Yellowhorn(Xanthoceras sorbifolium), especially its varieties, is the red petal yellowhorn(X. sorbifolium var. purpurea), an important tree species with great ornamental value, and its flower petals change color throu...Yellowhorn(Xanthoceras sorbifolium), especially its varieties, is the red petal yellowhorn(X. sorbifolium var. purpurea), an important tree species with great ornamental value, and its flower petals change color throughout the flowering period. In this study, we mainly focused on the mechanism of the petal color change with transcriptomics and metabolomics data. A phased chromosome-scale assembly of the red petal yellowhorn genome was generated using the PacBio high-fidelity reads, Illumina short reads, and Phase genomics Proximo Hi-C data. The final de novo assembly yielded 533.67 Mb with a contig N50 of 5.42 Mb, and 27 501 protein-coding genes were predicted. Notably, an alternate haplotig assembly was also obtained. Furthermore, a variation database for the alleles within the genome was constructed. Subsequently, the expression pattern of flower pigmentation-related genes and allelic expression imbalance events were investigated. Apart from 6 genes involved in the anthocyanin biosynthesis pathway regulated by the activation of 15 MYB-bHLH-WD40s, the increased expression of senescencerelated gene 1(SRG1) and 2-oxoglutarate-dependent dioxygenase(DIOX5) might also result in decreasing content of lutein and increasing abundance of(E/Z)-phytoene, cyanidin-3-O-rutinoside, and cyanidin-3-O-sambubioside. These changes in genes and metabolites were most likely related to the petal color change in red petal yellowhorn. This phased chromosome-scale genome assembly provides more accurate genomic information for future molecular breeding and facilitates allele function studies of the red petal yellowhorn.展开更多
Although a few cases of genetic epistasis in plants have been reported, the combined analysis of genetically phenotypic segregation and the related molecular mechanism remains rarely studied. Here, we have identified ...Although a few cases of genetic epistasis in plants have been reported, the combined analysis of genetically phenotypic segregation and the related molecular mechanism remains rarely studied. Here, we have identified a gene(named GaPC) controlling petal coloration in Gossypium arboreum and following a heritable recessive epistatic genetic model. Petal coloration is controlled by a single dominant gene,GaPC. A loss-of-function mutation of GaPC leads to a recessive gene Gapc that masks the phenotype of other color genes and shows recessive epistatic interactions. Map-based cloning showed that GaPC encodes an R2R3-MYB transcription factor. A 4814-bp long terminal repeat retrotransposon insertion at the second exon led to GaPC loss of function and disabled petal coloration. GaPC controlled petal coloration by regulating the anthocyanin and flavone biosynthesis pathways. Expression of core genes in the phenylpropanoid and anthocyanin pathways was higher in colored than in white petals. Petal color was conferred by flavonoids and anthocyanins, with red and yellow petals rich in anthocyanin and flavonol glycosides, respectively. This study provides new insight on molecular mechanism of recessive epistasis,also has potential breeding value by engineering GaPC to develop colored petals or fibers for multifunctional utilization of cotton.展开更多
Petal color change, a common phenomenon in angiosperms, is induced by various environmental and endogenous factors. Interestingly, this phenomenon is important for attracting pollinators and further reproductive succe...Petal color change, a common phenomenon in angiosperms, is induced by various environmental and endogenous factors. Interestingly, this phenomenon is important for attracting pollinators and further reproductive success. Quisqualis indica L.(Combretaceae) is a tropical Asian climber that undergoes sequential petal color change from white to pink to red. This color changing process is thought to be a good strategy to attract more pollinators. However, the underlying physiological and biochemical mechanisms driving this petal color change phenomenon is still underexplored. In this context, we investigated whether changes in pH, pollination, light, temperature or ethylene mediate petal color change. We found that the detected changes in petal pH were not significant enough to induce color alterations. Additionally, pollination and temperatures of 20-30℃did not alter the rate of petal color change; however, flowers did not open when exposed to constant temperatures at 15℃ or 35℃.Moreover, the application of ethylene inhibitor, i.e., silver thiosulphate, did not prevent color change. It is worth mentioning here that in our study we found light as a strong factor influencing the whole process of petal color change, as petals remained white under dark conditions. Altogether, the present study suggests that petal color change in Q. indica is induced by light and not by changes in petal pH, pollination, ethylene, or temperature, while extremely low or high temperatures affect flower anthesis. In summary, our findings represent the probable mechanism underlying the phenomenon of petal color change, which is important for understanding flower color evolution.展开更多
基金supported by the Central PublicInterest Scientific Institution Basal Research Fund (Grant No. CAFYBB2020QB001)the National Natural Science Foundation of China (Grant No. 31800571)。
文摘Yellowhorn(Xanthoceras sorbifolium), especially its varieties, is the red petal yellowhorn(X. sorbifolium var. purpurea), an important tree species with great ornamental value, and its flower petals change color throughout the flowering period. In this study, we mainly focused on the mechanism of the petal color change with transcriptomics and metabolomics data. A phased chromosome-scale assembly of the red petal yellowhorn genome was generated using the PacBio high-fidelity reads, Illumina short reads, and Phase genomics Proximo Hi-C data. The final de novo assembly yielded 533.67 Mb with a contig N50 of 5.42 Mb, and 27 501 protein-coding genes were predicted. Notably, an alternate haplotig assembly was also obtained. Furthermore, a variation database for the alleles within the genome was constructed. Subsequently, the expression pattern of flower pigmentation-related genes and allelic expression imbalance events were investigated. Apart from 6 genes involved in the anthocyanin biosynthesis pathway regulated by the activation of 15 MYB-bHLH-WD40s, the increased expression of senescencerelated gene 1(SRG1) and 2-oxoglutarate-dependent dioxygenase(DIOX5) might also result in decreasing content of lutein and increasing abundance of(E/Z)-phytoene, cyanidin-3-O-rutinoside, and cyanidin-3-O-sambubioside. These changes in genes and metabolites were most likely related to the petal color change in red petal yellowhorn. This phased chromosome-scale genome assembly provides more accurate genomic information for future molecular breeding and facilitates allele function studies of the red petal yellowhorn.
基金supported by the Fundamental Research Funds for the Central Universities(KYZZ2022003)Jiangsu Collaborative Innovation Center for Modern Crop Production project (No.10)。
文摘Although a few cases of genetic epistasis in plants have been reported, the combined analysis of genetically phenotypic segregation and the related molecular mechanism remains rarely studied. Here, we have identified a gene(named GaPC) controlling petal coloration in Gossypium arboreum and following a heritable recessive epistatic genetic model. Petal coloration is controlled by a single dominant gene,GaPC. A loss-of-function mutation of GaPC leads to a recessive gene Gapc that masks the phenotype of other color genes and shows recessive epistatic interactions. Map-based cloning showed that GaPC encodes an R2R3-MYB transcription factor. A 4814-bp long terminal repeat retrotransposon insertion at the second exon led to GaPC loss of function and disabled petal coloration. GaPC controlled petal coloration by regulating the anthocyanin and flavone biosynthesis pathways. Expression of core genes in the phenylpropanoid and anthocyanin pathways was higher in colored than in white petals. Petal color was conferred by flavonoids and anthocyanins, with red and yellow petals rich in anthocyanin and flavonol glycosides, respectively. This study provides new insight on molecular mechanism of recessive epistasis,also has potential breeding value by engineering GaPC to develop colored petals or fibers for multifunctional utilization of cotton.
基金funded by a grant from the National Nature Science Foundation of China(31670393 and 31170406)that was awarded to L.Zhang
文摘Petal color change, a common phenomenon in angiosperms, is induced by various environmental and endogenous factors. Interestingly, this phenomenon is important for attracting pollinators and further reproductive success. Quisqualis indica L.(Combretaceae) is a tropical Asian climber that undergoes sequential petal color change from white to pink to red. This color changing process is thought to be a good strategy to attract more pollinators. However, the underlying physiological and biochemical mechanisms driving this petal color change phenomenon is still underexplored. In this context, we investigated whether changes in pH, pollination, light, temperature or ethylene mediate petal color change. We found that the detected changes in petal pH were not significant enough to induce color alterations. Additionally, pollination and temperatures of 20-30℃did not alter the rate of petal color change; however, flowers did not open when exposed to constant temperatures at 15℃ or 35℃.Moreover, the application of ethylene inhibitor, i.e., silver thiosulphate, did not prevent color change. It is worth mentioning here that in our study we found light as a strong factor influencing the whole process of petal color change, as petals remained white under dark conditions. Altogether, the present study suggests that petal color change in Q. indica is induced by light and not by changes in petal pH, pollination, ethylene, or temperature, while extremely low or high temperatures affect flower anthesis. In summary, our findings represent the probable mechanism underlying the phenomenon of petal color change, which is important for understanding flower color evolution.
