AP2/EREBP(APETALA2/ethylene-responsive element binding proteins)是一个起源古老的转录因子超家族,它含有1个或2个由约60-70个氨基酸残基组成的非常保守的DNA结合域(DNA-bindingdomain),即AP2/ERF结构域。根据AP2/ERF结构域的数目,A...AP2/EREBP(APETALA2/ethylene-responsive element binding proteins)是一个起源古老的转录因子超家族,它含有1个或2个由约60-70个氨基酸残基组成的非常保守的DNA结合域(DNA-bindingdomain),即AP2/ERF结构域。根据AP2/ERF结构域的数目,AP2/EREBP转录因子可以分为2个亚族:EREBP亚族(具有1个AP2/ERF结构域)和AP2亚族(具有2个AP2/ERF结构域)。AP2亚族转录因子有调控花、胚珠和种子发育的功能,而EREBP亚族转录因子(包括DREB类和ERF类)的主要功能是调节植物对激素(乙烯和ABA等)、病原和胁迫(低温、干旱及高盐)等的应答反应。本文讨论了AP2/EREBP转录因子在植物发育和胁迫应答中的研究进展。展开更多
Water is the most abundant molecule in almost all living organisms. Aquaporins are channel proteins that play critical roles in controlling the water content of cells. Here, we report the identification of an AP2/EREB...Water is the most abundant molecule in almost all living organisms. Aquaporins are channel proteins that play critical roles in controlling the water content of cells. Here, we report the identification of an AP2/EREBP family transcription factor in Arabidopsis thaliana, TRANSLUCENT GREEN (TG), whose overexpression in transgenic plants gave enhanced drought tolerance and vitrified leaves. TG protein is localized in the nucleus, binds DRE and GCC elements in vitro, and acts as a transcriptional activator in yeast cells. Microarray analysis revealed a total of 330 genes regulated by TG, among which five genes encode aquaporins. A transient expression assay showed that TG directly binds to the promoters of three aquaporin genes, such as AtTIP1;1, AtTIP2;3, and AtPIP2;2, indicating that TG directly regulates the expression of these genes. Moreover, overexpression of AtTIP1;1 resulted in vitrified phenotypes in transgenic Arabidopsis plants, similar to those observed in TG overexpression lines. Water injection into wild-type leaves recapitulated the vitrified leaf phenotypes, which was reversed by cutting off the water supply from vascular bundles. Taken together, our data support that TG controls water balance in Arabidopsis through directly activating the expression of aquaporin genes.展开更多
Amylose content(AC) is the main factor determining the palatability, viscosity, transparency, and digestibility of rice(Oryza sativa)grains. AC in rice grains is mainly controlled by different alleles of the Waxy(Wx) ...Amylose content(AC) is the main factor determining the palatability, viscosity, transparency, and digestibility of rice(Oryza sativa)grains. AC in rice grains is mainly controlled by different alleles of the Waxy(Wx) gene. The AP2/EREBP transcription factor OsEBP89 interacts with the MYC-like protein OsBP5 to synergistically regulate the expression of Wx.Here, we determined that the GLYCOGEN SYNTHASE KINASE 5(OsGSK5, also named SHAGGY-like kinase 41 [OsSK41]) inhibits the transcriptional activation activity of OsEBP89 in rice grains during amylose biosynthesis. The loss of OsSK41 function enhanced Wx expression and increased AC in rice grains. By contrast, the loss of function of OsEBP89 reduced Wx expression and decreased AC in rice grains. OsSK41 interacts with OsEBP89 and phosphorylates four of its sites(Thr-28,Thr-30, Ser-238, and Thr-257), which makes OsEBP89 unstable and attenuates its interaction with OsBP5. Wx promoter activity was relatively weak when regulated by the phosphomimicvariantOsEBP89E–OsBP5but relatively strong when regulated by the nonphosphorylatable variant OsEBP89A–OsBP5.Therefore, OsSK41-mediated phosphorylation of OsEBP89 represents an additional layer of complexity in the regulation of amylose biosynthesis during rice grain development. In addition, our findings provide four possible sites for regulating rice grain AC via precise gene editing.展开更多
AP2/EREBP transcription factors (TFs) play very important roles in plant development, hormonal regulation and stress response. Upon genome-wide cDNA cloning, phylogenetic and expression pattern analyses of this plant ...AP2/EREBP transcription factors (TFs) play very important roles in plant development, hormonal regulation and stress response. Upon genome-wide cDNA cloning, phylogenetic and expression pattern analyses of this plant specific TF family, we found that three of the members including At1g71450, At1g50680 and At5g13910, were likely involved in responses to ABA, cold and salt. Complementary DNAs containing putative full-length ORFs of these three TFs were obtained and fused individually to the GAL4 DNA-binding domains. All the 3 genes functioned effectively as trans-activators using yeast one-hybrid assays. RT-PCR experiments showed that the At1g71450 gene was induced by ABA and low temperature; the At1g50680 gene was responsive to quite a few stress conditions, but especially to freezing temperature; and the At5g13910 gene was induced by high salt treatment, drought and ethyl-ene. By searching the ABRC T-DNA insertion mutant stocks, we obtained knockout lines for these TFs. Homozygous ko1 (At1g71450) plants showed a hypersensitive response to ABA during seed germina-tion and also in stomata movement. Homozygous ko2 (At1g50680) plants showed a significant reduc-tion in plant freezing tolerance compared to the wild type after chilling treatment. Homozygous ko3 (At5g13910) were less tolerant to high salinity than wild type plants. Our data suggest that At1g71450 is a negative regulator in ABA signaling, while At1g50680 and At5g13910 are positive regulators in cold and salt stress responses, respectively.展开更多
AP2/EREBP家族的转录因子在调控植物生长发育和应答环境胁迫方面具有重要作用。利用同源克隆结合RACE(rapid-amplification of cDNA ends)技术,从四合木(Tetraena mongolica)中克隆了AP2/EREBP家族的基因,将其命名为TmAP2-1(GenBank登录...AP2/EREBP家族的转录因子在调控植物生长发育和应答环境胁迫方面具有重要作用。利用同源克隆结合RACE(rapid-amplification of cDNA ends)技术,从四合木(Tetraena mongolica)中克隆了AP2/EREBP家族的基因,将其命名为TmAP2-1(GenBank登录号:JQ676996)。序列分析结果表明,该基因的开放阅读框长度为1452bp,编码483个氨基酸;比对结果显示TmAP2-1有2个AP2/ERF结构域,属于AP2/EREBP转录因子家族的AP2亚家族。亚细胞定位实验结果表明,TmAP2-1定位在细胞核中。该基因编码的蛋白在酵母中没有转录激活活性。利用Real-timePCR检测发现该基因在根、茎、叶等器官中均表达,且在叶中表达量最高。此外,TmAP2-1还受到NaCl、低温、PEG和ABA的强烈诱导,推测TmAP2-1可能参与四合木的逆境胁迫响应。在四合木愈伤组织中过表达该基因能够降低四合木愈伤组织中油脂的含量,同时提高可溶性糖的含量,暗示该基因可能通过影响糖代谢过程参与逆境胁迫响应。展开更多
文摘AP2/EREBP(APETALA2/ethylene-responsive element binding proteins)是一个起源古老的转录因子超家族,它含有1个或2个由约60-70个氨基酸残基组成的非常保守的DNA结合域(DNA-bindingdomain),即AP2/ERF结构域。根据AP2/ERF结构域的数目,AP2/EREBP转录因子可以分为2个亚族:EREBP亚族(具有1个AP2/ERF结构域)和AP2亚族(具有2个AP2/ERF结构域)。AP2亚族转录因子有调控花、胚珠和种子发育的功能,而EREBP亚族转录因子(包括DREB类和ERF类)的主要功能是调节植物对激素(乙烯和ABA等)、病原和胁迫(低温、干旱及高盐)等的应答反应。本文讨论了AP2/EREBP转录因子在植物发育和胁迫应答中的研究进展。
文摘Water is the most abundant molecule in almost all living organisms. Aquaporins are channel proteins that play critical roles in controlling the water content of cells. Here, we report the identification of an AP2/EREBP family transcription factor in Arabidopsis thaliana, TRANSLUCENT GREEN (TG), whose overexpression in transgenic plants gave enhanced drought tolerance and vitrified leaves. TG protein is localized in the nucleus, binds DRE and GCC elements in vitro, and acts as a transcriptional activator in yeast cells. Microarray analysis revealed a total of 330 genes regulated by TG, among which five genes encode aquaporins. A transient expression assay showed that TG directly binds to the promoters of three aquaporin genes, such as AtTIP1;1, AtTIP2;3, and AtPIP2;2, indicating that TG directly regulates the expression of these genes. Moreover, overexpression of AtTIP1;1 resulted in vitrified phenotypes in transgenic Arabidopsis plants, similar to those observed in TG overexpression lines. Water injection into wild-type leaves recapitulated the vitrified leaf phenotypes, which was reversed by cutting off the water supply from vascular bundles. Taken together, our data support that TG controls water balance in Arabidopsis through directly activating the expression of aquaporin genes.
基金financially supported by the Innovation Program of Shanghai Municipal Education Commission (2023ZKZD05)the National Natural Science Foundation of China (31971918, 32172043)+1 种基金the Agriculture Research System of Shanghai, China (Grant No. 202203)the Shanghai Science and Technology Innovation Action Plan Project (22N11900200)。
文摘Amylose content(AC) is the main factor determining the palatability, viscosity, transparency, and digestibility of rice(Oryza sativa)grains. AC in rice grains is mainly controlled by different alleles of the Waxy(Wx) gene. The AP2/EREBP transcription factor OsEBP89 interacts with the MYC-like protein OsBP5 to synergistically regulate the expression of Wx.Here, we determined that the GLYCOGEN SYNTHASE KINASE 5(OsGSK5, also named SHAGGY-like kinase 41 [OsSK41]) inhibits the transcriptional activation activity of OsEBP89 in rice grains during amylose biosynthesis. The loss of OsSK41 function enhanced Wx expression and increased AC in rice grains. By contrast, the loss of function of OsEBP89 reduced Wx expression and decreased AC in rice grains. OsSK41 interacts with OsEBP89 and phosphorylates four of its sites(Thr-28,Thr-30, Ser-238, and Thr-257), which makes OsEBP89 unstable and attenuates its interaction with OsBP5. Wx promoter activity was relatively weak when regulated by the phosphomimicvariantOsEBP89E–OsBP5but relatively strong when regulated by the nonphosphorylatable variant OsEBP89A–OsBP5.Therefore, OsSK41-mediated phosphorylation of OsEBP89 represents an additional layer of complexity in the regulation of amylose biosynthesis during rice grain development. In addition, our findings provide four possible sites for regulating rice grain AC via precise gene editing.
基金the National Natural Science Foundation of China (Grant No.30221120261)
文摘AP2/EREBP transcription factors (TFs) play very important roles in plant development, hormonal regulation and stress response. Upon genome-wide cDNA cloning, phylogenetic and expression pattern analyses of this plant specific TF family, we found that three of the members including At1g71450, At1g50680 and At5g13910, were likely involved in responses to ABA, cold and salt. Complementary DNAs containing putative full-length ORFs of these three TFs were obtained and fused individually to the GAL4 DNA-binding domains. All the 3 genes functioned effectively as trans-activators using yeast one-hybrid assays. RT-PCR experiments showed that the At1g71450 gene was induced by ABA and low temperature; the At1g50680 gene was responsive to quite a few stress conditions, but especially to freezing temperature; and the At5g13910 gene was induced by high salt treatment, drought and ethyl-ene. By searching the ABRC T-DNA insertion mutant stocks, we obtained knockout lines for these TFs. Homozygous ko1 (At1g71450) plants showed a hypersensitive response to ABA during seed germina-tion and also in stomata movement. Homozygous ko2 (At1g50680) plants showed a significant reduc-tion in plant freezing tolerance compared to the wild type after chilling treatment. Homozygous ko3 (At5g13910) were less tolerant to high salinity than wild type plants. Our data suggest that At1g71450 is a negative regulator in ABA signaling, while At1g50680 and At5g13910 are positive regulators in cold and salt stress responses, respectively.
文摘AP2/EREBP家族的转录因子在调控植物生长发育和应答环境胁迫方面具有重要作用。利用同源克隆结合RACE(rapid-amplification of cDNA ends)技术,从四合木(Tetraena mongolica)中克隆了AP2/EREBP家族的基因,将其命名为TmAP2-1(GenBank登录号:JQ676996)。序列分析结果表明,该基因的开放阅读框长度为1452bp,编码483个氨基酸;比对结果显示TmAP2-1有2个AP2/ERF结构域,属于AP2/EREBP转录因子家族的AP2亚家族。亚细胞定位实验结果表明,TmAP2-1定位在细胞核中。该基因编码的蛋白在酵母中没有转录激活活性。利用Real-timePCR检测发现该基因在根、茎、叶等器官中均表达,且在叶中表达量最高。此外,TmAP2-1还受到NaCl、低温、PEG和ABA的强烈诱导,推测TmAP2-1可能参与四合木的逆境胁迫响应。在四合木愈伤组织中过表达该基因能够降低四合木愈伤组织中油脂的含量,同时提高可溶性糖的含量,暗示该基因可能通过影响糖代谢过程参与逆境胁迫响应。