摘要
As one of the largest families of angiosperms,the Orchidaceae family is diverse.Dendrobium represents the second largest genus of the Orchidaceae.However,an assembled high-quality genome of species in this genus is lacking.Here,we report a chromosome-scale reference genome of Dendrobium chrysotoxum,an important ornamental and medicinal orchid species.The assembled genome size of D.chrysotoxum was 1.37 Gb,with a contig N50 value of 1.54 Mb.Of the sequences,95.75%were anchored to 19 pseudochromosomes.There were 30,044 genes predicted in the D.chrysotoxum genome.Two whole-genome polyploidization events occurred in D.chrysotoxum.In terms of the second event,whole-genome duplication(WGD)was also found to have occurred in other Orchidaceae members,which diverged mainly via gene loss immediately after the WGD event occurred;the first duplication was found to have occurred in most monocots(tau event).We identified sugar transporter(SWEET)gene family expansion,which might be related to the abundant medicinal compounds and fleshy stems of D.chrysotoxum.MADS-box genes were identified in D.chrysotoxum,as well as members of TPS and Hsp90 gene families,which are associated with resistance,which may contribute to the adaptive evolution of orchids.We also investigated the interplay among carotenoid,ABA,and ethylene biosynthesis in D.chrysotoxum to elucidate the regulatory mechanisms of the short flowering period of orchids with yellow flowers.The reference D.chrysotoxum genome will provide important insights for further research on medicinal active ingredients and breeding and enhances the understanding of orchid evolution.
基金
This project was supported by the Guangdong Innovation Research Team Fund(2014ZT05S078)
National Natural Science Foundation of China(grants 31571252 and 31772322)
Guangdong Special Support Program for Young Talents in Innovation Research of Science and Technology(2019TQ05N940)
Shenzhen Peacock Grant(827/000189)
Science and Technology Program of Guangdong Province,China(2019B121202006)
Program of Forestry Administration of Guangdong Province(E036011002)
Department for Wildlife and Forest Plant Protection of the National Forest and Grassland Administration(2019073010)
National Key Research and Development Program of China(No.2018YFD1000400)
Special Research Foundation of Hebei Agricultural University(YJ201848)
Natural Science Foundation of Hebei Province(C2019204295).
