CRWN nuclear lamina components maintain the H3K27me3 landscape and promote successful reproduction in Arabidopsis.

Arabidopsis lamin analogs CROWDED NUCLEIs (CRWNs) are necessary to maintain nuclear structure, genome function, and proper plant growth. However, whether and how CRWNs impact reproduction and genome-wide epigenetic modifications is unknown. Here, we investigate the role of CRWNs during the development of gametophytes, seeds, and endosperm, using genomic and epigenomic profiling methods. We observed defects in crwn mutant seeds including seed abortion and reduced germination rate. Quadruple crwn null genotypes were rarely transmitted through gametophytes. Because defects in seeds often stem from abnormal endosperm development, we focused on crwn1 crwn2 (crwn1/2) endosperm. These mutant seeds exhibited enlarged chalazal endosperm cysts and increased expression of stress-related genes and the MADS-box transcription factor PHERES1 and its targets. Previously, it was shown that PHERES1 expression is regulated by H3K27me3 and that CRWN1 interacts with the PRC2 interactor PWO1. Thus, we tested whether crwn1/2 alters H3K27me3 patterns. We observed a mild loss of H3K27me3 at several hundred loci, which differed between endosperm and leaves. These data indicate that CRWNs are necessary to maintain the H3K27me3 landscape, with tissue-specific chromatin and transcriptional consequences.

In situ Synthesis of Single Layered Metal-Organic Frameworks via Inkjet Printing on a Cellulose Nanofiber Film.

The inkjet printing is a simple method to develop pattern-controlled 2D metal-organic frameworks (MOFs) due to its cost-effectiveness and ease of operation. Despite the sophisticated structures of MOF crystals, the MOF surfaces are easily contaminated by the adsorption of an ink solution, and the printing nozzle can be clogged by the aggregates of MOFs during printing. Unlike the mixture inks of MOFs and a carrier medium, the surface-specific patterning by in situ synthesis provides the film surface with the controlled patterns of an MOF single layer having different morphologies of MOFs without changing the ink cartridges. It enables facile printing due to the low viscosity of inks and escapes the risk of nozzle clogging because MOFs are synthesized at the printed patterns on the substrates. The ion-exchanged cellulose nanofiber (CNF) films form strong coordination with metal ions enhancing the stability of the MOFs on the film surface. It also demonstrates the controlled coverage of the MOFs by the printing pass number and the carboxylate content of CNF and the tunable adsorption of the guest molecules for different loading capacities of the printed patterns.

Hydrochromic film for dynamic information storage using cellulose nanofibers and silica nanoparticles.

A hydrochromic composite film was fabricated by incorporating silica nanoparticles (SiNPs) with cellulose nanofibers (CNFs). The CNF/SiNP composite film underwent a reversible change in transparency in response to external moisture variation. The CNFs improved the dimensional stability of the CNF/SiNP composite film and induced morphological differences in SiNP agglomerates, which control the water vapor condensation in a porous film. The condensed water in the pores reduced the difference in refractive index over the CNF/SiNP film, enhancing its transparency. The selective transparency of the composite film was challenged by printing CNF/SiNP inks at different composition ratios. The differing susceptibility of the printed patterns to moisture provided selective transparency at specific patterns, which can store dynamic information such as QR or numerical codes by simple water vapor adsorption and desorption.