Dendrobium officinale,an important medicinal plant of the genus Dendrobium in Orchidaceae family,has been used as traditional Chinese medicine(TCM)for nearly thousands of years.Here,we report the first chromosome-leve...Dendrobium officinale,an important medicinal plant of the genus Dendrobium in Orchidaceae family,has been used as traditional Chinese medicine(TCM)for nearly thousands of years.Here,we report the first chromosome-level reference genome of D.officinale,based on Pac Bio long-reads,Illumina short-reads and HiC data.The high-quality assembled genome is 1.23 Gb long,with contig N50 of 1.44 Mb.A total of 93.53%genome sequences were assembled into 19 pseudochromosomes with a super scaffold N50 of 63.07 Mb.Through comparative genomic analysis,we explored the expanded gene families of D.officinale,and also their impact on environmental adaptation and biosynthesis of secondary metabolites.We further performed detailed transcriptional analysis of D.officinale,and identified the candidate genes involved in the biosynthesis of three main active ingredients,including polysaccharides,alkaloids and flavonoids.In addition,the MODIFYING WALL LIGNIN-1(MWL1)gene,which inferred from Genome-Wide Association Studies(GWAS)based on the resequencing date from D.officinale and five related species and their morphologic features,may contribute to the plant production(yield of stems)of D.officinale.Therefore,the high-quality reference genome reported in this study could benefits functional genomics research and molecular breeding of D.officinale.展开更多
The superlattice La-Y-Ni-based hydrogen storage alloys have high discharge capacity and are easy to prepare.However,there is still a gap in commercial applications because of the severe corrosion of the alloys in elec...The superlattice La-Y-Ni-based hydrogen storage alloys have high discharge capacity and are easy to prepare.However,there is still a gap in commercial applications because of the severe corrosion of the alloys in electrolyte and poor high-rate dischargeability(HRD).Therefore,(LaSmY)(NiMnAl)_(3.5) alloy was prepared by magnetic levitation induction melting,and then the alloy was coated with different contents(0.1 wt%-1.0 wt%) of nano-carbons by low-temperature sintering with sucrose as the carbon source in this work.The results show that the cyclic stability and HRD of the alloy first increase and then decrease with the increase of carbon contents.The kinetic results show that the electrocatalytic activity and conductivity of the alloy electrodes can be enhanced by carbon coating.The electrochemical properties of the alloy are the best when the carbon coating content is 0.3 wt%.Compared with the uncoated alloy,the maximum discharge capacity(C_(max)) improves from 354.5 to 359.0 mAh/g,the capacity retention rate after 300 cycles(S_(300)) enhances from 73.15% to 80.01%,and the HRD_(1200) of the alloy enhances from 74.39% to 74.39%.展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant No.31900268,31670330 and 32070353)Natural Science Foundation of Jiangsu Province,China(BK20190699)Natural science fund for colleges and universities in Jiangsu Province,China(19KJB180005)
文摘Dendrobium officinale,an important medicinal plant of the genus Dendrobium in Orchidaceae family,has been used as traditional Chinese medicine(TCM)for nearly thousands of years.Here,we report the first chromosome-level reference genome of D.officinale,based on Pac Bio long-reads,Illumina short-reads and HiC data.The high-quality assembled genome is 1.23 Gb long,with contig N50 of 1.44 Mb.A total of 93.53%genome sequences were assembled into 19 pseudochromosomes with a super scaffold N50 of 63.07 Mb.Through comparative genomic analysis,we explored the expanded gene families of D.officinale,and also their impact on environmental adaptation and biosynthesis of secondary metabolites.We further performed detailed transcriptional analysis of D.officinale,and identified the candidate genes involved in the biosynthesis of three main active ingredients,including polysaccharides,alkaloids and flavonoids.In addition,the MODIFYING WALL LIGNIN-1(MWL1)gene,which inferred from Genome-Wide Association Studies(GWAS)based on the resequencing date from D.officinale and five related species and their morphologic features,may contribute to the plant production(yield of stems)of D.officinale.Therefore,the high-quality reference genome reported in this study could benefits functional genomics research and molecular breeding of D.officinale.
基金The financial supports provided by the National Key R&D Program of China (2019YFE0103600)。
文摘The superlattice La-Y-Ni-based hydrogen storage alloys have high discharge capacity and are easy to prepare.However,there is still a gap in commercial applications because of the severe corrosion of the alloys in electrolyte and poor high-rate dischargeability(HRD).Therefore,(LaSmY)(NiMnAl)_(3.5) alloy was prepared by magnetic levitation induction melting,and then the alloy was coated with different contents(0.1 wt%-1.0 wt%) of nano-carbons by low-temperature sintering with sucrose as the carbon source in this work.The results show that the cyclic stability and HRD of the alloy first increase and then decrease with the increase of carbon contents.The kinetic results show that the electrocatalytic activity and conductivity of the alloy electrodes can be enhanced by carbon coating.The electrochemical properties of the alloy are the best when the carbon coating content is 0.3 wt%.Compared with the uncoated alloy,the maximum discharge capacity(C_(max)) improves from 354.5 to 359.0 mAh/g,the capacity retention rate after 300 cycles(S_(300)) enhances from 73.15% to 80.01%,and the HRD_(1200) of the alloy enhances from 74.39% to 74.39%.
