Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig ...Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig production.R2R3-MYB transcription factors have promotive or repressive regulatory roles in plant anthocyanin biosynthesis.In this study,113 R2R3-MYB genes were identified in Ficus carica,3 of which were assigned to the S4 subfamily of flavonoid-biosynthesis repressors.FcMYB57 was further recruited as a candidate anthocyaninbiosynthesis repressor based on its sequence features and expression,which was significantly negatively correlated with that of anthocyanin-biosynthesis structural genes.Transient overexpression of FcMYB57 in strawberry totally inhibited fruit pigmentation and significantly increased fruit firmness.The metabolomic analysis confirmed a significant reduction in the contents of cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside,as well as other flavonoids,and transmission electron microscopy revealed an increment in cell-wall thickness.Transcriptome analysis showed downregulation of anthocyanin-biosynthesis structural genes and upregulation of genes related to xylan synthesis.Yeast one-hybrid and dual luciferase assays demonstrated a negative regulatory effect of FcMYB57 on the promoter of FcUFGT3(UDP glucose-flavonoid 3-O-glcosyl-transferase).Yeast two-hybrid assay showed that FcMYB57 does not interact with FcbHLH42,3,14,MYC2,or FcTTG1,all of which have a previously identified or predicted role in flavonoid biosynthesis,however,interaction was detected with FcTPL(Topless),suggesting that FcMYB57 serves as an active repressor of anthocyanin biosynthesis.This is the first identification of an anthocyaninbiosynthesis repressor in fig,with a possible role in fig fruit quality.展开更多
The genetic code,once believed to be universal and immutable,is now known to contain many variations and is not quite universal.The basis for genome recoding strategy is genetic code variation that can be harnessed to...The genetic code,once believed to be universal and immutable,is now known to contain many variations and is not quite universal.The basis for genome recoding strategy is genetic code variation that can be harnessed to improve cellular properties.Thus,genome recoding is a promising strategy for the enhancement of genome flexibility,allowing for novel functions that are not commonly documented in the organism in its natural environment.Here,the basic concept of genetic code and associated mechanisms for the generation of genetic codon variants,including biased codon usage,codon reassignment,and ambiguous decoding,are extensively discussed.Knowledge of the concept of natural genetic code expansion is also detailed.The generation of recoded organisms and associated mechanisms with basic targeting components,including aminoacyl-tRNA synthetase–tRNA pairs,elongation factor EF-Tu and ribosomes,are highlighted for a comprehensive understanding of this concept.The research associated with the generation of diverse recoded organisms is also discussed.The success of genome recoding in diverse multicellular organisms offers a platform for expanding protein chemistry at the biochemical level with non-canonical amino acids,genetically isolating the synthetic organisms from the natural ones,and fighting viruses,including SARS-CoV2,through the creation of attenuated viruses.In conclusion,genome recoding can offer diverse applications for improving cellular properties in the genome-recoded organisms.展开更多
基金supported by the key research project for fig development of Weiyuan County(Grant No.1002-69199007),China.
文摘Dry fig is a traditional healthy snack and has important economic value in a number of Mediterranean and Middle Eastern countries.Cultivars with no anthocyanin accumulation in the fruit peel are preferred for dry fig production.R2R3-MYB transcription factors have promotive or repressive regulatory roles in plant anthocyanin biosynthesis.In this study,113 R2R3-MYB genes were identified in Ficus carica,3 of which were assigned to the S4 subfamily of flavonoid-biosynthesis repressors.FcMYB57 was further recruited as a candidate anthocyaninbiosynthesis repressor based on its sequence features and expression,which was significantly negatively correlated with that of anthocyanin-biosynthesis structural genes.Transient overexpression of FcMYB57 in strawberry totally inhibited fruit pigmentation and significantly increased fruit firmness.The metabolomic analysis confirmed a significant reduction in the contents of cyanidin-3-O-glucoside and pelargonidin-3-O-glucoside,as well as other flavonoids,and transmission electron microscopy revealed an increment in cell-wall thickness.Transcriptome analysis showed downregulation of anthocyanin-biosynthesis structural genes and upregulation of genes related to xylan synthesis.Yeast one-hybrid and dual luciferase assays demonstrated a negative regulatory effect of FcMYB57 on the promoter of FcUFGT3(UDP glucose-flavonoid 3-O-glcosyl-transferase).Yeast two-hybrid assay showed that FcMYB57 does not interact with FcbHLH42,3,14,MYC2,or FcTTG1,all of which have a previously identified or predicted role in flavonoid biosynthesis,however,interaction was detected with FcTPL(Topless),suggesting that FcMYB57 serves as an active repressor of anthocyanin biosynthesis.This is the first identification of an anthocyaninbiosynthesis repressor in fig,with a possible role in fig fruit quality.
文摘The genetic code,once believed to be universal and immutable,is now known to contain many variations and is not quite universal.The basis for genome recoding strategy is genetic code variation that can be harnessed to improve cellular properties.Thus,genome recoding is a promising strategy for the enhancement of genome flexibility,allowing for novel functions that are not commonly documented in the organism in its natural environment.Here,the basic concept of genetic code and associated mechanisms for the generation of genetic codon variants,including biased codon usage,codon reassignment,and ambiguous decoding,are extensively discussed.Knowledge of the concept of natural genetic code expansion is also detailed.The generation of recoded organisms and associated mechanisms with basic targeting components,including aminoacyl-tRNA synthetase–tRNA pairs,elongation factor EF-Tu and ribosomes,are highlighted for a comprehensive understanding of this concept.The research associated with the generation of diverse recoded organisms is also discussed.The success of genome recoding in diverse multicellular organisms offers a platform for expanding protein chemistry at the biochemical level with non-canonical amino acids,genetically isolating the synthetic organisms from the natural ones,and fighting viruses,including SARS-CoV2,through the creation of attenuated viruses.In conclusion,genome recoding can offer diverse applications for improving cellular properties in the genome-recoded organisms.
