstrate that M. verbenaceus is just as amenable to chemical mutagenesis and in planta transformation as the more extensively studied M. lewisii, making these two species an excellent platform for comparative developmental genetics studies of closely related species with dramatic phenotypic divergence.

Characterization and molecular evolution analysis of Periploca forrestii inferred from its complete chloroplast genome sequence.

Periploca forrestii, a medicinal plant of the family Apocynaceae, is known as an effective and widely used clinical prescription for the treatment of rheumatoid diseases. In this study, we de novo sequenced and assembled the completement chloroplast (cp) genome of P. forrestii based on combined Oxford Nanopore PromethION and Illumina data. The cp genome was 153 724 bp in length and had four subregions. Moreover, an 84 433 bp large single-copy and a 17 731 bp small single-copy were separated by 25 780 bp inverted repeats (IRs). The cp genome included 132 genes with 18 duplicates in the IRs. A total of 45 repeat structures and 183 simple sequence repeats were detected. Codon usage showed a bias toward A/T-ending codons. A comparative study of Apocynaceae revealed that an IR expansion occurred on P. forrestii. The Ka/Ks values of eight species of Apocynaceae suggested that positive selection was exerted on the psaI and ycf2 genes, which might reflect specific adaptions to the P. forrestii particular growth environment. Phylogenetic analysis indicated that Periplocoideae was a sister to Asclepiadoideae, forming a monophyletic group in the family Apocynaceae. This study provided an important P. forrestii genomic resource for future evolutionary studies and the phylogenetic reconstruction of the family Apocynaceae.

Broadband frequency modulation signal downconversion using a monolithic integrated mutual injection laser.

We propose a new, to the best of our knowledge, broadband signal downconversion scheme implemented by a monolithic integrated mutual injection laser. A mathematical derivation, simulation, and experimental verification are carried out. Because the period-one oscillation frequency can be selectively operated on a large scale by controlling the current on the integrated laser, the tuning downconversion range is realized without changing the experimental equipment. The experiment verifies that the downconversion of the linear frequency modulation signal with a bandwidth of 0.5 GHz from the center frequency of 18.75 to 0.85 GHz, and the spurious-free dynamic range (SFDR) has reached 71.7d B/H z 2/3. Compared with the scheme based on discrete components, the system has no electric local oscillator or external modulator, which provides a method for radar signal downconversion.

Four-channel all-optical wavelength conversion unit based on nonlinear effect of three-section monolithically integrated semiconductor lasers.

A simple and highly efficient four-channel all-optical wavelength conversion based on four-wave mixing effect of the directly modulated three-section monolithically integrated semiconductor laser is proposed and experimentally investigated. For this wavelength conversion unit, the spacing of the wavelength can be adjusted by tuning the bias current of the lasers and setting it to be 0.4 nm (50 GHz) as a demonstration is this work. A 50 Mbps 16-QAM signal centers at 4-8 GHz is experimentally switched to a targeted path. Up- or downconversion depends on a wavelength-selective switch, and the conversion efficiency can reach up to -2 to 0 dB. This work provides a new technology for photonic radio-frequency switching matrix and contributes to the integrated implementation of satellite transponders.

Simple multi-band linearly frequency-modulated signal generation with a multiplying bandwidth based on a gain-switching laser.

Multi-band linearly frequency-modulated (LFM) signal generation with a multiplying bandwidth is proposed and experimentally demonstrated. It is a simple photonics method based on the gain-switching state in a distributed feedback semiconductor laser without a complex external modulator and high-speed electrical amplifiers. With N comb lines, the carrier frequency and bandwidth of generated LFM signals are N times those of the reference signal. (N is the number of comb lines.) The number of bands and time-bandwidth products (TBWPs) of the generated signals could be easily adjusted by tuning the reference signal from an arbitrary waveform generator. Three-band LFM signals with carrier frequencies ranging from the X-band to K-band are given as an example, and the TBWP up to 20000. The results of auto-correlations of the generated waveforms are also given.

Plant Protection against Viruses: An Integrated Review of Plant Immunity Agents.

Plant viruses are an important class of pathogens that seriously affect plant growth and harm crop production. Viruses are simple in structure but complex in mutation and have thus always posed a continuous threat to agricultural development. Low resistance and eco-friendliness are important features of green pesticides. Plant immunity agents can enhance the resilience of the immune system by activating plants to regulate their metabolism. Therefore, plant immune agents are of great importance in pesticide science. In this paper, we review plant immunity agents, such as ningnanmycin, vanisulfane, dufulin, cytosinpeptidemycin, and oligosaccharins, and their antiviral molecular mechanisms and discuss the antiviral applications and development of plant immunity agents. Plant immunity agents can trigger defense responses and confer disease resistance to plants, and the development trends and application prospects of plant immunity agents in plant protection are analyzed in depth.

[Traditional Chinese medicine microbiomics and its research strategies].

The tight relationships between microbiome and traditional Chinese medicine(TCM)have been widely recognized. New technologies, results, and theories are emerging in the field of microbiomics in recent years with the advances in high-throughput sequencing and multi-omics technologies. Based on the previous research, the present study has proposed the concept of TCM microbiomics(TCMM), which is an interdisciplinary subject aiming at elucidating the functions and applications of microbiome in the areas of herb resources, herb processing, herb storage, and clinical effects by using modern technology of biology, ecology, and informatics. This subject essentially contains the structures, functions, interactions, molecular mechanisms, and application strategies of the microbiome associated with the quality, safety, and efficacy of TCM. Firstly, the development of the TCMM concept was summarized, with the profound understanding of TCMM on the complexity and entirety of microbiome being emphasized. Then, the research contents and applications of TCMM in promoting the sustainable development of herb resources, improving the standardization and diversification of herb fermentation, strengthening the safety of herb storage, and resolving the scientific connotation of theories and clinical efficacy of TCM are reviewed. Finally, the research strategies and methods of TCM microbiomics were elaborated from basic research, application research, and system research. TCMM is expected to promote the integrative development of TCM with frontier science and technology, thereby expanding the depth and scope of TCM study and facilitating TCM modernization.

[Prediction of global potential growth areas for Panax ginseng based on GMPGIS system and MaxEnt model].

The suitable habitat for the endangered and valuable medicinal herb Panax ginseng is gradually decreasing. It is crucial to investigate its suitable growing areas in China for global protection and sustainable utilization of P. ginseng. In this study, 371 distribution points of P. ginseng were collected, and 21 environmental factors were used as ecological indicators. The geographic information system for global medicinal plants(GMPGIS) system, MaxEnt model, and Thiessen polygon method were used to analyze the potential suitable areas for P. ginseng globally. The results showed that the key environmental variables affecting P. ginseng were precipitation in the hottest quarter(Bio18) and the coefficient of temperature seasonality(Bio4). The suitable habitats for P. ginseng were mostly located in the "One Belt, One Road" countries such as China, Japan, South Korea, North Korea, and Russia. The highly suitable habitats were mainly distributed along mountain ranges in southeastern Shandong, southern Shanxi and Shaanxi, northern Jiangsu, and northwestern Henan of China. Data analysis indicated that the current P. ginseng planting sites were all in high suitability zones, and the Thiessen polygon results showed that the geographic locations of P. ginseng production companies were unbalanced and urgently needed optimization. This study provides data support for P. ginseng planting site selection, scientific introduction, production layout, and long-term development planning.

[Comprehensive evaluation of Pinellia ternata germplasm resources based on phenotypic trait classification].

The evaluation of germplasm resources is the prerequisite for the development, utilization, and conservation of Chinese medicinal resources. The selection of excellent germplasm is the key to the breeding and orderly production of Pinellia ternata. In this study, 21 germplasm materials of P. ternata from major production areas in China were collected and analyzed for population diversity after phenotypic preliminary screening. The results have revealed that the P. ternata population has abundant phenotypic variation, and the phenotypic changes could be divided into five phenotypes in terms of organ trait variation. Further analysis of variation in 20 quantitative traits of the population revealed that the coefficient of variation for adenosine content(339.05%) was the largest, while the coefficient of variation for the underground plant height(16.35%) was the smallest. Correlation analysis showed that there was a strong correlation among various traits, with 52 pairs of traits showing highly significant correlation(P<0.01) and 19 pairs of traits showing a significant correlation(P<0.05). The 21 germplasms in the test could be classified into three major clusters by cluster analysis, with Cluster Ⅱ having the highest number and content of nucleosides, making it suitable for the selection and breeding of P. ternata varieties with high content of nucleosides. The yield in Cluster Ⅲ was higher than that in other groups, making it suitable for the selection and breeding of P. ternata varieties with a high yield. All trait indicators could be simplified into five principal component factors through principal component analysis, and the cumulative contribution rate was up to 86.04%. Further, comprehensive analysis using membership function and stepwise regression analysis identified nine traits, such as plant height, main leaf length, and underground plant height as characteristic indicators for the comprehensive evaluation of germplasm resources of P. ternata. BX007, BX008, and BX005 were identified as germplasms with both high yield and high uridine content, with BX007 having the highest uridine content of 479.51 µg·g~(-1). It belonged to the germplasm of P. ternata with double bulbils and could be cultivated as a potential good variety. Based on the phenotypic classification of P. ternata, systematic resource evaluation was carried out in this study, which could lay a foundation for the excavation of genetic resources and the breeding of new varieties of P. ternata.