Recent advances in particulate photocatalytic water splitting are reviewed and the pioneering works in scalable H2 evolution via photocatalytic OWS are presented.

The class 2/type II clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 system has been used successfully for simultaneous modification of multiple loci in plants. Two general strategies have been applied to coexpress multiple single guide RNAs (sgRNAs) to achieve multiplex gene editing in plant cells. One is to construct the multiple guide RNA expression cassettes into separate plasmids when direct gene delivery methods are adopted, such as biolistic bombardment and PEG-mediated protoplast transfection (Shan et al., 2013). The other is to assemble the multiple sgRNAs into a single vector when the Agrobacteria-mediated gene transformation method is used. These multiple sgRNAs can be driven by separate promoters (Ma et al., 2015; Zhang et al., 2016) or expressed as a single transcript for further processing by plant endogenous ribonucleases (Xie et al., 2015). Although these two strategies were reported to be efficient for introducing targeted gene modifications in plant genomes, the construction of CRISPR/ Cas9 vectors was complicated and laborious. Recently, Cpf1 (CRISPR from Prevotella and Francisella 1) was characterized as a novel class 2 system component that has distinct features compared with Cas9. It is a single RNA-guided endonuclease, recognizes the thymidine-rich protospacer-adjacent motif (PAM), and produces staggered cuts distal to the PAM site (Zetsche et al., 2015). This type V CRISPR/Cpf1 system has been demonstrated to have robust genome editing activity in mammalian cells (

No abstract

Base editing is a novel genome editing strategy that enables irreversible base conversion at target loci without the need for double stranded break induction or homology-directed repair. Here, we developed new adenine and cytosine base editors with engineered SpCas9 and SaCas9 variants that substantially expand the targetable sites in the rice genome. These new base editors can edit endogenous genes in the rice genome with various efficiencies. Moreover, we show that adenine and cytosine base editing can be simultaneously executed in rice. The new base editors described here will be useful in rice functional genomics research and will advance precision molecular breeding in crops.

Surface atomic arrangement and coordination of photocatalysts highly exposed to different crystal facets significantly affect the photoreactivity. However, controversies on the true photoreactivity of a specific facet in heterogeneous photocatalysis still exits. Herein, we exemplified well‐defined BiOBr nanosheets dominating with respective facets, (001) and (010), to track the reactivity of crystal facets for photocatalytic water splitting. The real photoreactivity of BiOBr‐(001) were evidenced to be significantly higher than BiOBr‐(010) for both hydrogen production and oxygen evolution reactions. Further in situ photochemical probing studies verified the distinct reactivity is not only owing to the highly exposed facets, but dominated by the co‐exposing facets, leading to an efficient spatial separation of photogenerated charges and further making the oxidation and reduction reactions separately occur with different reaction rates, which ordains the fate of the true photoreactivity.

Lead‐free inorganic halide perovskites have triggered appealing interests in various energy‐related applications including solar cells and photocatalysis. However, why perovskite‐structured materials exhibit excellent photoelectric properties and how the unique crystalline structures affect the charge behaviors are still not well elucidated but essentially desired. Herein, taking inorganic halide perovskite Cs3Bi2Br9 as a prototype, the significant derivation process of silver atoms incorporation to induce the structural transformation from Cs3Bi2Br9 to Cs2AgBiBr6, which brings about dramatic differences in photoelectric properties is unraveled. It is demonstrated that the silver incorporation results in the co‐operated orbitals hybridization, which makes the electronic distributions in conduction and valence bands of Cs2AgBiBr6 more dispersible, eliminating the strong localization of electron–hole pairs. As consequences of the electronic structures derivation, exhilarating changes in photoelectric properties like band structure, exciton binding energy, and charge carrier dynamics are verified experimentally and theoretically. Using photocatalytic hydrogen evolution activity under visible light as a typical evaluation, such crystalline structure transformation contributes to a more than 100‐fold enhancement in photocatalytic performances compared with pristine Cs3Bi2Br9, verifying the significant effect of structural derivations on the exhibited performances. The findings will provide evidences for understanding the origin of photoelectric properties for perovskites semiconductors in solar energy conversion.

Scalable solar hydrogen production by water splitting using particulate photocatalysts is promising for renewable energy utilization. However,p hotocatalytic overall water splitting is challenging owing to slow water oxidation kinetics, severe reverse reaction, and H 2 /O 2 gas separation. Herein, mimicking nature photosynthesis,apractically feasible approach named Hydrogen Farm Project (HFP) is presented, which is composed of solar energy capturing and hydrogen production subsystems integrated by as huttle ion loop,F e 3+ / Fe 2+ .W ell-defined BiVO 4 crystals with precisely tuned {110}/ {010} facets are ideal photocatalysts to realizethe HFP,giving up to 71 %q uantum efficiency for photocatalytic water oxidation and full forward reaction with nearly no reverse reaction. An overall solar-to-chemical efficiency over 1.9 % and as olar-to-hydrogen efficiency exceeding 1.8 %c ould be achieved. Furthermore,ascalable HFP panel for solar energy storage was demonstrated under sunlight outdoors.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

CRISPR/Cas9 genome editing relies on sgRNA-target DNA base pairing and a short downstream PAM sequence to recognize target DNA. The strict protospacer adjacent motif (PAM) requirement hinders applications of the CRISPR/Cas9 system since it restricts the targetable sites in the genomes. xCas9 and SpCas9-NG are two recently engineered SpCas9 variants that can recognize more relaxed NG PAMs, implying a great potential in addressing the issue of PAM constraint. Here we use stable transgenic lines to evaluate the efficacies of xCas9 and SpCas9-NG in performing gene editing and base editing in rice. We found that xCas9 can efficiently induce mutations at target sites with NG and GAT PAM sequences in rice. However, base editors containing xCas9 failed to edit most of the tested target sites. SpCas9-NG exhibited a robust editing activity at sites with various NG PAMs without showing any preference for the third nucleotide after NG. Moreover, we showed that xCas9 and SpCas9-NG have higher specificity than SpCas9 at the CGG PAM site. We further demonstrated that different forms of cytosine or adenine base editors containing SpCas9-NG worked efficiently in rice with broadened PAM compatibility. Taken together, our work has yielded versatile genome-engineering tools that will significantly expand the target scope in rice and other crops.