Arbuscular mycorrhizal (AM) fungi facilitate plant uptake of mineral nutrients and draw organic nutrients fromthe plant. Organic nutrients are thought to be supplied primarily in the formof sugars. ...Here we show that the AM fungus Rhizophagus irregularis is a fatty acid auxotroph and that fatty acids synthesized in the host plants are transferred to the fungus to sustain mycorrhizal colonization. The transfer is dependent on RAM2 (REQUIRED FOR ARBUSCULAR MYCORRHIZATION 2) and the ATP binding cassette transporter–mediated plant lipid export pathway. We further show that plant fatty acids can be transferred to the pathogenic fungus Golovinomyces cichoracerum and are required for colonization by pathogens. We suggest that themutualistic mycorrhizal and pathogenic fungi similarly recruit the fatty acid biosynthesis program to facilitate host invasion.
Endogenous nitric oxide (NO) is an important messenger molecule, which can directly activate K
transmission and cause relaxation of vascular smooth muscle. Here, inspired by the K
channel of smooth ...muscle cells, we report, a novel NO-regulated artificial nanochannel based on a spiro ring opening-closing reaction strategy. This nanofluidic diode system shows an outstanding NO selective response owing to the specific reaction between o-phenylenediamine (OPD) and NO on the channel surface with high ion rectification ratio (~6.7) and ion gating ratio (~4). Moreover, this NO gating system exhibits excellent reversibility and stability as well as high selectivity response. This system not only helps us understand the process of NO directly regulating biological ion channels, but also has potential application value in the field of biosensors.
Abstract
Cotton is one of the most important cash crops, its growth season coincides with a high incidence of diverse groups of pests, leading to heavy use of pesticides. Recent identification of a ...signaling protein as a candidate regulator of cotton extrafloral nectary provides a new insight into the formation of sophisticated defense mechanisms in plants.
Hot compression tests of Mg-Gd-Y-Zr alloy at different deformation temperatures and strains were carried out with Gleeble-1500 simulator at strain rate of 0.002 s−1. The microstructure evolution of ...400 °C/0.002 s−1 sample under different strain was analyzed emphatically by transmission electron microscopy and electron backscatter diffraction technology. Dynamic precipitation characteristics and nucleation-expansion mechanism of dynamic recrystallization (DRX) were discussed in detail. The results indicated that the dynamic precipitation takes place prior to DRX, and the morphology, size and distribution of precipitates change with increasing strain. At the later stage of deformation, the large-size hard phase β-Mg5(Gd,Y) can induce the particle-stimulated nucleation (PSN) mechanism under large strain and act as an effective nucleation site for DRX. In addition, we constructed a schematic diagram of the DRX nucleation-expansion mechanism of Mg-Gd-Y-Zr alloy under high temperature deformation. The first layer of DRX grains is formed by discontinuous dynamic recrystallization (DDRX) mechanism characterized by grain boundary bulge out, and the precipitates distributed at the original grain boundary promote DDRX nucleation; The expansion of necklace structure depends on continuous dynamic recrystallization (CDRX) mechanism; Subgrain division can further refine DRX grains.
Cotton, with cellulose-enriched mature fibers, is the largest source of natural textiles. Through a map-based cloning strategy, we isolated an industrially important lint fiber development gene (Li
...3) that encodes an MYB-MIXTA-like transcription factor (MML) on chromosome D12 (GhMML4_D12).
Virus-induced gene silencing or decreasing the expression of the GhMML4_D12 gene in n2NSM plants resulted in a significant reduction in epidermal cell prominence and lint fiber production. GhMML4_D12 is arranged in tandem with GhMML3, another MIXTA gene responsible for fuzz fiber development. These two very closely related MIXTA genes direct fiber initiation production in two specialized cell forms: lint and fuzz fibers. They may control the same metabolic pathways in different cell types.
The MIXTAs expanded in Malvaceae during their evolution and produced a Malvaceae-specific family that regulates epidermal cell differentiation, different from the gene family that regulates leaf hair trichome development. Cotton has developed a unique transcriptional regulatory network for fiber development.
Characterization of target genes regulating fiber production has provided insights into the molecular mechanisms underlying cotton fiber development and has allowed the use of genetic engineering to increase lint yield by inducing more epidermal cells to develop into lint rather than fuzz fibers.
Mg–Gd system alloys have been widely studied because they are applied in automotive, weaponry and aerospace applications and have a wide range of application scenarios due to the excellent strength ...and heat resistance properties. This work aims to systematically investigate the microstructure and high temperature mechanical properties of Mg-10Gd-3Y-xNd-0.5Zr alloy, and found that the microstructure of Mg-10Gd-3Y-0.5Zr alloy was mainly composed of α-Mg matrix, Mg5(Gd, Y) phase and Mg24(Y, Gd)5 phase. In which Nd element plays a role in the alloy to promote the precipitation phase precipitation and form the new phase Mg41Nd5, and the appropriate amount of Nd can refine the grain size. Moreover, Mg-10Gd-3Y-xNd-0.5Zr alloy has excellent mechanical properties in room and high temperature, with ultimate tensile strengths above 280 MPa at 200 °C–300 °C, 309 MPa at 250 °C, and especially at 350 °C, the tensile strength is still up to 195 MPa. The main strengthening phases are β" phase, β′ phase and 18-LPSO (Long-period stacking ordered) phase. The Mg-10Gd-3Y-2Nd-0.5Zr alloy has excellent high temperature creep resistance at (200 °C–300 °C)/(50–90 MPa). When creeping at 200 °C, β′ phase is completely transformed into β" phase. After creeping at 250 °C, β′ phase is transformed into β phase. After creeping at 300 °C, β phase grows significantly. Meanwhile, when the creep temperature and stress increase, the creep mechanism gradually changes from diffusion and grain boundary sliding mechanism to dislocation slip and dislocation climbing mechanism.
To compare the clinical efficacy of ultrasound cycloplasty (UCP) and endoscopic cyclophotocoagulation (ECP) in the treatment of secondary glaucoma. In a 12-month prospective single-center study, ...22 patients with secondary glaucoma were treated by high-intensity focused ultrasound (HIFU), and 23 patients with secondary glaucoma were treated by a semiconductor laser. At the final follow-up, the two groups' surgical outcomes were compared. A complete success was defined as an intraocular pressure (IOP) reduction of at least 20% from baseline and an IOP of > 5 mmHg and ≦ 21 mmHg, while a qualified success was defined as an IOP reduction of at least 20% from baseline and an IOP of > 5 mmHg. The secondary outcome was the average IOP, number of drugs, and complications at each follow-up compared with the baseline. The average preoperative IOPs in the UCP and ECP groups were 36.4 ± 9.5 mmHg (n = 2.3 drops, n = 0.2 tablets) and 34.5 ± 11.7 mmHg (n = 2.0 drops, n = 0.3 tablets), respectively. In the last follow-up, the success rate of UCP was 54% (with a decrease of 32%) and that of ECP was 65% (with a decrease of 35%), and the P-value between the two groups was > 0.05. However, there was a difference in the average IOP between these two groups 1 day and 1 week after the operation, and the IOP reduction efficiency in the ECP group was better. However, the amount of drug used after these two surgeries was significantly reduced. There were fewer postoperative complications in the UCP group (18 cases) than in the ECP group (35 cases). Both UCP and ECP can effectively reduce IOP in secondary glaucoma, and ECP has a better effect at the early stages. However, UCP has higher safety and tolerance for patients.
Cytochrome P450 enzymes (CYPs) play major roles in generating highly functionalized terpenoids, but identifying the exact biotransformation step(s) catalyzed by plant CYP in terpenoid biosynthesis is ...extremely challenging. Tanshinones are abietane-type norditerpenoid naphthoquinones that are the main lipophilic bioactive components of the Chinese medicinal herb danshen (Salvia miltiorrhiza). Whereas the diterpene synthases responsible for the conversion of (E,E,E)-geranylgeranyl diphosphate into the abietane miltiradiene, a potential precursor to tanshinones, have been recently described, molecular characterization of further transformation of miltiradiene remains unavailable. Here we report stableisotope labeling results that demonstrate the intermediacy of miltiradiene in tanshinone biosynthesis. We further use a next-generation sequencing approach to identify six candidate CYP genes being coregulated with the diterpene synthase genes in both the rhizome and danshen hairy roots, and demonstrate that one of these, CYP76AH1, catalyzes a unique four-electron oxidation cascade on miltiradiene to produce ferruginol both in vitro and in vivo. We then build upon the previous establishment of miltiradiene production in Saccharomyces cerevisiae, with incorporation of CYP76AH1 and phyto-CYP reductase genes leading to heterologous production of ferruginol at 10.5 mg/L As ferruginol has been found in many plants including danshen, the results and the approaches that were described here provide a solid foundation to further elucidate the biosynthesis of tanshinones and related diterpenoids. Moreover, these results should facilitate the construction of microbial cell factories for the production of phytoterpenoids.
This study investigates the problem of time-varying formation tracking (TVFT) control involving event-triggered and switching topological mechanisms. Specifically, TVFT is evaluated with a consensus ...analysis and deduced via the use of linear matrix inequality techniques combined with Lyapunov stability theory. This strategy obtains sufficient conditions for system stability and the feedback and coupling gains. In addition, the TVFT compensational signals are presented in two cases to enhance the algorithm’s applicability. Given that ideal multi-agent systems (MASs) should be highly flexible and resilient, we propose a co-design algorithm that strikes a balance between the need for a lower communication frequency and a reduction in the state disagreements of agents. Finally, the effectiveness of the theoretical analysis is demonstrated through 3D figures and comparison tables, from which it can be concluded that the communication frequency of the MAS was clearly reduced on the basis of ensuring consensus performance via applying the algorithm proposed in this paper.
MoS2 nanorods were successfully synthesized via hydrothermal method by adding sillicontungstic acid as an additive. The products were characterized by X-ray powder diffraction (XRD), X-ray ...photoelectron spectrum (XPS) and field-emission scanning electron microscopy (FESEM). XRD pattern result indicated that the as-prepared sample can be indexed to a mixture of hexagonal and rhombohedral phase MoS2. XPS showed that the nanorods were only composed of Mo and S with atomic ratio of 1:2. FESEM images revealed that the MoS2 rods had uniform sizes with mean diameters of about 20-50nm and lengths of 400-500nm. It was found that the addition of sillicontungstic acid played a crucial role in the formation of the rod-like MoS2 in our experiment. The possible formation mechanism of MoS2 nanorods is also discussed.
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