Rice (
) responds to various abiotic stresses during growth. Plant-specific NAM, ATAF1/2, and CUC2 (NAC) transcription factors (TFs) play an important role in controlling numerous vital growth and ...developmental processes. To date, 170 NAC TFs have been reported in rice, but their roles remain largely unknown. Herein, we discovered that the TF OsNAC006 is constitutively expressed in rice, and regulated by H
O
, cold, heat, abscisic acid (ABA), indole-3-acetic acid (IAA), gibberellin (GA), NaCl, and polyethylene glycol (PEG) 6000 treatments. Furthermore, knockout of
using the CRISPR-Cas9 system resulted in drought and heat sensitivity. RNA sequencing (RNA-seq) transcriptome analysis revealed that
regulates the expression of genes mainly involved in response to stimuli, oxidoreductase activity, cofactor binding, and membrane-related pathways. Our findings elucidate the important role of
in drought responses, and provide valuable information for genetic manipulation to enhance stress tolerance in future plant breeding programs.
Abstract
At the interface of van der Waals heterostructures, the crystal symmetry and the electronic structure can be reconstructed, giving rise to physical properties superior to or absent in parent ...materials. Here by studying a Bernal bilayer graphene moiré superlattice encapsulated by 30°-twisted boron nitride flakes, we report an unprecedented ferroelectric polarization with the areal charge density up to 10
13
cm
−2
, which is far beyond the capacity of a moiré band. The translated polarization ~5 pC m
−1
is among the highest interfacial ferroelectrics engineered by artificially stacking van der Waals crystals. The gate-specific ferroelectricity and co-occurring anomalous screening are further visualized via Landau levels, and remain robust for Fermi surfaces outside moiré bands, confirming their independence on correlated electrons. We also find that the gate-specific resistance hysteresis loops could be turned off by the other gate, providing an additional control knob. Furthermore, the ferroelectric switching can be applied to intrinsic properties such as topological valley current. Overall, the gate-specific ferroelectricity with strongly enhanced charge polarization may encourage more explorations to optimize and enrich this novel class of ferroelectricity, and promote device applications for ferroelectric switching of various quantum phenomena.
Salinity is a major abiotic stress factor that seriously affects plant growth. Many genes are involved in the response to salt stress with various metabolism pathways. A number of plant transcription ...factor family genes have been found to be involved in the salt stress response, and NAM, ATAF and CUC (NAC) transcription factors are thought to act as active regulators during abiotic stress, especially salt stress. In this study, we detected a rice NAC transcription factor coding gene, OsNAC041, and confirmed that it influenced the germination of seeds under salt stress and salt tolerance of plants. OsNAC041 was primarily expressed in the leaves and located in the nucleus. Furthermore, the CRISPR/Cas9 method was used to obtain a targeted osnac041 mutant, of which the plant height was higher than that of the wild-type, showing increased salt sensitivity. Moreover, RNA-seq analysis revealed a number of differentially expressed genes (DEGs) involved in several important signaling pathways in the osnac041 mutant. Subsequently, Kyoto Encyclopedia of Genes and Genomes annotation also revealed differential expression of DEGs associated with mitogen-activated protein kinase signaling, peroxisome, eukaryotic- type ABC transporters, photosynthesis and plant hormones, which are involved in stress-related signaling pathways. Overall, our study suggested that OsNAC041 was involved in the salt stress response in rice. These findings not only provide empirical evidence of OsNAC041 function, but also provide new insight into its potential application in rice resistance breeding.
Flat-band physics of moiré superlattices, originally discovered in the celebrated twisted bilayer graphene, have recently been intensively explored in multilayer graphene systems that can be further ...controlled by electric field. In this work, we experimentally find the evidence of correlated insulators at half filling of the electron moiré band of twisted monolayer–trilayer graphene with a twist angle around 1.2°. Van Hove singularity (VHS), manifested as enhanced resistance and zero Hall voltage, is observed to be distinct in conduction and valence flat bands. It also depends on the direction and magnitude of the displacement fields, consistent with the asymmetric crystal structure. While the resistance ridges at VHS can be enhanced by magnetic fields, when they cross commensurate fillings of the moiré superlattice in the conduction band, the enhancement is so strong that signatures of correlated insulator appear, which may further develop into an energy gap depending on the correlation strength. At last, Fermi velocity derived from temperature coefficients of resistivity is compared between conduction and valence bands with different displacement fields. It is found that electronic correlation has a negative dependence on the Fermi velocity, which in turn could be used to quantify the correlation strength.
Highly controlled electronic correlation in twisted graphene heterostructures has gained enormous research interests recently, encouraging exploration in a wide range of moiré superlattices beyond ...the celebrated twisted bilayer graphene. Here we characterize correlated states in an alternating twisted Bernal bilayer–monolayer–monolayer graphene of ∼ 1.74°, and find that both van Hove singularities and multiple correlated states are asymmetrically tuned by displacement fields. In particular, when one electron per moiré unit cell is occupied in the electron-side flat band, or the hole-side flat band (i.e., three holes per moiré unit cell), the correlated peaks are found to counterintuitively grow with heating and maximize around 20 K – a signature of Pomeranchuk effect. Our multilayer heterostructure opens more opportunities to engineer complicated systems for investigating correlated phenomena.
Moiré superlattices in van der Waals heterostructures have recently attracted enormous interests, due to the highly controllable electronic correlation that gives rise to superconductivity, ...ferromagnetism, and nontrivial topological properties. To gain a deep understanding of such exotic properties, it is essential to clarify the broken symmetry between spin and valley flavors which universally exists in these ground states. Here in a rhombohedral trilayer graphene crystallographically aligned with a hexagonal boron nitride, we report various kinds of symmetry-breaking transition tuned by displacement fields (
D
) and magnetic fields: (i) While it is well known that a finite
D
can enhance correlation to result in correlated insulators at fractional fillings of a flat band, we find the correlation gap emerges before the flavor is fully filled at a positive
D
, but the sequence is reversed at a negative
D
. (ii) Around zero
D
, electronic correlation can be invoked by narrow Landau levels, leading to quantum Hall ferromagnetism that lifts all the degeneracies including not only spin and valley but also orbital degrees of freedom. Our result unveils the complication of transitions between symmetry-breaking phases, shedding light on the mechanisms of various exotic phenomena in strongly correlated systems.
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•Poly (butylene adipate-co-terephthalate) (PBAT) was functionalized by grafting with glycidyl methacrylate (GMA) in the presence of the co-monomer N-vinyl pyrrolidone (NVP)•The ...introduction of NVP can significantly increase the graft efficiency of PBAT-GMA.•The high impact strength was attributed to reactive compatibilization between the epoxy functional groups in PBAT-GMA and the carboxyl groups in PLA.•The compatibilization mechanism of PLA/PBAT-GMA blend was revealed.
In the study, poly (butylene adipate-co-terephthalate) (PBAT) was grafted with glycidyl methacrylate (GMA) in the presence of the co-monomer N-vinyl pyrrolidone (NVP), and then it was employed to enhance the toughness of poly (lactic acid) (PLA). It was found the functionalized PBAT had a better toughening effect on PLA than neat PBAT. The PLA/PBAT-GMA (70/30) blend undergoes brittle-ductile transition when the graft monomer ratio of GMA:NVP:DCP exceeds 2:2:0.2. The impact strength of PLA/PBAT-GMA (3:3:0.3) blend reached 65.7 kJ/m2, with an elongation at break of 210.9 %. Additionally, rheological tests showed that the entanglement ability of chain segments was enhanced, it was ascribed to the improvement of the compatibility between PLA and PBAT-GMA owing to the compatibilization reaction between the epoxy functional groups in PBAT-GMA and the carboxyl groups in PLA, resulting in the formation of a new copolymer. DMA tests revealed that the Tg of PLA and PBAT-GMA were close to each other, confirming the improved compatibility of the PLA/PBAT-GMA blends. This offers a novel method for preparing super-though PLA.
The stacking heterostructure of graphene on bulk h-BN produces a moiré pattern with topographic corrugation. The corrugation of the moiré pattern expectantly induces a considerable curvature and a ...flexoelectric response, which calls for a detailed study. In this work, we used lateral force microscopy, a scanning technique to locally observe the moiré pattern and topographic corrugation. The curvature and flexoelectric potentials are derived from the measured topographic corrugation, revealing a huge curvature of ∼10
7
m
−1
and a flexoelectric potential of ∼10 mV in the hexagonal domain wall region (∼3-4 nm) of the moiré pattern. In addition, the domain walls of the moiré pattern also generate a clear electromechanical and frictional response, arising from the corrugation-induced flexoelectric response. In summary, the results of this work provide insights into the understanding of the flexoelectricity in the graphene/bulk h-BN and its associated electromechanical coupling behavior in the moiré pattern of a van der Waals stacking heterostructure.
The topographic corrugation and flexoelectric potential distribution of moire pattern.
Poly(butyleneadipate‐co‐terephthalate) (PBAT) was used to toughen poly(lactic acid) (PLA) with the addition of poly(methyl methacrylate)–poly(butyl acrylate)–poly(methyl methacrylate) (MAM) through ...melt blending. The impact toughness and tensile toughness of the PLA/PBAT/MAM ternary blends were greatly enhanced when the MAM content was higher than 5%. For PLA/PBAT/MAM (80/15/5) blend, the notched impact strength was as high as 42.4 kJ/m2, and the elongation at break reached 194.7%. The structure–property relationship of the PLA/PBAT/MAM ternary blends were studied through scanning electron microscopy, dynamic mechanical analysis, and contact angle measurements. It is found MAM and PBAT have a synergistic toughening effect on PLA, the MAM acts as not only a compatibilizer but also a toughening agent, which can improve the compatibility and enhance the interfacial adhesion between PLA and PBAT. As a result, the overall mechanical properties of PLA blends were improved significantly. This result provides a simple to operate and more efficient method for PLA toughening.
For the PLA/PBAT/MAM blend, the compatibility between PLA and PBAT was improved significantly due to the presence of MAM. The MAM acts as a “bridge” between PLA and PBAT at the interface, which reduces the interfacial tension between PLA and PBAT. Moreover, MAM acts as not only a compatibilizer but also a toughening agent, the overall mechanical properties of PLA blends were improved significantly. Therefore, MAM and PBAT have a synergistic toughening effect on PLA.
In transition metal dichalcogenides (TMDs), Ising superconductivity with an antisymmetric spin texture on the Fermi surface has attracted wide interest due to the exotic pairing and topological ...properties. However, it is not clear whether the Q valley with a giant spin splitting is involved in the superconductivity of heavily doped semiconducting 2H-TMDs. Here by taking advantage of a high-quality monolayer WS2 on hexagonal boron nitride flakes, we report an ionic-gating induced superconducting dome with a record high critical temperature of ∼6 K, accompanied by an emergent nonlinear Hall effect. The nonlinearity indicates the development of an additional high-mobility channel, which (corroborated by first principle calculations) can be ascribed to the population of Q valleys. Thus, multivalley population at K and Q is suggested to be a prerequisite for developing superconductivity. The involvement of Q valleys also provides insights to the spin textured Fermi surface of Ising superconductivity in the large family of transition metal dichalcogenides.
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