Efficient generation of targeted point mutations in the Brassica oleracea var.botrytis genome via a modified CRISPR/Cas9 system

In this study,we used the modified CRISPR/Cas9 system to produce targeted point mutations in cauliflower.Acetolactate synthase(ALS)and Centromere-specific histone H3 variant(CENH3)genes were selected as the base-editing targets and hypocotyls of cauliflower were used as explants.For ALS gene,a C-to-T conversion in the Pro182 codon(CCT)can alter the encoded amino acid,likely resulting in herbicide resistance,and a C-to-T mutation in the Leu133 codon(CTT)in the CENH3 gene may produce a haploid inducer.Results indicated that the transformation efficiency was 1.8%–4.5%and the mutation efficiencies for the ALS and CENH3 genes were approximately 22%and 87%,respectively.The ALS mutant cauliflower showed strong herbicide resistance,with possible immediate implications for broadleaf weed control in cauliflower fields.

A graph-based pan-genome of Brassica oleracea provides new insights into its domestication and morphotype diversification

The domestication of Brassica oleracea has resulted in diverse morphological types with distinct patterns of organ development.Here we report a graph-based pan-genome of B.oleracea constructed from high-quality genome assemblies of different morphotypes.The pan-genome harbors over 200 structural variant hotspot regions enriched in auxin-andflowering-related genes.Population genomic analyses revealed that early domestication of B.oleracea focused on leaf or stem development.Geneflows resulting from agricultural practices and variety improvement were detected among different morphotypes.Selective-sweep and pan-genome analyses identified an auxin-responsive small auxin up-regulated RNA gene and a CLAV-ATA3/ESR-RELATED family gene as crucial players in leaf–stem differentiation during the early stage of B.oleracea domestication and the BoKAN1 gene as instrumental in shaping the leafy heads of cabbage and Brussels sprouts.Our pan-genome and functional analyses further revealed that variations in the BoFLC2 gene play key roles in the divergence of vernalization andflowering characteristics among different morphotypes,and variations in thefirst intron of BoFLC3 are involved infine-tuning theflowering process in cauliflower.This study provides a comprehensive understanding of the pan-genome of B.oleracea and sheds light on the domestication and differential organ development of this globally important crop species.

Controlled fabrication of nanoscale wrinkle structure by fluorocarbon plasma for highly transparent triboelectric nanogenerator

In this paper,we report a novel nanoscale wrinkle-structure fabrication process using fluorocarbon plasma on poly(dimethylsiloxane)(PDMS)and Solaris membranes.Wrinkles with wavelengths of hundreds of nanometers were obtained on these two materials,showing that the fabrication process was universally applicable.By varying the plasma-treating time,the wavelength of the wrinkle structure could be controlled.Highly transparent membranes with wrinkle patterns were obtained when the plasmatreating time was o125 s.The transmittances of these membranes were 490%in the visible region,making it difficult to distinguish them from a flat membrane.The deposited fluorocarbon polymer also dramatically reduced the surface energy,which allowed us to replicate the wrinkle pattern with high precision onto other membranes without any surfactant coating.The combined advantages of high electron affinity and high transparency enabled the fabricated membrane to improve the performance of a triboelectric nanogenerator.This nanoscale,single-step,and universal wrinkle-pattern fabrication process,with the functionality of high transparency and ultra-low surface energy,shows an attractive potential for future applications in microand nanodevices,especially in transparent energy harvesters.

Self-Powered Intelligent Human-Machine Interaction for Handwriting Recognition

Handwritten signatures widely exist in our daily lives.The main challenge of signal recognition on handwriting is in the development of approaches to obtain information effectively.External mechanical signals can be easily detected by triboelectric nanogenerators which can provide immediate opportunities for building new types of active sensors capable of recording handwritten signals.In this work,we report an intelligent human-machine interaction interface based on a triboelectric nanogenerator.Using the horizontal-vertical symmetrical electrode array,the handwritten triboelectric signal can be recorded without external energy supply.Combined with supervised machine learning methods,it can successfully recognize handwritten English letters,Chinese characters,and Arabic numerals.The principal component analysis algorithm preprocesses the triboelectric signal data to reduce the complexity of the neural network in the machine learning process.Further,it can realize the anticounterfeiting recognition of writing habits by controlling the samples input to the neural network.The results show that the intelligent human-computer interaction interface has broad application prospects in signature security and humancomputer interaction.