Ultrasensitive Ti3C2Tx@Pt-Based Immunochromatography with Catalytic Amplification and a Dual Signal for the Detection of Chloramphenicol in Animal-Derived Foods.

Herein, a catalytic amplification enhanced dual-signal immunochromatographic assay (ICA) based on Pt nanoparticles (Pt NPs) modified with Ti3C2Tx MXene (Ti3C2Tx@Pt) was first developed for chloramphenicol (CAP) in animal-derived foods. Due to the large specific surface area and abundant active sites of Ti3C2Tx@Pt, they can be loaded with hundreds of Pt NPs to enhance their catalytic activity, resulting in a significant increase in the detection sensitivity; the sensitivity was up to 50-fold more sensitive than the reported ICA for CAP. The LODs of the developed method for milk/chicken/fish were 0.01 µg/kg, the LOQs were 0.03 µg/kg and the recovery rates were 80.5-117.0%, 87.2-118.1% and 92.7-117.9%, with corresponding variations ranging from 3.1 to 9.6%, 6.0 to 12.7% and 6.0 to 13.6%, respectively. The linear range was 0.0125-1.0 µg/kg. The results of the LC-MS/MS confirmation test on 30 real samples had a good correlation with that of our established method (R2 > 0.98), indicating the practical reliability of the established method. The above results indicated that an ICA based on the Ti3C2Tx@Pt nanozyme has excellent potential as a food safety detection tool.

A bamboo 'PeSAPK4-PeMYB99-PeTIP4-3' regulatory model involved in water transport.

Water plays crucial roles in expeditious growth and osmotic stress of bamboo. Nevertheless, the molecular mechanism of water transport remains unclear. In this study, an aquaporin gene, PeTIP4-3, was identified through a joint analysis of root pressure and transcriptomic data in moso bamboo (Phyllostachys edulis). PeTIP4-3 was highly expressed in shoots, especially in the vascular bundle sheath cells. Overexpression of PeTIP4-3 could increase drought and salt tolerance in transgenic yeast and rice. A co-expression pattern of PeSAPK4, PeMYB99 and PeTIP4-3 was revealed by WGCNA. PeMYB99 exhibited an ability to independently bind to and activate PeTIP4-3, which augmented tolerance to drought and salt stress. PeSAPK4 could interact with and phosphorylate PeMYB99 in vivo and in vitro, wherein they synergistically accelerated PeTIP4-3 transcription. Overexpression of PeMYB99 and PeSAPK4 also conferred drought and salt tolerance in transgenic rice. Further ABA treatment analysis indicated that PeSAPK4 enhanced water transport in response to stress via ABA signaling. Collectively, an ABA-mediated cascade of PeSAPK4-PeMYB99-PeTIP4-3 is proposed, which governs water transport in moso bamboo.

Unveiling the Biological Function of Phyllostachys edulis FBA6 (PeFBA6) through the Identification of the Fructose-1,6-Bisphosphate Aldolase Gene.

Fructose-1,6-bisphosphate aldolase (FBA) is a pivotal enzyme in various metabolic pathways, including glycolysis, gluconeogenesis, and the Calvin cycle. It plays a critical role in CO2 fixation. Building on previous studies on the FBA gene family in Moso bamboo, our study revealed the biological function of PeFBA6. To identify CSN5 candidate genes, this study conducted a yeast two-hybrid library screening experiment. Subsequently, the interaction between CSN5 and PeFBA6 was verified using yeast two-hybrid and LCI experiments. This investigation uncovered evidence that FBA may undergo deubiquitination to maintain glycolytic stability. To further assess the function of PeFBA6, it was overexpressed in rice. Various parameters were determined, including the light response curve, CO2 response curve, and the levels of glucose, fructose, sucrose, and starch in the leaves of overexpressing rice. The results demonstrated that overexpressed rice exhibited a higher saturation light intensity, net photosynthetic rate, maximum carboxylation rate, respiration rate, and increased levels of glucose, fructose, and starch than wild-type rice. These findings indicated that PeFBA6 not only enhanced the photoprotection ability of rice but also improved the photosynthetic carbon metabolism. Overall, this study enhanced our understanding of the function of FBA and revealed the biological function of PeFBA6, thereby providing a foundation for the development of excellent carbon fixation bamboo varieties through breeding.

A bamboo bHLH transcription factor PeRHL4 has dual functions in enhancing drought and phosphorus starvation tolerance.

ROOTHAIRLESS (RHL) is a typical type of basic helix-loop-helix (bHLH) transcription factor (TF), which has been reported to participate in various aspects of plant growth and in response to stress. However, the functions of RHL subfamily members in moso bamboo (Phyllostachys edulis) remain unknown. In this study, we identified 14 bHLH genes (PeRHL1-PeRHL14) in moso bamboo. Phylogenetic tree and conserved motif analyses showed that PeRHLs were clustered into three clades. The expression analysis suggested that PeRHL4 was co-expressed with PeTIP1-1 and PePHT1-1 in moso bamboo. Moreover, these three genes were all up-regulated in moso bamboo under drought stress and phosphate starvation. Y1H, DLR and EMSA assays demonstrated that PeRHL4 could activate the expression of PeTIP1-1 and PePHT1-1. Furthermore, overexpression of PeRHL4 could increase both drought and phosphate starvation tolerance in transgenic rice, in which the expression of OsTIPs and OsPHT1s was significantly improved, respectively. Overall, our results indicated that drought stress and phosphate starvation could induce the expression of PeRHL4, which in turn activated downstream genes involved in water and phosphate transport. Collectively, our findings reveal that PeRHL4 acting as a positive regulator contributes to enhancing the tolerance of moso bamboo under drought stress and phosphate starvation.

Chloroplast genome of Calamus tetradactylus revealed rattan phylogeny.

BACKGROUND: Calamus tetradactylus, a species primarily distributed in Vietnam, Laos, and southern China, is highly valued for its utilization as a small-diameter rattan material. While its physical and mechanical properties have been extensively studied, the genomic characteristics of C. tetradactylus remain largely unexplored. RESULTS: To gain a better understanding of its chloroplast genomic features and evolutionary relationships, we conducted sequencing and assembly of the chloroplast genome of C. tetradactylus. The complete chloroplast genome exhibited the typical highly conserved quartile structure, with specific variable regions identified in the single-copy region (like psbF-psbE, π = 0.10327, ndhF-rpl32, π = 0.10195), as well as genes such as trnT-GGU (π = 0.05764) and ycf1 (π = 0.03345) and others. We propose that these regions and genes hold potential as markers for species identification. Furthermore, phylogenetic analysis revealed that C. tetradactylus formed a distinct clade within the phylogenetic tree, alongside other Calamus species, and C. tetradactylus was most closely related to C. walkeri, providing support for the monophyly of the genus. CONCLUSION: The analysis of the chloroplast genome conducted in this study provides valuable insights that can contribute to the improvement of rattan breeding programs and facilitate sustainable development in the future.

Sarcopenia is associated with leukopenia in urothelial carcinoma patients who receive tislelizumab combined with gemcitabine and cisplatin therapy.

BACKGROUND: In the era of combination therapy, there has been limited research on body composition. Specific body composition, such as sarcopenia, possesses the potential to serve as a predictive biomarker for toxic effects and clinical response in patients with urothelial carcinoma (UC) undergoing tislelizumab combined with gemcitabine and cisplatin (T + GC). MATERIALS AND METHODS: A total of 112 UC patients who received T + GC were selected at the Affiliated Hospital of Xuzhou Medical University from April 2020 to January 2023. Baseline patient characteristics and detailed hematological parameters were collected using the electronic medical system and laboratory examinations. The computed tomography images of patients were analyzed to calculate psoas muscle mass index (PMI). We evaluated the association between sarcopenia (PMI < 4.5 cm2/m2 in men; PMI < 3.3 cm2/m2 in women) and both hematological toxicity and tumor response. RESULTS: Overall, of the 112 patients (65.2% male, median age 56 years), 43 (38.4%) were defined as sarcopenia. Patients with sarcopenia were notably older (p = 0.037), more likely to have hypertension (p = 0.009), and had poorer ECOG-PS (p = 0.027). Patients with sarcopenia were more likely to develop leukopenia (OR 2.969, 95% CI 1.028-8.575, p = 0.044) after receiving at least two cycles of T + GC. However, these significant differences were not observed in thrombocytopenia and anemia. There were no significant differences in the tumor response and grade 3-4 hematological toxicity between patients with sarcopenia and those without sarcopenia. CONCLUSIONS: Patients with sarcopenia were more likely to develop leukopenia after receiving T + GC. There were no notable alterations observed in relation to anemia or thrombocytopenia. No significant difference was found between the sarcopenia group and non-sarcopenia group in terms of tumor response and grade 3-4 hematological toxicity.

Contribution of 1O2 in the efficient degradation of organic pollutants with Cu0/Cu2O/CuO@N-C activated peroxymonosulfate: A Case study with tetracycline.

Peroxymonosulfate-mediated advanced oxidation processes (PMS-AOPs) degrading organic pollutants (Tetracycline (TC) as an example) in water with singlet oxygen (1O2) as the main reactive oxygen has received more and more attention. However, the generation mechanism of 1O2 is still unclear. Consequently, this study investigates the 1O2 formation mechanism during the activated PMS process using a nitrogen-copper-loaded carbon-based material (Cu0/Cu2O/CuO@N-C), synthesized by thermally decomposing organobase-modified HKUST-1 via a one-pot method. It was discovered that incorporating an organobase (Benzylamine) into the metal organic framework (MOF) precursor directs the MOF's self-assembly process and supplements its nitrogen content. This modification modulates the Nx-Cu-Oy active site formation in the material, selectively producing 1O2. Additionally, 1O2 was identified as the dominant reactive oxygen species in the Cu0/Cu2O/CuO@N-C-PMS system, contributing to TC degradation with a rate of 70.82%. The TC degradation efficiency remained high in the pH range of 3-11 and sustained its efficacy after five consecutive uses. Finally, based on the intermediates of TC degradation, three possible degradation pathways were postulated, and a reduction in the ecotoxicity of the degradation products was predicted. This work presents a novel and general strategy for constructing nitrogen-copper-loaded carbon-based materials for use in PMS-AOPs.

Spatial dynamics and risk assessment of phosphorus in the river sediment continuum (Qinhuai River basin, China).

This study investigated the concentration and fractionation of phosphorus (P) using sequential P extraction and their influencing factors by introducing the PLS-SEM model (partial least squares structural equation model) along this continuum from the Qinhuai River. The results showed that the average concentrations of inorganic P (IP) occurred in the following order: urban sediment (1499.1 mg/kg) > suburban sediment (846.1-911.9 mg/kg) > rural sediment (661.1 mg/kg) > natural sediment (179.9 mg/kg), and makes up to 53.9-87.1% of total P (TP). The same as the pattern of IP, OP nearly increased dramatically with increasing the urbanization gradient. This spatial heterogenicity of P along a river was attributed mainly to land use patterns and environmental factors (relative contribution affecting the P fractions: sediment nutrients > metals > grain size). In addition, the highest values of TP (2876.5 mg/kg), BAP (biologically active P, avg, 675.7 mg/kg), and PPI (P pollution index, ≥ 2.0) were found in urban sediments among four regions, indicating a higher environmental risk of P release, which may increase the risk of eutrophication in overlying water bodies. Collectively, this work improves the understanding of the spatial dynamics of P in the natural-rural-urban river sediment continuum, highlights the need to control P pollution in urban sediments, and provides a scientific basis for the future usage and disposal of P in sediments.

The addition of tislelizumab to gemcitabine and cisplatin chemotherapy increases thrombocytopenia in patients with urothelial carcinoma: A single-center study based on propensity score matching.

PURPOSE: Whether the addition of tislelizumab to gemcitabine and cisplatin (GC) chemotherapy increases the incidence of myelosuppression has not been well established. This study identified the risk factors for the development of myelosuppression in patients with urothelial carcinoma (UC) after receiving GC chemotherapy with or without tislelizumab. MATERIALS AND METHODS: We enrolled 192 UC patients who received GC with or without tislelizumab at the Affiliated Hospital of Xuzhou Medical University between July 2014 and November 2022. Patient baseline characteristics were included in the statistical analyses after adjusting for previously reported risk factors affecting survival using propensity score matching (1:1). Binary logistic regression analysis was used to identify the risk factors associated with posttreatment myelosuppression. RESULTS: A total of 192 patients were enrolled, of whom 96 were treated with tislelizumab plus gemcitabine and cisplatin (T + GC) and 96 with GC alone. The incidence of leukopenia, anemia, and thrombocytopenia of any grade was 50.0%, 70.8%, and 42.7%, respectively, in the T + GC group and 41.7%, 72.9%, and 20.8%, respectively, in the GC group. In multivariate analysis, patients aged over 70 years (OR = 2.486, 95% CI: 1.067-5.792, p = 0.035) and those who received T + GC (OR = 3.119, 95% CI: 1.576-6.173, p = 0.001) were more likely to develop thrombocytopenia. Patients aged over 70 years (OR = 3.213, 95% CI: 1.254-8.237, p = 0.015) were more likely to develop anemia, and patients with renal insufficiency (OR = 2.105, 95% CI: 1.035-4.280, p = 0.040) were more likely to develop leukopenia. Eventually, 99 (51.6%) patients with UC successfully completed all the treatment cycles. CONCLUSIONS: This study demonstrates that the addition of tislelizumab to GC chemotherapy led to a considerable increase in the occurrence of thrombocytopenia, whereas no significant changes were observed regarding anemia or leukopenia. It is crucial to fully inform patients at increased risk for myelosuppression of potential risks and closely monitor changes in their blood routines.

Core-Shell Au@Pd Bimetallic Nanozyme Mediated Mild Photothermal Therapy through Reactive Oxygen Species-Regulating Tumor Thermoresistance.

Mild photothermal therapy (mPTT), which circumvents the limitations of conventional photothermal therapy, is emerging and exhibits remarkable potential in clinical applications. Nevertheless, mPTT is not able to efficiently eradicate tumors because its therapeutic efficacy is dramatically diminished by stress-induced heat shock proteins (HSP). Herein, a core-shell structured Au@Pd (AP) bimetallic nanozyme was fabricated for reactive oxygen species (ROS) augmentation-induced mPTT. The nanocatalytic AP nanozymes with photothermal conversion performance harbor multienzymatic (catalase, oxidase, and peroxidase) activities to induce ROS storm formation. The generated ROS could suppress the heat-defense response of tumor cells by cleaving HSP. Overall, our work highlights a ROS-regulating strategy to counteract hyperthermia-associated resistance in mPTT.

Mild-Photothermal Effect Induced High Efficiency Ferroptosis-Boosted-Cuproptosis Based on Cu2 O@Mn3 Cu3 O8 Nanozyme.

A core-shell-structured Cu2 O@Mn3 Cu3 O8 (CMCO) nanozyme is constructed to serve as a tumor microenvironment (TME)-activated copper ionophore to achieve safe and efficient cuproptosis. The Mn3 Cu3 O8 shell not only prevents exposure of normal tissues to the Cu2 O core to reduce systemic toxicity but also exhibits enhanced enzyme-mimicking activity owing to the better band continuity near the Fermi surface. The glutathione oxidase (GSHOx)-like activity of CMCO depletes glutathione (GSH), which diminishes the ability to chelate Cu ions, thereby exerting Cu toxicity and inducing cuproptosis in cancer cells. The catalase (CAT)-like activity catalyzes the overexpressed H2 O2 in the TME, thereby generating O2 in the tricarboxylic acid (TCA) cycle to enhance cuproptosis. More importantly, the Fenton-like reaction based on the release of Mn ions and the inactivation of glutathione peroxidase 4 induced by the elimination of GSH results in ferroptosis, accompanied by the accumulation of lipid peroxidation and reactive oxygen species that can cleave stress-induced heat shock proteins to compromise their protective capacity of cancer cells and further sensitize cuproptosis. CMCO nanozymes are partially sulfurized by hydrogen sulfide in the colorectal TME, exhibiting excellent photothermal properties and enzyme-mimicking activity. The mild photothermal effect enhances the enzyme-mimicking activity of the CMCO nanozymes, thus inducing high-efficiency ferroptosis-boosted-cuproptosis.

Low-Temperature Photothermal Therapy Platform Based on Pd Nanozyme-Modified Hydrogenated TiO2.

In photothermal treatments (PTTs), normal tissues around cancerous tumors get injured by excessive heat, whereas damaged cancer cells are easily restored by stress-induced heat shock proteins (HSPs) at low temperatures. Therefore, to achieve a unique tumor microenvironment (TME), it is imperative to increase PTT efficiency and reduce normal tissue injury by adopting appropriate reactive oxygen species (ROS) and lipid peroxides (LPO) cross-linked with HSPs. In the present research, a potential strategy for mild photothermal treatments (mPTTs) was proposed by initiating localized catalytic chemical reactions in TME based on Pd nanozyme-modified hydrogenated TiO2 (H-TiO2@Pd). In vitro and in vivo evaluations demonstrated that H-TiO2@Pd had good peroxidase-like activities (POD), glutathione oxidase-like activities (GSHOx), and photodynamic properties and also satisfactory biocompatibility for 4T1 cells. Localized catalytic chemical reactions in H-TiO2@Pd significantly depleted GSH to downregulate the protein expression of GPX4 and promoted the accumulation of LPO and ROS, which consumed HSP70 or inhibited its function in 4T1 cells. Hence, the as-constructed low-temperature photothermal therapeutic platform based on Pd nanozyme-modified H-TiO2 can be a promising candidate to develop a safe and effective mPTT for cancer treatments.

Role of plectin and its interacting molecules in cancer.

Plectin, as the cytolinker and scaffolding protein, are widely expressed and abundant in many tissues, and has involved in various cellular activities contributing to tumorigenesis, such as cell adhesion, migration, and signal transduction. Due to the specific expression and differential localization of plectin in cancer, most researchers focus on the role of plectin in cancer, and it has emerged as a potent driver of malignant hallmarks in many human cancers, which provides the possibility for plectin to be widely used as a biomarker and therapeutic target in the early diagnosis and targeted drug delivery of the disease. However, there is still a lack of systematic review on the interaction molecules and mechanism of plectin. Herein, we summarized the structure, expression and function of plectin, and mainly focused on recent studies on the functional and physical interactions between plectin and its interacting molecules, shedding light on the potential of targeting plectin for cancer therapy.

In Planta Gene Expression and Gene Editing in Moso Bamboo Leaves.

A novel in planta gene transformation method was developed for bamboo, which avoids the need for time-consuming and labor-intensive callus induction and regeneration processes. This method involves Agrobacterium-mediated gene expression via wounding and vacuum for bamboo seedlings. It successfully demonstrated the expression of exogenous genes, such as the RUBY reporter and Cas9 gene, in bamboo leaves. The highest transformation efficiency for the accumulation of betalain in RUBY seedlings was achieved using the GV3101 strain, with a percentage of 85.2% after infection. Although the foreign DNA did not integrate into the bamboo genome, the method was efficient in expressing the exogenous genes. Furthermore, a gene editing system has also been developed with a native reporter using this method, from which an in situ mutant generated by the edited bamboo violaxanthin de-epoxidase gene (PeVDE) in bamboo leaves, with a mutation rate of 17.33%. The mutation of PeVDE resulted in decreased non-photochemical quenching (NPQ) values under high light, which can be accurately detected by a fluorometer. This makes the edited PeVDE a potential native reporter for both exogenous and endogenous genes in bamboo. With the reporter of PeVDE, a cinnamoyl-CoA reductase gene was successfully edited with a mutation rate of 8.3%. This operation avoids the process of tissue culture or callus induction, which is quick and efficient for expressing exogenous genes and endogenous gene editing in bamboo. This method can improve the efficiency of gene function verification and will help reveal the molecular mechanisms of key metabolic pathways in bamboo.

Advancements and challenges in bamboo breeding for sustainable development.

Bamboo is a highly renewable biomass resource with outstanding ecological, economic and social benefits. However, its lengthy vegetative growth stage and uncertain flowering period have hindered the application of traditional breeding methods. In recent years, significant progress has been made in bamboo breeding. While technical advances in bamboo breeding have been impressive, it is essential to also consider the broader implications we can learn from bamboo's extraordinary features for sustainable development. This review provides an overview of the current status of bamboo breeding technology, including a detailed history of bamboo breeding divided into four eras, a comprehensive map of bamboo germplasm gardens worldwide, with a focus on China, and a summary of available transgenic technologies for gene function verification and genetic improvement. As the demand for bamboo as a sustainable and renewable resource increases continuously, breeding objectives should be focused on enhancing yield, wood properties and adaptability to diverse environmental conditions. In particular, priority should be given to improving fiber length, internode length and wall thickness, as well as regulating lignin and cellulose content for papermaking, substitute for plastic and other applications. Furthermore, we highlight the challenges and opportunities for future research and development in bamboo breeding, including the application of omics technologies, artificial intelligence and the development of new breeding methods. Finally, by integrating the technical advances in bamboo breeding with a discussion of its broader implications for sustainable development, this review provides a comprehensive framework for the development of bamboo industry.

Improving ultrafiltration of algae-laden water with chitosan quaternary ammonium salt enhanced by sodium percarbonate.

Ultrafiltration (UF) is extensively used for algae removal because of its ability to retain algal cells with high efficiency, but it still faces the problem of membrane fouling and low retention capacity of dissolved organics. Hence, a strategy of coagulation with chitosan quaternary ammonium salt (HTCC) enhanced by sodium percarbonate (SPC) pre-oxidation was proposed to improve the UF performance. The fouling resistances were calculated by a resistance-in-series model based on Darcy's formula, and the membrane fouling mechanism was evaluated using a pore plugging-cake filtration model. The effect of SPC-HTCC treatment on the properties of algal foulants was explored, and the result showed that the water quality was improved with the maximum removal rates of 78.8 %, 52.4 % and 79.5 % for algal cells, dissolved organic carbon and turbidity, respectively. The SPC could achieve a mild oxidation effect that degraded the electronegative organics attached to algal cells without destroying the cell integrity, making the algal pollutants easier to agglomerate through subsequent HTCC coagulation by forming larger flocs. In terms of membrane filtration, the terminal normalized flux was increased from 0.25 to 0.71, with the reversible and irreversible resistances reduced by 90.8 % and 40.2 %, individually. The synergistic treatment reduced the accumulation of algal cells and algae-derived organics on the membrane surface as inferred from the interface fouling characteristics. The interfacial free energy analysis showed that the synergistic treatment reduced the adhesion of contaminants to the membrane surface, as well as the attraction among pollutants. Overall, the proposed process has high application prospects for algae-laden water purification.

Calcium sulfite oxidation activated by ferrous iron integrated with membrane filtration for removal of typical algal contaminants.

Oxidation treatment of algae-laden water may cause cells rupture and emission of intracellular organics, thus restricting its further popularization. As a moderate oxidant, calcium sulfite could be slowly released in the liquid phase, thus exhibiting a potential to maintain the cells integrity. To this end, calcium sulfite oxidation activated by ferrous iron was proposed integrated with ultrafiltration (UF) for removal of Microcystis aeruginosa, Chlorella vulgaris and Scenedesmus quadricauda. The organic pollutants were significantly eliminated, and the repulsion between algal cells was obviously weakened. Through fluorescent components extraction and molecular weights distribution analyses, the degradation of fluorescent substances and the generation of micromolecular organics were verified. Moreover, the algal cells were dramatically agglomerated and formed larger flocs under the premise of maintaining high cell integrity. The terminal normalized flux was ascended from 0.048-0.072 to 0.711-0.956, and the fouling resistances were extraordinarily decreased. Due to the distinctive spiny structure and minimal electrostatic repulsion, Scenedesmus quadricauda was easier to form flocs, and its fouling was more readily mitigated. The fouling mechanism was remarkably altered through postponing the formation of cake filtration. The membrane interface characteristics including microstructures and functional groups firmly proved the fouling control efficiency. The reactive oxygen species (i.e., SO4•- and 1O2) generated through the principal reactions and Fe-Ca composite flocs played dominant roles in alleviating membrane fouling. Overall, the proposed pretreatment exhibits a brilliant application potential for enhancing UF in algal removal.

A new biotechnology for in-planta gene editing and its application in promoting flavonoid biosynthesis in bamboo leaves.

BACKGROUND: Bamboo is a perennial and renewable biomass forest resource and its leaf flavonoid is an antioxidant for biological and pharmacological research. The established genetic transformation and gene editing systems in bamboo are significantly limited by the dependence on bamboo regeneration capability. The way to improve the flavonoid content in bamboo leaves through biotechnology is still not feasible. RESULTS: Here, we developed an in-planta, Agrobacterium-mediated gene expression method for exogenous genes via wounding and vacuum in bamboo. We demonstrated that the RUBY served as a reporter efficiently expressed in bamboo leaves and shoots, albeit unable to integrate into the chromosome. We have also developed a gene editing system by creating an in situ mutant of the bamboo violaxanthin de-epoxidase (PeVDE) gene in bamboo leaves, with lower NPQ values under the fluorometer, which can serve as a native reporter for gene editing. Furthermore, the bamboo leaves with increased flavonoid content were achieved by knocking out the cinnamoyl-CoA reductase genes. CONCLUSIONS: Our method can be applied for the functional characterization of novel genes in a short time and is helpful for bamboo leaf flavonoid biotechnology breeding in the future.

Identification and characterization of CircRNA-associated CeRNA networks in moso bamboo under nitrogen stress.

BACKGROUND: Nitrogen is a macronutrient element for plant growth and development. Circular RNAs (circRNAs) serve as pivotal regulators for the coordination between nutrient supply and plant demand. Moso bamboo (Phyllostachys edulis) is an excellent plant with fast growth, and the mechanism of the circRNA-target module in response to nitrogen remains unclear. RESULTS: Deep small RNA sequencing results of moso bamboo seedlings under different concentrations of KNO3 (N0 = 0 mM, N6 = 6 mM, N18 = 18 mM) were used to identify circRNAs. A total of 549 circRNAs were obtained, of which 309 were generated from corresponding parental coding genes including 66 new ones. A total of 536 circRNA-parent genes were unevenly distributed in 24 scaffolds and were associated with root growth and development. Furthermore, 52 differentially expressed circRNAs (DECs) were obtained, including 24, 33 and 15 DECs from three comparisons of N0 vs. N6, N0 vs. N18 and N6 vs. N18, respectively. Based on integrative analyses of the identified DECs, differentially expressed mRNAs (DEGs), and miRNAs (DEMs), a competitive endogenous RNA (ceRNA) network was constructed, including five DECs, eight DEMs and 32 DEGs. A regulatory module of PeSca_6:12,316,320|12,372,905-novel_miR156-PH02Gene35622 was further verified by qPCR and dual-luciferase reporter assays. CONCLUSION: The results indicated that circRNAs could participate in multiple biological processes as miRNA sponges, including organ nitrogen compound biosynthesis and metabolic process regulation in moso bamboo. Our results provide valuable information for further study of circRNAs in moso bamboo under fluctuating nitrogen conditions.

Development of dual-visible reporter assays to determine the DNA-protein interaction.

The application of DNA-protein interaction reporter assays for relational or ratiometric measurements within an experimental system is popular in biological research. However, the existing reporter-based interaction assays always require special equipment, expensive chemicals, and a complicated operation. Here, we developed a DNA-protein interaction technology integrating two visible reporters, RUBY and UV-visible GFP (eYGFPuv), which allows the expression of the cassette reporter contained cis-acting DNA element (DE) fused upstream of TATA box and RUBY, and a constitutive promoter regulating eYGFPuv in the same construct. The interaction of transcription factor (TF) and the DE can be detected by co-expressed the cassette reporter and TF in tobacco leaves where the cassette reporter alone serves as a control. We also revealed that eight function-unknown bamboo AP2/ERFs interacted with the DE of ANT-AP2R1R2 (ABE), DRE (DBE), GCC-box (EBE), and RAV1 binding element (RBE), respectively, which are consistent with the results by dual-luciferase reporter assays. Thus, the dual-visible reporters offer a convenient, visible, and cost-saving alternative to other existing techniques for DNA-protein interaction in plants.