Heat stress caused by global warming requires the development of thermotolerant crops to sustain yield.It is necessary to understand the molecular mechanisms that underlie heat tolerance in plants.Strigolactones(SLs)a...Heat stress caused by global warming requires the development of thermotolerant crops to sustain yield.It is necessary to understand the molecular mechanisms that underlie heat tolerance in plants.Strigolactones(SLs)are a class of carotenoid-derived phytohormones that regulate plant development and responses to abiotic or biotic stresses.Although SL biosynthesis and signaling processes are well established,genes that directly regulate SL biosynthesis have rarely been reported.Here,we report that the MYB-like transcription factor AtMYBS1/AtMYBL,whose gene expression is repressed by heat stress,functions as a negative regulator of heat tolerance by directly inhibiting SL biosynthesis in Arabidopsis.Overexpression of AtMYBS1 led to heat hypersensitivity,whereas atmybs1 mutants displayed increased heat tolerance.Expression of MAX1,a critical enzyme in SL biosynthesis,was induced by heat stress and downregulated in AtMYBS1-overexpression(OE)plants but upregulated in atmybs1 mutants.Overexpression of MAX1 in the AtMYBS1-OE background reversed the heat hypersensitivity of AtMYBS1-OE plants.Loss of MAX1 function in the atmyb1 background reversed the heat-tolerant phenotypes of atmyb1 mutants.Yeast one-hybrid assays,chromatin immunoprecipitation‒qPCR,and transgenic analyses demonstrated that AtMYBS1 directly represses MAX1 expression through the MYB binding site in the MAX1 promoter in vivo.The atmybs1d14 double mutant,like d14 mutants,exhibited hypersensitivity to heat stress,indicating the necessary role of SL signaling in AtMYBS1-regulated heat tolerance.Our findings provide new insights into the regulatory network of SL biosynthesis,facilitating the breeding of heat-tolerant crops to improve crop production in a warming world.展开更多
目的:构建Max二聚化蛋白1(Max dimerization protein 1,Mad1)的真核表达载体,研究Mad1对胃癌细胞增殖和迁移能力的影响。方法:利用DNA重组技术将Mad1基因克隆至pEGFP-N1载体,构建重组真核表达载体pEGFP-N1-Mad1。经酶切和测序鉴定后,采...目的:构建Max二聚化蛋白1(Max dimerization protein 1,Mad1)的真核表达载体,研究Mad1对胃癌细胞增殖和迁移能力的影响。方法:利用DNA重组技术将Mad1基因克隆至pEGFP-N1载体,构建重组真核表达载体pEGFP-N1-Mad1。经酶切和测序鉴定后,采用脂质体转染技术将重组质粒瞬时转染人胃癌AGS细胞,RT-PCR及Western blot检测Mad1基因和蛋白的表达。荧光显微镜观察Mad1在AGS细胞内的定位情况。CCK-8和Transwell实验研究Mad1对胃癌AGS细胞增殖和迁移能力的影响。结果:成功构建携带Mad1基因的真核表达载体pEGFP-N1-Mad1。将重组质粒瞬时转染AGS细胞后,RT-PCR和Western blot检测到Mad1基因和蛋白的表达。Mad1基因表达产物定位于AGS细胞核中。CCK-8和Transwell实验结果显示,转染Mad1的AGS细胞与转染空载体的AGS细胞及正常AGS细胞相比,细胞增殖活力和迁移能力明显降低。结论:成功构建了真核表达载体p EGFP-N1-Mad1,研究表明Mad1可以抑制胃癌AGS细胞的增殖和迁移。展开更多
The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and ca...The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and cancerous cervical tissue.Normal epithelial and immortalized cervical epithelial carcinoma cell lines were used to construct 3-D artificial normal cervical and cervical cancerous tissues.De-epidermised dermis（DED） was used as a scaffold for both models.Morphological analyses were conducted by using hematoxylin and eosin staining and characteristics of the models were studied by analyzing the expression of different structural cytokeratins and differential protein marker MAX dimerisation protein 1（Mad1） using immunohistochemical technique.Haematoxylin and eosin staining results showed that normal cervical tissue had multi epithelial layers while cancerous cervical tissue showed dysplastic changes.Immunohistochemistry staining revealed that for normal cervix model cytokeratin 10 was expressed in the upper stratified layer of the epithelium while cytokeratin 5 was expressed mainly in the middle and basal layer.Cytokeratin 19 was weakly expressed in a few basal cells.Cervical cancer model showed cytokeratin 19 expression in different epithelial layers and weak or no expression for cytokeratin 5 and cytokeratin 10.Madl expression was detected in some suprabasal cells.The 3-D in vitro models showed stratified epithelial layers and expressed the same types and patterns of differentiation marker proteins as seen in corresponding in vivo tissue in either normal cervical or cervical cancerous tissue.These findings imply that they can serve as functional normal and cervical cancer models.展开更多
financially supported by the Genetically Modified Organisms Breeding Major Projects of China （2014ZX08004）;the National Natural Science Foundation of China （31301340）;the Modern Agro-industry Technology Research S...financially supported by the Genetically Modified Organisms Breeding Major Projects of China （2014ZX08004）;the National Natural Science Foundation of China （31301340）;the Modern Agro-industry Technology Research System of China （CARS-004-PS10）;the Program for Changjiang Scholars and Innovative Research Team in University, China （PCSIRT13073）;the Jiangsu Collaborative Innovation Center for Modern Crop Production;an Openend Fund by State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, China （ZW2013009）展开更多
基金supported by Henan Agricultural University(30500689).
文摘Heat stress caused by global warming requires the development of thermotolerant crops to sustain yield.It is necessary to understand the molecular mechanisms that underlie heat tolerance in plants.Strigolactones(SLs)are a class of carotenoid-derived phytohormones that regulate plant development and responses to abiotic or biotic stresses.Although SL biosynthesis and signaling processes are well established,genes that directly regulate SL biosynthesis have rarely been reported.Here,we report that the MYB-like transcription factor AtMYBS1/AtMYBL,whose gene expression is repressed by heat stress,functions as a negative regulator of heat tolerance by directly inhibiting SL biosynthesis in Arabidopsis.Overexpression of AtMYBS1 led to heat hypersensitivity,whereas atmybs1 mutants displayed increased heat tolerance.Expression of MAX1,a critical enzyme in SL biosynthesis,was induced by heat stress and downregulated in AtMYBS1-overexpression(OE)plants but upregulated in atmybs1 mutants.Overexpression of MAX1 in the AtMYBS1-OE background reversed the heat hypersensitivity of AtMYBS1-OE plants.Loss of MAX1 function in the atmyb1 background reversed the heat-tolerant phenotypes of atmyb1 mutants.Yeast one-hybrid assays,chromatin immunoprecipitation‒qPCR,and transgenic analyses demonstrated that AtMYBS1 directly represses MAX1 expression through the MYB binding site in the MAX1 promoter in vivo.The atmybs1d14 double mutant,like d14 mutants,exhibited hypersensitivity to heat stress,indicating the necessary role of SL signaling in AtMYBS1-regulated heat tolerance.Our findings provide new insights into the regulatory network of SL biosynthesis,facilitating the breeding of heat-tolerant crops to improve crop production in a warming world.
基金supported by the Middlesex University,particularly in the award of a Postgraduate Research Studentship that provided the necessary financial support for this research
文摘The use of three dimensional in vitro systems in cancer research is a promising path for developing effective anticancer therapies.The aim of this study was to engineer a functional 3-D in vitro model of normal and cancerous cervical tissue.Normal epithelial and immortalized cervical epithelial carcinoma cell lines were used to construct 3-D artificial normal cervical and cervical cancerous tissues.De-epidermised dermis（DED） was used as a scaffold for both models.Morphological analyses were conducted by using hematoxylin and eosin staining and characteristics of the models were studied by analyzing the expression of different structural cytokeratins and differential protein marker MAX dimerisation protein 1（Mad1） using immunohistochemical technique.Haematoxylin and eosin staining results showed that normal cervical tissue had multi epithelial layers while cancerous cervical tissue showed dysplastic changes.Immunohistochemistry staining revealed that for normal cervix model cytokeratin 10 was expressed in the upper stratified layer of the epithelium while cytokeratin 5 was expressed mainly in the middle and basal layer.Cytokeratin 19 was weakly expressed in a few basal cells.Cervical cancer model showed cytokeratin 19 expression in different epithelial layers and weak or no expression for cytokeratin 5 and cytokeratin 10.Madl expression was detected in some suprabasal cells.The 3-D in vitro models showed stratified epithelial layers and expressed the same types and patterns of differentiation marker proteins as seen in corresponding in vivo tissue in either normal cervical or cervical cancerous tissue.These findings imply that they can serve as functional normal and cervical cancer models.
基金financially supported by the Genetically Modified Organisms Breeding Major Projects of China (2014ZX08004)the National Natural Science Foundation of China (31301340)+3 种基金the Modern Agro-industry Technology Research System of China (CARS-004-PS10)the Program for Changjiang Scholars and Innovative Research Team in University, China (PCSIRT13073)the Jiangsu Collaborative Innovation Center for Modern Crop Productionan Openend Fund by State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, China (ZW2013009)
文摘financially supported by the Genetically Modified Organisms Breeding Major Projects of China （2014ZX08004）;the National Natural Science Foundation of China （31301340）;the Modern Agro-industry Technology Research System of China （CARS-004-PS10）;the Program for Changjiang Scholars and Innovative Research Team in University, China （PCSIRT13073）;the Jiangsu Collaborative Innovation Center for Modern Crop Production;an Openend Fund by State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, China （ZW2013009）
