Wound-Induced Temporal Reprogramming of Gene Expression during Agarwood Formation in <i>Aquilaria sinensis</i>

Agarwood is a resinous heartwood of Aquilaria sinensis that is formed in response to mechanical wounding. However, the transcriptional response of A. sinensis to mechanical wounding during the agarwood formation process is still unclear. Here, three five-year-old A. sinensis trees were mechanically damaged by a chisel, and time-series transcriptomic analysis of xylem tissues in the treated area (TA) was performed at 15 (TA1), 70 (TA2) and 180 days after treatment (TA3). Samples from untreated areas at the corresponding time points (UA1, UA2, UA3, respectively) were collected as controls. A total of 1862 (TA1 vs. UA1), 961 (TA2 vs. UA2), 1370 (TA3 vs. UA3), 3305 (TA2 vs. TA1), 2625 (TA3 vs. TA1), 2899 (TA3 vs. TA2), 782 (UA2 vs. UA1), 4443 (UA3 vs. UA1) and 4031 (UA3 vs. UA2) genes were differentially expressed (DEGs). Functional enrichment analysis showed that DEGs were significantly enriched for secondary metabolic processes, signal transduction and transcriptional regulation processes. Most of the genes involved in lignin biosynthesis were more abundant in the TA groups, which included phenylalanine ammonia-lyase, 4-coumarate CoA ligase, cinnamate 4-hydroxylase, caffeoyl-CoA O-methyltransferase and cinnamoyl-CoA reductase. DEGs involved in sesquiterpene biosynthesis were also identified. Hydroxymethylglutaryl-CoA synthase, 3-hydroxy-3-methylglutaryl-coenzyme A reductase, phosphomevalonate kinase and terpene synthase genes were significantly increased in the TA groups, promoting sesquiterpene biosynthesis in the wounded xylem tissues. The TF-gene transcriptomic networks suggested that MYB DNA-binding, NAM, WRKY, HLH and AP2 TFs co-expressed with genes related to lignin and sesquiterpene synthesis, indicating their critical regulatory roles in the biosynthesis of these compounds. Overall, our study reveals a dynamic transcriptional response of A. sinensis to mechanical wounding, provides a resource for identifying candidate genes for molecular breeding of agarwood quality, and sheds light on the molecular mechanisms of agarwood formation in A. sinensis

Transcriptome Analysis Reveals Gene Expression Changes during Repair from Mechanical Wounding in Aquilaria sinensis

Plants repair their mechanical wounds by reprogramming secondary metabolism. However, which genes are reprogrammed during this repair process in Aquilaria sinensis has rarely been studied. Here, we used high-throughput RNA sequencing to explore the changes in the transcriptome of Aquilaria&rsquo;s xylem, six months after the stem was subjected to mechanical wounding. In total, 1165 transcripts were differentially accumulated, of which 1002 transcripts were increased and 163 were decreased in their abundances (|log2 (fold change)| &ge; 1 and FDR &le; 0.05). The majority of these genes encode products involved in plant secondary metabolism, transcription regulation, and phytohormone metabolism and signaling. The up-regulated genes were classified into 15 significantly enriched GO terms and were involved in 83 pathways, whereas the down-regulated genes were classified into 5 significantly enriched GO terms and represented 43 pathways. Gene annotation demonstrated that 100 transcripts could encode transcription factors (TFs), such as WRKY, AP2, MYB, and Helix-loop-helix (HLH) TFs. We inferred that the differential expression of TFs, genes associated with plant hormones, phenylpropanoid biosynthesis, and sesquiterpenoid biosynthesis may contribute to the repair of the stem after mechanical wounding in A. sinensis. Using co-expression analysis and prediction of TF binding sites, a TF&ndash;gene regulatory network for Aquilaria lignin biosynthesis was constructed. This included the MYB, HLH, WRKY, and AP2 TFs, and the COMT1, 4CLL7, and CCR1 genes. The changes in 10 candidate genes were validated by quantitative reverse-transcription PCR, indicating significant differences between the treated and untreated areas. Our study provides global gene expression patterns under mechanical wounding and would be valuable to further studies on the molecular mechanisms of plant repair in A. sinensis

Transcriptome Analysis Reveals Gene Expression Changes during Repair from Mechanical Wounding in <i>Aquilaria sinensis</i>

Plants repair their mechanical wounds by reprogramming secondary metabolism. However, which genes are reprogrammed during this repair process in Aquilaria sinensis has rarely been studied. Here, we used high-throughput RNA sequencing to explore the changes in the transcriptome of Aquilaria’s xylem, six months after the stem was subjected to mechanical wounding. In total, 1165 transcripts were differentially accumulated, of which 1002 transcripts were increased and 163 were decreased in their abundances (|log2 (fold change)| ≥ 1 and FDR ≤ 0.05). The majority of these genes encode products involved in plant secondary metabolism, transcription regulation, and phytohormone metabolism and signaling. The up-regulated genes were classified into 15 significantly enriched GO terms and were involved in 83 pathways, whereas the down-regulated genes were classified into 5 significantly enriched GO terms and represented 43 pathways. Gene annotation demonstrated that 100 transcripts could encode transcription factors (TFs), such as WRKY, AP2, MYB, and Helix-loop-helix (HLH) TFs. We inferred that the differential expression of TFs, genes associated with plant hormones, phenylpropanoid biosynthesis, and sesquiterpenoid biosynthesis may contribute to the repair of the stem after mechanical wounding in A. sinensis. Using co-expression analysis and prediction of TF binding sites, a TF–gene regulatory network for Aquilaria lignin biosynthesis was constructed. This included the MYB, HLH, WRKY, and AP2 TFs, and the COMT1, 4CLL7, and CCR1 genes. The changes in 10 candidate genes were validated by quantitative reverse-transcription PCR, indicating significant differences between the treated and untreated areas. Our study provides global gene expression patterns under mechanical wounding and would be valuable to further studies on the molecular mechanisms of plant repair in A. sinensis

Genetic mechanism of high-quality shale gas reservoirs in the Wufeng–LongmaxiFms in the Sichuan Basin

The Upper Ordovician WufengFm and the Lower Silurian LongmaxiFm are important strata for shale gas exploration and development in the Sichuan Basin, but the genetic mechanism, evolutionary history and the controlling effect of mineral diagenetic evolution on the formation of shale gas reservoirs are not clear. In this paper, the evolution history of organic matter pores and the diagenetic evolution of minerals were analyzed based on the analysis of petrology, mineralogy and organic geochemistry, combined with basin simulation and practical shale gas exploration and development. Then, the types and genetic mechanisms of high-quality shale gas reservoirs were discussed, and the development intervals of high-quality shale gas reservoirs were determined. And the following research results are obtained. First, the shale gas development intervals of Wufeng–LongmaxiFms in the Sichuan Basin are mainly dominated by siliceous shale, limy siliceous shale and clayey shale. Rock type has an important controlling effect on the types and characteristics of shale reservoir space. Siliceous shale and limy siliceous shale have the highest reservoir capacity with the most developed organic pores. Second, the diagenetic evolution of minerals controls the formation of shale gas reservoirs. Biogenic silica, formed in the early diagenetic stage, together with terrestrial detrital silica and pyrite, constitutes particle support lattices in the form of microcrystalline aggregates, so as to resist the compaction effectively and preserve a great number of residual intergranular pores, which is beneficial to the formation of high-quality shale gas reservoirs. Third, siliceous shale in the WF2–LM4 graptolite zone (from WufengFm to the bottom of LongmaxiFm) presents a high-quality reservoir genetic mechanism of “multicellular algae controlling hydrocarbon source, biogenic silica controlling framework, and co-evolution controlling a high-quality reservoir”. In conclusion, the siliceous shale and limy siliceous shale in the WF2–LM4 graptolite zones are the main development intervals of high-quality shale gas reservoirs in the Sichuan Basin. It is also a valuable reference for the Upper Ordovician-Lower Silurianshale gas exploration and development in other countries and regions worldwide

Achieving high overall energy storage performance of KNN-based transparent ceramics by ingenious multiscale designing

Dielectric capacitors show significant advantages of faster charge-discharge time over solid oxide fuel cells, Li-ion batteries, and electrochemical capacitors and have been considered the best candidates for next-generation high-performance pulsed power systems. Considering the advantage of the feasibility of efficient multifunctional coupling, which meets the integration trend of electronic devices and relies on the excellent transmittance of KNN-based ceramics, we chose KNN-based systems in this work. (1 − x)(K0.5Na0.5)NbO3-xBa0.9Ca0.1Zr0.15Ti0.85O3 ceramics were fabricated by employing conventional solid state technology, and as expected, the substitution of Ba/Ca by K/Na in the A-site and the substitution of Zr/Ti by Nb in the B-site strongly decreased the leakage current of pristine KNN. By multiscale designing, a Wrec of 7.83 J cm−3 with an η of 81.02%, which has huge advantages over both BCZT-based systems and KNN-based systems, was finally achieved when the x equals 0.30, and such an excellent energy storage performance was caused by both high maximum polarization and high large electric breakdown strength. According to their microstructure characterization, the former was caused by the existence of high polarization boundaries induced by the lattice mismatch between the two phases, and the latter was proved by the combined effect of conductive mechanism transition and interface engineering. In addition, relatively high energy storage frequency stability, thermal stability, and polarization fatigue endurance were also obtained, and the charge-discharge behavior indicated their potential in practical applications. The work offered a new concept for designing energy storage capacitors with high overall performance.</p

Mechanochemical Synthesis of Pt/Nb2CTx MXene Composites for Enhanced Electrocatalytic Hydrogen Evolution

Production of hydrogen from water splitting has been considered as a promising solution for energy conversion and storage. Since a noble metal-based structure is still the most satisfactory but scarce kind of catalyst, it is significant to allow for practical application of such catalysts by engineering the heterogeneous structure and developing green and facile synthetic strategies. Herein, we report a mechanochemical ball milling synthesis of platinum nanoclusters immobilized on a 2D transition metal carbide MXene (Nb2CTx) as an enhanced catalyst for hydrogen evolution. After annealing at 600 °C, ultrafine Pt3Nb nanoclusters are formed on the Pt/Nb2CTx catalyst. As prepared, the Pt/Nb2CTx-600 catalyst demonstrates superior electrochemical HER activity and stability with an ultralow overpotential of 5 mV and 46 mV to achieve 10 mA cm−2 and 100 mA cm−2, respectively, in comparison with other Nb2CTx-based catalysts and commercial Pt/C catalysts. Moreover, the remarkable durability is also confirmed by accelerated durability tests (ADTs) and long-term chronoamperometry (CA) tests. The excellent HER performance was attributed to high Pt dispersion and more active site exposure by the mechanochemical process and thermal treatment. Such results suggest that the mechanochemical strategy provides a novel approach for rational design and cost-effective production of electrocatalysts, also providing other potential applications in a wide range of areas

Cable‐Car Electrocatalysis to Drive Fully Decoupled Water Splitting

Abstract The increasing demand for clean energy conversion and storage has increased interest in hydrogen production via electrolytic water splitting. However, the simultaneous production of hydrogen and oxygen in this process poses a challenge in extracting pure hydrogen without using ionic conducting membranes. Researchers have developed various innovative designs to overcome this issue, but continuous water splitting in separated tanks remains a desirable approach. This study presents a novel, continuous roll‐to‐roll process that enables fully decoupled hydrogen evaluation reaction (HER) and oxygen evolution reaction (OER) in two separate electrolyte tanks. The system utilizes specially designed “cable‐car” electrodes (CCE) that cycle between the HER and OER tanks, resulting in continuous hydrogen production with a purity of over 99.9% and Coulombic efficiency of 98% for prolonged periods. This membrane‐free water splitting system offers promising prospects for scaled‐up industrial‐scale green hydrogen production, as it reduces the cost and complexity of the system, and allows for the use of renewable energy sources to power the electrolysis process, thus reducing the carbon footprint of hydrogen production

Lithium Deposition-Induced Fracture of Carbon Nanotubes and Its Implication to Solid-State Batteries

The increasing demand for safe and dense energy storage has shifted research focus from liquid electrolyte-based Li-ion batteries toward solid-state batteries (SSBs). However, the application of SSBs is impeded by uncontrollable Li dendrite growth and short circuiting, the mechanism of which remains elusive. Herein, we conceptualize a scheme to visualize Li deposition in the confined space inside carbon nanotubes (CNTs) to mimic Li deposition dynamics inside solid electrolyte (SE) cracks, where the high-strength CNT walls mimic the mechanically strong SEs. We observed that the deposited Li propagates as a creeping solid in the CNTs, presenting an effective pathway for stress relaxation. When the stress-relaxation pathway is blocked, the Li deposition-induced stress reaches the gigapascal level and causes CNT fracture. Mechanics analysis suggests that interfacial lithiophilicity critically governs Li deposition dynamics and stress relaxation. Our study offers critical strategies for suppressing Li dendritic growth and constructing high-energy-density, electrochemically and mechanically robust SSBs