Purple-leafed plants not only have a higher resistance to biotic and abiotic stresses,but also have higher ornamental value.Anthocyanins are vital for leaf color formation,growth and development of purple leaves.Howev...Purple-leafed plants not only have a higher resistance to biotic and abiotic stresses,but also have higher ornamental value.Anthocyanins are vital for leaf color formation,growth and development of purple leaves.However,the molecular mechanism underlying purple leaf formation in Lagerstroemia indica remains unclear.Metabolomic and transcriptomic analysis of purple-leafed cultivar‘Ebony Embers’and greenleafed cultivar‘Arapahoe’showed that the high expression of anthocyanin structure genes induced hyperaccumulation of cyanidin and pelargonidin derivatives,making the leaves purple.LfiHY5,LfiMYB75 and LfibHLH1 were identified using correlation analysis and weighted gene co-expression network analysis.In‘Arapahoe’‘Ebony Embers’population,LfiHY5 and LfiMYB75 showed significant positive correlation with leaf anthocyanin content.Transient expression of LfiMYB75 and LfiHY5 in tobacco and purple-leafed crape myrtle indicated that the two genes activated anthocyanin synthesis.Yeast two-hybrid analysis showed that LfiMYB75 and LfibHLH1 could form a complex that enhanced anthocyanin synthesis.Yeast monohybrid and dual-luciferase assays confirmed that LfiHY5 activated the expression of LfiMYB75,to activate the transcription of anthocyanin structural genes LfiCHS and LfiANS.Moreover,there were three alleles of LfiHY5 in crape myrtle,and the different sequences had different activation effects on LfiMYB75.In conclusion,the results showed that LfiHY5 led to upregulate the transcription of LfiMYB75,and LfiMYB75 formed a complex with LfibHLH1,which increased the transcription level of LfiCHS and LfiANS to affect anthocyanin synthesis in crape myrtle.展开更多
Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisi...Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisive role in the biosynthesis of anthocyanins. Studies have shown that the transcriptional levels of an- thocyanins are mainly regulated by MYB-bHLH-WD40 ternary complex. This paper summarized the structure characteristics of MYB-bHLH-WD40 ternary complex and its regulatory role in anthocyanin biosynthesis pathway, focusing on the regulation mechanism of several important model plants by MYB-bHIM-WD40 complex.展开更多
In complex, constantly changing environments, plants have developed astonishing survival strategies. These elaborated strategies rely on rapid and precise gene regulation mediated by transcription factors （TFs）. TFs...In complex, constantly changing environments, plants have developed astonishing survival strategies. These elaborated strategies rely on rapid and precise gene regulation mediated by transcription factors （TFs）. TFs represent a large fraction of plant genomes and among them, MYBs and basic helix-loop-helix （bHLHs） have unique inherent properties specific to plants. Proteins of these two TF families can act as homo- or heterodimers, associate with proteins from other protein families, or form MYB/bHLH complexes to regulate distinct cellular processes. The ability of MYBs and bHLHs to interact with multiple protein part- ners has evolved to keep up with the increased metabolic complexity of multi-cellular organisms. Associ- ation and disassociation of dynamic TF complexes in response to developmental and environmental cues are controlled through a plethora of regulatory mechanisms specifically modulating TF activity. Regulation of TFs at the protein level is critical for efficient and precise control of their activity, and thus provides the mechanistic basis for a rapid on-and-off switch of TF activity. In this review, examples of post-translational modifications, protein-protein interactions, and subcellular mobilization of TFs are discussed with regard to the relevance of these regulatory mechanisms for the specific activation of MYBs and bHLHs in response to a given environmental stimulus.展开更多
The phytohormones ethylene(ET)and jasmonate(JA)regulate plant development,growth,and defense responses;however,the molecular basis for their signaling crosstalk is unclear.Here,we show that JA-ZIM-domain(JAZ)proteins,...The phytohormones ethylene(ET)and jasmonate(JA)regulate plant development,growth,and defense responses;however,the molecular basis for their signaling crosstalk is unclear.Here,we show that JA-ZIM-domain(JAZ)proteins,which repress JA signaling,repress trichome initiation/branching and anthocyanin accumulation,and inhibit the transcriptional activity of the basic helix-loop-helix(bHLH)-MYBmembers(GLABRA3(GL3)-GL1 and TRANSPARENT TESTA 8(TT8)-MYB75)of WD-repeat/bHLH/MYB(WBM)complexes.The ET-stabilized transcription factors ETHYLENEINSENSITIVE3(EIN3)and EIN3-LIKE1(EIL1)were found to bind to several members of WBM complexes,including GL3,ENHANCER OF GLABRA3(EGL3),TT8,GL1,MYB75,and TRANSPARENT TESTA GLABRA1(TTG1).This binding repressed the transcriptional activity of the b HLH-MYB proteins and inhibited anthocyanin accumulation,trichome formation,and defenses against insect herbivores while promoting root hair formation.Conversely,the JA-activated b HLH members GL3,EGL3,and TT8 of WBM complexes were able to interact with and attenuate the transcriptional activity of EIN3/EIL1 at the HOOKLESS1 promoter,and their overexpression inhibited apical hook formation.Thus,this study demonstrates a molecular framework for signaling crosstalk between JA and ET in plant development,secondary metabolism,and defense responses.展开更多
基金the National Key R and D Program of China(Grant Nos.2019YFD1000402,2019YFD1001004)the World-Class Discipline Construction and Characteristic Development Guidance Funds for Beijing Forestry University(Grant No.2019XKJS0323).
文摘Purple-leafed plants not only have a higher resistance to biotic and abiotic stresses,but also have higher ornamental value.Anthocyanins are vital for leaf color formation,growth and development of purple leaves.However,the molecular mechanism underlying purple leaf formation in Lagerstroemia indica remains unclear.Metabolomic and transcriptomic analysis of purple-leafed cultivar‘Ebony Embers’and greenleafed cultivar‘Arapahoe’showed that the high expression of anthocyanin structure genes induced hyperaccumulation of cyanidin and pelargonidin derivatives,making the leaves purple.LfiHY5,LfiMYB75 and LfibHLH1 were identified using correlation analysis and weighted gene co-expression network analysis.In‘Arapahoe’‘Ebony Embers’population,LfiHY5 and LfiMYB75 showed significant positive correlation with leaf anthocyanin content.Transient expression of LfiMYB75 and LfiHY5 in tobacco and purple-leafed crape myrtle indicated that the two genes activated anthocyanin synthesis.Yeast two-hybrid analysis showed that LfiMYB75 and LfibHLH1 could form a complex that enhanced anthocyanin synthesis.Yeast monohybrid and dual-luciferase assays confirmed that LfiHY5 activated the expression of LfiMYB75,to activate the transcription of anthocyanin structural genes LfiCHS and LfiANS.Moreover,there were three alleles of LfiHY5 in crape myrtle,and the different sequences had different activation effects on LfiMYB75.In conclusion,the results showed that LfiHY5 led to upregulate the transcription of LfiMYB75,and LfiMYB75 formed a complex with LfibHLH1,which increased the transcription level of LfiCHS and LfiANS to affect anthocyanin synthesis in crape myrtle.
基金Supported by Research Project of Sichuan University of Science&Engineering(No.2011RC12,2014KY02)Scientific Research Foundation of the Education Department of Sichuan Province(No.15ZA0222)Research Project of Liquor Making Biological Technology and Application of Key Laboratory of Sichuan Province(NJ2013-06)
文摘Anthocyanins are main coloring substances in plants with various functions such as antioxidant , preventing cardiovascular diseases , and inhibiting oncogenesis. The regulation of transcriptional levels plays a decisive role in the biosynthesis of anthocyanins. Studies have shown that the transcriptional levels of an- thocyanins are mainly regulated by MYB-bHLH-WD40 ternary complex. This paper summarized the structure characteristics of MYB-bHLH-WD40 ternary complex and its regulatory role in anthocyanin biosynthesis pathway, focusing on the regulation mechanism of several important model plants by MYB-bHIM-WD40 complex.
文摘In complex, constantly changing environments, plants have developed astonishing survival strategies. These elaborated strategies rely on rapid and precise gene regulation mediated by transcription factors （TFs）. TFs represent a large fraction of plant genomes and among them, MYBs and basic helix-loop-helix （bHLHs） have unique inherent properties specific to plants. Proteins of these two TF families can act as homo- or heterodimers, associate with proteins from other protein families, or form MYB/bHLH complexes to regulate distinct cellular processes. The ability of MYBs and bHLHs to interact with multiple protein part- ners has evolved to keep up with the increased metabolic complexity of multi-cellular organisms. Associ- ation and disassociation of dynamic TF complexes in response to developmental and environmental cues are controlled through a plethora of regulatory mechanisms specifically modulating TF activity. Regulation of TFs at the protein level is critical for efficient and precise control of their activity, and thus provides the mechanistic basis for a rapid on-and-off switch of TF activity. In this review, examples of post-translational modifications, protein-protein interactions, and subcellular mobilization of TFs are discussed with regard to the relevance of these regulatory mechanisms for the specific activation of MYBs and bHLHs in response to a given environmental stimulus.
基金supported by the National Natural Science Foundation of China(31400254 and 31670315)Tsinghua University Initiative Scientific Research Program+3 种基金the grant from Beijing Municipal Commission of Education and Beijing Natural Science Foundation(KZ202210028044)the Beijing Nova Program(Z171100001117037)the funding from the Tsinghua-Peking Center for Life Sciencesthe Project of Graduate Student Academic Innovation of Capital Normal University(010-2255074)。
文摘The phytohormones ethylene(ET)and jasmonate(JA)regulate plant development,growth,and defense responses;however,the molecular basis for their signaling crosstalk is unclear.Here,we show that JA-ZIM-domain(JAZ)proteins,which repress JA signaling,repress trichome initiation/branching and anthocyanin accumulation,and inhibit the transcriptional activity of the basic helix-loop-helix(bHLH)-MYBmembers(GLABRA3(GL3)-GL1 and TRANSPARENT TESTA 8(TT8)-MYB75)of WD-repeat/bHLH/MYB(WBM)complexes.The ET-stabilized transcription factors ETHYLENEINSENSITIVE3(EIN3)and EIN3-LIKE1(EIL1)were found to bind to several members of WBM complexes,including GL3,ENHANCER OF GLABRA3(EGL3),TT8,GL1,MYB75,and TRANSPARENT TESTA GLABRA1(TTG1).This binding repressed the transcriptional activity of the b HLH-MYB proteins and inhibited anthocyanin accumulation,trichome formation,and defenses against insect herbivores while promoting root hair formation.Conversely,the JA-activated b HLH members GL3,EGL3,and TT8 of WBM complexes were able to interact with and attenuate the transcriptional activity of EIN3/EIL1 at the HOOKLESS1 promoter,and their overexpression inhibited apical hook formation.Thus,this study demonstrates a molecular framework for signaling crosstalk between JA and ET in plant development,secondary metabolism,and defense responses.
