Sulfur vacancy and p-n junction synergistically boosting interfacial charge transfer and separation in ZnIn2S4/NiWO4 heterostructure for enhanced photocatalytic hydrogen evolution.

Constructing a p-n heterojunction with vacancy is advantageous for speeding up carrier separation and migration due to the synergy of the built-in electric field and electron capture of the vacancy. Herein, a sulfur vacancy riched-ZnIn2S4/NiWO4 p-n heterojunction (VZIS/NWO) photocatalyst was rationally designed and fabricated for photocatalytic hydrogen evolution. The composition and structure of VZIS/NWO were characterized. The existence of sulfur vacancy was confirmed through X-ray photoelectron spectroscopy, high-resolution transmission electron microscope, and electron paramagnetic resonance technology. The p-n heterojunction formed by ZnIn2S4 and NiWO4 was proved to provide a convenient channel to boost interfacial charge migration and separation. By reducing the band gap, the vacancy engineer can improve light absorption as well as serve as an electron trap to improve photo-induced electron-hole separation. Benefiting from the synergy of p-n heterojunction and vacancy, the optimal VZIS/NWO-5 catalyst exhibits dramatically enhanced H2 generation performance, which is about 10-fold that of the pristine ZnIn2S4. This work emphasizes the synergy between p-n heterojunction and sulfur vacancy for enhancing photocatalytic hydrogen evolution performance.

BEtarget: A versatile web-based tool to design guide RNAs for base editing in plants.

CRISPR-dependent base editors enable direct nucleotide conversion without the introduction of double-strand DNA break or donor DNA template, thus expanding the CRISPR toolbox for genetic manipulation. However, designing guide RNAs (gRNAs) for base editors to enable gene correction or inactivation is more complicated than using the CRISPR system for gene disruption. Here, we present a user-friendly web tool named BEtarget dedicated to the design of gRNA for base editing. It is currently supported by 46 plant reference genomes and 5 genomes of non-plant model organisms. BEtarget supports the design of gRNAs with different types of protospacer adjacent motifs (PAM) and integrates various functions, including automatic identification of open reading frame, prediction of potential off-target sites, annotation of codon change, and assessment of gRNA quality. Moreover, the program provides an interactive interface for users to selectively display information about the desired target sites. In brief, we have developed a flexible and versatile web-based tool to simplify complications associated with the design of base editing technology. BEtarget is freely accessible at https://skl.scau.edu.cn/betarget/.

Methylesterification of cell-wall pectin controls the diurnal flower-opening times in rice.

Flowers are the core reproductive organ of plants, and flowering is essential for cross-pollination. Diurnal flower-opening time is thus a key trait influencing reproductive isolation, hybrid breeding, and thermostability in plants. However, the molecular mechanisms controlling this trait remain unknown. Here, we report that rice Diurnal Flower Opening Time 1 (DFOT1) modulates pectin methylesterase (PME) activity to regulate pectin methylesterification levels of the lodicule cell walls, which affect lodicule swelling to control diurnal flower-opening time. DFOT1 is specifically expressed in the lodicules, and its expression gradually increases with the approach to flowering but decreases with flowering. Importantly, a knockout of DFOT1 showed earlier diurnal flower opening. We demonstrate that DFOT1 interacts directly with multiple PMEs to promote their activity. Knockout of PME40 also resulted in early diurnal flower opening, whereas overexpression of PME42 delayed diurnal flower opening. Lower PME activity was observed to be associated with higher levels of pectin methylesterification and the softening of cell walls in lodicules, which contribute to the absorption of water by lodicules and cause them to swell, thus promoting early diurnal flower opening. Higher PME activity had the opposite effect. Collectively, our work uncovers a molecular mechanism underlying the regulation of diurnal flower-opening time in rice, which would help reduce the costs of hybrid breeding and improve the heat tolerance of flowering plants by avoiding higher temperatures at anthesis.

A chromosome-level genome assembly of the wild rice Oryza rufipogon facilitates tracing the origins of Asian cultivated rice.

Oryza rufipogon Griff. is a wild progenitor of the Asian cultivated rice Oryza sativa. To better understand the genomic diversity of the wild rice, high-quality reference genomes of O. rufipogon populations are needed, which also facilitate utilization of the wild genetic resources in rice breeding. In this study, we generated a chromosome-level genome assembly of O. rufipogon using a combination of short-read sequencing, single-molecule sequencing, BioNano and Hi-C platforms. The genome sequence (399.8 Mb) was assembled into 46 scaffolds on the 12 chromosomes, with contig N50 and scaffold N50 of 13.2 Mb and 20.3 Mb, respectively. The genome contains 36,520 protein-coding genes, and 49.37% of the genome consists of repetitive elements. The genome has strong synteny with those of the O. sativa subspecies indica and japonica, but containing some large structural variations. Evolutionary analysis unveiled the polyphyletic origins of O. sativa, in which the japonica and indica genome formations involved different divergent O. rufipogon (including O. nivara) lineages, accompanied by introgression of genomic regions between japonica and indica. This high-quality reference genome provides insight on the genome evolution of the wild rice and the origins of the O. sativa subspecies, and valuable information for basic research and rice breeding.

[Isolation and Characterization of Microbes from Pericarpium Citri Reticulatae].

OBJECTIVE: The longer the Pericarpium Citri Reticulatae is preserved, the better medicinal values will be. The present work aims to isolate beneficial microbes isolated from the 7-year orange peel that might be used to produce high quality Pericarpium Citri Reticulatae. METHODS: The microbes isolated from the 7-year orange peel using 4 mediums were grouped by SDS-PAGE patterns of the whole-cell protein electrophoresis and IS-PCR DNA fingerprinting. The representative strains were further studied by physiological and biochemical tests, and phylogeny analysis. RESULTS: Total 23 bacteria were obtained from the 7-year orange peel. These strains were classified into 4 groups: the strains of group I belonged to Bacillus; the strains of group II, group III and group IV were closed to Paenibacillus. CONCLUSION: Among the representative strains of group I, II, III and IV, only the representative strain cp20 of group II has the ability of strong utilizing citrate obviously. The strain cp20 of group II were further applied to making Pericarpium Citri Reticulatae.