Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,...Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this genus.In this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate analyses.Molecular dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle Miocene.Cymbidium spp.migration to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene period.Our analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon intensity.Favorable hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle Miocene.The transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification rates.This study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.展开更多
Cymbidium goeringii is an economically important ornamental plant,and flower color is one of the main features of C.goeringii that contributes to its high economic value.To clarify the molecular mechanisms underlying ...Cymbidium goeringii is an economically important ornamental plant,and flower color is one of the main features of C.goeringii that contributes to its high economic value.To clarify the molecular mechanisms underlying the role of anthocyanins in mediating differences in color among varieties,liquid chromatography–tandem mass spectrometry was used to perform anthocyanin-targeted metabolomics of seven C.goeringii varieties,including‘Jin Qian Yuan’(JQY),‘Jin Xiu Qian Yuan’(JXQY),‘Miao Jiang Su Die’(MJSD),‘Qian Ming Su’(QMS),‘Shi Chan’(SC),and‘Yang Ming Su’(YMS),as well as the C.goeringii.We detected 64 anthocyanins,including cyanidins,delphinidins,malvidins,pelargonidins,peonidins,petunidins,procyanidins,and flavonoids.We identified six shared differentially accumulated metabolites(DAMs),including cyanidin-3-O-rutinoside,delphinidin-3-Osophoroside,pelargonidin-3-O-rutinoside,peonidin-3-O-(6-O-malonyl-beta-D-glucoside),peonidin-3-Osophoroside,and chalcone.Most DAMs were enriched in the anthocyanin biosynthesis pathway.Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the differentially expressed metabolites were significantly enriched in the anthocyanin biosynthesis pathway.Analysis of the content of differentially expressed metabolites indicated that peonidin-3-O-(6-O-malonyl-beta-D-glucoside)was the key metabolite underlying color differences among C.goeringii varieties.Procyanidin B2,pelargonidin-3-O-galactoside,and naringenin might also affect the color formation of JQY and QMS,SC,and MJSD,respectively.The results of this study shed light on the metabolic mechanism underlying flower color differences in C.goeringii at the molecular level.Our findings will aid future studies of the mechanism of flower color regulation in C.goeringii and have implications for the breeding of new varieties.展开更多
The random amplified polymorphic DNA (RAPD) marker was assessed to detect the genetic relationships among 48 hybrid Cymbidium cultivars from Japan, Korea, China, and USA, and 2 species of native Cymbidium. Twenty pr...The random amplified polymorphic DNA (RAPD) marker was assessed to detect the genetic relationships among 48 hybrid Cymbidium cultivars from Japan, Korea, China, and USA, and 2 species of native Cymbidium. Twenty primers were screened from 100 random decamer primers, and a total of 258 DNA bands were amplified, 253 of which (98.1%) were polymorphic. The average number of polymorphic DNA bands amplified by each primer was 12.6. All cultivars were distinguishable when a number of primers were considered. Genetic similarities among the cultivars and species were estimated based on the amount of band sharing ranging from 0.364-0.817 with an average of 0.581. According to the data, a dendrogram of genetic relationship, which was constructed using the UPGMA method, showed that all the tested cultivars and native species were classified into five cluster groups with the similarity coefficient of 0.592. It revealed that the genetic relationships among tested accessions were to some extent related with their origin, flower colour, branch type, and genealogy. It further indicated that the RAPD technique is a useful tool for studying the genetic relationships among hybrid Cymbidium cultivars.展开更多
The floral morphology of Cymbidium ensifolium,a well-known orchid in China,has increasingly attracted horticultural and commercial attention.However,the molecular mechanisms that regulate flower development defects in...The floral morphology of Cymbidium ensifolium,a well-known orchid in China,has increasingly attracted horticultural and commercial attention.However,the molecular mechanisms that regulate flower development defects in C.ensifolium mutants are poorly understood.In this work,we examined a domesticated variety of C.ensifolium named‘CuiYuMuDan',or leaf-like flower mutant,which lacks typical characteristics of orchid floral organs but continues to produce sepal-to leaf-like structures along the inflorescence.We used comparative transcriptome analysis to identify 6234 genes that are differentially expressed between mutant and wild-type flowers.The majority of these differentially expre ssed genes are involved in membrane-building,anabolism regulation,and plant hormone signal transduction,implying that in the leaf-like mutant these processes play roles in the development of flower defects.In addition,we identified 152 differentially expre ssed transcription factors,including the bHLH,MYB,MIKC,and WRKY gene families.Moreover,we found 20 differentially expressed genes that are commonly involved in flower development,including MADS-box genes,CLAVATA3(CLV3),WUSCHEL(WUS),and PERIANTHIA(PAN).Among them,floral homeotic genes were further investigated by phylogenetic analysis and expression validation,which displayed distinctive spatial expression patterns and significant changes between the wild type and the mutant.This is the first report on the C.ensifolium leaf-like flower mutant transcriptome.Our results shed light on the molecular regulation of orchid flower development,and may improve our understanding of floral patterning regulation and advance molecular breeding of Chinese orchids.展开更多
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB31000000)The 14th Five-Year Plan of the Xishuangbanna Tropical Botanical Garden,Chinese Academy of Sciences (XTBG-1450101)+3 种基金the Science and Technology Basic Resources Investigation Program of China (2021FY100200)the Key Basic Research Program of Yunnan Province,China (202101BC070003)the Yunnan Revitalization Talent Support Program"Young Talent"and"Innovation Team"ProjectsEcological and Environmental Conservation Program from the Department of Ecology and Environment of Yunnan Province。
文摘Cymbidium(Orchidaceae:Epidendroideae),with around 60 species,is widely-distributed across Southeast Asia,providing a nice system for studying the processes that underlie patterns of biodiversity in the region.However,phylogenetic relationships of Cymbidium have not been well resolved,hampering investigations of species diversification and the biogeographical history of this genus.In this study,we construct a plastome phylogeny of 56 Cymbidium species,with four well-resolved major clades,which provides a framework for biogeographical and diversification rate analyses.Molecular dating and biogeographical analyses show that Cymbidium likely originated in the region spanning northern IndoBurma to the eastern Himalayas during the early Miocene(~21.10 Ma).It then rapidly diversified into four major clades in East Asia within approximately a million years during the middle Miocene.Cymbidium spp.migration to the adjacent regions(Borneo,Philippines,and Sulawesi)primarily occurred during the Pliocene-Pleistocene period.Our analyses indicate that the net diversification rate of Cymbidium has decreased since its origin,and is positively associated with changes in temperature and monsoon intensity.Favorable hydrothermal conditions brought by monsoon intensification in the early Miocene possibly contributed to the initial rapid diversification,after which the net diversification rate was reduced with the cooling climate after the middle Miocene.The transition from epiphytic to terrestrial habits may have enabled adaptation to cooler environments and colonization of northern niches,yet without a significant effect on diversification rates.This study provides new insights into how monsoon activity and temperature changes affected the diversification dynamics of plants in Southeast Asia.
基金supported by the Study on Resource Collection and New Variety Breeding of the Guizhou Mountainous Characteristic Flower C.goeringii(QianKeHe[2022]General 107)the Key Laboratory of National Forestry and Grassland Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern China,Guizhou Academy of Forestry.
文摘Cymbidium goeringii is an economically important ornamental plant,and flower color is one of the main features of C.goeringii that contributes to its high economic value.To clarify the molecular mechanisms underlying the role of anthocyanins in mediating differences in color among varieties,liquid chromatography–tandem mass spectrometry was used to perform anthocyanin-targeted metabolomics of seven C.goeringii varieties,including‘Jin Qian Yuan’(JQY),‘Jin Xiu Qian Yuan’(JXQY),‘Miao Jiang Su Die’(MJSD),‘Qian Ming Su’(QMS),‘Shi Chan’(SC),and‘Yang Ming Su’(YMS),as well as the C.goeringii.We detected 64 anthocyanins,including cyanidins,delphinidins,malvidins,pelargonidins,peonidins,petunidins,procyanidins,and flavonoids.We identified six shared differentially accumulated metabolites(DAMs),including cyanidin-3-O-rutinoside,delphinidin-3-Osophoroside,pelargonidin-3-O-rutinoside,peonidin-3-O-(6-O-malonyl-beta-D-glucoside),peonidin-3-Osophoroside,and chalcone.Most DAMs were enriched in the anthocyanin biosynthesis pathway.Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the differentially expressed metabolites were significantly enriched in the anthocyanin biosynthesis pathway.Analysis of the content of differentially expressed metabolites indicated that peonidin-3-O-(6-O-malonyl-beta-D-glucoside)was the key metabolite underlying color differences among C.goeringii varieties.Procyanidin B2,pelargonidin-3-O-galactoside,and naringenin might also affect the color formation of JQY and QMS,SC,and MJSD,respectively.The results of this study shed light on the metabolic mechanism underlying flower color differences in C.goeringii at the molecular level.Our findings will aid future studies of the mechanism of flower color regulation in C.goeringii and have implications for the breeding of new varieties.
文摘The random amplified polymorphic DNA (RAPD) marker was assessed to detect the genetic relationships among 48 hybrid Cymbidium cultivars from Japan, Korea, China, and USA, and 2 species of native Cymbidium. Twenty primers were screened from 100 random decamer primers, and a total of 258 DNA bands were amplified, 253 of which (98.1%) were polymorphic. The average number of polymorphic DNA bands amplified by each primer was 12.6. All cultivars were distinguishable when a number of primers were considered. Genetic similarities among the cultivars and species were estimated based on the amount of band sharing ranging from 0.364-0.817 with an average of 0.581. According to the data, a dendrogram of genetic relationship, which was constructed using the UPGMA method, showed that all the tested cultivars and native species were classified into five cluster groups with the similarity coefficient of 0.592. It revealed that the genetic relationships among tested accessions were to some extent related with their origin, flower colour, branch type, and genealogy. It further indicated that the RAPD technique is a useful tool for studying the genetic relationships among hybrid Cymbidium cultivars.
基金grants from National Key R&D Program(2018YFD1000404)the National Natural Science Foundation of China(31672184)+3 种基金the Natural Science Foundation of Guangdong Province(2017A030312004)Guangzhou Science and Technology Project(201707010307,201904020026)Innovation Team of Modern Agricultural Industry Technology System in Guangdong Province(2019KJ121)the Guangdong Academy of Agricultural Sciences Discipline Team Construction Project(201612TD,2017A070702008,201721).
文摘The floral morphology of Cymbidium ensifolium,a well-known orchid in China,has increasingly attracted horticultural and commercial attention.However,the molecular mechanisms that regulate flower development defects in C.ensifolium mutants are poorly understood.In this work,we examined a domesticated variety of C.ensifolium named‘CuiYuMuDan',or leaf-like flower mutant,which lacks typical characteristics of orchid floral organs but continues to produce sepal-to leaf-like structures along the inflorescence.We used comparative transcriptome analysis to identify 6234 genes that are differentially expressed between mutant and wild-type flowers.The majority of these differentially expre ssed genes are involved in membrane-building,anabolism regulation,and plant hormone signal transduction,implying that in the leaf-like mutant these processes play roles in the development of flower defects.In addition,we identified 152 differentially expre ssed transcription factors,including the bHLH,MYB,MIKC,and WRKY gene families.Moreover,we found 20 differentially expressed genes that are commonly involved in flower development,including MADS-box genes,CLAVATA3(CLV3),WUSCHEL(WUS),and PERIANTHIA(PAN).Among them,floral homeotic genes were further investigated by phylogenetic analysis and expression validation,which displayed distinctive spatial expression patterns and significant changes between the wild type and the mutant.This is the first report on the C.ensifolium leaf-like flower mutant transcriptome.Our results shed light on the molecular regulation of orchid flower development,and may improve our understanding of floral patterning regulation and advance molecular breeding of Chinese orchids.