The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H...The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H screen using BrrTCP4b as the bait,which unveiled an interaction between BrrTCP4b and BrrTTG1,a pivotal WD40-repeat protein transcription factor in the MYB-bHLH-WD40(MBW)complex.This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation.Furthermore,it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex,resulting in decreased expression of BrrGL2,a positive regulator of trichomes development.In contrast,AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana.Overall,this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip,indicating a divergence from the mechanisms observed in model plant A.thaliana.The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.展开更多
1-Deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) is an important enzyme involved in the 2-C-methyi-D- erythritol-4-phosphate (MEP) pathway which provides the basic five-carbon units for isoprenoid biosynthesi...1-Deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) is an important enzyme involved in the 2-C-methyi-D- erythritol-4-phosphate (MEP) pathway which provides the basic five-carbon units for isoprenoid biosynthesis. To investigate the role of the MEP pathway in plant development and metabolism, we carried out detailed analyses on a dxr mutant (GK_215C01) and two DXR transgenic co-suppression fines, OX-DXR-L2 and OX-DXR-L7. We found that the dxr mutant was albino and dwarf. It never bolted, had significantly reduced number of trichomes and most of the stomata could not close normally in the leaves. The two co-suppression lines produced more yellow inflorescences and albino sepals with no trichomes. The transcription levels of genes involved in tricbome initiation were found to be strongly affected, including GLABRA1, TRANSPARENT TESTA GLABROUS 1, TRIPTYCHON and SPINDLY, expression of which is regulated by gibberellic acids (GAs). Exogenous application of GA3 could partially rescue the dwarf phenotype and the trichome initiation of dxr, whereas exogenous application of abscisic acid (ABA) could rescue the stomata closure defect, suggesting that lower levels of both GA and ABA contribute to the phenotype in the dxr mutants. We further found that genes involved in the biosynthetic pathways of GA and ABA were coordinately regulated. These results indicate that disruption of the plastidial MEP pathway leads to biosynthetic deficiency of photosynthetic pigments, GAs and ABA, and thus the developmental abnormalities, and that the flux from the cytoplasmic mevalonate pathway is not sufficient to rescue the deficiency caused by the blockage of the plastidial MEP pathway. These results reveal a critical role for the MEP biosynthetic pathway in controlling the biosynthesis of isoprenoids.展开更多
Trichome formation has been extensively studied as a mechanistic model for epidermal cell differentiation and cell morphogenesis in plants. However, the genetic and molecular mechanisms underlying trichome formation ...Trichome formation has been extensively studied as a mechanistic model for epidermal cell differentiation and cell morphogenesis in plants. However, the genetic and molecular mechanisms underlying trichome formation (i.e., initiation and elongation) in rice remain largely unclear. Here, we report an AP2/ERF transcription factor, Hairy Leaf 6 (HL6), which controls trichome formation in rice. Functional analyses revealed that HL6 transcriptionally regulates trichome elongation in rice, which is dependent on functional OsWOX3B, a homeodomain-containing protein that acts as a key regulator in trichome initiation. Biochemical and molecular genetic analyses demonstrated that HL6 physically interacts with OsWOX3B, and both of them regulate the expression of some auxin-related genes during trichome formation, in which OsWOX3B likely enhances the binding ability of HL6 with one of its direct target gene, OsYUCCA5. Popu- lation genetic analysis indicated that HL6 was under negative selection during rice domestication. Taken together, our findings provide new insights into the molecular regulatory network of trichome formation in rice.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences,Pan-Third Pole Environment Study for a Green Silk Road(Pan-TPE)(XDA2004010306)the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2019QZKK0502)Science and Technology Program of Xizang Autonomous Region(XZ202001ZY0003G).
文摘The number of trichomes significantly increased in CRISPR/Cas9-edited BrrTCP4b turnip(Brassica rapa var.rapa)plants.However,the underlying molecular mechanism remains to be uncovered.In this study,we performed the Y2H screen using BrrTCP4b as the bait,which unveiled an interaction between BrrTCP4b and BrrTTG1,a pivotal WD40-repeat protein transcription factor in the MYB-bHLH-WD40(MBW)complex.This physical interaction was further validated through bimolecular luciferase complementation and co-immunoprecipitation.Furthermore,it was found that the interaction between BrrTCP4b and BrrTTG1 could inhibit the activity of MBW complex,resulting in decreased expression of BrrGL2,a positive regulator of trichomes development.In contrast,AtTCP4 is known to regulate trichomes development by interacting with AtGL3 in Arabidopsis thaliana.Overall,this study revealed that BrrTCP4b is involved in trichome development by interacting with BrrTTG1 in turnip,indicating a divergence from the mechanisms observed in model plant A.thaliana.The findings contribute to our understanding of the regulatory mechanisms governing trichome development in the non-model plants turnip.
基金Acknowledgments This work was supported by the National Natural Science Foundation of China (NSFC Grant 90717003 to L-J Qu).
文摘1-Deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) is an important enzyme involved in the 2-C-methyi-D- erythritol-4-phosphate (MEP) pathway which provides the basic five-carbon units for isoprenoid biosynthesis. To investigate the role of the MEP pathway in plant development and metabolism, we carried out detailed analyses on a dxr mutant (GK_215C01) and two DXR transgenic co-suppression fines, OX-DXR-L2 and OX-DXR-L7. We found that the dxr mutant was albino and dwarf. It never bolted, had significantly reduced number of trichomes and most of the stomata could not close normally in the leaves. The two co-suppression lines produced more yellow inflorescences and albino sepals with no trichomes. The transcription levels of genes involved in tricbome initiation were found to be strongly affected, including GLABRA1, TRANSPARENT TESTA GLABROUS 1, TRIPTYCHON and SPINDLY, expression of which is regulated by gibberellic acids (GAs). Exogenous application of GA3 could partially rescue the dwarf phenotype and the trichome initiation of dxr, whereas exogenous application of abscisic acid (ABA) could rescue the stomata closure defect, suggesting that lower levels of both GA and ABA contribute to the phenotype in the dxr mutants. We further found that genes involved in the biosynthetic pathways of GA and ABA were coordinately regulated. These results indicate that disruption of the plastidial MEP pathway leads to biosynthetic deficiency of photosynthetic pigments, GAs and ABA, and thus the developmental abnormalities, and that the flux from the cytoplasmic mevalonate pathway is not sufficient to rescue the deficiency caused by the blockage of the plastidial MEP pathway. These results reveal a critical role for the MEP biosynthetic pathway in controlling the biosynthesis of isoprenoids.
文摘Trichome formation has been extensively studied as a mechanistic model for epidermal cell differentiation and cell morphogenesis in plants. However, the genetic and molecular mechanisms underlying trichome formation (i.e., initiation and elongation) in rice remain largely unclear. Here, we report an AP2/ERF transcription factor, Hairy Leaf 6 (HL6), which controls trichome formation in rice. Functional analyses revealed that HL6 transcriptionally regulates trichome elongation in rice, which is dependent on functional OsWOX3B, a homeodomain-containing protein that acts as a key regulator in trichome initiation. Biochemical and molecular genetic analyses demonstrated that HL6 physically interacts with OsWOX3B, and both of them regulate the expression of some auxin-related genes during trichome formation, in which OsWOX3B likely enhances the binding ability of HL6 with one of its direct target gene, OsYUCCA5. Popu- lation genetic analysis indicated that HL6 was under negative selection during rice domestication. Taken together, our findings provide new insights into the molecular regulatory network of trichome formation in rice.