2-(2-Phenylethyl)chromones (PECs) are the primary constituents of agarwood, a valuable aromatic resin widely used in traditional oriental medicine and incense production, exhibiting diverse pharmacological activities. While we have previously reported a polyketide synthase (AsPECPS) playing a crucial role in the biosynthesis of PECs in agarwood, the intrinsic regulatory mechanisms underlying PEC biosynthesis remain largely elusive. Here, we successfully characterised a new 1R-subtype myeloblastosis (MYB) transcription factor (AsMYB1) from Aquilaria sinensis whose expression is significantly induced under salt treatment. Further overexpression, RNA interference (RNAi) and gene-editing experiments confirmed the positive regulatory role of AsMYB1 in PEC biosynthesis. AsMYB1 specifically bound to cis-elements in the promoter of AsPECPS to enhance its transcription, thereby promoting PEC accumulation under salt stress. A 14-3-3 family protein designated AsGRF1 was characterised to interact with AsMYB1 both in vivo and in vitro, and knockdown or knockout of AsGRF1 led to a dramatic reduction in AsPECPS expression and PECs' accumulation. Furthermore, AsGRF1 may positively facilitate AsMYB1-mediated activation of PEC production under salt stress by elevating AsPECPS expression through increasing the transcriptional activity, nuclear localisation and stability of AsMYB1. Our findings suggest that the AsGRF1-AsMYB1-AsPECPS module synergistically facilitates salt-induced PEC metabolism, inspiring potential biotechnological strategies to improve agarwood quality through metabolic engineering.

Two novel alkaloids, dahurine G (1) and its epimer dahurine H (2) were isolated from the roots of Angelica dahurica. The planar structures of 1 and 2 were elucidated through a comprehensive analysis of their spectroscopic and spectrometric data, including nuclear magnetic resonance (NMR), infrared (IR), and high-resolution electrospray ionization mass spectrometry (HRESIMS). Biomimetic synthesis, initiated with (2S,3R,4S)-4-hydroxyisoleucine, enabled the unequivocal determination of the absolute configurations of 1 and 2, while also yielding an unnatural analogue (3) as a byproduct. Compounds 1, 2 and the synthetic analogue 3 all contain a distinctive butenolide moiety, which is commonly observed in plant signaling molecules such as strigolactones (SLs) and karrikins (KARs). Further experiments demonstrated that all three compounds significantly promote seed germination in both model plants (Arabidopsis thaliana and Nicotiana benthamiana) and vital crops (Zea mays and Oryza sativa), as well as radicle elongation in Z. mays and O. sativa. The findings suggest that compounds 1-3 may play a significant role in seedling germination and early root development, thereby demonstrating considerable potential for agricultural applications.

Echinacoside (ECH), one of the most representative phenylethanoid glycosides (PhGs), has considerable neuroprotective effects and is an effective ingredient in numerous commercial drugs. Here, we elucidate the complete ECH biosynthetic pathway in the medicinal plant Cistanche tubulosa. In total, 14 related genes are cloned and functionally characterized. Two upstream pathways for tyrosol biosynthesis from L-tyrosine are identified: one includes separate decarboxylation, deamination and reduction steps; the other uses microbial-like transamination, decarboxylation and reduction steps. In addition, a distinct downstream assembly process from tyrosol to ECH is revealed that includes sequential glucosylation, acylation, hydroxylation, and rhamnosylation to form acteoside, and ends with a final glucosylation converting acteoside to ECH. Furthermore, the de novo synthesis of 23 PhG derivatives is achieved via the heterologous expression of different combinations of the functional genes in tobacco. Our findings provide insights into the biosynthesis of ECH and a platform for alternative production of complex PhGs.

Paeonia lactiflora Pall., a member of Paeoniaceae family, is a medicinal herb widely used in traditional Chinese medicine. Chloroplasts are multifunctional organelles containing distinct genetic material. This study provides a foundation for identifying P. lactiflora, protecting and utilizing germplasm resources, and supporting molecular breeding efforts. In this study, five complete chloroplast genome sequences of P. lactiflora samples originating from different regions in China were sequenced using the Illumina NovaSeq 4000 platform. All five P. lactiflora chloroplasts had a typical cyclic tetrameric structure with 130 genes annotated. Comparative genomic analysis indicated that rpoB and psbK-psbI function as the potential specific DNA barcodes for intraspecific identification of P. lactiflora. PCR amplification of rpoB and psbK-psbI was performed on 246 samples from 7 production areas, achieving 100

IntroductionSalvia miltiorrhiza radix et rhizoma (Danshen) is a crucial medicinal material for treating cardiovascular and cerebrovascular diseases. However, the presence of adulterants and intraspecific variability poses challenges to its clinical safety.MethodsThis study collected samples of S. miltiorrhiza from various regions and commonly encountered adulterants. The composition differences of S. miltiorrhiza radix and its adulterants were analyzed by fingerprint and broad-target metabolomics. Chloroplast genome was used to distinguish intra-genus species and DNA barcoding was used to identify germplasm sources.ResultsThe fingerprinting analysis proved that there is no chemical composition consistency between S. miltiorrhiza radix and its adulterants. Broad-targeted metabolomics can distinguish S. miltiorrhiza radix from Salvia yunnanensis radix, Dipsacus asperoides radix, and Arctium lappa radix. Additionally, comparative chloroplast genome analysis indicated that atpF and rps4-trnT-UGU were the potential DNA barcodes for S. miltiorrhiza. 259 samples from 13 provinces and 21 origins were amplified and sequenced, resulting in the identification of 62 haplotypes. The unique haplotypes found in Shanxi Luoyang, Shandong Qingdao and other places can be used as molecular geographic markers for the identification of the germplasm source of S. miltiorrhiza.DiscussionThis study systematically differentiates S. miltiorrhiza from its adulterants and highlights the potential of unique haplotypes as markers for sourcing. The findings provide strong scientific evidence for the clinical safety of S. miltiorrhiza, emphasizing the importance of proper cultivation, selection, and breeding of varieties.

PnNAC03 positively regulates saponin biosynthesis and lignin accumulation during secondary cell wall formation by directly binding to the promoters of key saponin and lignin biosynthetic genes. The NAC transcription factor family plays a crucial role in the regulation of secondary metabolites biosynthesis. Saponins are the major bioactive compounds for Panax notoginseng, which is a world-globally recognized medicinal plant and possesses multiple pharmacological activities. The secondary cell wall is essential for P.notoginseng growth and stress resistance. However, the role of NAC transcription factors in regulating both saponin biosynthesis and secondary cell wall formation remains largely unknown. In this study, we characterized an NAC transcription factor, PnNAC03, which is a nuclear-localized protein and functions as a transcriptional activator. Silencing of PnNAC03 with the RNAi method in P. notoginseng calli resulted in a significant reduction in the content of saponin and the expression of key saponin biosynthetic genes, including PnSS, PnSE, and PnDS. Additionally, PnNAC03 specifically bound to the promoters of these genes, thereby enhancing their expression. Overexpression of PnNAC03 in Arabidopsis thaliana led to the increase of secondary cell wall thickness and lignin content, as well as upregulation of the expression of AtPAL and AtC4H. RNAi-mediated silencing of PnNAC03 in P. notoginseng further confirmed its role in lignin biosynthesis, as lignin content and the expression levels of PnPAL and PnC4H were significantly reduced. Furthermore, PnNAC03 could directly bind to the promoters of PAL and C4H genes in both A. thaliana and P. notoginseng. Collectively, our results highlight the dual regulatory role of PnNAC03 in promoting both saponin biosynthesis and lignin accumulation, providing valuable insights for the molecular breeding of P. notoginseng.

The integration of nucleic acid isothermal amplification with CRISPR/Cas12a detection technologies has significantly advanced molecular diagnostics. However, the challenge of integrating both assays into a one-pot reaction to reduce operational complexity and the risk of aerosol contamination has persisted. In this study, we developed a one-pot assay that combines these two powerful tools to improve the detection of genetically modified organisms (GMOs). Targeting the widely used Cauliflower Mosaic Virus 35S promoter (P-CaMV 35S) and the nopaline synthase terminator (T-NOS) from Agrobacterium tumefaciens in genetically modified (GM) crops, we employed a definitive screening design (DSD) approach to optimize the balance between ERA amplification and Cas12a activity. This optimization was achieved by enhancing ERA amplification and precisely adjusting the concentrations of Cas12a and other reaction components, resulting in an efficient and streamlined process. The optimized one-pot ERA-CRISPR/Cas12a system achieved a detection sensitivity of 10 copies per reaction for both P-CaMV 35S and T-NOS within 40 min at 40 degrees C, and was capable of detecting GMO content as low as 0.1% in spiked samples. Moreover, with minimal equipment requirements, such as an LED blue light and a smartphone for result interpretation, this method is highly user-friendly. Combining rapid detection, high specificity, and operational simplicity, this system represents a significant advancement in supporting GMO regulation and global trade, and serves as a promising model for the development of future nucleic acid-based assays.

2-Phenylethylchromones (PECs) and 2-styrylchromones (SCs) are the primary components responsible for the delightful fragrance and bioactivity of agarwood, a highly valuable aromatic resinous heartwood. PECs are derived from a common precursor with a diarylpentanoid skeleton (C6-C5-C6). However, the biosynthesis of SCs remains unclear. In this study, based on the successful conversion of the PEC skeleton, rather than a dehydrogenated diarylpentanoid, into SCs by Aquilaria sinensis suspension cells, we demonstrated that double bond formation of the styryl group in SCs occurs after the creation of the PEC skeleton, not before this step from a dehydrogenated diarylpentanoid precursor. Through transcriptomic data mining, transient expression in Nicotiana benthamiana and A. sinensis suspension cells, we identified a new 2-oxoglutarate-dependent oxygenase (As2OG1) that plays a crucial role in the conversion of PECs into SCs. Further protein structure prediction and mutagenesis studies, combined with probing of the catalytic potential of As2OG1 using chemically synthesized hydroxylated intermediates, suggested that As2OG1 possibly uses diradical or carbocation intermediates, rather than hydroxylated intermediates, to install double bonds in SCs. The results not only provide insights into the molecular mechanism of agarwood formation but also facilitate the overproduction of pharmaceutically important SCs using metabolic engineering approaches.

As a main way to reuse straw resources in the farmland, returning straw to the soil can effectively alleviate the adverse effects of direct straw burning on the soil and environment. Although there are previous studies on this aspect, few studies investigate the impact of the annual return of rice and wheat straws on wheat yield and soil properties. In this study, wheat ‘Annong 1124’ was used as the material. The four experimental treatments include: neither rice nor wheat straw returned to the field (R0), wheat straw returned to the field (RW), rice straw returned to the field (RR) and, both rice and wheat straw returned to the field (R2) were set up. The effects of different amounts of straw returning on soil physical and chemical properties, soil nutrient content, dry matter accumulation, and yield of wheat were studied, to clarify the characteristics of wheat yield formation, soil properties, and nutrient content changes under the condition of rice and wheat annual straw return. The results showed that straw returning increased soil aggregate content and root activity of wheat at the jointing stage. Still, they decreased soil pH and root activity at the flowering stage and increased soil aggregate content at small particle size (d ≤ 0.5 mm and 0.50 mm < d ≤ 1.00 mm). Straw incorporation (R2, RR, and RW) decreased soil urease activity in the early growth stage, increased soil urease activity in the late wheat growth stage, and increased soil nutrient content. Straw returning improved the dry matter quantity of wheat at the jointing stage and had a great difference in the dry matter accumulation of wheat at the flowering stage. RR and R2 treatments reduced the dry matter accumulation of wheat at anthesis by 11.97

Enhancing crop diversification in intensive fields has the potential to increase crop yield and reduce environmental footprint. However, these relationships at the landscape scale remained unclear in intensive farming. Addressing this gap, this paper aims to elucidate how crop yield, resources use efficiency (RUE), and environmental footprint (EF) vary with crop diversification levels in the North China Plain. Management practices, including crop pattern, field size, and agronomic inputs, were collected for 421 landscapes of 1 × 1 km subplots using Sentinel-2 and Landsat-8 images and survey. The results showed that, at the landscape scale, energy and fertilizer contributed over 53 %, and 37 % of the carbon footprint, respectively. N fertilizer constituted >98 % of the nitrogen footprint. P fertilizer accounted for over 80 %, while electricity comprised >13 % of the phosphorus footprint. Compared with simplified landscapes, diversified landscapes exhibited several significant features: 1) 56 % reduction of the area ratio of winter wheat-summer maize double crop pattern (WM), 2) a significant decrease in field size, 3) the decreased use of total NPK fertilizers at 32 %, 30 %, and 30 %, respectively, 4) the increased inputs of irrigation water, diesel, electricity, pesticide and labour at 21 %, 19 %, 21 %, 77 %, and 92 %, respectively. Although yield could be reduced at 33 % when transforming simplified landscapes into moderately diversified ones, they increased with the further promotion of crop diversification. Thus, the diversified landscapes could achieve a balance in yield, RUE, and EF to enhance sustainability, whereas simplified landscapes can similarly achieve a balance to benefit productivity. We emphasize the viable potential of diversified landscapes to enhance sustainable agricultural development by optimizing crop composition. This analysis offers pioneering evidence of landscape-scale agronomic and environmental performances of crop diversification.

Anemarrhena asphodeloides is a common medicinal material used in clinical prescriptions and Chinese patent medicine. In this study, the Illumina platform was used to obtain the chloroplast genome sequences of seven kinds of A. asphodeloides from different areas. The specific DNA barcodes were screened by comparative genomics analysis, and the DNA barcodes were used to identify the germplasm resources and analyze the genetic diversity of A. asphodeloides samples from different areas in China. All the seven chloroplast genomes had a ring structure. The total length was 156 801-156 930 bp, and 113 genes were annotated, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. The comparative genomics analysis showed that rps16, trnG-GCC, atpF, rpoB, ycf3, rpl16, ndhF, trnS-GCU＿trnG-GCC, petN-psbM, and ndhF-rpl32 were potential candidates for specific DNA barcodes of A. asphodeloides. In this study, the second intron of ycf3 and atpF intron sequences with a sequence length of 700-800 bp and easy amplification were selected for polymerase chain reaction(PCR) amplification and sequencing of 594 samples from 26 areas. The sequence analysis showed that six and eight haplotypes of ycf3 and atpF sequences could be identified, respectively, and 17 haplotypes could be identified by combined analysis of the two sequences, which were named Hap1-Hap17. The haplotype diversity(H_d), nucleotide diversity(P_i), and genetic distance of A. asphodeloides in 26 populations were 0.68, 0.93×10~(-3), and 0-0.003 1, respectively, indicating that the genetic diversity within the species of A. asphodeloides is rich. The intermediary adjacent network analysis showed that Hap5 was the oldest haplotype, which was mainly distributed in Yixian county of Baoding, Hebei province, Hequ county of Xinzhou, Shanxi province, and Xiangfen county of Linfen, Shanxi province. This study has important guiding significance for the identification of A. asphodeloides species, the protection and development of germplasm resources, and the identification of production areas, and it provides a research basis for further revealing the genetic evolution law of A. asphodeloides.

Paeonia lactiflora Pall. is a species with significant medicinal and economic value. In this study, five complete chloroplast genome sequences of P. lactiflora samples originating from different regions in China were sequenced using the Illumina NovaSeq 4000 platform. All five P. lactiflora chloroplasts had a typical cyclic tetrameric structure with 130 genes annotated. Comparative genomic analysis indicated that rpoB and psbK-psbI function as potential specific DNA barcodes for intraspecific identification of P. lactiflora. PCR amplification of rpoB and psbK-psbI was performed on 246 samples from 7 production areas, achieving 100% amplification efficiency. Sequence analysis revealed that 5 and 10 haplotypes were identified based on rpoB and psbK-psbI, respectively. The joint analysis of two sequences identified 15 haplotypes named Hap1ཞHap15. Hap5 emerged as the most prevalent and geographically widespread haplotype across China. Haplotypic diversity (Hd) was 0.786, and nucleotide diversity was 0.00281, suggesting that P. lactiflora had high genetic diversity at the species level. The Neighbor-Joining tree showed that the 15 haplotypes were clustered into two branches, indicating extensive genetic exchange between clusters. The introduction of new individuals or rare genes into different clusters through gene flow increased genetic variation within clusters, enriching P. lactiflora genetic diversity. This study provides a foundation for identifying P. lactiflora, protecting and utilizing germplasm resources, and supporting molecular breeding efforts.

PnNAC2 positively regulates saponin biosynthesis by binding the promoters of key biosynthetic genes, including PnSS, PnSE, and PnDS. PnNAC2 accelerates flowering through directly associating with the promoters of FT genes. NAC transcription factors play an important regulatory role in both terpenoid biosynthesis and flowering. Saponins with multiple pharmacological activities are recognized as the major active components of Panax notoginseng. The P. notoginseng flower is crucial for growth and used for medicinal and food purposes. However, the precise function of the P. notoginseng NAC transcription factor in the regulation of saponin biosynthesis and flowering remains largely unknown. Here, we conducted a comprehensive characterization of a specific NAC transcription factor, designated as PnNAC2, from P. notoginseng. PnNAC2 was identified as a nuclear-localized protein with transcription activator activity. The expression profile of PnNAC2 across various tissues mirrored the accumulation pattern of total saponins. Knockdown experiments of PnNAC2 in P. notoginseng calli revealed a significant reduction in saponin content and the expression level of pivotal saponin biosynthetic genes, including PnSS, PnSE, and PnDS. Subsequently, Y1H assays, dual-LUC assays, and electrophoretic mobility shift assays (EMSAs) demonstrated that PnNAC2 exhibits binding affinity to the promoters of PnSS, PnSE and PnDS, thereby activating their transcription. Additionally, an overexpression assay of PnNAC2 in Arabidopsis thaliana witnessed the acceleration of flowering and the induction of the FLOWERING LOCUS T (FT) gene expression. Furthermore, PnNAC2 demonstrated the ability to bind to the promoters of AtFT and PnFT genes, further activating their transcription. In summary, these results revealed that PnNAC2 acts as a multifunctional regulator, intricately involved in the modulation of triterpenoid saponin biosynthesis and flowering processes.

Context: Nitrogen (N) plays integral roles in plant growth and yield. Finding ways to increase plant yield with reduced N usage will promote both agricultural and environmental sustainability. Melatonin acts as a multifunctional regulatory molecule in numerous metabolic processes crucial for plant growth and development as well as response to environmental stresses. The effects of melatonin on the material accumulation and transport, source-sink dynamics, as well as its association with yield and quality formation of peanut (Arachis hypogaea L.) remain unclear, especially at different N levels. Objectives: We aim to investigate the response mechanism of melatonin in peanut plants subjected to reduced N application, in order to confirm the hypothesis that melatonin regulates carbon and N accumulation and transport, and coordinates source-sink relationships to increase production and improve quality. Methods: This study examined the effects of two seed dressing treatments (with or without 0.5 mu M MT) and three N fertilizer levels (90, 135, and 180 kg/ha) using a randomized complete block design with split plots and three biological replications over 2021 and 2022. The evaluation focused on photosynthetic physiology, enzyme activities related to carbon and N metabolism, accumulation and transport of dry matter and N, yield, and quality, while exploring the relationships among these variables. Results: Melatonin-treated plants had more stable carbon and N metabolism than the untreated ones. This stability was linked to improved photosynthesis, sucrose production, and N assimilation, especially at the reduced N levels (90 and 135 kg/ha). Across three N levels and two years of field tests, MT increased peanut dry matter by 23.49 % from 455.63 g/m2 to 562.66 g/m2, enhanced the accumulation and mobilization of dry matter and N to grains by increasing peanut grain mass by 22.41-29.07 % at different N levels. This process appears to subsequently elevate the effective pod rate, leading to an average increase in pod yield, fat and protein content by 12.63 %, 7.95 %, and 10.33 %, respectively, over a two-year period and across three N application levels. Conclusions: Plants subjected to melatonin treatment exhibited a coordinated source-sink relationship, which is manifested in high photosynthetic capacity and a high proportion of assimilates transported to pods, thus promoting effective proportions and pod fullness to improve peanut yield and quality under reduced N application. Significance: Our research provided insights into the response mechanism of melatonin on peanut carbon and N metabolism across various N treatments, contributing to a deeper understanding of how melatonin enhances crop yield and quality.

2-(2-Phenylethyl)chromones (PECs) are the primary constituents responsible for the promising pharmacological activities and unique fragrance of agarwood. However, the O-methyltransferases (OMTs) involved in the formation of diverse methylated PECs have not been reported. In this study, we identified one Mg2+-dependent caffeoyl-CoA-OMT subfamily enzyme (AsOMT1) and three caffeic acid-OMT subfamily enzymes (AsOMT2-4) from NaCl-treated Aquilaria sinensis calli. AsOMT1 not only converts caffeoyl-CoA to feruloyl-CoA but also performs nonregioselective methylation at either the 6-OH or 7-OH position of 6,7-dihydroxy-PEC. On the other hand, AsOMT2-4 preferentially utilizes PECs as substrates to produce structurally diverse methylated PECs. Additionally, AsOMT2-4 also accepts nonPEC-type substrates such as caffeic acid and apigenin to generate methylated products. Protein structure prediction and site-directed mutagenesis revealed that residues of L313 and I318 in AsOMT3, as well as S292 and F313 in AsOMT4 determine the distinct regioselectivity of these two OMTs toward apigenin. These findings provide important biochemical evidence of the remarkable structural diversity of PECs in agarwood.

Ethnopharmacological relevanceDa-Chai-Hu-Tang (DCHT), a Chinese traditional herbal compound, has been utilized for the treatment of Hepatic diseases in China for over 1,800 years. The DCHT formula contains eight herbals: Bupleurum chinense DC. (chaihu), Scutellaria baicalensis Georgi (huangqin), Paeonia lactiflora Pall. (baishao), Pinellia ternata (Thunb.) Makino (banxia), Rheum officinale Baill. (dahuang), Citrus × aurantium L. (zhishi), Zingiber officinale Roscoe (shengjiang), Ziziphus jujuba Mill. (dazao). Clinical studies have demonstrated the effectiveness of DCHT in hepatocellular carcinoma (HCC) and its ability to enhance the immunity of patients with hepatocellular carcinoma. A total of 20 Chinese articles have been published on the use of DCHT in treating HCC.Aim of the studyThe study aimed to validate the effect of DCHT in HCC cells and to identify related targets (TP53, AKT1, BCL2, STAT3) in treating HCC by DCHT in vitro experiments.Materials and methodsCell proliferation and migration were investigated in vitro. Flow cytometry analysis was used to evaluate the cell cycle and apoptosis. Apoptotic bodies in HepG2 cells were observed using a confocal microscope. Biochemical detection was employed to analyze LDH release, MDA levels, and SOD levels. Bioinformatics analysis was used to predict core targets between DCHT and HCC, as well as potential signaling pathways. The protein levels of metastasis-associated, apoptosis, and PI3K, AKT, p-AKT, and STAT3 were further determined through Western blotting.ResultsFollowing treatment with DCHT, the inhibition of viability, migration, and G2/M arrest was observed in HepG2 cells. Flow cytometry analysis and Morphological apoptosis studies provided evidence that DCHT could induce apoptosis in HepG2 cells. Biochemical detection revealed that DCHT could increase LDH release and the level of MDA, and inhibit the viability of the SOD. Bioinformatics analysis identified key targets such as TP53, AKT1, BCL2, STAT3. The PI3K/AKT/STAT3 signaling pathway emerged as a critical pathway in the KEGG enrichment analysis. Western blotting results indicated that DCHT could enhance the expression of E-cadherin, p53, and Bax, while reducing the content of N-cadherin, Bcl-2, PI3K, p-AKT, AKT1, and STAT3.ConclusionsThe results proved that DCHT could inhibit the progression and metastasis of HCC by regulating the expression of E-cadherin, N-cadherin, p53, Bax, Bcl-2, PI3K, p-AKT, AKT, and STAT3 through the PI3K/AKT/STAT3 signaling pathway.

Type III polyketide synthases play significant roles in the biosynthesis of multiple plant secondary metabolites and plant adjustment to environmental stresses. AsPECPS, a type III polyketide synthase, is the key enzyme involved in the biosynthesis of 2-(2-phenylethyl) chromone derivatives which are the main components determining the quality of agarwood and special defensive substances of Aquilaria sinensis. However, the functions of AsPECPS in plant resistance have not been shown. Our findings indicated that AsPECPS was localized in the cytoplasm and cell wall. The expression of AsPECPS was significantly induced by salt stress and abscisic acid (ABA) treatment. Heterologous overexpression of AsPECPS in Nicotiana benthamiana enhanced the salt-stress tolerance at post-gemination stage showed by the transgenic plants with increased fresh weight, height, root length, and number of lateral roots. Furthermore, the overexpressing lines (OE) in soil retained more lateral roots, more proline content and lower malondialdehyde content under salinity stress. Additionally, AsPECPS-OE plants were less sensitive to ABA as indicated through the OE lines showing higher gemination rate, greater survival rate, and better growth characteristics. Further analyses demonstrated that the transgenic plants accumulated lower levels of ROS through down-regulating the expression of Rboh family genes and up-regulating the expression and activities of antioxidant enzymes under salt stress and ABA treatment. Overexpression of AsPECPS modulated the abundance of genes associated with ABA signaling pathway under ABA treatment. Taken together, our results indicated that overexpression of AsPECPS in N. benthamiana enhanced the plant tolerance to salt and ABA stresses. Overexpression of AsPECPS in N. benthamiana, a type III polyketide synthase involved in the biosynthesis of 2-(2-phenylethyl) chromone, enhanced the plant tolerance to salt and ABA stresses.

The chloroplast genomes of five Fritillaria ussuriensis materials from different production areas were comparatively analyzed, atpF and petB were screened as specific DNA barcodes, and the population identification and genetic diversity of F. ussuriensis were analyzed based on them. The F. ussuriensis chloroplast genome showed a total length of 151 515–151 548 bp with a typical tetrad structure and encoded 130 genes. atpF and petB were used to amplify 183 samples from 13 populations, and they could identify 6 and 9 haplotypes, respectively. Joint analysis of the two sequences revealed 18 haplotypes, named H1–H18, with the most widely distributed and most abundant being H4. Ten haplotypes were unique for 7 populations that they could be used to distinguish from others. Haplotype diversity and nucleotide diversity were 0.99 and 2.09 × 10−3, respectively, indicating the genetic diversity was relatively rich. The results of the intermediary adjacency network showed that H5 was the oldest haplotype, and stellate radiation was centered around it, indicating that population expansion occurred in genuine production areas. This study lays a theoretical foundation for the population identification, genetic evolution, and breed selection of F. ussuriensis.

Xanthocillin is a unique natural product with an isonitrile group and shows remarkable antibacterial activity. In this study, the genome of an endophytic fungus Penicillium chrysogenum MT-40 isolated from Huperzia serrata was sequenced, and the gene clusters with the potential to synthesize xanthocillin analogues were mined by local BLAST and various bioinformatics analysis tools. As a result, a biosynthetic gene cluster (named for) responsible for the biosynthesis of xanthocillin analogues was identified by further heterologous expression of the key genes in Aspergillus oryzae NSAR1. Specifically, the ForB catalyzes the synthesis of 2-formamido-3-(4-hydroxyphenyl) acrylic acid, and the ForG catalyzes the dimerization of 2-formamido-3-(4-hydroxyphenyl) acrylic acid to produce the xanthocillin analogue N, N'-(1, 4-bis (4-hydroxyphenyl) buta-1, 3-diene-2, 3-diyl) diformamide. The results reported here provide a reference for further discovery of xanthocillin analogues from fungi.