Symbiotic System Establishment between Piriformospora indica and Glycine max and Its Effects on the Antioxidant Activity and Ion-Transporter-Related Gene Expression in Soybean under Salt Stress.

The utilization of symbiosis with beneficial microorganisms has considerable potential for increasing growth and resistance under abiotic stress. The endophytic root fungus Piriformospora indica has been shown to improve plant growth under salt and drought stress in diverse plant species, while there have been few reports of the interaction of P. indica with soybean under salt stress. In this study, the symbiotic system of P. indica and soybean (Glycine max L.) was established, and the effect of P. indica on soybean growth and salt tolerance was investigated. The colonized and non-colonized soybeans were subjected to salt stress (200 mmol/L NaCl), and the impairments in chlorophyll and increasing relative conductivity that can be caused by salt stress were alleviated in the P. indica-colonized plants. The accumulation of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion (O2−) were lower than that in non-colonized plants under salt treatment, whereas the activities of antioxidant enzymes were significantly increased by P. indica colonization, including superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione reductase (GR). Importantly, without salt treatment, the Na+ concentration was lower, and the K+ concentration was higher in the roots compared with non-colonized plants. Differential expressions of ion transporter genes were found in soybean roots after P. indica colonization. The P. indica colonization positively regulated the transcription level of PM H+-ATPase, SOS1, and SOS2. The study shows that P. indica enhances the growth and salt tolerance of soybean, providing a strategy for the agricultural production of soybean plants in saline-alkali soils.

Overexpression of MsRCI2D and MsRCI2E Enhances Salt Tolerance in Alfalfa (Medicago sativa L.) by Stabilizing Antioxidant Activity and Regulating Ion Homeostasis.

Rare cold-inducible 2 (RCI2) genes from alfalfa (Medicago sativa L.) are part of a multigene family whose members respond to a variety of abiotic stresses by regulating ion homeostasis and stabilizing membranes. In this study, salt, alkali, and ABA treatments were used to induce MsRCI2D and MsRCI2E expression in alfalfa, but the response time and the expression intensity of the MsRCI2D,-E genes were different under specific treatments. The expression intensity of the MsRCI2D gene was the highest in salt- and alkali-stressed leaves, while the MsRCI2E gene more rapidly responded to salt and ABA treatment. In addition to differences in gene expression, MsRCI2D and MsRCI2E differ in their subcellular localization. Akin to MtRCI2D from Medicago truncatula, MsRCI2D is also localized in the cell membrane, while MsRCI2E is different from MtRCI2E, localized in the cell membrane and the inner membrane. This difference might be related to an extra 20 amino acids in the C-terminal tail of MsRCI2E. We investigated the function of MsRCI2D and MsRCI2E proteins in alfalfa by generating transgenic alfalfa chimeras. Compared with the MsRCI2E-overexpressing chimera, under high-salinity stress (200 mmol·L-1 NaCl), the MsRCI2D-overexpressing chimera exhibited a better phenotype, manifested as a higher chlorophyll content and a lower MDA content. After salt treatment, the enzyme activities of SOD, POD, CAT, and GR in MsRCI2D- and -E-overexpressing roots were significantly higher than those in the control. In addition, after salt stress, the Na+ content in MsRCI2D- and -E-transformed roots was lower than that in the control; K+ was higher than that in the control; and the Na+/K+ ratio was lower than that in the control. Correspondingly, H+-ATPase, SOS1, and NHX1 genes were significantly up-regulated, and the HKT gene was significantly down-regulated after 6 h of salt treatment. MsRCI2D was also found to regulate the expression of the MsRCI2B and MsRCI2E genes, and the MsRCI2E gene could alter the expression of the MsRCI2A, MsRCI2B, and MsRCI2D genes. MsRCI2D- and -E-overexpressing alfalfa was found to have higher salt tolerance, manifested as improved activity of antioxidant enzymes, reduced content of reactive oxygen species, and sustained Na+ and K+ ion balance by regulating the expression of the H+-ATPase, SOS1, NHX1, HKT, and MsRCI2 genes.

Electric-Field-Mediated Electron Tunneling of Supramolecular Naphthalimide Nanostructures for Biomimetic H2 Production.

The design and synthesis of two semiconducting bis (4-ethynyl-bridging 1, 8-naphthalimide) bolaamphiphiles (BENI-COO- and BENI-NH3+ ) to fabricate supramolecular metal-insulator-semiconductor (MIS) nanostructures for biomimetic hydrogen evolution under visible light irradiation is presented. A H2 evolution rate of ca. 3.12 mmol g-1 ⋅h-1 and an apparent quantum efficiency (AQE) of ca. 1.63 % at 400 nm were achieved over the BENI-COO- -NH3+ -Ni MIS photosystem prepared by electrostatic self-assembly of BENI-COO- with the opposite-charged DuBois-Ni catalysts. The hot electrons of photoexcited BENI-COO- nanofibers were tunneled to the molecular Ni collectors across a salt bridge and an alkyl region of 2.2-2.5 nm length at a rate of 6.10×108  s-1 , which is five times larger than the BENI-NH3+ nanoribbons (1.17×108  s-1 ). The electric field benefited significantly the electron tunneling dynamics and compensated the charge-separated states insufficient in the BENI-COO- nanofibers.

Locomotion Control of Cyborg Insects by Charge-Balanced Biphasic Electrical Stimulation.

The integration of electronic stimulation devices with insects in the context of cyborg insect systems has great application potential, particularly in the fields of environmental monitoring, urban surveillance, and rescue missions. Despite considerable advantages compared to the current robot technology, including flexibility, durability, and low energy consumption, this integration faces certain challenges related to the potential risk of charge accumulation caused by prolonged and repetitive electrical stimulations. To address these challenges, this study proposes a universal system for remote signal output control using infrared signals. The proposed system integrates high-precision digital-to-analog converters capable of generating customized waveform electrical stimulation signals within defined ranges. This enhances the accuracy of locomotion control in cyborg insects while maintaining real-time control and dynamic parameter adjustment. The proposed system is verified by experiments. The experimental results show that the signals generated by the proposed system have a success rate of over 76.25% in controlling the turning locomotion of cyborg insects, which is higher than previously reported results. In addition, the charge-balanced characteristics of these signals can minimize muscle tissue damage, thus substantially enhancing control repeatability. This study provides a comprehensive solution for the remote control and monitoring of cyborg insects, whose flexibility and adaptability can meet various application and experimental requirements. The results presented in this study lay a robust foundation for further advancement of various technologies, particularly those related to cyborg insect locomotion control systems and wireless control mechanisms for cyborg insects.

Controllable adhesive mechanisms via the internal fibers in soft footpads of honeybees.

The dynamic adhesive systems in nature have served as inspirations for the development of intelligent adhesive surfaces. However, the mechanisms underlying the rapid controllable contact adhesion observed in biological systems have never been adequately explained. Here, the control principle for the unfolding adhesive footpads (alterable contact area) of honeybees is investigated. The footpads can passively unfold, even without neuro-muscular reflexes, in response to specific dragging activity (generating shear force) toward their bodies. This passive unfolding is attributed to the structural features of the soft footpads, which cooperate closely with shear force. Then, the hierarchical structures supported by numerous branching fibers were observed and analyzed. Experimental and theoretical findings demonstrated that shear force can decrease fibril angles with respect to the shear direction, which consequently induces the rotation of the interim contact area of the footpads and achieves their passive unfolding. Furthermore, the decrease in fibril angles can lead to an increase in the liquid pressure within the footpads, and subsequently enhance their unfolding. This study presents a novel approach for passively controlling the contact areas in adhesive systems, which can be applied to develop various bioinspired switchable adhesive surfaces.

A Review of Energy Supply for Biomachine Hybrid Robots.

Biomachine hybrid robots have been proposed for important scenarios, such as wilderness rescue, ecological monitoring, and hazardous area surveying. The energy supply unit used to power the control backpack carried by these robots determines their future development and practical application. Current energy supply devices for control backpacks are mainly chemical batteries. To achieve self-powered devices, researchers have developed solar energy, bioenergy, biothermal energy, and biovibration energy harvesters. This review provides an overview of research in the development of chemical batteries and self-powered devices for biomachine hybrid robots. Various batteries for different biocarriers and the entry points for the design of self-powered devices are outlined in detail. Finally, an overview of the future challenges and possible directions for the development of energy supply devices used to biomachine hybrid robots is provided.

The impact of knowledge transfer performance on the artificial intelligence industry innovation network: An empirical study of Chinese firms.

As a core driving force of the most recent round of industrial transformation, artificial intelligence has triggered significant changes in the world economic structure, profoundly changed our life and way of thinking, and achieved an overall leap in social productivity. This paper aims to examine the effect of knowledge transfer performance on the artificial intelligence industry innovation network and the path artificial intelligence enterprises can take to promote sustainable development through knowledge transfer in the above context. First, we construct a theoretical hypothesis and conceptual model of the innovation network knowledge transfer mechanism within the artificial intelligence industry. Then, we collect data from questionnaires distributed to Chinese artificial intelligence enterprises that participate in the innovation network. Moreover, we empirically analyze the impact of innovation network characteristics, organizational distance, knowledge transfer characteristics, and knowledge receiver characteristics on knowledge transfer performance and verify the hypotheses proposed in the conceptual model. The results indicate that innovation network centrality and organizational culture distance have a significant effect on knowledge transfer performance, with influencing factors including network scale, implicit knowledge transfer, receiver's willingness to receive, and receiver's capacity to absorb knowledge. For sustainable knowledge transfer performance on promoting Chinese artificial intelligence enterprises innovation, this paper finally delivers valuable insights and suggestions.

Overexpression of MsSiR enhances alkali tolerance in alfalfa (Medicago sativa L.) by increasing the glutathione content.

The sulfite reductase gene in Medicago sativa L. (MsSiR) encodes sulfite reductase (SiR) and catalyses the conversion of sulfite to sulfate in the sulfite assimilation pathway. In this study, we investigated the role of MsSiR in alfalfa by generating transgenic alfalfa that ectopically expressed MsSiR under the control of the CaMV35S promoter. The differences in alkali tolerance between the MsSiR-overexpressing and wild-type (WT) plants were analyzed, and the MsSiR-overexpressing plants exhibited an improved phenotype under alkali stress. Compared to WT plants, these plants demonstrated improved antioxidant activity as well as decreased H2O2 and O2- contents and increased glutathione reduced (GSH), Cysteine (Cys) and glutathione oxidized (GSSG) contents. MsSiR-overexpressing plants also exhibited high levels of adenosyl phosphosulfate reductases (APR), sulfite oxidase (SO) and MsSiR expression under alkali stress. It was speculated that MsSiR is involved in sulfur metabolism pathways, including the stabilization of sulfate and sulfite levels and the synthesis of GSH. These two processes achieve alkali tolerance by positively regulating the detoxification and antioxidant activities of alfalfa.

Co-pyrolysis of biomass and soapstock in a downdraft reactor using a novel ZSM-5/SiC composite catalyst.

A ZSM-5/SiC composite catalyst was synthesized and characterized by Brunauer-Emmett-Teller analysis, X-ray diffraction, and scanning electron microscopy in this study. The composite catalyst had the characteristics of ZSM-5 and SiC, and the surface of SiC grew evenly with a layer of ZSM-5. The effect of the composite catalyst on the product distribution and chemical composition in a co-pyrolysis downdraft system was investigated. In a down system with a catalytic temperature of 450 °C, a feed-to-catalyst ratio of 2:1, and a soybean-soapstock-to-straw ratio of 1:1, the proportions of alkanes, olefins, aromatics, and phenoxy compounds were 6.82%, 4.5%, 73.56% and 11.11%, respectively. The composite catalyst combined the catalytic performance of ZSM-5 and SiC, increasing the proportion of aromatics and decreasing the proportion of oxygen-containing compound in the bio-oil. Moreover, the composite catalyst maintained its activity after reusing several times.

Genome assembly of a tropical maize inbred line provides insights into structural variation and crop improvement.

Maize is one of the most important crops globally, and it shows remarkable genetic diversity. Knowledge of this diversity could help in crop improvement; however, gold-standard genomes have been elucidated only for modern temperate varieties. Here, we present a high-quality reference genome (contig N50 of 15.78 megabases) of the maize small-kernel inbred line, which is derived from a tropical landrace. Using haplotype maps derived from B73, Mo17 and SK, we identified 80,614 polymorphic structural variants across 521 diverse lines. Approximately 22% of these variants could not be detected by traditional single-nucleotide-polymorphism-based approaches, and some of them could affect gene expression and trait performance. To illustrate the utility of the diverse SK line, we used it to perform map-based cloning of a major effect quantitative trait locus controlling kernel weight-a key trait selected during maize improvement. The underlying candidate gene ZmBARELY ANY MERISTEM1d provides a target for increasing crop yields.