In the past two decades, members of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE （SPL） family of transcription factors, first identified in Antirrhinum majus, have emerged as pivotal regulators of diverse biological p...In the past two decades, members of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE （SPL） family of transcription factors, first identified in Antirrhinum majus, have emerged as pivotal regulators of diverse biological processes in plants, including the timing of vegetative and reproductive phase change, leaf development, tillering/branching, plastochron, panicle/tassel architecture, fruit ripening, fertility, and response to stresses. Transcripts of a subset of SPLs are targeted for cleavage and/or translational repres- sion by microRNA156s （miR156s）. The levels of miR156s are regulated by both endogenous developmental cues and various external stimuli. Accumulating evidence shows that the regulatory circuit around the miR156/SPL module is highly conserved among phylogenetically distinct plant species, and plays impor- tant roles in regulating plant fitness, biomass, and yield. With the expanding knowledge and a mechanistic understanding of their roles and regulatory relationship, we can now harness the miR156/SPL module as a plethora of tools to genetically manipulate crops for optimal parameters in growth and development, and ultimately to maximize yield by intelligent design of crops.展开更多
During the course of their life cycles, plants undergo various morphological and physiological changes un- derlying juvenile-to-adult and adult-to-flowering phase transitions. To flower or not to flower is a key step ...During the course of their life cycles, plants undergo various morphological and physiological changes un- derlying juvenile-to-adult and adult-to-flowering phase transitions. To flower or not to flower is a key step of plasticity of a plant toward the start of its new life cycle. In addition to the previously revealed intrinsic genetic programs, exogenous cues, and endogenous cues, a class of small non-coding RNAs, microRNAs （miRNAs）, plays a key role in plants making the decision to flower by integrating into the known flowering pathways. This review highlights the age-dependent flowering pathway with a focus on a number of timing miRNAs in determining such a key process. The contributions of other miRNAs which exist mainly outside the age pathway are also discussed. Approaches to study the flowering-determining miRNAs, their inter- actions, and applications are presented.展开更多
Plant reproductive organs are vulnerable to heat, but regulation of heat-shock responses in inflorescence is largely uncharacterized. Here, we report that two of the SQUAMOSA PROMOTER BINDING PROTEIN- LIKE （SPL） tra...Plant reproductive organs are vulnerable to heat, but regulation of heat-shock responses in inflorescence is largely uncharacterized. Here, we report that two of the SQUAMOSA PROMOTER BINDING PROTEIN- LIKE （SPL） transcriptional factors in Arabidopsis, SPL1 and SPL12, act redundantly in thermotolerance at the reproductive stage. The spll-1 sp112-1 inflorescences displayed hypersensitivity to heat stress, whereas overexpression of SPL 1 or SPL 12 enhanced the thermotolerance in both Arabidopsis and tobacco. RNA sequencing revealed 1939 upregulated and 1479 downregulated genes in wild-type inflorescence upon heat stress, among which one-quarter （1,040） was misregulated in spll-1 sp112-1, indicating that SPL1 and SPL12 contribute greatly to the heat-triggered transcriptional reprogramming in inflorescence. Notably, heat stress induced a large number of abscisic acid （ABA） responsive genes, of which -39% were disturbed in heat induction in spll-1 sp112-1 inflorescence. Preapplication of ABA and overex- pression of SPL1 restored the inflorescence thermotolerance in spll-1 sp112-1 and in the ABA biosynthesis mutant aba2-1, but not in the pyl sextuple mutant defective in ABA receptors PYR 1/PYL 1/PYL2/PYL4/PYL5/ PYL8. Thus, inflorescence thermotolerance conferred by SPL1 and SPL2 involves PYL-mediated ABA signaling. The molecular network consisting of SPL1 and SPL12 illustrated here shed new light on the mechanisms of plant thermotolerance at the reproductive stage.展开更多
Environmental sensitivity varies across developmental phases in flowering plants. In the juvenile phase, mi- croRNA156 （miR156）-mediated repression of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE （SPL） transcription fac...Environmental sensitivity varies across developmental phases in flowering plants. In the juvenile phase, mi- croRNA156 （miR156）-mediated repression of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE （SPL） transcription factors renders Arabidopsis plants incompetent to floral inductive signals, including long- day （LD） photoperiod. During the vegetative phase transition, which accompanies a reduction of miR156 and a concomitant elevation of its targets, plants acquire reproductive competence such that LD signals promote flowering. However, it remains largely unknown how developmental signals are associated with photoperiodic flowering. Here, we show that SPL3, SPL4, and SPL5 （SPL3/4/5） potentiate the FLOWERING LOCUS T （FT）-FD module in photoperiodic flowering. SPL3/4/5 function as transcriptional activators through the interaction with FD, a basic leucine zipper transcription factor which plays a critical role in photoperiodic flowering. SPL3/4/5 can directly bind to the promoters of APETALA1, LEAFY, and FRUITFULL, thus mediating their activation by the FT-FD complex. Our findings demonstrate that SPL3/ 4/5 act synergistically with the FT-FD module to induce flowering under LDs, providing a long-sought mo- lecular knob that links developmental aging and photoperiodic flowering.展开更多
BRASSINAZOLE-RESISTANT 1 family proteins(BZRs)are central transcription factors that govern brassinosteroid(BR)-regulated gene expression and plant growth.However,it is unclear whether there exists a BZR-independent p...BRASSINAZOLE-RESISTANT 1 family proteins(BZRs)are central transcription factors that govern brassinosteroid(BR)-regulated gene expression and plant growth.However,it is unclear whether there exists a BZR-independent pathway that mediates BR signaling.In this study,we found that disruption of all BZRs in Arabidopsis generated a hextuple mutant(bzr-h)displaying vegetative growth phenotypes that were almost identical to those of the null mutant of three BR receptors,bri1brl1brl3(bri-t).By RNA sequencing,we found that global gene expression in bzr-h was unaffected by 2 h of BR treatment.The anthers of bzr-h plants were loculeless,but a similar phenotype was not observed in bri-t,suggesting that BZRs have a BR signaling-independent regulatory role in anther development.By real-time PCR and in situ hybridization,we found that the expression of SPOROCYTELESS(SPL),which encodes a transcription factor essential for anther locule development,was barely detectable in bzr-h,suggesting that BZRs regulate locule development by affecting SPL expression.Our findings reveal that BZRs are indispensable transcription factors required for both BR signaling and anther locule development,providing new insight into the molecular mechanisms underlying the microsporogenesis in Arabidopsis.展开更多
SPL(squamosa promoter-binding protein like)基因家族是植物特有的一类转录因子,主要通过结合下游基因启动子区的顺式作用元件GTAC基序,从而参与调控下游基因的表达。SPLs转录因子在植物的生长发育、信号传导、应答环境胁迫等方面有...SPL(squamosa promoter-binding protein like)基因家族是植物特有的一类转录因子,主要通过结合下游基因启动子区的顺式作用元件GTAC基序,从而参与调控下游基因的表达。SPLs转录因子在植物的生长发育、信号传导、应答环境胁迫等方面有着重要的作用。目前研究表明,大豆SPL转录因子在参与调控大豆植株分枝数,产量和生育期等方面扮演重要作用。文章首先从该家族转录因子的克隆入手,回顾该基因家族的由来历史,然后介绍其结构上的保守性和独特性,最后重点综述SPL转录因子在植物中的调控网络,及其生物学功能,并对其在大豆及其它农作物生产上的应用前景及其调控植物性状的具体机制进行展望。展开更多
WRKY12 and WRKY13 are two WRKY transcription factors that play important roles in the control of flowering time under short-day(SD)conditions.The temporally regulated expression of WRKY12 and WRKY13 indicates that the...WRKY12 and WRKY13 are two WRKY transcription factors that play important roles in the control of flowering time under short-day(SD)conditions.The temporally regulated expression of WRKY12 and WRKY13 indicates that they may be involved in the age-mediated flowering pathway.However,their roles in this pathway are poorly understood.Here,we show that the transcription of WRKY12 and WRKY13 is directly regulated by SQUAMOSA PROMOTER BINDING-LIKE 10(SPLio),a transcription factor downstream of the age pathway.Binding and activation analyses revealed that SPL10 functions as a positive regulator of WRKY12 and a negative regulator of WRKY13.Further mechanistic investigation revealed that WRKY12 and WRKY13 physically interact with SPL10 and that both of them bind to the promoter of miRiy2b.Thus,the WRKY12-SPL10 and WRKY13-SPL10 interactions facilitate and inhibit SPL10 transcriptional function,respectively,to regulate miRiy2b expression.Together,our results show that WRKY12 and WRKY13 participate in the control of age-mediated flowering under SD conditions though physically interacting with SPLs and co-regulating the target gene miRi72b.展开更多
文摘In the past two decades, members of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE （SPL） family of transcription factors, first identified in Antirrhinum majus, have emerged as pivotal regulators of diverse biological processes in plants, including the timing of vegetative and reproductive phase change, leaf development, tillering/branching, plastochron, panicle/tassel architecture, fruit ripening, fertility, and response to stresses. Transcripts of a subset of SPLs are targeted for cleavage and/or translational repres- sion by microRNA156s （miR156s）. The levels of miR156s are regulated by both endogenous developmental cues and various external stimuli. Accumulating evidence shows that the regulatory circuit around the miR156/SPL module is highly conserved among phylogenetically distinct plant species, and plays impor- tant roles in regulating plant fitness, biomass, and yield. With the expanding knowledge and a mechanistic understanding of their roles and regulatory relationship, we can now harness the miR156/SPL module as a plethora of tools to genetically manipulate crops for optimal parameters in growth and development, and ultimately to maximize yield by intelligent design of crops.
文摘During the course of their life cycles, plants undergo various morphological and physiological changes un- derlying juvenile-to-adult and adult-to-flowering phase transitions. To flower or not to flower is a key step of plasticity of a plant toward the start of its new life cycle. In addition to the previously revealed intrinsic genetic programs, exogenous cues, and endogenous cues, a class of small non-coding RNAs, microRNAs （miRNAs）, plays a key role in plants making the decision to flower by integrating into the known flowering pathways. This review highlights the age-dependent flowering pathway with a focus on a number of timing miRNAs in determining such a key process. The contributions of other miRNAs which exist mainly outside the age pathway are also discussed. Approaches to study the flowering-determining miRNAs, their inter- actions, and applications are presented.
文摘Plant reproductive organs are vulnerable to heat, but regulation of heat-shock responses in inflorescence is largely uncharacterized. Here, we report that two of the SQUAMOSA PROMOTER BINDING PROTEIN- LIKE （SPL） transcriptional factors in Arabidopsis, SPL1 and SPL12, act redundantly in thermotolerance at the reproductive stage. The spll-1 sp112-1 inflorescences displayed hypersensitivity to heat stress, whereas overexpression of SPL 1 or SPL 12 enhanced the thermotolerance in both Arabidopsis and tobacco. RNA sequencing revealed 1939 upregulated and 1479 downregulated genes in wild-type inflorescence upon heat stress, among which one-quarter （1,040） was misregulated in spll-1 sp112-1, indicating that SPL1 and SPL12 contribute greatly to the heat-triggered transcriptional reprogramming in inflorescence. Notably, heat stress induced a large number of abscisic acid （ABA） responsive genes, of which -39% were disturbed in heat induction in spll-1 sp112-1 inflorescence. Preapplication of ABA and overex- pression of SPL1 restored the inflorescence thermotolerance in spll-1 sp112-1 and in the ABA biosynthesis mutant aba2-1, but not in the pyl sextuple mutant defective in ABA receptors PYR 1/PYL 1/PYL2/PYL4/PYL5/ PYL8. Thus, inflorescence thermotolerance conferred by SPL1 and SPL2 involves PYL-mediated ABA signaling. The molecular network consisting of SPL1 and SPL12 illustrated here shed new light on the mechanisms of plant thermotolerance at the reproductive stage.
文摘Environmental sensitivity varies across developmental phases in flowering plants. In the juvenile phase, mi- croRNA156 （miR156）-mediated repression of SQUAMOSA PROMOTER-BINDING PROTEIN-LIKE （SPL） transcription factors renders Arabidopsis plants incompetent to floral inductive signals, including long- day （LD） photoperiod. During the vegetative phase transition, which accompanies a reduction of miR156 and a concomitant elevation of its targets, plants acquire reproductive competence such that LD signals promote flowering. However, it remains largely unknown how developmental signals are associated with photoperiodic flowering. Here, we show that SPL3, SPL4, and SPL5 （SPL3/4/5） potentiate the FLOWERING LOCUS T （FT）-FD module in photoperiodic flowering. SPL3/4/5 function as transcriptional activators through the interaction with FD, a basic leucine zipper transcription factor which plays a critical role in photoperiodic flowering. SPL3/4/5 can directly bind to the promoters of APETALA1, LEAFY, and FRUITFULL, thus mediating their activation by the FT-FD complex. Our findings demonstrate that SPL3/ 4/5 act synergistically with the FT-FD module to induce flowering under LDs, providing a long-sought mo- lecular knob that links developmental aging and photoperiodic flowering.
基金grants from the National Natural Science Foundation of China(91417313 to W.T.)the Department of Education of Hebei Province(LJRC015 to W.T.)the "One Hundred Talents Project"of Hebei Province(E2013100004 to Y.S.).
文摘BRASSINAZOLE-RESISTANT 1 family proteins(BZRs)are central transcription factors that govern brassinosteroid(BR)-regulated gene expression and plant growth.However,it is unclear whether there exists a BZR-independent pathway that mediates BR signaling.In this study,we found that disruption of all BZRs in Arabidopsis generated a hextuple mutant(bzr-h)displaying vegetative growth phenotypes that were almost identical to those of the null mutant of three BR receptors,bri1brl1brl3(bri-t).By RNA sequencing,we found that global gene expression in bzr-h was unaffected by 2 h of BR treatment.The anthers of bzr-h plants were loculeless,but a similar phenotype was not observed in bri-t,suggesting that BZRs have a BR signaling-independent regulatory role in anther development.By real-time PCR and in situ hybridization,we found that the expression of SPOROCYTELESS(SPL),which encodes a transcription factor essential for anther locule development,was barely detectable in bzr-h,suggesting that BZRs regulate locule development by affecting SPL expression.Our findings reveal that BZRs are indispensable transcription factors required for both BR signaling and anther locule development,providing new insight into the molecular mechanisms underlying the microsporogenesis in Arabidopsis.
文摘SPL(squamosa promoter-binding protein like)基因家族是植物特有的一类转录因子,主要通过结合下游基因启动子区的顺式作用元件GTAC基序,从而参与调控下游基因的表达。SPLs转录因子在植物的生长发育、信号传导、应答环境胁迫等方面有着重要的作用。目前研究表明,大豆SPL转录因子在参与调控大豆植株分枝数,产量和生育期等方面扮演重要作用。文章首先从该家族转录因子的克隆入手,回顾该基因家族的由来历史,然后介绍其结构上的保守性和独特性,最后重点综述SPL转录因子在植物中的调控网络,及其生物学功能,并对其在大豆及其它农作物生产上的应用前景及其调控植物性状的具体机制进行展望。
基金The authors thank Jia-wei Wang(Institute of Plant Physiology and Ecology,Shanghai Institutes for Biological Sciences)for sharing research materials.This work was supported by the Natural Science Foundation of China(3180102331671274)+2 种基金the Young Elite Scientists Sponsorship Program by CAST(2017QNRC001)the Youth Innovation Promotion Association CAS(to H.W.)the CAS "Light of West China"Program(to H.W.),and the program for Innovative Research Team of Yunnan Province(2014HC017).
文摘WRKY12 and WRKY13 are two WRKY transcription factors that play important roles in the control of flowering time under short-day(SD)conditions.The temporally regulated expression of WRKY12 and WRKY13 indicates that they may be involved in the age-mediated flowering pathway.However,their roles in this pathway are poorly understood.Here,we show that the transcription of WRKY12 and WRKY13 is directly regulated by SQUAMOSA PROMOTER BINDING-LIKE 10(SPLio),a transcription factor downstream of the age pathway.Binding and activation analyses revealed that SPL10 functions as a positive regulator of WRKY12 and a negative regulator of WRKY13.Further mechanistic investigation revealed that WRKY12 and WRKY13 physically interact with SPL10 and that both of them bind to the promoter of miRiy2b.Thus,the WRKY12-SPL10 and WRKY13-SPL10 interactions facilitate and inhibit SPL10 transcriptional function,respectively,to regulate miRiy2b expression.Together,our results show that WRKY12 and WRKY13 participate in the control of age-mediated flowering under SD conditions though physically interacting with SPLs and co-regulating the target gene miRi72b.
