Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that ...Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that bolts easily with a shorter photoperiod than European spinach. This is one of the main reasons that Oriental spinach is difficult to grow year-round. In order to understand spinach flowering mechanisms and obtain knowledge for spinach breeding, we isolated one CONSTANS-like (COL) and two FLOWERING LOCUS T (FT) homologs, which are key components of photoperiodic regulation of flowering time, from a Japanese cultivar. The expression of SoCOL1 showed diurnal rhythm with the highest expression at the end of the dark cycle. This diurnal rhythm is similar to the expression of BvCOL1 from sugar beet (Beta vulgaris), whose flower-promoting effect was observed when overexpressed in Arabidopsis. Phylogenetic analysis showed that SoCOL1 is the closest homolog of BvCOL1, suggesting that SoCOL1 is an ortholog of BvCOL1. SoFT1 and SoFT2 are closely related to BvFT1 and BvFT2, respectively. The expression of SoFT1 and SoFT2 were induced in advance of flower bud formation after changing the photoperiod, but the expression level of SoFT1 was much lower than SoFT2. Currently, we are speculating that SoFT2 is a flower-promoting factor of spinach, and that SoFT1 has a role in light signaling because the expression of SoFT1 showed a diurnal rhythm.展开更多
Plants have evolved a remarkable ability to sense and respond to changes in photoperiod,allowing adjustments to their growth and development based on seasonal and environmental cues.The floral transition is a pivotal ...Plants have evolved a remarkable ability to sense and respond to changes in photoperiod,allowing adjustments to their growth and development based on seasonal and environmental cues.The floral transition is a pivotal stage in plant growth and development,signifying a shift from vegetative to reproductive growth.CONSTANS(CO),a central photoperiodic response factor conserved in various plants,mediates day-length signals to control the floral transition,although its mechanisms of action vary among plants with different day-length requirements.In addition,recent studies have uncovered roles for CO in organ development and stress responses.These pleiotropic roles in model plants and crops make CO a potentially fruitful target for molecular breeding aimed at modifying crop agronomic traits.This review systematically traces research on CO,from its discovery and functional studies to the exploration of its regulatory mechanisms and newly discovered functions,providing important insight into the roles of CO and laying a foundation for future research.展开更多
Plants monitor daylength to synchronize their flowering time with their surroundings and thus maximize reproductive fitness.In Arabidopsis(Arabidopsis thaliana),CONSTANS(CO)activates the expression of FLOWERING LOCUS ...Plants monitor daylength to synchronize their flowering time with their surroundings and thus maximize reproductive fitness.In Arabidopsis(Arabidopsis thaliana),CONSTANS(CO)activates the expression of FLOWERING LOCUS T(FT);this activation is a crucial aspect of the daylength-dependent regulation of flowering time.Here,we demonstrate that the basic leucine zipper 3(bZIP3)transcription factor is important for CO-induced FT expression under long photoperiod conditions in Arabidopsis.We isolated bZIP3 as a CO-interacting protein by yeast two-hybrid screening and verified bZIP3-CO complex formation in Arabidopsis through coimmunoprecipitation assays.The temporal and spatial expression patterns of bZIP3 are very similar to those of CO,and bZIP3 protein levels fluctuate throughout the day,with high abundance in the late afternoon.The bzip3 mutant displayed delayed flowering under long photoperiods,whereas bZIP3 overexpression accelerated flowering regardless of daylength.bZIP3 directly binds to the FT promoter region containing CO-responsive elements in vivo.FT messenger RNA(m RNA)levels in the bzip3 mutant and bZIP3 overexpression lines correlated with their flowering times and changed only during the daytime.bZIP3 overexpression resulted in significantly lower FT transcript levels in the co mutant background than in the wild type.Furthermore,bZIP3 forms a complex with ASYMMETRIC LEAVES1(AS1),a CO partner that helps CO induce FT expression.The bzip3 as1 double mutant flowered later than the two single mutants under longer daylengths,and FT mRNA levels were much lower in the double mutant than in the bzip3 single mutant.Collectively,our findings uncover a new layer of photoperiod-dependent FT regulation in which bZIP3 facilitates CO to activate FT transcription by forming a complex with AS1.展开更多
Plants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the environment.Among these processes,the floral transition is essential to ensure reproductive success and is finely...Plants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the environment.Among these processes,the floral transition is essential to ensure reproductive success and is finelyregulated by several internal andexternal genetic networks.The photoperiodic pathway,which controls plant response to day length,is one of the most important pathways controlling flowering.In Arabidopsis photoperiodic flowering,CONSTANS(CO)is the central gene activating the expression of the florigen FLOWERING LOCUS T(FT)in the leaves at the end of a long day.The circadian clock strongly regulates Co expression.However,to date,no evidence has been reported regarding a feedbackloop from the photoperiod pathway back to the circadian clock.Using transcriptional networks,we have identified relevant network motifs regulating the interplay between the circadian clock and the photoperiod pathway.Gene expression,chromatin immunoprecipitation experiments,and phenotypic analysis allowed us to elucidate the role of Co over the circadian clock.Plants with altered cO expression showed a different internal clock period,measured by daily leaf rhythmic movements.We showed that co upregulates the expression of key genes related to the circadian clock,such as CCA1,LHY,PRR5,and Gl,at the end of a long day by bindingto specific sites on their promoters.Moreover,a high numberof PRR5-repressed target genes are upregulated by CO,and this could explain the phase transition promoted by CO.The CO-PRR5 complex interacts with the bZiP transcriptionfactor HY5andhelps to localize the complex in the promoters of clock genes.Taken together,our results indicate that there may be a feedback loop in which co communicates back to the circadian clock,providing seasonal information to the circadian system.展开更多
文摘Spinach (Spinacia oleracea L.) develops leaf rosettes under short-day conditions, and starts reproductive growth including bolting and flowering under long-day conditions. Japanese people prefer Oriental spinach that bolts easily with a shorter photoperiod than European spinach. This is one of the main reasons that Oriental spinach is difficult to grow year-round. In order to understand spinach flowering mechanisms and obtain knowledge for spinach breeding, we isolated one CONSTANS-like (COL) and two FLOWERING LOCUS T (FT) homologs, which are key components of photoperiodic regulation of flowering time, from a Japanese cultivar. The expression of SoCOL1 showed diurnal rhythm with the highest expression at the end of the dark cycle. This diurnal rhythm is similar to the expression of BvCOL1 from sugar beet (Beta vulgaris), whose flower-promoting effect was observed when overexpressed in Arabidopsis. Phylogenetic analysis showed that SoCOL1 is the closest homolog of BvCOL1, suggesting that SoCOL1 is an ortholog of BvCOL1. SoFT1 and SoFT2 are closely related to BvFT1 and BvFT2, respectively. The expression of SoFT1 and SoFT2 were induced in advance of flower bud formation after changing the photoperiod, but the expression level of SoFT1 was much lower than SoFT2. Currently, we are speculating that SoFT2 is a flower-promoting factor of spinach, and that SoFT1 has a role in light signaling because the expression of SoFT1 showed a diurnal rhythm.
基金support from the National Key R&D Program of China(2021YFF1001203)the National Natural Science Foundation of China(Nos.32270374 and 31900212)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515012406)the Guangzhou Municipal Science and Technology Project(No.202201010641)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)the Youth Innovation Promotion Association,Chinese Academy of Sciences(No.2023362)。
文摘Plants have evolved a remarkable ability to sense and respond to changes in photoperiod,allowing adjustments to their growth and development based on seasonal and environmental cues.The floral transition is a pivotal stage in plant growth and development,signifying a shift from vegetative to reproductive growth.CONSTANS(CO),a central photoperiodic response factor conserved in various plants,mediates day-length signals to control the floral transition,although its mechanisms of action vary among plants with different day-length requirements.In addition,recent studies have uncovered roles for CO in organ development and stress responses.These pleiotropic roles in model plants and crops make CO a potentially fruitful target for molecular breeding aimed at modifying crop agronomic traits.This review systematically traces research on CO,from its discovery and functional studies to the exploration of its regulatory mechanisms and newly discovered functions,providing important insight into the roles of CO and laying a foundation for future research.
基金supported partly by the grant from the National Institutes of Health Grant(No.R01GM079712 to T.I.)the Basic Science Research Program through the National Research Foundation(NRF)of Korea funded by the Ministry of Education(Nos.RS-2020-NR04950 and 2020R1A6A1A03044344 to W.S.C.)supported by the National Research Foundation(NRF)of Korea grant funded by the Korean government(MSIT)(No.RS-2024-00336624 to J.C.H.and No.2021R1A4A1032888 and No.RS-2025-00562751 to Y.H.S.)。
文摘Plants monitor daylength to synchronize their flowering time with their surroundings and thus maximize reproductive fitness.In Arabidopsis(Arabidopsis thaliana),CONSTANS(CO)activates the expression of FLOWERING LOCUS T(FT);this activation is a crucial aspect of the daylength-dependent regulation of flowering time.Here,we demonstrate that the basic leucine zipper 3(bZIP3)transcription factor is important for CO-induced FT expression under long photoperiod conditions in Arabidopsis.We isolated bZIP3 as a CO-interacting protein by yeast two-hybrid screening and verified bZIP3-CO complex formation in Arabidopsis through coimmunoprecipitation assays.The temporal and spatial expression patterns of bZIP3 are very similar to those of CO,and bZIP3 protein levels fluctuate throughout the day,with high abundance in the late afternoon.The bzip3 mutant displayed delayed flowering under long photoperiods,whereas bZIP3 overexpression accelerated flowering regardless of daylength.bZIP3 directly binds to the FT promoter region containing CO-responsive elements in vivo.FT messenger RNA(m RNA)levels in the bzip3 mutant and bZIP3 overexpression lines correlated with their flowering times and changed only during the daytime.bZIP3 overexpression resulted in significantly lower FT transcript levels in the co mutant background than in the wild type.Furthermore,bZIP3 forms a complex with ASYMMETRIC LEAVES1(AS1),a CO partner that helps CO induce FT expression.The bzip3 as1 double mutant flowered later than the two single mutants under longer daylengths,and FT mRNA levels were much lower in the double mutant than in the bzip3 single mutant.Collectively,our findings uncover a new layer of photoperiod-dependent FT regulation in which bZIP3 facilitates CO to activate FT transcription by forming a complex with AS1.
基金a European Union contract LONGFLOW,MSCAIF-2018-838317 and CSIC LONGFLOW,CONV_EXT_014.The financial support of the Spanish Ministry for Science and Innovations(MICINN/FEDER)PID2020-117018RB-I00 to F.V.is also acknowledged.We thank Prof.George Coupland(MPiPZ,Cologne,Germany)for discussion and critical reading of the manuscript.
文摘Plants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the environment.Among these processes,the floral transition is essential to ensure reproductive success and is finelyregulated by several internal andexternal genetic networks.The photoperiodic pathway,which controls plant response to day length,is one of the most important pathways controlling flowering.In Arabidopsis photoperiodic flowering,CONSTANS(CO)is the central gene activating the expression of the florigen FLOWERING LOCUS T(FT)in the leaves at the end of a long day.The circadian clock strongly regulates Co expression.However,to date,no evidence has been reported regarding a feedbackloop from the photoperiod pathway back to the circadian clock.Using transcriptional networks,we have identified relevant network motifs regulating the interplay between the circadian clock and the photoperiod pathway.Gene expression,chromatin immunoprecipitation experiments,and phenotypic analysis allowed us to elucidate the role of Co over the circadian clock.Plants with altered cO expression showed a different internal clock period,measured by daily leaf rhythmic movements.We showed that co upregulates the expression of key genes related to the circadian clock,such as CCA1,LHY,PRR5,and Gl,at the end of a long day by bindingto specific sites on their promoters.Moreover,a high numberof PRR5-repressed target genes are upregulated by CO,and this could explain the phase transition promoted by CO.The CO-PRR5 complex interacts with the bZiP transcriptionfactor HY5andhelps to localize the complex in the promoters of clock genes.Taken together,our results indicate that there may be a feedback loop in which co communicates back to the circadian clock,providing seasonal information to the circadian system.
