A high-quality Actinidia chinensis(kiwifruit)genome

Actinidia chinensis(kiwifruit)is a perennial horticultural crop species of the Actinidiaceae family with high nutritional and economic value.Two versions of the A.chinensis genomes have been previously assembled,based mainly on relatively short reads.Here,we report an improved chromosome-level reference genome of A.chinensis(v3.0),based mainly on PacBio long reads and Hi-C data.The high-quality assembled genome is 653 Mb long,with 0.76%heterozygosity.At least 43%of the genome consists of repetitive sequences,and the most abundant long terminal repeats were further identified and account for 23.38%of our novel genome.It has clear improvements in contiguity,accuracy,and gene annotation over the two previous versions and contains 40,464 annotated protein-coding genes,of which 94.41%are functionally annotated.Moreover,further analyses of genetic collinearity revealed that the kiwifruit genome has undergone two whole-genome duplications:one affecting all Ericales families near the K-T extinction event and a recent genus-specific duplication.The reference genome presented here will be highly useful for further molecular elucidation of diverse traits and for the breeding of this horticultural crop,as well as evolutionary studies with related taxa.

A chromosome-scale genome assembly of Isatis indigotica,an important medicinal plant used in traditional Chinese medicine

Isatis indigotica(2n=14)is an important medicinal plant in China.Its dried leaves and roots(called Isatidis Folium and Isatidis Radix,respectively)are broadly used in traditional Chinese medicine for curing diseases caused by bacteria and viruses such as influenza and viral pneumonia.Various classes of compounds isolated from this species have been identified as effective ingredients.Previous studies based on transcriptomes revealed only a few candidate genes for the biosynthesis of these active compounds in this medicinal plant.Here,we report a high-quality chromosome-scale genome assembly of I.indigotica with a total size of 293.88 Mb and scaffold N50=36.16 Mb using single-molecule real-time long reads and high-throughput chromosome conformation capture techniques.We annotated 30,323 highconfidence protein-coding genes.Based on homolog searching and functional annotations,we identified many candidate genes involved in the biosynthesis of main active components such as indoles,terpenoids,and phenylpropanoids.In addition,we found that some key enzyme-coding gene families related to the biosynthesis of these components were expanded due to tandem duplications,which likely drove the production of these major active compounds and explained why I.indigotica has excellent antibacterial and antiviral activities.Our results highlighted the importance of genome sequencing in identifying candidate genes for metabolite synthesis in medicinal plants.

Microstructure refinement-homogenization and flexural strength improvement of Al_(2)O_(3) ceramics fabricated by DLP-stereolithography integrated with chemical precipitation coating process

In this study,the chemical precipitation coating(CP)process was creatively integrated with DLP-stereolithography based 3D printing for refining and homogenizing the microstructure of 3D printed Al_(2)O_(3) ceramic.Based on this novel approach,Al_(2)O_(3)powder was coated with a homogeneous layer of amorphous Y2O3,with the coated AI2O3 powder found to make the microstructure of 3D printed Al_(2)O_(3) ceramic more uniform and refined,as compared with the conventional mechanical mixing(MM)of Al_(2)O_(3) and Y_(2)O_(3) powders.The grain size of Al_(2)O_(3) in Sample CP is 64.44%and 51.43%lower than those in the monolithic Al_(2)O_(3) ceramic and Sample MM,respectively.Sample CP has the highest flexural strength of 455.37±32.17 MPa,which is 14.85%and 25.45%higher than those of Samples MM and AL,respectively;also Sample CP has the highest Weibull modulus of 16.88 among the three kinds of samples.Moreover,the fine grained Sample CP has a close thermal conductivity to the coarse grained Sample MM because of the changes in morphology of Y_(3)Al_(5)O_(12) phase from semi-connected(Sample MM)to isolated(Sample CP).Finally,specially designed fin-type Al_(2)O_(3) ceramic heat sinks were successfully fabricated via the novel integrated process,which has been proven to be an effective method for fabricating complex-shaped Al_(2)O_(3) ceramic components with enhanced flexural strength and reliability.