Single-repeat R3 MYB transcription factors like CPC （CAPRICE） are known to play roles in developmental processes such as root hair differentiation and trichome initiation. However, none of the six Arabidopsis single...Single-repeat R3 MYB transcription factors like CPC （CAPRICE） are known to play roles in developmental processes such as root hair differentiation and trichome initiation. However, none of the six Arabidopsis single-repeat R3 MYB members has been reported to regulate flavonoid biosynthesis. We show here that CPC is a negative regulator of anthocyanin biosynthesis. In the process of using CPC to test GAL4-dependent driver lines, we observed a repression of anthocyanin synthesis upon GAL4-mediated CPC overexpression. We demonstrated that this is not due to an increase in nutrient uptake because of more root hairs. Rather, CPC expression level tightly controls anthocyanin accumulation. Microarray analysis on the whole genome showed that, of 37 000 features tested, 85 genes are repressed greater than three-fold by CPC overexpression. Of these 85, seven are late anthocyanin biosynthesis genes. Also, anthocyanin synthesis genes were shown to be down-regulated in 35S：：CPC overexpression plants. Transient expression results suggest that CPC competes with the R2R3-MYB transcription factor PAP1/2, which is an activator of anthocyanin biosynthesis genes. This report adds anthocyanin biosynthesis to the set of programs that are under CPC control, indicating that this regulator is not only for developmental programs （e.g. root hairs, trichomes）, but can influence anthocyanin pigment synthesis.展开更多
The phytohormone abscisic acid （ABA） plays crucial roles in plant development and plant responses to environmental stresses. Although ABA receptors and a minimal set of core molecular components have recently been d...The phytohormone abscisic acid （ABA） plays crucial roles in plant development and plant responses to environmental stresses. Although ABA receptors and a minimal set of core molecular components have recently been discovered, understanding of the ABA signaling pathway is still far from complete. In this work, we characterized the function of ROP11, a member of the plant-specific ROP small GTPases family, in the ABA signaling process. ROP11 is preferentially expressed in guard cells in all plant organs with stomata. Expression of a constitutively active ROP11 （CA-ROP11） suppresses ABA-mediated responses, whereas reduced expression of ROP11 or expression of its dominant-negative form （DN-ROP11） causes the opposite phenotypes. The affected ABA-mediated responses by ROP11 include seed germination, seedling growth, stomatal closure, induction of ABA-responsive genes, as well as plant response to drought stress. Furthermore, we showed that ROP11 and its closest-related family member, ROP10, act in parallel in mediating these responses. ABA treatment does not affect ROP11 transcription and protein abundance; however, it causes the accumulation of CA-ROP11 in the nucleus. These results demonstrated that ROP11 is a negative regulator of multiple ABA responses in Arabidopsis.展开更多
Abscisic acid （ABA） plays crucial roles in plant growth and development, as well as in response to various environmental stresses. To date, many regulatory genes involved in the ABA response network have been identi...Abscisic acid （ABA） plays crucial roles in plant growth and development, as well as in response to various environmental stresses. To date, many regulatory genes involved in the ABA response network have been identified; however, their roles have remained to be fully elucidated. In this study, we iden- tified AtYY1, an Arabidopsis homolog of the mammalian C2H2 zinc-finger transcription factor Yin Yang 1 （YY1）, as a novel negative regulator of the ABA response. AtYY1 is a dual-function transcription factor with both repression and activation domains. The expression of AtYY1 was induced by ABA and stress conditions including high salt and dehydration. The yyl mutant was more sensitive to ABA and NaCI than the wild-type, while overexpressing AtYY1 plants were less sensitive. AtYY1 loss also enhanced ABA-induced stomatal closing and drought resistance. Moreover, AtYYI can bind the ABA REPRESSOR1 （ABR1） promoter and directly upregulate ABR1 expression, as well as negatively regulate ABA- and saR-responsive gene expression. Additional analysis indicated that ABA INSENSITIVE4 （ABI4） might positively regulate AtYY1 expression and that ABR1 can antagonize this regulation. Our findings provide direct evidence that AtYY1 is a novel negative regulator of the ABA response network and that the ABI4-AtYY1-ABR1 regulatory pathway may fine-tune ABA-responsive gene expression in Arabidopsis.展开更多
Arabidopsis NON-EXPRESSOR OF PR1 （NPR1） is a transcription co-activator that plays a central role in regulating the transcriptional response to plant pathogens. The NPR family consists of NPR1 and five NPRl-like gen...Arabidopsis NON-EXPRESSOR OF PR1 （NPR1） is a transcription co-activator that plays a central role in regulating the transcriptional response to plant pathogens. The NPR family consists of NPR1 and five NPRl-like genes. The NPR1 paralog NPR3 has recently been shown to function as a receptor of the plant hormone salicylic acid and to mediate proteosomal degradation of NPR1. The function of NPR3 protein during early flower development was revealed through a detailed molecular-genetic analysis including promoter transcriptional fusion analysis, phenotype characterization of npr3-3 mutants/overexpressors, and whole-plant fitness analysis. The physical interaction between NPR3 and NPR1/ TGA2 was explored using bimolecular fluorescence complementation analysis in onion epidermal cells, Here, we show that NPR3 expression was strongest in the petals and sepals of developing flowers and declined after flower opening. Consistently with this observation, an npr3 knockout mutant displayed enhanced resistance to Pseudomonas syringae infection of immature flowers, but not leaves. Developing npr3 flowers exhibited increased levels of basal and induced PR1 transcript accumulation. However, the npr3 mutant showed lower fitness compared to Col-0 in the absence of pathogen. Moreover, NPR3 was shown to interact with NPR1 and TGA2 in vivo. Our data suggest that NPR3 is a negative regulator of defense responses during early flower development and it may function through the association with both NPR1 and TGA2.展开更多
BACKGROUND Pancreatic ductal cancer(PDAC)has high malignancy and poor prognosis.Long noncoding RNAs(lncRNAs)are associated with high levels of malignancy,including PDAC.However,the biological and clinical significance...BACKGROUND Pancreatic ductal cancer(PDAC)has high malignancy and poor prognosis.Long noncoding RNAs(lncRNAs)are associated with high levels of malignancy,including PDAC.However,the biological and clinical significance of negative regulator of antiviral response(NRAV)in PDAC is unclear.AIM To study the regulatory role of lncRNA NRAV in PDAC.METHODS GEPIA analyzed lncRNA NRAV and miRNA(miR-299-3p)expression levels in PDAC tissues and measured them in PDAC cells by quantitative measurements in real time.The specific role of NRAV and miR-299-3p in cell proliferation and transfer potential was evaluated by cell formation analysis,Cell Counting Kit-8 and Transwell analysis.The relationship between NRAV and miR-299-3p was studied by predictive bioinformatics,RNA immunoassay,and fluorescence enzyme analysis.In vivo experiments included transplantation of simulated tumor cells under naked mice.RESULTS The expression level of lncRNA NRAV was higher in both tumor tissues and cell lines of PDAC and was negatively associated with the clinical survival of PDAC patients.Functionally,overexpression of NRAV promoted cell proliferation and metastasis of PDAC cells,while knockdown of NRAV reversed these effects.Finally,NRAV was performed as a molecular sponge of miR-299-3p.Moreover,overexpression of miR-299-3p could reverse the promoting effects of NRAV on cell proliferation and metastasis of PDAC cells.CONCLUSION NRAV facilitates progression of PDAC as a molecular sponge of miR-299-3p and may be a potential molecular marker for diagnosis and treatment of PDAC.展开更多
NRL3 is essential for the growth and development of rice leaves.In this study,we found that the loss function of NRL3 also delayed heading date under natural long daylight and short daylight conditions.The yeast two-h...NRL3 is essential for the growth and development of rice leaves.In this study,we found that the loss function of NRL3 also delayed heading date under natural long daylight and short daylight conditions.The yeast two-hybrid and the bimolecular fluorescence complementation proved that NRL3interacts with OsK4,a Snf1-related kinase.OsK4 localized to the nucleus and expressed in various rice tissues.The rhythmic expression pattern of Os K4 was similar to NRL3 under long daylight and short daylight conditions.Knock-out mutants of Os K4 exhibited early heading under long daylight conditions,indicating that it acts as a negative regulator of heading date in rice.Interestingly,the OsK4 mutant under the nrl3 mutant background rescued the late heading phenotype of nrl3 under long daylight conditions,suggesting that Os K4 functions downstream of NRL3.Moreover,both NRL3 and Os K4 controlled heading date through regulating the expression of Hd3a and RFT1 genes.These findings shed light on the heading date regulation in rice and provide a sound theoretical base to improve regional adaptability of rice.展开更多
文摘Single-repeat R3 MYB transcription factors like CPC （CAPRICE） are known to play roles in developmental processes such as root hair differentiation and trichome initiation. However, none of the six Arabidopsis single-repeat R3 MYB members has been reported to regulate flavonoid biosynthesis. We show here that CPC is a negative regulator of anthocyanin biosynthesis. In the process of using CPC to test GAL4-dependent driver lines, we observed a repression of anthocyanin synthesis upon GAL4-mediated CPC overexpression. We demonstrated that this is not due to an increase in nutrient uptake because of more root hairs. Rather, CPC expression level tightly controls anthocyanin accumulation. Microarray analysis on the whole genome showed that, of 37 000 features tested, 85 genes are repressed greater than three-fold by CPC overexpression. Of these 85, seven are late anthocyanin biosynthesis genes. Also, anthocyanin synthesis genes were shown to be down-regulated in 35S：：CPC overexpression plants. Transient expression results suggest that CPC competes with the R2R3-MYB transcription factor PAP1/2, which is an activator of anthocyanin biosynthesis genes. This report adds anthocyanin biosynthesis to the set of programs that are under CPC control, indicating that this regulator is not only for developmental programs （e.g. root hairs, trichomes）, but can influence anthocyanin pigment synthesis.
基金supported by the National Basic Research Program of China(973Program)(2009CB119100)the National Natural Science Foundation of China(90717121)
文摘The phytohormone abscisic acid （ABA） plays crucial roles in plant development and plant responses to environmental stresses. Although ABA receptors and a minimal set of core molecular components have recently been discovered, understanding of the ABA signaling pathway is still far from complete. In this work, we characterized the function of ROP11, a member of the plant-specific ROP small GTPases family, in the ABA signaling process. ROP11 is preferentially expressed in guard cells in all plant organs with stomata. Expression of a constitutively active ROP11 （CA-ROP11） suppresses ABA-mediated responses, whereas reduced expression of ROP11 or expression of its dominant-negative form （DN-ROP11） causes the opposite phenotypes. The affected ABA-mediated responses by ROP11 include seed germination, seedling growth, stomatal closure, induction of ABA-responsive genes, as well as plant response to drought stress. Furthermore, we showed that ROP11 and its closest-related family member, ROP10, act in parallel in mediating these responses. ABA treatment does not affect ROP11 transcription and protein abundance; however, it causes the accumulation of CA-ROP11 in the nucleus. These results demonstrated that ROP11 is a negative regulator of multiple ABA responses in Arabidopsis.
基金This work was financially supported by grants from the National Transgenic Animals ＆ Plants Research Project （2009ZX08009-069B, 2013ZX08009-003）, the State Key Basic Research and Development Plan （2010CB126003）, and the China Postdoctoral Science Foundation （20080430370）.
文摘Abscisic acid （ABA） plays crucial roles in plant growth and development, as well as in response to various environmental stresses. To date, many regulatory genes involved in the ABA response network have been identified; however, their roles have remained to be fully elucidated. In this study, we iden- tified AtYY1, an Arabidopsis homolog of the mammalian C2H2 zinc-finger transcription factor Yin Yang 1 （YY1）, as a novel negative regulator of the ABA response. AtYY1 is a dual-function transcription factor with both repression and activation domains. The expression of AtYY1 was induced by ABA and stress conditions including high salt and dehydration. The yyl mutant was more sensitive to ABA and NaCI than the wild-type, while overexpressing AtYY1 plants were less sensitive. AtYY1 loss also enhanced ABA-induced stomatal closing and drought resistance. Moreover, AtYYI can bind the ABA REPRESSOR1 （ABR1） promoter and directly upregulate ABR1 expression, as well as negatively regulate ABA- and saR-responsive gene expression. Additional analysis indicated that ABA INSENSITIVE4 （ABI4） might positively regulate AtYY1 expression and that ABR1 can antagonize this regulation. Our findings provide direct evidence that AtYY1 is a novel negative regulator of the ABA response network and that the ABI4-AtYY1-ABR1 regulatory pathway may fine-tune ABA-responsive gene expression in Arabidopsis.
文摘Arabidopsis NON-EXPRESSOR OF PR1 （NPR1） is a transcription co-activator that plays a central role in regulating the transcriptional response to plant pathogens. The NPR family consists of NPR1 and five NPRl-like genes. The NPR1 paralog NPR3 has recently been shown to function as a receptor of the plant hormone salicylic acid and to mediate proteosomal degradation of NPR1. The function of NPR3 protein during early flower development was revealed through a detailed molecular-genetic analysis including promoter transcriptional fusion analysis, phenotype characterization of npr3-3 mutants/overexpressors, and whole-plant fitness analysis. The physical interaction between NPR3 and NPR1/ TGA2 was explored using bimolecular fluorescence complementation analysis in onion epidermal cells, Here, we show that NPR3 expression was strongest in the petals and sepals of developing flowers and declined after flower opening. Consistently with this observation, an npr3 knockout mutant displayed enhanced resistance to Pseudomonas syringae infection of immature flowers, but not leaves. Developing npr3 flowers exhibited increased levels of basal and induced PR1 transcript accumulation. However, the npr3 mutant showed lower fitness compared to Col-0 in the absence of pathogen. Moreover, NPR3 was shown to interact with NPR1 and TGA2 in vivo. Our data suggest that NPR3 is a negative regulator of defense responses during early flower development and it may function through the association with both NPR1 and TGA2.
基金Supported by the National Natural Science Foundation of China,No.81974372
文摘BACKGROUND Pancreatic ductal cancer(PDAC)has high malignancy and poor prognosis.Long noncoding RNAs(lncRNAs)are associated with high levels of malignancy,including PDAC.However,the biological and clinical significance of negative regulator of antiviral response(NRAV)in PDAC is unclear.AIM To study the regulatory role of lncRNA NRAV in PDAC.METHODS GEPIA analyzed lncRNA NRAV and miRNA(miR-299-3p)expression levels in PDAC tissues and measured them in PDAC cells by quantitative measurements in real time.The specific role of NRAV and miR-299-3p in cell proliferation and transfer potential was evaluated by cell formation analysis,Cell Counting Kit-8 and Transwell analysis.The relationship between NRAV and miR-299-3p was studied by predictive bioinformatics,RNA immunoassay,and fluorescence enzyme analysis.In vivo experiments included transplantation of simulated tumor cells under naked mice.RESULTS The expression level of lncRNA NRAV was higher in both tumor tissues and cell lines of PDAC and was negatively associated with the clinical survival of PDAC patients.Functionally,overexpression of NRAV promoted cell proliferation and metastasis of PDAC cells,while knockdown of NRAV reversed these effects.Finally,NRAV was performed as a molecular sponge of miR-299-3p.Moreover,overexpression of miR-299-3p could reverse the promoting effects of NRAV on cell proliferation and metastasis of PDAC cells.CONCLUSION NRAV facilitates progression of PDAC as a molecular sponge of miR-299-3p and may be a potential molecular marker for diagnosis and treatment of PDAC.
基金Supported by the National Natural Science Foundation of China(31630002,31470183,21661140002)by the Shanghai Pujiang Program from the Shanghai Municipal Council of Science and Technology~~
文摘【目的】DNA磷硫酰化修饰是DNA骨架上非桥接的氧原子以序列选择性和R-构型被硫取代的一种新型DNA修饰。目前,磷硫酰化修饰在多种细菌、古生菌以及人类致病菌中多有发现,但其分子调控机制尚不清楚。为了全面解析磷硫酰化修饰的调控机制,本文选择荧光假单胞菌Pf0-1为研究对象,开展了其DNA磷硫酰化修饰的调控机制研究。【方法】首先,构建了spfB基因缺失和回补菌株,使用碘能特异性断裂磷硫酰化修饰DNA的方法,研究了该基因缺失对修饰表型的影响。利用cDNA在相邻同方向的基因间隔区进行PCR,确定了磷硫酰化修饰基因簇spf BCDE内的共转录单元。通过荧光定量RT-PCR,分析了spfB基因缺失突变株中磷硫酰化修饰基因的转录量。利用异源表达并纯化得到的重组蛋白SpfB进行了体外功能研究。通过EMSA实验,验证了SpfB蛋白具有与spfB启动子序列结合活性。通过DNase I footprinting实验,精确定位了Spf B蛋白与DNA结合序列。【结果】spf B基因的缺失加剧了磷硫酰化修饰DNA断裂所致电泳条带弥散的表型,spf B基因的回补能够恢复该表型,证明spf B基因负调控磷硫酰化修饰。鉴定了spf基因簇中只含有1个共转录单元,且该共转录单元在?spfB突变株中转录水平明显上升。通过EMSA和DNase I footprint实验,检测了SpfB蛋白与磷硫酰化修饰基因spf BCDE的启动子区域5′-TGTTTGT-3′相结合。【结论】SpfB作为转录调控因子负调控磷硫酰化修饰基因spf BCDE的表达,为解析磷硫酰化修饰的调控机制和全面理解基因组上的部分修饰特征奠定了基础。
基金supported by the China National Natural Science Foundation(Grant No.31871597)the Key Research and Development Program of Zhejiang Province,China(Grant No.2021C02063-2)+2 种基金the Key Research and Development Program of China National Rice Research Institute(Grant No.CNRRI-2020-02)the Science and Technology Project of Jiangxi Provincial Department of Education,China(Grant No.GJJ180217)the Project supported by Jiangxi Youth Science Foundation,China(Grant No.20202BAB215001)。
文摘NRL3 is essential for the growth and development of rice leaves.In this study,we found that the loss function of NRL3 also delayed heading date under natural long daylight and short daylight conditions.The yeast two-hybrid and the bimolecular fluorescence complementation proved that NRL3interacts with OsK4,a Snf1-related kinase.OsK4 localized to the nucleus and expressed in various rice tissues.The rhythmic expression pattern of Os K4 was similar to NRL3 under long daylight and short daylight conditions.Knock-out mutants of Os K4 exhibited early heading under long daylight conditions,indicating that it acts as a negative regulator of heading date in rice.Interestingly,the OsK4 mutant under the nrl3 mutant background rescued the late heading phenotype of nrl3 under long daylight conditions,suggesting that Os K4 functions downstream of NRL3.Moreover,both NRL3 and Os K4 controlled heading date through regulating the expression of Hd3a and RFT1 genes.These findings shed light on the heading date regulation in rice and provide a sound theoretical base to improve regional adaptability of rice.
