Transcriptome disclosure of hormones inducing stigma exsertion in Nicotiana tabacum by corolla shortening.

BACKGROUND: Stigma exsertion is an essential agricultural trait that can promote cross-pollination to improve hybrid seed production efficiency. However, the molecular mechanism controlling stigma exsertion remains unknown. RESULTS: In this study, the Nicotiana tabacum cv. K326 and its two homonuclear-heteroplasmic lines, MSK326 (male-sterile) and MSK326SE (male-sterile and stigma exserted), were used to investigate the mechanism of tobacco stigma exsertion. A comparison of the flowers between the three lines showed that the stigma exsertion of MSK326SE was mainly due to corolla shortening. Therefore, the corollas of the three lines were sampled and presented for RNA-seq analysis, which found 338 candidate genes that may cause corolla shortening. These genes were equally expressed in K326 and MSK326, but differentially expressed in MSK326SE. Among these 338 genes, 15 were involved in hormone synthesis or signal transduction pathways. Consistently, the content of auxin, dihydrozeatin, gibberellin, and jasmonic acid was significantly decreased in the MSK326SE corolla, whereas abscisic acid levels were significantly increased. Additionally, seven genes involved in cell division, cell cycle, or cell expansion were identified. Protein-protein interaction network analysis identified 45 nodes and 79 protein interactions, and the largest module contained 20 nodes and 52 protein interactions, mainly involved in the hormone signal transduction and pathogen defensive pathways. Furthermore, a putative hub gene coding a serine/threonine-protein kinase was identified for the network. CONCLUSIONS: Our results suggest that hormones may play a key role in regulating tobacco stigma exsertion induced by corolla shortening.

Analysis and Prevention of Rock Burst Risk of Working Face under the Influence of Continuous Irregular Triangular Coal Pillar Stress Concentration Area.

Irregular coal pillars inevitably appear in the layout of the current long-wall mining method, which easily forms stress concentrations and becomes a heavy disaster area of rock burst. In order to solve the impact risk of irregular coal pillar working face, it is necessary to study the instability mechanism of the coal pillar and put forward effective prevention and control measures. Based on the research background of 14320 working face of the Dongtan Coal Mine in the Yanzhou mining area of China, this paper studies the prediction and prevention of rock bursts in this kind of coal pillar by means of theoretical calculation, numerical simulation, engineering analogy, and field monitoring. The results show that (1) the absolute stability of coal pillar is that the width of coal pillar B reaches twice the support pressure of 2L, and the possibility of instability from large to small is coal pillars 2, 5, 3, 1, and 4. (2) The ratio of coal pillar strength to its average load determines the stability coefficient of the coal pillar, and it is judged that coal pillars 1 and 4 are in a stable state, coal pillars 3 and 5 are in a limit equilibrium state, and coal pillar 2 is in an unstable state. The numerical simulation shows that the maximum stress value inside the coal pillar during the mining process is basically consistent with the theoretical calculation of the bearing strength of the coal pillar. (3) The new evaluation method is used to evaluate the rock burst risk degree of the working face roadway: 156.75 m is a strong rock burst risk zone, 728.18 m is a medium rock burst risk zone, and 176.88 m is a weak rock burst risk zone. (4) Regional prevention and local prevention measures are proposed for the risk of rock burst in the roadway, which reduces the stress concentration of the coal pillar. It is verified that the pressure relief effect is remarkable, and the safe mining of such an irregular coal pillar working face is completed, which provides a solution for studying and solving such rock burst risk.

Comparison between thermal ablation and surgery in low risk papillary thyroid carcinoma: a prospective study.

Objective: To conduct a comparative analysis of the efficacy, safety, and impact on quality of life outcomes between thermal ablation and surgical interventions in patients diagnosed with papillary thyroid carcinoma (PTC). Methods: A prospective study was undertaken, enrolling patients with PTC ≤5mm who underwent radiofrequency ablation (RFA), laser ablation (LA), or surgery, for analysis of efficacy and safety outcomes. The Thyroid Cancer-Specific Quality of Life questionnaire was administered to all patients before treatment and at 3, 6, and 12 months post-treatment. Results: A total of 162 eligible patients were included in the study. Major complications were not observed in the RFA and LA groups, while five cases were reported in the surgery group, although no statistically significant differences were observed. Minor complications were documented in two, three, and 14 patients in the RFA, LA, and surgery groups, respectively, with no significant variances noted. Surgical duration and hospitalization time were notably shorter in the thermal ablation groups. At the final follow-up, complete disappearance of nodules was seen in 71.4% of cases treated with RFA and 71.0% of cases managed with LA, with no significant disparities between the groups. Both RFA and LA exhibited similar effects on quality of life, with thermal ablation techniques showing better functional outcomes in comparison to surgery. Across all groups, adverse effects were most pronounced at the 3-month post-treatment mark but gradually reverted to baseline levels in the thermal ablation group, contrasting with the surgery group. Conclusions: For PTC ≤5mm, both RFA and LA exhibited similar cancer control outcomes and superior quality of life on par with surgery, while minimizing complications. These findings underscore the promise of RFA and LA as potential standard treatments for small PTCs, subject to further confirmation in future studies.

Characterization of the DUF868 gene family in Nicotiana and functional analysis of NtDUF868-E5 involved in pigment metabolism.

Domains of unknown function (DUF) proteins represent a large group of uncharacterized protein families. The DUF868 gene family in Nicotiana has not yet been described. In the present study, we identified 12, 11, and 25 DUF868 family members in the genome of Nicotiana sylvestris, N. tomentosiformis, and N. tabacum, respectively. Based on phylogenetic analysis, these were categorized into five groups (A-E). Within each group, the gene structures, motifs, and tertiary structures showed high similarity. NtDUF868 family expansion during evolution was mainly driven by segmental duplication events. MicroRNA (miRNA) target site prediction identified 12 miRNA members that target 16 NtDUF868 family genes. The promoters of these genes contain cis-regulatory elements responsive to light, phytohormones, and abiotic stresses. Expression profiling revealed their tissue- and stage-specific expression patterns. RNA-sequencing and quantitative reverse transcription PCR revealed that the NtDUF868 family genes are potentially involved in the response to abiotic and biotic stresses, particularly drought and hormone stresses, and in the resistance to black shank and bacterial wilt. We generated transformed plants using NtDUF868-E5 overexpression and gene-editing vectors. NtDUF868-E5 overexpression resulted in enhanced tobacco plant growth and development, leading to increased leaf photosynthetic capacity and higher chlorophyll and carotenoid contents. This study provided a comprehensive genome-wide analysis of the DUF868 gene family, shedding light on their potential roles in plant growth and stress responses.

NtGCN2 confers cadmium tolerance in Nicotiana tabacum L. by regulating cadmium uptake, efflux, and subcellular distribution.

General control non-derepressible-2 (GCN2) is widely expressed in eukaryotes and responds to biotic and abiotic stressors. However, the precise function and mechanism of action of GCN2 in response to cadmium (Cd) stress in Nicotiana tabacum L. (tobacco) remains unclear. We investigated the role of NtGCN2 in Cd tolerance and explored the mechanism by which NtGCN2 responds to Cd stress in tobacco by exposing NtGCN2 transgenic tobacco lines to different concentrations of CdCl2. NtGCN2 was activated under 50 µmol·L-1 CdCl2 stress and enhanced the Cd tolerance and photosynthetic capacities of tobacco by increasing chlorophyll content and antioxidant capacity by upregulating NtSOD, NtPOD, and NtCAT expression and corresponding enzyme activities and decreasing malondialdehyde and O2·- contents. NtGCN2 enhanced the osmoregulatory capacity of tobacco by elevating proline (Pro) and soluble sugar contents and maintaining low levels of relative conductivity. Finally, NtGCN2 enhanced Cd tolerance in tobacco by reducing Cd uptake and translocation, promoting Cd efflux, and regulating Cd subcellular distribution. In conclusion, NtGCN2 improves the tolerance of tobacco to Cd through a series of mechanisms, namely, increasing antioxidant, photosynthetic, and osmoregulation capacities and regulating Cd uptake, translocation, efflux, and subcellular distribution. This study provides a scientific basis for further exploration of the role of NtGCN2 in plant responses to Cd stress and enhancement of the Cd stress signaling network in tobacco.

Stabilizing electron-rich Ni single-atoms on black phosphorus nanosheets boosts photocatalytic carbon dioxide reduction.

The development of unique single-atom catalysts with electron-rich feature is essential to promoting the photocatalytic CO2 reduction, yet remains a big challenge. Here, a conceptionally new single-atom catalyst constructed from atomically dispersed Ni-P3 species on black phosphorus (BP) nanosheets (BP-Ni) is synthesized for realizing highly efficient visible-light-driven CO2 reduction when trapping photogenerated electrons from homogeneous light absorbers in the presence of triethanolamine as the sacrificial agent. Both the experimental and theoretical calculation data reveal that the Ni-P3 species on BP nanosheets own the electron-rich feature that can improve the photogenerated charge separation efficiency and lower the activation barrier of CO2 conversion. This unique feature makes BP-Ni exhibit the much higher activity as cocatalyst in the photocatalytic CO2 reduction than BP nanosheets. The BP-Ni can also be applied as a cocatalyst for enhanced photocatalytic CO2 reduction after combining with CdSe/S colloidal crystal photocatalyst. The present study offers valuable inspirations for the design and construction of effective catalytic sites toward photocatalytic CO2 reduction reactions.

Enhanced Capacitive Deionization of Hollow Mesoporous Carbon Spheres/MOFs Derived Nanocomposites by Interface-Coating and Space-Encapsulating Design.

Exploring new carbon-based electrode materials is quite necessary for enhancing capacitive deionization (CDI). Here, hollow mesoporous carbon spheres (HMCSs)/metal-organic frameworks (MOFs) derived carbon materials (NC(M)/HMCSs and NC(M)@HMCSs) are successfully prepared by interface-coating and space-encapsulating design, respectively. The obtained NC(M)/HMCSs and NC(M)@HMCSs possess a hierarchical hollow nanoarchitecture with abundant nitrogen doping, high specific surface area, and abundant meso-/microporous pores. These merits are conducive to rapid ion diffusion and charge transfer during the adsorption process. Compared to NC(M)/HMCSs, NC(M)@HMCSs exhibit superior electrochemical performance due to their better utilization of the internal space of hollow carbon, forming an interconnected 3D framework. In addition, the introduction of Ni ions is more conducive to the synergistic effect between ZIF(M)-derived carbon and N-doped carbon shell compared with other ions (Mn, Co, Cu ions). The resultant Ni-1-800-based CDI device exhibits excellent salt adsorption capacity (SAC, 37.82 mg g-1) and good recyclability. This will provide a new direction for the MOF nanoparticle-driven assembly strategy and the application of hierarchical hollow carbon nanoarchitecture to CDI.