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 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 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
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.
