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Epigenetic modifications are crucial for plant development. EFD (ExineFormationDefect) encodes a SAM-dependent methyltransferase that is essential for the pollen wall pattern formation and male fertility in Arabidopsis. In this study, we find that the expression of DRM2, a de novo DNA methyltransferase in plants, complements for the defects in efd, suggesting its potential de novo DNA methyltransferase activity. Genetic analysis indicates that EFD functions through HB21, as the knockout of HB21 fully restores fertility in efd mutants. DNA methylation and histone modification analyses reveal that EFD represses the transcription of HB21 through epigenetic mechanisms. Additionally, we demonstrate that HB21 directly represses the expression of genes crucial for pollen formation and anther dehiscence, including CalS5, RPG1/SWEET8, CYP703A2 and NST2. Collectively, our findings unveil a double negative regulatory cascade mediated by epigenetic modifications that coordinates anther development, offering insights into the epigenetic regulation of this process. Epigenetic modifications are crucial for plant development. Here, the authors find an epigenetically mediated double negative cascade for pollen formation and anther dehiscence, offering new insights into epigenetic regulation of anther development. [ABSTRACT FROM AUTHOR]

Fabrication of waterproof decorative paintings has attracted a great deal of interest. In this work, in situ reaction using poly(glycidyl methacrylate) (PGMA) and polyhedral oligomeric silsesquioxane with amino group at end (amino-POSS) was utilized to fabricate coatings at surfaces of papery/cloth decorative paintings via spray, which endowed the decorative paintings with excellent hydrophobicity, transparency, and weather ability. Firstly, ring opening of epoxy groups in PGMA, cross-linking structure in coatings, and strong coating/painting interface adhesion were achieved. Then, surface morphology of coatings was observed, and high surface roughness was confirmed. Next, high transparency and thermal stability of coatings were confirmed. Finally, surface water-contact-angles (WCAs) of coatings with various substrates were tested as a function of POSS content. Weathering resistances of coating surface on cloth substrate were studied. Coatings exhibit excellent properties such as high light transmittance (over 80%), high glass-transition temperature (upper limit ~ 113 ℃), high hydrophobicity (maximum WCA ~ 149°), and strong weathering resistances (the aged WCAs over 140°). Work innovation lies in simultaneously gained high hydrophobicity, good transparency, and strong weather ability. This work might pave a road for fabricating excellent coatings for protecting decorative paintings. [ABSTRACT FROM AUTHOR]

Inorganic quantum dots (QDs) are used in color displays because of wide photo-absorption and controllable photoluminescence (PL) colors, but their PL stability may be low due to surface defects. To overcome it, we prepared CdTe QDs with different sizes (~ 3.8, 4.4 and 5.0 nm) and poly(glycidyl methacrylate) (PGMA)/CdTe composite films. An increased size of QDs made them emit the green, yellow and red light successively. With an increased PL emission wavelength, the films emitted bright light with various colors. Compared to QDs solutions, the composite films have the almost unchanged fluorescence emission wavelengths (536–612 nm) and high PL intensity. The latter has an improved PL stability under optical and thermal conditions. The green-emitting film maintains ~ 81% of PL intensity after 24 h of photo-irradiation as well as ~ 91% of PL intensity at 120 °C. The green and white light-emitting diode (LED) devices were prepared using composite films, and the fluorescent emissions with bright colors were acquired. This study provides a valuable guideline for preparing the polymer/inorganic quantum dot composite films used in the LED poster display screens with bright stable fluorescence emissions. [ABSTRACT FROM AUTHOR]

Aerosol jet printing has the potential to fabricate fine features on various substrates due to its large stand-off distance. However, the presence of overspray and instability, particularly at high printing resolutions, has limited its widespread application. In this study, we introduce an efficient approach called annular acoustic focusing for aerosol jet printing. By determining the optimal focusing frequency (5.8 MHz) for silver nanoparticles using a particle ejection model, we achieve precise and stable printing. We also propose a modified print nozzle geometry, resulting in ultrafine traces (line width < 6 μm, overspray < 0.1 μm). Compared to printing without acoustic focusing, the line width of the traces decreases to 60 ± 5% while their conductivity increases to 180 ± 5%. Additionally, several 8 h experiments demonstrate excellent printing stability. This research opens up possibilities for the fabrication of conformal electronics with high precision and improved conductivity using aerosol jet printing. Overspray and instability at high resolution has limited the widespread application of aerosol jet printing. Here, authors introduce an annular acoustic field coupled with a modified nozzle geometry, resulting in fine traces (line width <6 μm, overspray < 0.1 μm) with excellent printing stability. [ABSTRACT FROM AUTHOR]