As one of the largest gene families, F-box domain proteins have important roles in regulating various developmental processes and stress responses. In this study, we have investigated a rice F-box domain gene, MAIF1. The MAIF1 protein is mainly localized in the plasma membrane and nucleus. MAIF1 expression is induced rapidly and strongly by abscisic acid (ABA) and abiotic stresses. MAIF1 expression is also induced in root tips by sucrose, independent of its hydrolytic hexose products, glucose and fructose, and the plant hormones auxin and cytokinin. Overexpression of MAIF1 reduces rice ABA sensitivity and abiotic stress tolerance and promotes rice root growth. These results suggest that MAIF1 is involved in multiple signaling pathways in regulating root growth. Growth restraint in plants is an acclimatization strategy against abiotic stress. Our results also suggest that MAIF1 plays the negative role in response to abiotic stress possibly by regulating root growth.

SUMMARYSmall silencing RNAs (sRNAs) are non-coding RNA regulators that negatively regulate gene expression by guiding mRNA degradation, translation repression or chromatin modification. Plant sRNAs play crucial roles in various developmental processes, hormone signaling, immune responses and adaptation to a variety of abiotic stresses. miR441 and miR446 were previously annotated as microRNAs (miRNAs) because their precursors can form typical stem-loop structures, but are not considered as real miRNAs because of inconsistency with some ancillary criteria of the recent guidelines for annotation of plant miRNAs. We tentatively rename them small interfering (si)R441 and siR446, respectively, in this study. It has recently been shown that the precursors of siR441 and siR446 might originate from the miniature inverted-repeat transposable element (MITE) Stowaway1. In this report, we show that, in contrast with Dicer-like (DCL)3-and RNA-dependent RNA polymerase (RDR)2-dependent MITE-derived ra-siRNAs, siR441 and siR446 are processed by OsDCL3a but independent of OsRDR2, indicating that siR441 and siR446 are generated from single-stranded stem-loop precursors. We also show that abscisic acid (ABA) and abiotic stresses downregulate the expression of siR441 and siR446 but, surprisingly, increase the accumulation of their precursors in rice plants, implying that processing of siRNA precursors is inhibited. We provide evidence to show that this defective processing is due to increased precursor accumulation per se, possibly by intermolecular self-pairing of the processing intermediate sequences, thus hindering their normal processing. Functional examinations indicate that siR441 and siR446 are positive regulators of rice ABA signaling and tolerance to abiotic stress, possibly by regulating MAIF1 expression.

We report hierarchical‐ordered ZIF−L(Zn)@Ti3C2Tx MXene core–sheath fibers, in which a ZIF−L(Zn) nanowall array sheath is grown vertically on an anisotropic Ti3C2Tx core by Ti−O−Zn/Ti−F−Zn chemical bonds. Through highly efficient microfluidic assembly and microchannel reactions, ZIF−L(Zn)@Ti3C2Tx exhibits well‐developed micro‐/mesoporosity, ordered ionic pathways, fast interfacial electron conduction and large‐scale fabrication, significantly boosting charges dynamic transport and intercalation. The resultant ZIF−L(Zn)@Ti3C2Tx fiber presents large capacitance (1700 F cm−3) and outstanding rate performance in a 1 M H2SO4 electrolyte. Additionally, ZIF−L(Zn)@Ti3C2Tx fiber‐based solid‐state asymmetric supercapacitors deliver high energy density (19.0 mWh cm−3), excellent capacitance (854 F cm−3), large deformable/wearable capabilities and long‐time cyclic stability (20 000 cycles), which realize natural sunlight‐induced self‐powered applications to drive water level/earthquake alarm devices.

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All-inorganic perovskite quantum dots (QDs) (CsPbX3, X = Cl, Br, I) become promising candidate materials for the new generation of light-emitting diodes for their narrow emission spectrum, high photoluminescence quantum yield, and adjustable emission wavelength. However, the perovskite QDs materials still face instability against moisture, high-temperature, and UV-light. Many strategies have been reported to improve the photoluminescence (PL) performance of QDs while increasing their stability. These strategies can be divided into three main categories: doping engineering, surface ligand modification, coating strategies. This paper reviews the recent research progress of surface ligands, inorganic and polymer coating, and metal ions doping of CsPbX3 QDs. Partial substitution of Pb2+ with non-toxic or low-toxic metal ions can improve the formation energy of the perovskite lattice and reduce its toxicity. The surface polymer modification can use their ligands to bond with the uncoordinated lead and halogen ions on perovskite QDs surface to reduce surface defects, thereby improving the PL intensity and stability. In addition, the organic or inorganic coating materials on perovskite QDs can effectively avoid their contact with the external environment, thereby improving the stability of the perovskite. The optical properties of the modified QDs, including transient absorption spectra, temperature-dependent PL spectra, time-resolved photoluminescence (TRPL) spectra properties, etc. were discussed to explain the physical mechanism. The potential applications of all-inorganic perovskite QDs as down-conversion fluorescent materials in light-emitting diodes are presented. Finally, we provide some possible methods to further improve the PL performance of the all-inorganic perovskite QDs.

To better understand the response of rice to nutrient stress, we have taken a systematic approach to identify rice genes that respond to deficiency of macronutrients and affect rice growth. We report here the expression and biological functions of a previously uncharacterized rice gene that we have named NRR (nutrition response and root growth). NRR is alternatively spliced, producing two 5'-coterminal transcripts, NRRa and NRRb, encoding two proteins of 308 and 223 aa, respectively. Compared to NRRb, NRRa possesses an additional CCT domain at the C-terminus. Expression of NRR in rice seedling roots was significantly influenced by deficiency of macronutrients. Knock-down of expression of NRRa or NRRb by RNA interference resulted in enhanced rice root growth. By contrast, overexpression of NRRa in rice exhibited significantly retarded root growth. These results revealed that both NRRa and NRRb played negative regulatory roles in rice root growth. Our findings suggest that NRRa and NRRb, acting as the key components, modulate the rice root architecture with the availability of macronutrients.

The Sr0.95Ba0.05TiO3 (SBT) nanometer film is prepared on the commercially available Pt/TiO2/SiO2/Si substrate by radio-frequency magnetron sputtering. The x-ray diffraction pattern and the scanning electron microscope image of the cross-sectional profile of the SBT nanometer film are depicted. The memristive mechanism is inferred. The mathematical model is calculated, where M(q) denotes the memristance depending on the quantity of electric charge, and q(t) denotes the quantity of electric charge depending on the time. The theoretical I–V characteristics of the SBT nanometer film are obtained by the mathematical model. The results show that the theoretical I–V characteristics are consistent with the measured I–V characteristics. Moreover, the mathematical model could guide the research on applications of the memristor.