PaMYB11 promotes suberin deposition in Norway spruce embryogenic tissue during cryopreservation: A novel resistance mechanism against osmosis.

The osmotic resistance mechanism has been extensively studied in whole plants or plant tissues. However, little is known about it in embryogenic tissue (ET) which is widely used in plant-based biotechnological systems. Suberin, a cell wall aliphatic and aromatic heteropolymer, plays a critical role in plant cells against osmosis stress. The suberin regulatory biosynthesis has rarely been studied in gymnosperms. Here, PaMYB11, a subgroup 11 R2R3-MYB transcription factor, plays a key role in the osmotic resistance of Norway spruce (Picea abies) ETs during cryoprotectant pretreatment. Thus, RNA-seq, histological, and analytical chemical analyses are performed on the stable transformations of PaMYB11-OE and PaMYB11-SRDX in Norway spruce ETs. DAP-seq, Y1H, and LUC are further combined to explore the PaMYB11 targets. Activation of PaMYB11 is necessary and sufficient for suberin lamellae deposition on Norway spruce embryogenic cell walls, which plays a decisive role in ET survival under osmotic stress. Transcriptome analysis shows that PaMYB11 enhances suberin lamellae monomer synthesis by promoting very long-chain fatty acid (VLCFA) synthesis. PaPOP, PaADH1, and PaTET8L, the first two (PaADH1 and PaPOP, included) involved in VLCFA synthesis, are proved to be the direct targets of PaMYB11. Our study identified a novel osmotic response directed by PaMYB11 in Norway spruce ET, which provides a new understanding of the resistance mechanism against osmosis in gymnosperms.

Climate of origin shapes variations in wood anatomical properties of 17 Picea species.

BACKGROUND: Variations in hydraulic conductivity may arise from species-specific differences in the anatomical structure and function of the xylem, reflecting a spectrum of plant strategies along a slow-fast resource economy continuum. Spruce (Picea spp.), a widely distributed and highly adaptable tree species, is crucial in preventing soil erosion and enabling climate regulation. However, a comprehensive understanding of the variability in anatomical traits of stems and their underlying drivers in the Picea genus is currently lacking especially in a common garden. RESULTS: We assessed 19 stem economic properties and hydraulic characteristics of 17 Picea species grown in a common garden in Tianshui, Gansu Province, China. Significant interspecific differences in growth and anatomical characteristics were observed among the species. Specifically, xylem hydraulic conductivity (Ks) and hydraulic diameter exhibited a significant negative correlation with the thickness to span ratio (TSR), cell wall ratio, and tracheid density and a significant positive correlation with fiber length, and size of the radial tracheid. PCA revealed that the first two axes accounted for 64.40% of the variance, with PC1 reflecting the trade-off between hydraulic efficiency and mechanical support and PC2 representing the trade-off between high embolism resistance and strong pit flexibility. Regression analysis and structural equation modelling further confirmed that tracheid size positively influenced Ks, whereas the traits DWT, D_r, and TSR have influenced Ks indirectly. All traits failed to show significant phylogenetic associations. Pearson's correlation analysis demonstrated strong correlations between most traits and longitude, with the notable influence of the mean temperature during the driest quarter, annual precipitation, precipitation during the wettest quarter, and aridity index. CONCLUSIONS: Our results showed that xylem anatomical traits demonstrated considerable variability across phylogenies, consistent with the pattern of parallel sympatric radiation evolution and global diversity in spruce. By integrating the anatomical structure of the stem xylem as well as environmental factors of origin and evolutionary relationships, our findings provide novel insights into the ecological adaptations of the Picea genus.

Cation Triggered Self-Assembly of α-Lactalbumin Nanotubes.

Metal ions play a dual role in biological systems. Although they actively participate in vital life processes, they may contribute to protein aggregation and misfolding and thus contribute to development of diseases and other pathologies. In nanofabrication, metal ions mediate the formation of nanostructures with diverse properties. Here, we investigated the self-assembly of α-lactalbumin into nanotubes induced by coordination with metal ions, screened among the series Mn2+, Co2+, Ni2+, Zn2+, Cd2+, and Au3+. Our results revealed that the affinity of metal ions toward hydrolyzed α-lactalbumin peptides not only impacts the kinetics of nanotube formation but also influences their length and rigidity. These findings expand our understanding of supramolecular assembly processes in protein-based materials and pave the way for designing novel materials such as metallogels in biochip and biosensor applications.

Enhancing biofilm penetration and antibiofilm efficacy with protein nanocarriers against pathogenic biofilms.

Nanocarriers play an important role in enhancing the efficacy of antibiotics against biofilms by improving their penetration and prolonging retention in pathogenic biofilms. Herein, the multifunctional nanocarriers including nanospheres (NS) and nanotubes (NT) with a high biocompatibility and biodegradability were prepared through self-assembly of partially hydrolyzed α-lactalbumin. The effects of these two different shaped nanocarriers on the delivery of antibiotics for biofilm treatment were examined by conducting in vitro antibiofilm experiment and in vivo infected wound model. The strong affinity of NS and NT for the bacterial surface allows antibiotics to be concentrated in the bacteria. Notably, the high permeability of NT into biofilms facilitates deeper penetration and the easier diffusion of loaded antibiotics within the biofilm. Furthermore, the acidic biofilm environment triggers the release of antibiotics from the NT, resulting in the accumulation of high local antibiotic concentrations. Therefore, NT could efficiently clean and inhibit the biofilm formation while also destroying the mature biofilms. In a S. aureus infected wound animal model, treatment with antibiotic-loaded NT demonstrated accelerated healing of S. aureus infected wounds when compared to free antibiotic treatment. These findings indicate that NT nanocarrier strategy is promising for treating bacterial biofilm infections, offering the potential for lower antibiotics dosages and preventing the overuse of antibiotics.

Transistor-based immunosensor using AuNPs-Ab2-HRP enzyme nanoprobe for the detection of antigen biomarker in human blood.

Alpha-fetoprotein (AFP) is inextricably linked to various diseases, including liver cancer. Thus, detecting the content of AFP in biology has great significance in diagnosis, treatment, and intervention. Motivated by the urgent need for affordable and convenient electronic sensors in the analysis and detection of aqueous biological samples, we combined the solution-gated graphene transistor (SGGT) with the catalytic reaction of enzyme nanoprobes (HRP-AuNPs-Ab2) to accurately sense AFP. The SGGT immunosensor demonstrated high specificity and stability, excellent selectivity, and excessive linearity over a range of 4 ng/mL to 500 ng/mL, with the lower detection limit down to 1.03 ng/mL. Finally, clinical samples were successfully detected by the SGGT immunosensor, and the results were consistent with chemiluminescence methods that are popular in hospitals for detecting AFP. Notably, the SGGT immunosensor is also recyclable, so it has excellent potential for use in high-throughput detection.

CaWRKY50 Acts as a Negative Regulator in Response to Colletotrichum scovillei Infection in Pepper.

Chili anthracnose is one of the most common and destructive fungal pathogens that affects the yield and quality of pepper. Although WRKY proteins play crucial roles in pepper resistance to a variety of pathogens, the mechanism of their resistance to anthracnose is still unknown. In this study, we found that CaWRKY50 expression was obviously induced by Colletotrichum scovillei infection and salicylic acid (SA) treatments. CaWRKY50-silencing enhanced pepper resistance to C. scovillei, while transient overexpression of CaWRKY50 in pepper increased susceptibility to C. scovillei. We further found that overexpression of CaWRKY50 in tomatoes significantly decreased resistance to C. scovillei by SA and reactive oxygen species (ROS) signaling pathways. Moreover, CaWRKY50 suppressed the expression of two SA-related genes, CaEDS1 (enhanced disease susceptibility 1) and CaSAMT1 (salicylate carboxymethyltransferase 1), by directly binding to the W-box motif in their promoters. Additionally, we demonstrated that CaWRKY50 interacts with CaWRKY42 and CaMIEL1 in the nucleus. Thus, our findings revealed that CaWRKY50 plays a negative role in pepper resistance to C. scovillei through the SA-mediated signaling pathway and the antioxidant defense system. These results provide a theoretical foundation for molecular breeding of pepper varieties resistant to anthracnose.

An update of aurones: food resource, health benefit, biosynthesis and application.

Aurones are a subclass of active flavonoids characterized with a scaffold of 2-benzylidene-3(2H)-benzofuranone. This type of chemicals are widely distributed in fruit, vegetable and flower, and contribute to human health. In this review, we summarize the natural aurones isolated from dietary plants. Their positive effects on immunomodulation, antioxidation, cancer prevention as well as maintaining the health status of cardiovascular, nervous system and liver organs are highlighted. The biosynthesis strategies of plant-derived aurones are elaborated to provide solutions for their limited natural abundance. The potential application of natural aurones in food coloration are also discussed. This paper combines the up-to-date information and gives a full image of dietary aurones.

A 3D phytic acid cross-linked high-porous conductive hydrogel integrating g-C3N4 for electrochemical multiplex sensing of heavy metal ions.

It is a great challenge to develop an effective super-sensitive capture method for multiplex heavy metal ions (HMIs), because HMIs is extremely toxic to public health and the environment, what's more their contamination is usually multiplex ions pollution. In this work, a 3D high-porous conductive polymer hydrogel was designed and prepared with high-stable and easy mass production, which is very favorable for the industrialization. The polymer hydrogel (g-C3N4-P(Ani-Py)-PAAM) was formed from the mixture of aniline pyrrole copolymer and acrylamide cross-linked with phytic acid as dopant and cross-linker and integrated with g-C3N4. The 3D networked high-porous hydrogel not only exhibits excellent electrical conductivity, but also provides a large surface area for increasing the number of immobilized ions. Importantly, the 3D high-porous conductive polymer hydrogel was applied successfully in electrochemical multiplex sensing of HIMs. The prepared sensor used differential pulse anodic stripping voltammetry exhibited high sensitivities, low detection limit and wide detection ranges for Cd2+, Pb2+, Hg2+ and Cu2+, respectively. Moreover, the sensor showed a high accuracy in lake water test. The preparation and application of the hydrogel in electrochemical sensor provided an availability strategy to capture and detect the various HMIs by electrochemistry in solution and has great commercial application prospect.

Non-Cardiotoxic Tetradecanoic Acid-2,4-Dinitrophenol Ester Nanomicelles in Microneedles Exert Potent Anti-Obesity Effect by Regulating Adipocyte Browning and Lipogenesis.

Sustained oral uncoupler 2,4-dinitrophenol (DNP) administration exerts prominent anti-obesity effects, but the adipose tissue off-target disadvantage leads to systemic adverse effects. A novel non-cardiotoxicity DNP delivery method using a biocompatible microneedles patch containing the amphiphilic tetradecanoic acid-DNP ester (TADNP) is described, which is synthesized via esterification on the phenolic hydroxyl of DNP. The TADNP is self-assembled as nanomicelles, which enhance the endocytosis rate of DNP by adipocytes and its permeation in isolated adipose tissues. The microenvironment of adipose tissues promotes the massive release of DNP and plasma and simulated gastrointestinal fluids. The microneedles-delivered TADNP nanomicelles (MN-TADNP) effectively deliver DNP in treated adipose tissues and reduce DNP content in off-target organs. Both oral and MN patch-delivered TADNP micelles effectively exert anti-obesity effects in a mouse model of high-fat diet-induced obesity; and noteworthily, MN-TADNP exhibit more satisfactory biosafety than oral administration. Here, a smart MN patch loaded with tetradecanoic acid-modified DNP is reported, which enhances its accumulation in adipose tissues and exerts an anti-obesity effect without causing any systemic toxicity.

Genome-Wide Identification of Histone Deacetylases and Their Roles Related with Light Response in Tartary Buckwheat (Fagopyrum tataricum).

Histone deacetylases (HDACs), known as histone acetylation erasers, function crucially in plant growth and development. Although there are abundant reports focusing on HDACs of Arabidopsis and illustrating their important roles, the knowledge of HDAC genes in Tartary buckwheat (Polygonales Polygonaceae Fagopyrum tataricum (L.) Gaertn) is still scarce. In the study, a total of 14 HDAC genes were identified and divided into three main groups: Reduced Potassium Dependency-3/His-52 tone Deacetylase 1 (RPD3/HDA1), Silent Information Regulator 2 (SIR2), and the plant-53 specific HD2. Domain and motif composition analysis showed there were conserved domains and motifs in members from the same subfamilies. The 14 FtHDACs were distributed asymmetrically on 7 chromosomes, with three segmental events and one tandem duplication event identified. The prediction of the cis-element in promoters suggested that FtHDACs probably acted in numerous biological processes including plant growth, development, and response to environmental signals. Furthermore, expression analysis based on RNA-seq data displayed that all FtHDAC genes were universally and distinctly expressed in diverse tissues and fruit development stages. In addition, we found divergent alterations in FtHDACs transcript abundance in response to different light conditions according to RNA-seq and RT-qPCR data, indicating that five FtHDACs might be involved in light response. Our findings could provide fundamental information for the HDAC gene family and supply several targets for future function analysis of FtHDACs related with light response of Tartary buckwheat.

Comparative transcriptome and genome analysis unravels the response of Tatary buckwheat root to nitrogen deficiency.

Tartary buckwheat (Fagopyrum tataricum Garetn.), a dicotyledonous herbaceous crop, has good adaptation to low nitrogen (LN) condition. The plasticity of roots drives the adaption of Tartary buckwheat under LN, but the detailed mechanism behind the response of TB roots to LN remains unclear. In this study, the molecular mechanism of two Tartary buckwheat genotypes' roots with contrasting sensitivity in response to LN was investigated by integrating physiological, transcriptome and whole-genome re-sequencing analysis. LN improved primary and lateral root growth of LN-sensitive genotype, whereas the roots of LN-insensitive genotype showed no response to LN. 2, 661 LN-responsive differentially expressed genes (DEGs) were identified by transcriptome analysis. Of these genes, 17 N transport and assimilation-related and 29 hormone biosynthesis and signaling genes showed response to LN, and they may play important role in Tartary buckwheat root development under LN. The flavonoid biosynthetic genes' expression was improved by LN, and their transcriptional regulations mediated by MYB and bHLH were analyzed. 78 transcription factors, 124 small secreted peptides and 38 receptor-like protein kinases encoding genes involved in LN response. 438 genes were differentially expressed between LN-sensitive and LN-insensitive genotypes by comparing their transcriptome, including 176 LN-responsive DEGs. Furthermore, nine key LN-responsive genes with sequence variation were identified, including FtNRT2.4, FtNPF2.6 and FtMYB1R1. This paper provided useful information on the response and adaptation of Tartary buckwheat root to LN, and the candidate genes for breeding Tartary buckwheat with high N use efficiency were identified.

Identification and Analysis of the CBF Gene Family in Three Species of Acer under Cold Stress.

The C-Repeat Binding Factor (CBF) gene family has been identified and characterized in multiple plant species, and it plays a crucial role in responding to low temperatures. Presently, only a few studies on tree species demonstrate the mechanisms and potential functions of CBFs associated with cold resistance, while our study is a novel report on the multi-aspect differences of CBFs among three tree species, compared to previous studies. In this study, genome-wide identification and analysis of the CBF gene family in Acer truncatum, Acer pseudosieboldianum, and Acer yangbiense were performed. The results revealed that 16 CBF genes (five ApseCBFs, four AcyanCBFs, and seven AtruCBFs) were unevenly distributed across the chromosomes, and most CBF genes were mapped on chromosome 2 (Chr2) and chromosome 11 (Chr11). The analysis of phylogenetic relationships, gene structure, and conserved motif showed that 16 CBF genes could be clustered into three subgroups; they all contained Motif 1 and Motif 5, and most of them only spanned one exon. The cis-acting elements analysis showed that some CBF genes might be involved in hormone and abiotic stress responsiveness. In addition, CBF genes exhibited tissue expression specificity. High expressions of ApseCBF1, ApseCBF3, AtruCBF1, AtruCBF4, AtruCBF6, AtruCBF7, and ApseCBF3, ApseCBF4, ApseCBF5 were detected on exposure to low temperature for 3 h and 24 h. Low expressions of AtruCBF2, AtruCBF6, AtruCBF7 were detected under cold stress for 24 h, and AtruCBF3 and AtruCBF5 were always down-regulated under cold conditions. Taken together, comprehensive analysis will enhance our understanding of the potential functions of the CBF genes on cold resistance, thereby providing a reference for the introduction of Acer species in our country.

The intracellular fate and transport mechanism of shape, size and rigidity varied nanocarriers for understanding their oral delivery efficiency.

Nanocarriers have become an effective strategy to overcome epithelial absorption barriers. During the absorption process, the endocytosis mechanisms, cell internalization pathways, and transport efficiency of nanocarriers are greatly impacted by their physical properties. To understand the relationship between physical properties of nanocarriers and their abilities overcoming multiple absorption barriers, nanocarriers with variable physical properties were prepared via self-assembly of hydrolyzed α-lactalbumin peptide fragments. The impacts of size, shape, and rigidity of nanocarriers on epithelial cells endocytosis mechanisms, internalization pathways, transport efficiency, and bioavailability were studied systematically. The results showed that nanospheres were mainly internalized via clathrin-mediated endocytosis, which was then locked in lysosomes and degraded enzymatically in cytoplasm. While macropinocytosis was the primary pathway of nanotubes and transported to the endoplasmic reticulum and Golgi apparatus, resulting in a high drug concentration and sustained release in cytoplasm. Besides, nanotubes can overcome the multi-drug resistance by inhibiting the P-glycoprotein efflux. Furthermore, nanotubes can open intercellular tight-junctions instantaneously and reversibly, which promotes transport into blood circulation. The aqueous solubility of hydrophobic bioactive mangiferin (Mgf) was improved by nanocarriers. Most importantly, the bioavailability of Mgf was the highest for cross-linked short nanotube (CSNT) which outperformed free Mgf and other formulations by in vivo pharmacokinetic studies. Finally, Mgf-loaded CSNT showed an excellent therapeutic efficiency in vivo for the intervention of streptozotocin-induced diabetes. These results indicate that cross-linked α-lactalbumin nanotubes could be an effective nanocarrier delivery system for improving the epithelium cellular absorption and bioavailability of hydrophobic bioactive compounds.

Histone demethylase MaJMJ15 is involved in the regulation of postharvest banana fruit ripening.

Histone methylation plays important roles in plant development. However, the role of histone methylation in fruit ripening remains unclear. Here, a total of 16 Jumonji domain-containing proteins (JMJs) were identified from banana genome. During fruit ripening, expression of MaJMJ15 was significantly upregulated. Exogenous ethylene accelerated the upregulation whereas 1-methylcyclopropene delayed the process, suggesting that MaJMJ15 positively regulates banana fruit ripening. MaJMJ15 is an H3K27me3 site-specific demethylase. Transient overexpression of MaJMJ15 promoted banana fruit ripening. Moreover, the global H3K27me3 was decreased by MaJMJ15. Furthermore, MaJMJ15 directly targeted several key ripening-related genes (RRGs) in banana including NAC transcription factor 1/2 (MaNAC1/2), 1-aminocyclopropane-1-carboxylate synthase 1 (MaACS1), 1-aminocyclopropane-1-carboxylate oxidase 1 (MaACO1) and expansin 2 (MaEXP2), removed H3K27me3 from their chromatin, and activated their expression. Our data suggest that MaJMJ15 is an H3K27me3 demethylase, which is involved in the regulation of banana fruit ripening by activating expression of key RRGs via removal of H3K27me3.

Effects of Storage Temperature, Packaging Material and Wash Treatment on Quality and Shelf Life of Tartary Buckwheat Microgreens.

Tartary buckwheat microgreens (TBM) are popular worldwide products but display an extremely short shelf life. Thus, the effects of storage temperature, packaging material, and wash treatment on the quality and shelf life were analyzed. Headspace composition, weight loss, electrolyte leakage, microbial population and sensory quality were investigated during storage. Results showed that shelf life and quality of TBM decreased with the increment of storage temperature when stored at 5-25 °C. During 5 °C storage, LDPE bags were the best packaging materials for preserving the quality of LDPE, PE and HDPE bags. On the basis of 5 °C and LDPE packages, ClO2 + citric acid wash treatment could further inhibit quality deterioration and extend the shelf life. The results demonstrated bioactive constituents and antioxidant capacity were significantly affected by storage time. The study provides insights into developing optimal packaging and storage conditions for TBM.

Integrated metabolomic and transcriptomic analyses reveal different metabolite biosynthesis profiles of Juglans mandshurica in shade.

Light is not only a very important source of energy for the normal growth and development of plants, but also a regulator of many development and metabolic processes. The mechanism of plant growth and development under low light conditions is an important scientific question. With the promulgation of the law to stop natural forest cutting, understory regeneration is an important method for artificial forest afforestation. Here, the growth and physiological indexes of Juglans mandshurica, an important hardwood species in Northeast China, were measured under different shade treatments. In addition, transcriptome and metabolome were compared to analyze the molecular mechanism of shade tolerance in J. mandshurica. The results showed that the seedling height of the shade treatment group was significantly higher than that of the control group, and the 50% light (L50) treatment was the highest. Compared with the control group, the contents of gibberellin, abscisic acid, brassinolide, chlorophyll a, and chlorophyll b in all shade treatments were significantly higher. However, the net photosynthetic rate and water use efficiency decreased with increasing shade. Furthermore, the transcriptome identified thousands of differentially expressed genes in three samples. Using enrichment analysis, we found that most of the differentially expressed genes were enriched in photosynthesis, plant hormone signal transduction and chlorophyll synthesis pathways, and the expression levels of many genes encoding transcription factors were also changed. In addition, analysis of differentially accumulated metabolites showed that a total of 470 differential metabolites were identified, and flavonoids were the major differential metabolites of J. mandshurica under light stress. These results improved our understanding of the molecular mechanism and metabolite accumulation under light stress in J. mandshurica.

Genome-wide identification and transcriptome analysis of the heavy metal-associated (HMA) gene family in Tartary buckwheat and their regulatory roles under cadmium stress.

Heavy metal-associated (HMA) genes are those related to heavy metal transport and detoxification in plants. HMA genes have not been reported in Tartary buckwheat so far. In this study, we accessed the HMA genes of Tartary buckwheat by genome-wide identification for the first time. A total of 56 HMA genes were identified, including 36 ATX1 (antioxidant protein1) genes, 13 HIPP (heavy metal-associated isoprenylated plant protein) genes, and 7 P1B-ATPase (P1B-type adenosine triphosphatase) genes. These gene structures, motif compositions, chromosomal distribution, phylogenetic relationship, duplication events, interaction networks, cis-acting elements, and transcriptional expression under cadmium (Cd) stress were investigated. Among them, genes in HIPP and ATX1 subfamilies were more closely related. The 56 HMA genes were involved in the regulation of metal ion transport and homeostasis by binding metal ions, likely triggered by signals transducted by plant hormones. Fifteen of these HMA genes played regulatory roles under Cd stress. FtP1bA1 was identified to be a core gene involved in the defense regulation of Cd stress. Our results provide not only the first overview and characteristics of HMA genes in the whole genome of Tartary buckwheat but also a valuable reference for the functional analysis of HMA genes under Cd stress. Understanding changes in gene regulation induced by Cd stress lays the foundation for breeding resistant varieties.

The kinetic mechanism of cations induced protein nanotubes self-assembly and their application as delivery system.

The amphiphilic proteins can be used as building blocks (BBs) forming various self-assemblies. Understanding their self-assembly mechanism is important for designing novel nanomaterials. Herein, the BBs dimers were first prepared from carboxyl-abundant enzymolyzed α-lactalbumin (α-lac) at 50 °C. Then the unidentate coordination of Ca2+ between the BBs caused a ß-sheet stacking to further self-assemble into nanotubes (NTs). Compared with the traditional "one-pot" method, a step-wise new method was applied to study hydrolysis, aggregation and self-assembly processes separately. The α-lac was hydrolyzed into 11 kDa amphiphilic peptides independent of temperature while a BBs dimer was formed at 50 °C by hydrophobic interaction. Ca2+ induced a conformational change of BBs and promoted these BBs gradually aggregate into 10 strands of filaments, which twisted into helical ribbons by electrostatic repulsion. Ca2+ further induced the twisted helical ribbons closed into NTs driven by the reduction of line tension energy. Besides, the carboxyl-Ca2+ coordination dominated NTs elongation in the longitudinal direction and filaments aggregation in the lateral direction with the same binding stoichiometry of 1:1 respectively. Finally, NTs successfully encapsulated curcumin and improved the viscosity of liquid food. α-Lac NTs show a high potential as a delivery system for food applications.

Integrated Transcriptome and Metabolome Analyses Reveal the Anthocyanin Biosynthesis Pathway in AmRosea1 Overexpression 84K Poplar.

Populus alba × Populus glandulosa (84K poplar) is model material with excellent genetic engineering resource and ornamental value. In our study, AmRosea1 (Antirrhinum majus) was overexpressed in 84K poplar, and the transgenic 84K (AM) poplar with high content of anthocyanin exhibited red pigmentation leaves. The transcriptome analysis between wild type (WT) and AM showed that 170 differentially expressed genes (DEGs) (86 up-regulated and 84 down-regulated) were found, and some DEGs were involved in flavone and flavonol biosynthesis, flavonoid biosynthesis and anthocyanin biosynthesis. The metabolome analysis showed that 13 anthocyanins-related differentially accumulated metabolites (DAMs) were detected in AM. The correlation analysis between DEGs and DAMs were performed, and the results revealed that 18 DEGs, including 11 MYB genes, two BZ1 genes, one FG2 gene, one ANS gene, and three IF7MAT genes, were negatively or positively correlated with 13 DAMs. The phylogenetic analysis demonstrated that there was high homology between AmRosea1 and PagMYB113, and MYB113 co-expressed with BZ1, ANS and DFR directly. Our results elucidated the molecular mechanism of plant color change mediated by anthocyanin biosynthesis pathway, which laid the foundation for the development and utilization of colorful woody plant.

Dynamic transcriptome and co-expression analysis suggest the potential roles of small secreted peptides from Tartary buckwheat (Fagopyrum tataricum) in low nitrogen stress response.

Small secreted peptides (SSPs) regulate nitrogen (N) response and signaling in plants. Although much progress has been made in understanding the functions of SSPs in N response, very little information is available regarding non-model plants. Tartary buckwheat (Fagopyrum tataricum), a dicotyledonous crop, has a good adaptability to low N (LN) stress; however, little is known regarding the associated mechanisms underlying this adaptation. In this study, 932 putative SSPs were genome-wide characterized in TB genome. Of these SSPs, 233 SSPs were annotated as established SSPs, such as CLE, RALF, PSK, and CEP peptides. The gene expression of 675 putative SSPs was detected in five tissues and 258 SSPs were tissue-specific expressed genes. To analyze the responses of TB SSPs to LN, the dynamic expression analysis of TB roots under LN stress was conducted by RNA-seq. The expression of 378 putative TB SSP genes was detected with diverse expression patterns under LN stress, and some important LN-responsive SSPs were identified. Co-expression analysis suggested SSPs may regulate the adaptability of TB under LN conditions by modulating the expression of the genes involved in N transport and assimilation and IAA signaling. Furthermore, 53 LN stress-responsive RLKs encoding genes were identified and they were predicted as potential SSP receptors. This study expands the repertoire of SSPs in plants and provides useful information for further investigation of the functions of Tartary buckwheat SSPs in LN stress responses.