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Recently, CRISPR/Cas9 technology has emerged as a powerful approach for targeted genome modification in eukaryotic organisms from yeast to human cell lines. Its successful application in several plant species promises enormous potential for basic and applied plant research. However, extensive studies are still needed to assess this system in other important plant species, to broaden its fields of application and to improve methods. Here we showed that the CRISPR/Cas9 system is efficient in petunia (Petunia hybrid), an important ornamental plant and a model for comparative research. When PDS was used as target gene, transgenic shoot lines with albino phenotype accounted for 55.6%-87.5% of the total regenerated T0 Basta-resistant lines. A homozygous deletion close to 1 kb in length can be readily generated and identified in the first generation. A sequential transformation strategy-introducing Cas9 and sgRNA expression cassettes sequentially into petunia-can be used to make targeted mutations with short indels or chromosomal fragment deletions. Our results present a new plant species amenable to CRIPR/Cas9 technology and provide an alternative procedure for its exploitation.During the past three decades, great efforts and achievements have been made in developing efficient tools for targeted genome modification in plants 1,2 . Before the CRISPR/ Cas9 system (CRISPR: clustered regularly interspaced short palindromic repeats; Cas9: CRISPR-associated protein 9) was introduced into plant research in 2013 3-10 , three classes of sequence-specific nucleases had been used for plant genome engineering: zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and meganucleases 11 . Against this background, due to its versatility, design simplicity, high efficiency and low cost, the CRISPR/Cas9 technique has rapidly become a focus of attention over the past three years 1,2,[12][13][14][15] . The CRISPR/Cas9 system is composed of Cas9 nuclease and customizable sgRNA. The sgRNA guides Cas9 to recognize target DNA and create double strand breaks (DSBs) which trigger non-homologous end joining (NHEJ) and homologous recombination (HR) repair pathways, resulting in genome modifications 16 . Genome modification is based on the repair of DSBs 11,17 . Because previous reports show that the efficiency of DSB repair pathways differs between species and also cell types 1,17 , it is important to investigate the feasibility of the CRISPR/ Cas9 system in each plant species of interest.To date, the primary application of the CRISPR/Cas9 system in plants has been the creation of gene knock-outs 13,15 . It has been successfully used to induce genetic modification in plants including Arabidopsis 3,[6][7][8][18][19][20] 34 . These reports show that CRISPR/ Cas9-mediated targeted mutagenesis is efficient in plants. Analysis also suggests that the production of mutations by CRISPR/Cas9 in plants is highly specific 20,23 and can be stably transmitted to subsequent generations following classic Mendelian law [18][19][...

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Electron transfer between metal-oxides and supports considerably affects the oxidative desulfurization (ODS) performance of catalysts, while this is far from being well understood. Herein, molybdenum dioxide with oxygen vacancies (V O -MoO 2 ) catalysts derived from Mo-based metal-organic frameworks are anchored on electron-rich nitrogen-doped carbon nanotubes (NC) to obtain excellent ODS activity and reusability. Results show that either dibenzothiophene (DBT) or 4,6-dimethyldibenzothiophene (4,6-DMDBT) is removed 100% on the composite catalyst (V O -MoO 2 @NC) within 40 min of reaction when cumene hydroperoxide is chosen as an oxidant. After five cycles of reaction, DBT and 4,6-DMDBT removal still exceeded 99.5 and 95.0%, respectively. Results from density functional theory calculations and characterizations confirm that the strong electron-donating effect of NC on V O -MoO 2 can promote the dispersion of V O -MoO 2 and reduce the bond energy of the MoO bond, leading to exposure of active sites and enrichment of oxygen vacancies (V O ).Furthermore, the strong interfacial electrostatic interaction caused by the electron transfer from NC to V O -MoO 2 can reduce the leaching of active sites of the catalyst. This study provides a versatile strategy of constructing strong electronic interaction between metal-oxide and support via anchoring on NC for the design of high-performance ODS catalysts.

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