Integrated Multiomics and Synergistic Functional Network Revealed the Mechanism in the Tolerance of Different Ecotypes of Salvia miltiorrhiza Bge. to Doxycycline Pollution.

Tetracycline pollution in soil irreversibly damages the biosafety of plants by inhibiting the mitochondrial function. Some traditional Chinese medicine (TCM) plants, such as Salvia miltiorrhiza Bunge, have a strong tolerance to mitochondrial damage. We comprehensively compared the doxycycline (DOX) tolerances of two ecotypes of S. miltiorrhiza in the Sichuan and Shandong provinces and found that the Sichuan ecotype had a lower yield reduction, more stable accumulation of medicinal ingredients, higher mitochondrial integrity, and a more robust antioxidant system. The synergetic response networks under DOX pollution of both ecotypes were constructed using RNA sequencing and ultrahigh-performance liquid chromatography-tandem mass spectrometry. The differentiation of the downstream pathways of aromatic amino acids (AAAs) produced variations in the DOX tolerance of S. miltiorrhiza in different regions. The Sichuan ecotype maintained redox homeostasis and xylem development by activating salvianolic acid and indole biosynthesis, while the Shandong ecotype balanced chemical and mechanical defenses by regulating the flavonoid biosynthesis. Rosmarinic acid, a downstream AAA molecule, maintains the mitochondrial homeostasis of plant seedlings under DOX pollution by targeting the ABCG28 transporter. We also highlight the significance of downstream AAA small molecules in guiding the development of bio-based environmental pollution remediation agents.

Genome-Wide Analysis of the MADS-box Gene Family and Expression Analysis during Anther Development in Salvia miltiorrhiza.

MADS-box genes constitute a large family of transcription factors that play important roles in plant growth and development. However, our understanding of MADS-box genes involved in anther development and male sterility in Salvia miltiorrhiza is still limited. In this study, 63 MADS-box genes were identified from the genome of the male sterility ecotype Sichuan S. miltiorrhiza (S. miltiorrhiza_SC) unevenly distributed among eight chromosomes. Phylogenetic analysis classified them into two types and 17 subfamilies. They contained 1 to 12 exons and 10 conserved motifs. Evolution analysis showed that segmental duplication was the main force for the expansion of the SmMADS gene family, and duplication gene pairs were under purifying selection. Cis-acting elements analysis demonstrated that the promoter of SmMADS genes contain numerous elements associated with plant growth and development, plant hormones, and stress response. RNA-seq showed that the expression levels of B-class and C-class SmMADS genes were highly expressed during anther development, with SmMADS11 likely playing an important role in regulating anther development and male fertility in S. miltiorrhiza_SC. Overall, this study provides a comprehensive analysis of the MADS-box gene family in S. miltiorrhiza, shedding light on their potential role in anther development and male sterility.

Anatomy and Comparative Transcriptome Reveal the Mechanism of Male Sterility in Salvia miltiorrhiza.

Salvia miltiorrhiza Bunge is an important traditional herb. Salvia miltiorrhiza is distributed in the Sichuan province of China (here called SC). Under natural conditions, it does not bear seeds and its sterility mechanism is still unclear. Through artificial cross, there was defective pistil and partial pollen abortion in these plants. Electron microscopy results showed that the defective pollen wall was caused by delayed degradation of the tapetum. Due to the lack of starch and organelle, the abortive pollen grains showed shrinkage. RNA-seq was performed to explore the molecular mechanisms of pollen abortion. KEGG enrichment analysis suggested that the pathways of phytohormone, starch, lipid, pectin, and phenylpropanoid affected the fertility of S. miltiorrhiza. Moreover, some differentially expressed genes involved in starch synthesis and plant hormone signaling were identified. These results contribute to the molecular mechanism of pollen sterility and provide a more theoretical foundation for molecular-assisted breeding.

Inheritance and QTL Mapping for Flower Color in Salvia miltiorrhiza Bunge.

Salvia miltiorrhiza Bunge is an outcross-pollinated plant with diverse flower colors, ranging from white to purple. To clarify the genetic basis of S. miltiorrhiza flower color, we crossed white-flowered S. miltiorrhiza f. alba with dark violet-flowered S. miltiorrhiza, and selfed F1 to obtain an F2 population. The RGB color system was used to describe the flower color of the parents, F1 progeny, and F2 individuals. Afterward, we used genotyping-by-sequencing technology to construct a high-density linkage map of S. miltiorrhiza based on the F2 population. Finally, the linkage map was used to locate the QTLs of the genes that control flower color in S. miltiorrhiza. Through measurement and cluster analysis of the R, G, and B values of flowers from the parents, F1, and F2 individuals, it was found that the purple flower color of S. miltiorrhiza is a quantitative trait controlled by 2 loci of major genes. The genetic map contained 605 SNPs with a total length of 738.3 cM in 8 linkage groups (LGs), and the average distance between 2 markers was 1.22 cM. Based on the constructed genetic map and the flower R, G, B, and R+G+B values, 2 QTLs were detected for flower color, located on LG4 and LG5. The results of this study lay the foundation for cloning genes that control flower color and studying the molecular mechanism of flower color regulation in S. miltiorrhiza.

Optimization of Ultrasound-Assisted Extraction of Flavonoids from Olive (Olea europaea) Leaves, and Evaluation of Their Antioxidant and Anticancer Activities.

Olea europaea leaves are the major byproduct of olive farming. In this study, ultrasound-assisted extraction of flavonoids from olive leaves was optimized using response surface methodology, and the flavonoid compounds and their antioxidant and anticancer activities were investigated by high performance liquid chromatography. The results showed that the optimized conditions for achieving the maximum yield of flavonoids (74.95 mg RE/g dm) were 50 °C temperature, 270 W power, 50 min time, and 41 mL/g liquid-solid ratio. There was a significant difference in the total flavonoid content between the aged and young leaves harvested in April and July, and six main components were quantified. Among them, luteolin-4'-O-glucoside was the most predominant flavonoid compound, followed by apigenin-7-O-glucoside and rutin. Olive leaves also contained small amounts of luteolin, apigenin, and quercetin. Additionally, excellent antioxidant activity was exhibited when tested with the DPPH assay; superoxide radical-scavenging ability and reducing power was also tested. The anticancer activity of the flavonoids was assessed using HeLa cervical cancer cells, and it was observed that increasing concentrations of olive leaf flavonoids resulted in decreased cancer cell viability. These results suggest that the flavonoids from olive leaves could be used as a potential source of natural antioxidants for the pharmaceutical and food industries.

Phylogeny and differentiation of the St genome in Elymus L. sensu lato (Triticeae; Poaceae) based on one nuclear DNA and two chloroplast genes.

BACKGROUND: Hybridization and polyploidization can be major mechanisms for plant evolution and speciation. Thus, the process of polyploidization and evolutionary history of polyploids is of widespread interest. The species in Elymus L. sensu lato are allopolyploids that share a common St genome from Pseudoroegneria in different combinations with H, Y, P, and W genomes. But how the St genome evolved in the Elymus s. l. during the hybridization and polyploidization events remains unclear. We used nuclear and chloroplast DNA-based phylogenetic analyses to shed some light on this process. RESULTS: The Maximum likelihood (ML) tree based on nuclear ribosomal internal transcribed spacer region (nrITS) data showed that the Pseudoroegneria, Hordeum and Agropyron species served as the St, H and P genome diploid ancestors, respectively, for the Elymus s. l. polyploids. The ML tree for the chloroplast genes (matK and the intergenic region of trnH-psbA) suggests that the Pseudoroegneria served as the maternal donor of the St genome for Elymus s. l. Furthermore, it suggested that Pseudoroegneria species from Central Asia and Europe were more ancient than those from North America. The molecular evolution in the St genome appeared to be non-random following the polyploidy event with a departure from the equilibrium neutral model due to a genetic bottleneck caused by recent polyploidization. CONCLUSION: Our results suggest the ancient common maternal ancestral genome in Elymus s. l. is the St genome from Pseudoroegneria. The evolutionary differentiation of the St genome in Elymus s. l. after rise of this group may have multiple causes, including hybridization and polyploidization. They also suggest that E. tangutorum should be treated as C. dahurica var. tangutorum, and E. breviaristatus should be transferred into Campeiostachys. We hypothesized that the Elymus s. l. species origined in Central Asia and Europe, then spread to North America. Further study of intraspecific variation may help us evaluate our phylogenetic results in greater detail and with more certainty.

Antioxidant activities and functional properties of enzymatic protein hydrolysates from defatted Camellia oleifera seed cake.

Seed cake protein (SCP) from Camellia oleifera was hydrolyzed by five commercial proteases (Flavorzyme, Trypsin, Neutrase, Papain, Alcalase). Amino acid composition, molecular weight distribution, antioxidant activity and functional property of the seed cake protein hydrolysates (SCPH) were investigated. Enzymatic hydrolysis improved protein solubility significantly but impaired the foaming and emulsifying property. Hydrolysate generated by alcalase had the highest hydrolysis degree (DH) and antioxidant activity, and displayed excellent protein solubility over wide range of pH, while hydrolysate prepared by flavorzyme showed better copper chelating capacity and emulsifying stability with low molecular weight distribution. Trypsin-treated SCPH showed better foaming property than original protein. The results indicated that enzyme type greatly influenced the molecular weight, functional property and antioxidant activity of SCPH. It was also found that electing appropriate protease and controlling the DH could be enhanced or reduced functional property according to actual applications.

Evolutionary pattern of rDNA following polyploidy in Leymus (Triticeae: Poaceae).

Ribosomal ITS polymorphism and its ancestral genome origin of polyploid Leymus were examined to infer the evolutionary outcome of rDNA gene following allopolyploid speciation and to elucidate the geographic pattern of ITS variation. The results demonstrated that different polyploids have experienced varying fates, including maintenance or homogenization of divergent arrays, occurrence of chimeric repeats and potential pseudogenes. Our data suggested that (1) the Ns, P/F, and St genomic types in Leymus were originated from Psathyrostachys, Agropyron/Eremopyrum, and Pseudoroegneria, respectively; (2) the occurrence of a higher proportion of Leymus species with predominant uniparental rDNA type might associate with the segmental allopolyploid origin, nucleolar dominance of alloploids, and rapid radiation of Leymus; (3) maintenance of multiple parental ITS types in allopolyploid might result from long generation times associated to vegetative multiplication, number and chromosomal location of ribosomal loci and/or recurrent hybridization; (4) the rDNA genealogical structure of Leymus species might associate with the geographic origins; and (5) ITS sequence clade shared by Leymus species from Central Asia, North America, and Nordic might be an outcome of ancestral ITS homogenization. Our results shed new light on understanding evolutionary outcomes of rDNA following allopolyploid speciation and geographic isolation.

The physiological response of Artemisia annua L. to salt stress and salicylic acid treatment.

Salinity has a great influence on plant growth and distribution. A few existing reports on Artemisia annua L. response to salinity are concentrated on plant growth and artemisinin content; the physiological response and salt damage mitigation are yet to be understood. In this study, the physiological response of varying salt stresses (50, 100, 200, 300, or 400 mM NaCl) on A. annua L. and the effect of exogenous salicylic acid (0.05 or 0.1 mM) at 300-mM salt stress were investigated. Plant growth, antioxidant enzyme activity, proline, and mineral element level were determined. In general, increasing salt concentration significantly reduced plant growth. Superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were stimulated by salt treatment to a higher enzyme activity in treated plants than those in untreated plants. Content of proline had a visible range of increment in the salt-treated plants. Distribution of mineral elements was in inconformity: Na(+) and Ca(2+) were mainly accumulated in the roots; K(+) and Mg(2+) were concentrated in leaves and stems, respectively. Alleviation of growth arrest was observed with exogenous applications of salicylic acid (SA) under salt stress conditions. The activity of SOD and POD was notably enhanced by SA, but the CAT action was suppressed. While exogenous SA had no discernible effect on proline content, it effectively inhibited excessive Na(+) absorption and promoted Mg(2+) absorption. Ca(2+) and K(+) contents showed a slight reduction when supplemented with SA. Overall, the positive effect of SA towards resistance to the salinity of A. annua will provide some practical basis for A. annua cultivation.

Identification and characterization of a novel tyrosine aminotransferase gene (SmTAT3-2) promotes the biosynthesis of phenolic acids in Salvia miltiorrhiza Bunge.

Rosmarinic acid (RA) and salvianolic acid B (SAB) are main phenolic acids in Salvia miltiorrhiza Bunge have been widely used in the treatment of cardiovascular and cerebrovascular diseases due to their excellent pharmacological activity. RA is a precursor of SAB, and tyrosine transaminase (TAT, EC 2.6.1.5) is a crucial rate-limiting enzyme in their metabolism pathway. This study identified a novel TAT gene, SmTAT3-2, and found that it is a new transcript derived from unconventional splicing of SmTAT3. We used different substrates for enzymatic reaction with SmTAT1, SmTAT3 and SmTAT3-2. Subcellular localization of SmTAT1 and SmTAT3-2 was completed based on submicroscopic techniques. In addition, they were overexpressed and CRISPR/Cas9 gene edited in hairy roots of S. miltiorrhiza. Revealed SmTAT3-2 and SmTAT1 showed a stronger affinity for L-tyrosine than SmTAT3, localized in the cytoplasm, and promoted the synthesis of phenolic acid. In overexpressed SmTAT3-2 hairy roots, the content of RA and SAB was significantly increased by 2.53 and 3.38 fold, respectively, which was significantly higher than that of overexpressed SmTAT1 strain compared with EV strain. These findings provide a valuable key enzyme gene for the phenolic acids metabolism pathway and offer a theoretical basis for the clinical application.

Effects of natural extract from medicinal herbs on broilers experimentally infected with Eimeria tenella.

This study aimed to evaluate the effects of natural extracts from nine medicinal herbs (SMA) on the growth performance, immunity, and intestinal integrity of broilers experimentally infected with Eimeria tenella. A total of 252 one-day-old broiler chicks were divided into 7 groups with 3 replicates per group and 12 broilers per cage. The groups were uninfected-untreated blank control group (BC), infected-untreated negative control group (NC), SMA treatment groups, Chinese medicine positive control group (CM), and chemical drug positive control group (CD). The SMA groups were infected and fed a basal diet supplemented with 0.6 (SMA-L), 0.8 (SMA-M), and 1.0 (SMA-H) g/kg SMA. The CM and CD groups were infected and fed a basal diet supplemented with 15 g/kg Jiqiuchong San and 0.2 g/kg Diclazuril, respectively. Results showed that feeding SMA could significantly reduce the number of oocysts in infected chickens, especially 1.0 g/kg SMA, which exhibited moderate anticoccidial efficacy. When infected with E. tenella, the supplementation of 1.0 g/kg SMA increased the renal index; restored the hepatic, splenic, and bursal indexes to BC levels; increased the levels of immunoglobulin A (IgA), IgM, and IgY; and reduced the contents of tumor necrosis factor (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6), and IL-10 of the infected chickens. Moreover, treatment with 1.0 g/kg SMA alleviated the pathological changes in cecal tissue and increased the contents of zonula occludens-1 (ZO-1), occludin, claudin-1, and mucoprotein 2 (mucin-2) in cecal tissues of E. tenella-infected chickens. We found that 1.0 g/kg SMA reduced the number of oocysts, improved immunity, and alleviated intestinal barrier damage, which could improve the growth performance of infected chickens. Thus, SMA proved to be an effective natural extract against E. tenella and has the potential to be used as an efficient anticoccidial drug or additive.

ZnO quantum dots alleviate salt stress in Salvia miltiorrhiza by enhancing growth, scavenging reactive oxygen species, and modulating stress-responsive genes.

Experiments were conducted to investigate the alleviating effects of ZnO quantum dots (ZnO QDs) on salt stress in Salvia miltiorrhiza by comparing them with conventional ZnO nanoparticles (ZnO NPs). The results demonstrated that compared with salt stress alone, foliar application of ZnO QDs significantly improved the biomass as well as the total chlorophyll and carotenoids contents under salt stress. ZnO QDs reduced H2O2 and MDA levels, decreased non-enzymatic antioxidant (ASA and GSH) content, and improved antioxidant enzyme (POD, SOD, CAT, PAL, and PPO) activity under salt stress. Metal elemental analysis further demonstrated that the ZnO QDs markedly increased Zn and K contents while decreasing Na content, resulting in a lower Na/K ratio compared to salt stress alone. Finally, RNA sequencing results indicated that ZnO QDs primarily regulated genes associated with stress-responsive pathways, including plant hormone signal transduction, the MAPK signaling pathway, and metabolic-related pathways, thereby alleviating the adverse effects of salt stress. In comparison, ZnO NPs did not exhibit similar effects in terms of improving plant growth, enhancing the antioxidant system, or regulating stress-responsive genes under salt stress. These findings highlight the distinct advantages of ZnO QDs and suggest their potential as a valuable tool for mitigating salt stress in plants.

Physiological and molecular mechanisms of carbon quantum dots alleviating Cu2+ toxicity in Salvia miltiorrhiza bunge.

Excessive Cu2+ is toxic to plants. Carbon quantum dots (CQDs) exhibit certain chelating properties towards heavy metals, and they also demonstrate antioxidant activities. To explore the mechanism for alleviating the Cu2+ toxicity of Salvia miltiorrhiza Bunge mediated by CQDs, CQDs that contained CC, CO, H-O, C-N and C-O functional groups with particle size less than 10 nm and that emitted blue fluorescence were prepared. S. miltiorrhiza seedlings were treated with 200 µM of Cu2+ and 500 mg/L of CQDs to relieve stress. Exogenous CQDs effectively restored plant phenotype; reduced Cu2+, H2O2 and malondialdehyde contents and restored total superoxide dismutase, peroxidase and catalase activities under Cu2+ toxicity. Simultaneously, an association network of Cu2+ transport-related and metabolic pathway genes of phenolic acids and terpenoids was established on the basis of cross-species transcriptome analysis. Combined with reverse transcription quantitative real-time polymerase chain reaction analysis, the potential molecular mechanism of CQDs, i.e. promoting phenolic acid biosynthesis to alleviate Cu2+ toxicity, was revealed by activating the expression of key enzyme genes of phenolic acid synthesis. This study provides a theoretical basis for Cu2+ pollution prevention and control in plants. It also laid a foundation for alleviating Cu stress by using CQDs in agricultural production.

Physiological and molecular mechanisms of ZnO quantum dots mitigating cadmium stress in Salvia miltiorrhiza.

This study delved into the physiological and molecular mechanisms underlying the mitigation of cadmium (Cd) stress in the model medicinal plant Salvia miltiorrhiza through the application of ZnO quantum dots (ZnO QDs, 3.84 nm). A pot experiment was conducted, wherein S. miltiorrhiza was subjected to Cd stress for six weeks with foliar application of 100 mg/L ZnO QDs. Physiological analyses demonstrated that compared to Cd stress alone, ZnO QDs improved biomass, reduced Cd accumulation, increased the content of photosynthetic pigments (chlorophyll and carotenoids), and enhanced the levels of essential nutrient elements (Ca, Mn, and Cu) under Cd stress. Furthermore, ZnO QDs significantly lowered Cd-induced reactive oxygen species (ROS) content, including H2O2, O2-, and MDA, while enhancing the activity of antioxidant enzymes (SOD, POD, APX, and GSH-PX). Additionally, ZnO QDs promoted the biosynthesis of primary and secondary metabolites, such as total protein, soluble sugars, terpenoids, and phenols, thereby mitigating Cd stress in S. miltiorrhiza. At the molecular level, ZnO QDs were found to activate the expression of stress signal transduction-related genes, subsequently regulating the expression of downstream target genes associated with metal transport, cell wall synthesis, and secondary metabolite synthesis via transcription factors. This activation mechanism contributed to enhancing Cd tolerance in S. miltiorrhiza. In summary, these findings shed light on the mechanisms underlying the mitigation of Cd stress by ZnO QDs, offering a potential nanomaterial-based strategy for enhancing Cd tolerance in medicinal plants.

Phylogenetic relationships and Y genome origin in Elymus L. sensu lato (Triticeae; Poaceae) based on single-copy nuclear Acc1 and Pgk1 gene sequences.

To estimate the origin and genomic relationships of the polyploid species within Elymus L. sensu lato, two unlinked single-copy nuclear gene (Acc1 and Pgk1) sequences of eighteen tetraploids (StH and StY genomes) and fourteen hexaploids (StStH, StYP, StYH, and StYW genomes) were analyzed with those of 35 diploid taxa representing 18 basic genomes in Triticeae. Sequence and phylogenetic analysis suggested that: (1) the St, H, W, and P genomes were donated by Pseudoroegneria, Hordeum, Australopyrum, and Agropyron, respectively, while the Y genome is closely related to the Xp genome in Peridictyon sanctum; (2) different hexaploid Elymus s.l. species may derived their StY genome from different StY genome tetraploid species via independent origins; (3) due to incomplete lineage sorting and/or hybridization events, the genealogical conflict between the two gene trees suggest introgression involving some Elymus s.l. species, Pseudoroegneria, Agropyron and Aegilops/Triticum; (4) it is reasonable to recognize the StH genome species as Elymus sensu stricto, the StY genome species as Roegneria, the StYW genome species as Anthosachne, the StYH genome species as Campeiostachys, and the StYP genome species as Kengyilia. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Elymus s.l. species.

Targeted Therapy of Acute Liver Injury via Cryptotanshinone-Loaded Biomimetic Nanoparticles Derived from Mesenchymal Stromal Cells Driven by Homing.

Acute liver injury (ALI) has the potential to compromise hepatic function rapidly, with severe cases posing a considerable threat to human health and wellbeing. Conventional treatments, such as the oral administration of antioxidants, can inadvertently lead to liver toxicity and other unwanted side effects. Mesenchymal stromal cells (MSCs) can target therapeutic agents directly to inflammatory sites owing to their homing effect, and they offer a promising avenue for the treatment of ALI. However, the efficacy and feasibility of these live cell products are hampered by challenges associated with delivery pathways and safety concerns. Therefore, in this work, MSC membranes were ingeniously harnessed as protective shells to encapsulate synthesized PLGA nanoparticle cores (PLGA/MSCs). This strategic approach enabled nanoparticles to simulate endogenous substances and yielded a core-shell nano-biomimetic structure. The biomimetic nanocarrier remarkably maintained the homing ability of MSCs to inflammatory sites. In this study, cryptotanshinone (CPT)-loaded PLGA/MSCs (CPT@PLGA/MSC) were prepared. These nanoparticles can be effectively internalized by LO2 cells. They reduced cellular oxidative stress and elevated inflammatory levels. In vivo results suggested that, after intravenous administration, CPT@PLGA/MSCs significantly reduced uptake by the reticuloendothelial system and immune recognition compared to PLGA nanoparticles without MSC membrane coatings, subsequently resulting in their targeted and enhanced accumulation in the liver. The effectiveness of CPT@PLGA/MSCs in alleviating carbon tetrachloride-induced oxidative stress and inflammation in a mouse model was unequivocally demonstrated through comprehensive histological examination and liver function tests. This study introduces a pioneering strategy with substantial potential for ALI treatment.

[Neuroprotective effect of longistyline A against corticosterone-induced neurotoxicity in PC12 cells].

This study is to investigate the protective effect of longistyline A against corticosterone-induced neurotoxicity in PC12 cells. While PC12 cells were exposed to 100 micromol x L(-1) corticosterone for 48 h, cell survival rate was reduced and lactate dehydrogenase (LDH) release increased. In parallel, corticosterone caused significant elevations of DNA fragmentation, [Ca2+]i and caspase-3 activity. However, when the PC12 cells were incubated with longistyline A (4.0, 8.0 and 16.0 micromol x L(-1)) in the presence of 100 micromol x L(-1) corticosterone for 48 h, the effects were evidently alleviated, but dose-dependent manner was not obvious. In summary, longistyline A could generate a neuroprotective effect against corticosterone-induced neurotoxicity in PC12 cells possibly by decreasing [Ca2+]i and caspase-3 activity.

Identification of Salvia miltiorrhiza Bunge with high and low cadmium accumulation and insight into the mechanisms of cadmium accumulation.

Salvia miltiorrhiza Bunge is used as a Chinese herbal medicine (CHM) particularly its roots. No relevant reports at home and abroad have been made on the mechanism of cadmium (Cd) accumulation in S. miltiorrhiza. The Cd accumulation characteristics of S. miltiorrhiza from main cultivation areas in China were evaluated for the first time to obtain high and low Cd accumulation in S. miltiorrhiza roots. Results showed obvious differences in the Cd enrichment capacity of S. miltiorrhiza from different cultivation areas. We took the lead in identifying the germplasm resources of S. miltiorrhiza with high and low Cd accumulation, that is, S. miltiorrhiza roots from Pingyi Shangdong (SDPY) belongs to the resource with high Cd accumulation (SDPY-H) and that from Zhongjiang Sichuan (SCZJ) is the resources with low Cd accumulation (SCZJ-L) based on relevant physiological and biochemical indexes. Although the Cd content of SDPY-H was apparently higher than that from SCZJ-L, its translocation factor from root to aboveground part is significantly lower than that in SCZJ-L. Therefore, planting SCZJ-L is not only an economic and effective way to use Cd in slightly and moderately polluted soil, but also its aboveground part can be used for phytoremediation. Changes in Cd content before and after the use of transpiration inhibitor indicate that SDPY-H enriched Cd through the symplastic pathway, whereas SCZJ-L mainly enriched Cd through the apoplastic pathways. In addition, the role of the symplastic pathway in SCZJ-L is weaker than that in SDPY-H, which were preliminarily revealed by fluorescent quantitative polymerase chain reaction. The significant reduction of the SmNramps transcription expression amount is one of the reasons for the low Cd accumulation of SCZJ-L.

Comparative transcriptome analysis reveals key insights into male sterility in Salvia miltiorrhiza Bunge.

BACKGROUND: Large-scale heterosis breeding depends upon stable, inherited male sterility lines. We accidentally discovered a male sterility line (SW-S) in the F1progeny of a Salvia miltiorrhiza Bunge from Shandong, China (purple flowers) crossed with a S. miltiorrhiza f. alba from Sichuan, China (white flowers). We sought to provide insights into the pollen development for male sterility in S. miltiorrhiza. METHODS: The phenotypic and cytological features of the SW-S and fertile control SW-F were observed using scanning electron microscopy and paraffin sections to identify the key stage of male sterility. Transcriptome profiles were recorded for anthers at the tetrad stage of SW-S and SW-F using Illumina RNA-Seq. RESULTS: The paraffin sections showed that sterility mainly occurred at the tetrad stage of microspore development, during which the tapetum cells in the anther compartment completely fell off and gradually degraded in the sterile line. There was little-to-no callose deposited around the microspore cells. The tetrad microspore was shriveled and had abnormal morphology. Therefore, anthers at the tetrad stage of SW-S and fertile control SW-F were selected for comparative transcriptome analysis. In total, 266,722,270 clean reads were obtained from SW-S and SW-F, which contained 36,534 genes. There were 2,571 differentially expressed genes (DEGs) in SW-S and SW-F, of which 63.5% were downregulated. Gene Ontology (GO) enrichment analysis indicated that the differentially expressed genes were enriched in 56 functional groups (GO terms); of these, all DEGs involved in microgametogenesis and developmental maturation were downregulated in SW-S. These results were confirmed by quantitative RT-PCR. The two GO terms contained 18 DEGs, among which eight DEGs (namely: GPAT3, RHF1A, phosphatidylinositol, PFAS, MYB96, MYB78, Cals5, and LAT52) were related to gamete development. There were 10 DEGs related to development and maturation, among which three genes were directly related to pollen development (namely: ACT3, RPK2, and DRP1C). Therefore, we believe that these genes are directly or indirectly involved in the pollen abortion of SW-S. Our study provides insight into key genes related to sterility traits in S. miltiorrhiza, and the results can be further exploited in functional and mechanism studies.

The complete chloroplast genome sequence of herb Nardostachys jatamans (family: Valerianaceae) in China.

Nardostachys jatamans is an endemic herb in China, distributes mainly in Southeast Gansu, South Qinghai and West Sichuan of Qinghai-Tibet Plateau. In this study, the complete chloroplast genome (a typical quadripartite structure) sequence of N. jatamans was reported. The length of the DNA molecule was 155,268 bp with a large single-copy region (LSC: 87,263 bp), small single-copy region (SSC: 17,327 bp) and inverted repeats (IRa and IRb: 25,339 bp). The overall GC content was 38.56%. It has a total of 129 genes, containing 83 protein-coding genes, 38 tRNA genes, and eight rRNA genes. The phylogenetic analysis has shown that N. jatamans is sister to Valeriana offcinalis. The chloroplast genome provides the basis for development and utilization of N. jatamans in future.