Plants belonging to the genus Taraxacum are widespread all over the world,which contain rubber-producing and non-rubberproducing species.However,the genomic basis underlying natural rubber(NR)biosynthesis still needs ...Plants belonging to the genus Taraxacum are widespread all over the world,which contain rubber-producing and non-rubberproducing species.However,the genomic basis underlying natural rubber(NR)biosynthesis still needs more investigation.Here,we presented high-quality genome assemblies of rubber-producing T.kok-saghyz TK1151 and non-rubber-producing T.mongolicum TM5.Comparative analyses uncovered a large number of genetic variations,including inversions,translocations,presence/absence variations,as well as considerable protein divergences between the two species.Two gene duplication events were found in these two Taraxacum species,including one common ancestral whole-genome triplication and one subsequent round of gene amplification.In genomes of both TK1151 and TM5,we identified the genes encoding for each step in the NR biosynthesis pathway and found that the SRPP and CPT gene families have experienced a more obvious expansion in TK1151 compared to TM5.This study will have large-ranging implications for the mechanism of NR biosynthesis and genetic improvement of NR-producing crops.展开更多
Taraxacum kok-saghyz Rodin(TKS)is a promising alternative crop source for producing high-quality natural rubber(NR)and has become an ideal model plant for studying NR biosynthesis,regulation mechanisms,and production....Taraxacum kok-saghyz Rodin(TKS)is a promising alternative crop source for producing high-quality natural rubber(NR)and has become an ideal model plant for studying NR biosynthesis,regulation mechanisms,and production.So far,only a very limited number of functional genes related to NR biosynthesis have been identified in TKS.To achieve a systematic identification of its novel functional genes,we developed a mutant system denoted sense/antisense RNA expression(SARE)and have generated more than 8,000 transgenic TKS plants.A series of mutants with altered phenotypes,particularly changes in NR contents,were identified.To evaluate the efficiency of this library,we chose one mutant,c112,which exhibits a significant increase in NR content,for in-depth characterization.The c112 mutant arose from the sense insertion of a dormancy-associated gene1(DRM1)/auxin repressed protein(ARP)gene,which we named high natural rubber content1(HRC1).In the c112 mutant,the concentrations of NR precursors isopentenyl pyrophosphate and dimethylallyl diphosphate decreased,while geranylgeranyl diphosphate increased,suggesting that HRC1 regulates metabolic flux in NR biosynthesis.In summary,the developed TKS SARE mutant library provides valuable genetic resources for identifying key functional genes to accelerate the domestication of TKS from wild species to economic crops through molecular breeding.展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA24030504 and XDA24040305)the National Natural Science Foundation of China(32000144)the Key Research Program of the Chinese Academy of Sciences(ZDRW-ZS-2018-2)。
文摘Plants belonging to the genus Taraxacum are widespread all over the world,which contain rubber-producing and non-rubberproducing species.However,the genomic basis underlying natural rubber(NR)biosynthesis still needs more investigation.Here,we presented high-quality genome assemblies of rubber-producing T.kok-saghyz TK1151 and non-rubber-producing T.mongolicum TM5.Comparative analyses uncovered a large number of genetic variations,including inversions,translocations,presence/absence variations,as well as considerable protein divergences between the two species.Two gene duplication events were found in these two Taraxacum species,including one common ancestral whole-genome triplication and one subsequent round of gene amplification.In genomes of both TK1151 and TM5,we identified the genes encoding for each step in the NR biosynthesis pathway and found that the SRPP and CPT gene families have experienced a more obvious expansion in TK1151 compared to TM5.This study will have large-ranging implications for the mechanism of NR biosynthesis and genetic improvement of NR-producing crops.
基金supported by grants from the National Key Research and Development Program of China(2023YFA0914801)the National Natural Science Foundation of China(32000312)+1 种基金the Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA24030504 and XDC06010103)。
文摘Taraxacum kok-saghyz Rodin(TKS)is a promising alternative crop source for producing high-quality natural rubber(NR)and has become an ideal model plant for studying NR biosynthesis,regulation mechanisms,and production.So far,only a very limited number of functional genes related to NR biosynthesis have been identified in TKS.To achieve a systematic identification of its novel functional genes,we developed a mutant system denoted sense/antisense RNA expression(SARE)and have generated more than 8,000 transgenic TKS plants.A series of mutants with altered phenotypes,particularly changes in NR contents,were identified.To evaluate the efficiency of this library,we chose one mutant,c112,which exhibits a significant increase in NR content,for in-depth characterization.The c112 mutant arose from the sense insertion of a dormancy-associated gene1(DRM1)/auxin repressed protein(ARP)gene,which we named high natural rubber content1(HRC1).In the c112 mutant,the concentrations of NR precursors isopentenyl pyrophosphate and dimethylallyl diphosphate decreased,while geranylgeranyl diphosphate increased,suggesting that HRC1 regulates metabolic flux in NR biosynthesis.In summary,the developed TKS SARE mutant library provides valuable genetic resources for identifying key functional genes to accelerate the domestication of TKS from wild species to economic crops through molecular breeding.
