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
Rosa sterilis S.D.Shi is an important economic tree in China that produces fruits with high nutritional and medicinal value.Many of R.sterills’organs are covered with different types of trichomes or prickles that dir...Rosa sterilis S.D.Shi is an important economic tree in China that produces fruits with high nutritional and medicinal value.Many of R.sterills’organs are covered with different types of trichomes or prickles that directly affect fruit appearance and plant management.This study used RNA sequencing technology to analyze the transcriptomes of two parts of the inflorescence branch,namely inflorescence stems with flagellated trichomes and pedicels with both flagellated and glandular trichomes.Comparative transcriptomic analysis showed that many transcription factors(TFs)are potentially involved in the formation and development of trichomes.The accumulation of RsETC1,a TF of the R3-MYB family,was significantly higher in inflorescence stems than in pedicels;quantitative reverse transcription PCR(qRTPCR)verified that its expression was significantly higher in inflorescence stems than in pedicels during the first three development stages,indicating its inhibitory action on the initiation of glandular trichomes in R.sterilis.The mRNA level of RsETC1 accumulated to significantly higher levels in trichomeless tissues than in tissues with trichromes,suggesting that this gene may inhibit the formation of trichomes in R.sterilis.Over-expression of RsETC1 in Arabidopsis resulted in glabrous phenotypes,and the expression of trichome-related endogenous genes,except for TTG1,was markedly reduced.In addition,the contents of the phytohormones jasmonic acid(JA),gibberellin A3(GA_(3)),and cytokinins(CKs)in pedicels were significantly higher than those in inflorescence stems,and the expression patterns of the genes related to hormone biosynthesis and signal transduction presented consistent responses,suggesting that the transduction of these hormones might be crucial for trichome initiation and development.These data provide a new perspective for revealing the molecular mechanism of trichome formation in R.sterilis.展开更多
Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and...Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and M2PK on the transcription of human immunodeficiency virus type 1(HIV-1)was tested.The results indicated that M2PK could enhance HIV-1 transcription from its long terminal repeat(LTR)promoter,while RPK did not have such an effect.Specific down-regulation of M2PK could inhibit HIV-1 transcription from its LTR region.Furthermore,it was found that the C terminal region of M2PK is responsible for this effect.Collectively,the cellular factor M2PK that is expressed in thymocytes could facilitate the transcription of HIV-1.展开更多
目的:构建大鼠线粒体转录因子TFAM(A)、线粒体转录因子TFB1M(B1)、线粒体转录TFB2M(B2)及线粒体RNA聚合酶(POLRMT)的质粒标准品,为检测内耳细胞线粒体TFAM、TFB1M、TFB2M、POLRMT的mRNA表达水平做基础。方法:设计特异性引物和探针,提取...目的:构建大鼠线粒体转录因子TFAM(A)、线粒体转录因子TFB1M(B1)、线粒体转录TFB2M(B2)及线粒体RNA聚合酶(POLRMT)的质粒标准品,为检测内耳细胞线粒体TFAM、TFB1M、TFB2M、POLRMT的mRNA表达水平做基础。方法:设计特异性引物和探针,提取大鼠内耳组织总mRNA逆转录成c DNA,PCR扩增、纯化目的片段,将纯化产物与p Zero Back/blunt载体重组,提取重组质粒,经测序鉴定后,用实时荧光绝对定量PCR建立标准曲线。结果:测序结果与各目的序列一致,获得良好的标准曲线(R2>0.99)。结论:成功构建了各目的基因的质粒标准品。展开更多
The alternative splicing of select genes is an important mechanism to regulate responses to endogenous and environmental signals in plants.However,the role of alternative splicing in regulating fruit ripening remains ...The alternative splicing of select genes is an important mechanism to regulate responses to endogenous and environmental signals in plants.However,the role of alternative splicing in regulating fruit ripening remains unclear.Here,we discovered that MaMYB16L,an R1-type MYB transcription factor,undergoes alternative splicing and generates two transcripts,the full-length isoform MaMYB16L and a truncated form MaMYB16S,in banana fruit.During banana fruit ripening,the alternative splicing process intensifies with downregulated MaMYB16L and upregulated MaMYB16S.Moreover,MaMYB16L is a transcriptional repressor that directly binds with the promoters of many genes associated with starch degradation and MaDREB2,a positive ripening regulator,and represses their expression.In contrast,MaMBY16S lacks a DNA-binding domain but competitively combines and forms non-functional heterodimers with functional MaMYB16L.MaMYB16L-MaMYB16S heterodimers decrease the binding capacity and transrepression activity of MaMYB16L.The downregulation of MaMYB16L and the upregulation of MaMYB16S,that is,a decreased ratio of active to non-active isoforms,facilitates the activation of ripening-related genes and thereby promotes fruit ripening.Furthermore,the transient overexpression of MaMYB16S promotes banana fruit ripening,whereas the overexpression of MaMYB16L delays this process.Therefore,the alternative splicing of MaMYB16L might generate a self-controlled regulatory loop to regulate banana fruit ripening.展开更多
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supported by grants from the Joint Fund of the National Natural Science Foundation of China and the Karst Science Research Center of Guizhou Province,China(U1812401)the Talent Project of Guizhou Province,China(20164016)。
文摘Rosa sterilis S.D.Shi is an important economic tree in China that produces fruits with high nutritional and medicinal value.Many of R.sterills’organs are covered with different types of trichomes or prickles that directly affect fruit appearance and plant management.This study used RNA sequencing technology to analyze the transcriptomes of two parts of the inflorescence branch,namely inflorescence stems with flagellated trichomes and pedicels with both flagellated and glandular trichomes.Comparative transcriptomic analysis showed that many transcription factors(TFs)are potentially involved in the formation and development of trichomes.The accumulation of RsETC1,a TF of the R3-MYB family,was significantly higher in inflorescence stems than in pedicels;quantitative reverse transcription PCR(qRTPCR)verified that its expression was significantly higher in inflorescence stems than in pedicels during the first three development stages,indicating its inhibitory action on the initiation of glandular trichomes in R.sterilis.The mRNA level of RsETC1 accumulated to significantly higher levels in trichomeless tissues than in tissues with trichromes,suggesting that this gene may inhibit the formation of trichomes in R.sterilis.Over-expression of RsETC1 in Arabidopsis resulted in glabrous phenotypes,and the expression of trichome-related endogenous genes,except for TTG1,was markedly reduced.In addition,the contents of the phytohormones jasmonic acid(JA),gibberellin A3(GA_(3)),and cytokinins(CKs)in pedicels were significantly higher than those in inflorescence stems,and the expression patterns of the genes related to hormone biosynthesis and signal transduction presented consistent responses,suggesting that the transduction of these hormones might be crucial for trichome initiation and development.These data provide a new perspective for revealing the molecular mechanism of trichome formation in R.sterilis.
基金This work was supported by the National Basic Research Program of China(973 Program)(No.2006CB504305)National Special Research Program of Major Infectious Diseases(No.2008ZX10001-002)the 111 Project(No.B06018).
文摘Both thymocytes and tumor cells express M2 type isoenzyme of pyruvate kinase(M2PK),which is different from R type isoenzyme of pyruvate kinase(RPK)that is expressed in erythrocytes.In this report,the effect of RPK and M2PK on the transcription of human immunodeficiency virus type 1(HIV-1)was tested.The results indicated that M2PK could enhance HIV-1 transcription from its long terminal repeat(LTR)promoter,while RPK did not have such an effect.Specific down-regulation of M2PK could inhibit HIV-1 transcription from its LTR region.Furthermore,it was found that the C terminal region of M2PK is responsible for this effect.Collectively,the cellular factor M2PK that is expressed in thymocytes could facilitate the transcription of HIV-1.
文摘目的:构建大鼠线粒体转录因子TFAM(A)、线粒体转录因子TFB1M(B1)、线粒体转录TFB2M(B2)及线粒体RNA聚合酶(POLRMT)的质粒标准品,为检测内耳细胞线粒体TFAM、TFB1M、TFB2M、POLRMT的mRNA表达水平做基础。方法:设计特异性引物和探针,提取大鼠内耳组织总mRNA逆转录成c DNA,PCR扩增、纯化目的片段,将纯化产物与p Zero Back/blunt载体重组,提取重组质粒,经测序鉴定后,用实时荧光绝对定量PCR建立标准曲线。结果:测序结果与各目的序列一致,获得良好的标准曲线(R2>0.99)。结论:成功构建了各目的基因的质粒标准品。
基金supported by the National Natural Science Foundation of China(Nos.31830070,31871856,31772041)the Science and Technology Planning Project of Guangzhou(Nos.201804020041,201904010014)National Basic Research Program of China(No.2013CB127104).
文摘The alternative splicing of select genes is an important mechanism to regulate responses to endogenous and environmental signals in plants.However,the role of alternative splicing in regulating fruit ripening remains unclear.Here,we discovered that MaMYB16L,an R1-type MYB transcription factor,undergoes alternative splicing and generates two transcripts,the full-length isoform MaMYB16L and a truncated form MaMYB16S,in banana fruit.During banana fruit ripening,the alternative splicing process intensifies with downregulated MaMYB16L and upregulated MaMYB16S.Moreover,MaMYB16L is a transcriptional repressor that directly binds with the promoters of many genes associated with starch degradation and MaDREB2,a positive ripening regulator,and represses their expression.In contrast,MaMBY16S lacks a DNA-binding domain but competitively combines and forms non-functional heterodimers with functional MaMYB16L.MaMYB16L-MaMYB16S heterodimers decrease the binding capacity and transrepression activity of MaMYB16L.The downregulation of MaMYB16L and the upregulation of MaMYB16S,that is,a decreased ratio of active to non-active isoforms,facilitates the activation of ripening-related genes and thereby promotes fruit ripening.Furthermore,the transient overexpression of MaMYB16S promotes banana fruit ripening,whereas the overexpression of MaMYB16L delays this process.Therefore,the alternative splicing of MaMYB16L might generate a self-controlled regulatory loop to regulate banana fruit ripening.
