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Chu LL, Zheng WX, Liu HQ, Sheng XX, Wang QY, Wang Y, Hu CG, Zhang JZ. ACC SYNTHASE4 inhibits gibberellin biosynthesis and FLOWERING LOCUS T expression during citrus flowering. PLANT PHYSIOLOGY 2024; 195:479-501. [PMID: 38227428 DOI: 10.1093/plphys/kiae022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 01/17/2024]
Abstract
Flowering is an essential process in fruit trees. Flower number and timing have a substantial impact on the yield and maturity of fruit. Ethylene and gibberellin (GA) play vital roles in flowering, but the mechanism of coordinated regulation of flowering in woody plants by GA and ethylene is still unclear. In this study, a lemon (Citrus limon L. Burm) 1-aminocyclopropane-1-carboxylic acid synthase gene (CiACS4) was overexpressed in Nicotiana tabacum and resulted in late flowering and increased flower number. Further transformation of citrus revealed that ethylene and starch content increased, and soluble sugar content decreased in 35S:CiACS4 lemon. Inhibition of CiACS4 in lemon resulted in effects opposite to that of 35S:CiACS4 in transgenic plants. Overexpression of the CiACS4-interacting protein ETHYLENE RESPONSE FACTOR3 (CiERF3) in N. tabacum resulted in delayed flowering and more flowers. Further experiments revealed that the CiACS4-CiERF3 complex can bind the promoters of FLOWERING LOCUS T (CiFT) and GOLDEN2-LIKE (CiFE) and suppress their expression. Moreover, overexpression of CiFE in N. tabacum led to early flowering and decreased flowers, and ethylene, starch, and soluble sugar contents were opposite to those in 35S:CiACS4 transgenic plants. Interestingly, CiFE also bound the promoter of CiFT. Additionally, GA3 and 1-aminocyclopropanecarboxylic acid (ACC) treatments delayed flowering in adult citrus, and treatment with GA and ethylene inhibitors increased flower number. ACC treatment also inhibited the expression of CiFT and CiFE. This study provides a theoretical basis for the application of ethylene to regulate flower number and mitigate the impacts of extreme weather on citrus yield due to delayed flowering.
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Affiliation(s)
- Le-Le Chu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Wei-Xuan Zheng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Hai-Qiang Liu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Xing-Xing Sheng
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Qing-Ye Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Yue Wang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Chun-Gen Hu
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Jin-Zhi Zhang
- National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
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Kaur H, Manchanda P, Sidhu GS, Chhuneja P. Genome-wide identification and characterization of flowering genes in Citrus sinensis (L.) Osbeck: a comparison among C. Medica L., C. Reticulata Blanco, C. Grandis (L.) Osbeck and C. Clementina. BMC Genom Data 2024; 25:20. [PMID: 38378481 PMCID: PMC10880302 DOI: 10.1186/s12863-024-01201-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 01/30/2024] [Indexed: 02/22/2024] Open
Abstract
BACKGROUND Flowering plays an important role in completing the reproductive cycle of plants and obtaining next generation of plants. In case of citrus, it may take more than a year to achieve progeny. Therefore, in order to fasten the breeding processes, the juvenility period needs to be reduced. The juvenility in plants is regulated by set of various flowering genes. The citrus fruit and leaves possess various medicinal properties and are subjected to intensive breeding programs to produce hybrids with improved quality traits. In order to break juvenility in Citrus, it is important to study the role of flowering genes. The present study involved identification of genes regulating flowering in Citrus sinensis L. Osbeck via homology based approach. The structural and functional characterization of these genes would help in targeting genome editing techniques to induce mutations in these genes for producing desirable results. RESULTS A total of 43 genes were identified which were located on all the 9 chromosomes of citrus. The in-silico analysis was performed to determine the genetic structure, conserved motifs, cis-regulatory elements (CREs) and phylogenetic relationship of the genes. A total of 10 CREs responsible for flowering were detected in 33 genes and 8 conserved motifs were identified in all the genes. The protein structure, protein-protein interaction network and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was performed to study the functioning of these genes which revealed the involvement of flowering proteins in circadian rhythm pathways. The gene ontology (GO) and gene function analysis was performed to functionally annotate the genes. The structure of the genes and proteins were also compared among other Citrus species to study the evolutionary relationship among them. The expression study revealed the expression of flowering genes in floral buds and ovaries. The qRT-PCR analysis revealed that the flowering genes were highly expressed in bud stage, fully grown flower and early stage of fruit development. CONCLUSIONS The findings suggested that the flowering genes were highly conserved in citrus species. The qRT-PCR analysis revealed the tissue specific expression of flowering genes (CsFT, CsCO, CsSOC, CsAP, CsSEP and CsLFY) which would help in easy detection and targeting of genes through various forward and reverse genetic approaches.
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Affiliation(s)
- Harleen Kaur
- School of Agricultural Biotechnology, College of Agriculture, Punjab Agricultural University, Ludhiana, 141001, Punjab, India
| | - Pooja Manchanda
- School of Agricultural Biotechnology, College of Agriculture, Punjab Agricultural University, Ludhiana, 141001, Punjab, India.
| | - Gurupkar S Sidhu
- School of Agricultural Biotechnology, College of Agriculture, Punjab Agricultural University, Ludhiana, 141001, Punjab, India
| | - Parveen Chhuneja
- School of Agricultural Biotechnology, College of Agriculture, Punjab Agricultural University, Ludhiana, 141001, Punjab, India
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Lee Z, Kim S, Choi SJ, Joung E, Kwon M, Park HJ, Shim JS. Regulation of Flowering Time by Environmental Factors in Plants. PLANTS (BASEL, SWITZERLAND) 2023; 12:3680. [PMID: 37960036 PMCID: PMC10649094 DOI: 10.3390/plants12213680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/19/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023]
Abstract
The timing of floral transition is determined by both endogenous molecular pathways and external environmental conditions. Among these environmental conditions, photoperiod acts as a cue to regulate the timing of flowering in response to seasonal changes. Additionally, it has become clear that various environmental factors also control the timing of floral transition. Environmental factor acts as either a positive or negative signal to modulate the timing of flowering, thereby establishing the optimal flowering time to maximize the reproductive success of plants. This review aims to summarize the effects of environmental factors such as photoperiod, light intensity, temperature changes, vernalization, drought, and salinity on the regulation of flowering time in plants, as well as to further explain the molecular mechanisms that link environmental factors to the internal flowering time regulation pathway.
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Affiliation(s)
- Zion Lee
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea; (Z.L.); (S.K.); (S.J.C.); (E.J.)
| | - Sohyun Kim
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea; (Z.L.); (S.K.); (S.J.C.); (E.J.)
| | - Su Jeong Choi
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea; (Z.L.); (S.K.); (S.J.C.); (E.J.)
| | - Eui Joung
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea; (Z.L.); (S.K.); (S.J.C.); (E.J.)
| | - Moonhyuk Kwon
- Division of Life Science, ABC-RLRC, PMBBRC, Gyeongsang National University, Jinju 52828, Republic of Korea;
| | - Hee Jin Park
- Department of Biological Sciences and Research Center of Ecomimetics, College of Natural Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jae Sung Shim
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea; (Z.L.); (S.K.); (S.J.C.); (E.J.)
- Institute of Synthetic Biology for Carbon Neutralization, Chonnam National University, Gwangju 61186, Republic of Korea
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Takagi H, Hempton AK, Imaizumi T. Photoperiodic flowering in Arabidopsis: Multilayered regulatory mechanisms of CONSTANS and the florigen FLOWERING LOCUS T. PLANT COMMUNICATIONS 2023; 4:100552. [PMID: 36681863 PMCID: PMC10203454 DOI: 10.1016/j.xplc.2023.100552] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 12/20/2022] [Accepted: 01/18/2023] [Indexed: 05/11/2023]
Abstract
The timing of flowering affects the success of sexual reproduction. This developmental event also determines crop yield, biomass, and longevity. Therefore, this mechanism has been targeted for improvement along with crop domestication. The underlying mechanisms of flowering are highly conserved in angiosperms. Central to these mechanisms is how environmental and endogenous conditions control transcriptional regulation of the FLOWERING LOCUS T (FT) gene, which initiates floral development under long-day conditions in Arabidopsis. Since the identification of FT as florigen, efforts have been made to understand the regulatory mechanisms of FT expression. Although many transcriptional regulators have been shown to directly influence FT, the question of how they coordinately control the spatiotemporal expression patterns of FT still requires further investigation. Among FT regulators, CONSTANS (CO) is the primary one whose protein stability is tightly controlled by phosphorylation and ubiquitination/proteasome-mediated mechanisms. In addition, various CO interaction partners, some of them previously identified as FT transcriptional regulators, positively or negatively modulate CO protein activity. The FT promoter possesses several transcriptional regulatory "blocks," highly conserved regions among Brassicaceae plants. Different transcription factors bind to specific blocks and affect FT expression, often causing topological changes in FT chromatin structure, such as the formation of DNA loops. We discuss the current understanding of the regulation of FT expression mainly in Arabidopsis and propose future directions related to this topic.
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Affiliation(s)
- Hiroshi Takagi
- Department of Biology, University of Washington, Seattle, WA 98195-1800, USA; Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
| | - Andrew K Hempton
- Department of Biology, University of Washington, Seattle, WA 98195-1800, USA
| | - Takato Imaizumi
- Department of Biology, University of Washington, Seattle, WA 98195-1800, USA; Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan.
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Zhou H, Zeng RF, Liu TJ, Ai XY, Ren MK, Zhou JJ, Hu CG, Zhang JZ. Drought and low temperature-induced NF-YA1 activates FT expression to promote citrus flowering. PLANT, CELL & ENVIRONMENT 2022; 45:3505-3522. [PMID: 36117312 DOI: 10.1111/pce.14442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Flower induction in adult citrus is mainly regulated by drought and low temperatures. However, the mechanism of FLOWERING LOCUS T regulation of citrus flowering (CiFT) under two flower-inductive stimuli remains largely unclear. In this study, a citrus transcription factor, nuclear factor YA (CiNF-YA1), was found to specifically bind to the CiFT promoter by forming a complex with CiNF-YB2 and CiNF-YC2 to activate CiFT expression. CiNF-YA1 was induced in juvenile citrus by low temperature and drought treatments. Overexpression of CiNF-YA1 increased drought susceptibility in transgenic citrus, whereas suppression of CiNF-YA1 enhanced drought tolerance in silenced citrus plants. Furthermore, a GOLDEN2 - LIKE protein (CiFE) that interacts with CiFT protein was also isolated. Further experimental evidence showed that CiFE binds to the citrus LEAFY (CiLFY) promoter and activates its expression. In addition, the expressions of CiNF-YA1 and CiFE showed a seasonal increase during the floral induction period and were induced by artificial drought and low-temperature treatments at which floral induction occurred. These results indicate that CiNF-YA1 may activate CiFT expression in response to drought and low temperatures by binding to the CiFT promoter. CiFT then forms a complex with CiFE to activate CiLFY, thereby promoting the flowering of adult citrus.
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Affiliation(s)
- Huan Zhou
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Ren-Fang Zeng
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Tian-Jia Liu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Xiao-Yan Ai
- Institute of Pomology and Tea, Hubei Academy of Agricultural Sciences, Wuhan, China
| | - Meng-Ke Ren
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jing-Jing Zhou
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Chun-Gen Hu
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Jin-Zhi Zhang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
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Li J, Lin K, Zhang S, Wu J, Fang Y, Wang Y. Genome-Wide Analysis of Myeloblastosis-Related Genes in Brassica napus L. and Positive Modulation of Osmotic Tolerance by BnMRD107. FRONTIERS IN PLANT SCIENCE 2021; 12:678202. [PMID: 34220898 PMCID: PMC8248502 DOI: 10.3389/fpls.2021.678202] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/30/2021] [Indexed: 06/01/2023]
Abstract
Myeloblastosis (MYB)-related transcription factors comprise a large subfamily of the MYB family. They play significant roles in plant development and in stress responses. However, MYB-related proteins have not been comprehensively investigated in rapeseed (Brassica napus L.). In the present study, a genome-wide analysis of MYB-related transcription factors was performed in rapeseed. We identified 251 Brassica napus MYB (BnMYB)-related members, which were divided phylogenetically into five clades. Evolutionary analysis suggested that whole genome duplication and segmental duplication events have played a significant role in the expansion of BnMYB-related gene family. Selective pressure of BnMYB-related genes was estimated using the Ka/Ks ratio, which indicated that BnMYB-related genes underwent strong purifying selection during evolution. In silico analysis showed that various development-associated, phytohormone-responsive, and stress-related cis-acting regulatory elements were enriched in the promoter regions of BnMYB-related genes. Furthermore, MYB-related genes with tissue or organ-specific, stress-responsive expression patterns were identified in B. napus based on temporospatial and abiotic stress expression profiles. Among the stress-responsive MYB-related genes, BnMRD107 was strongly induced by drought stress, and was therefore selected for functional study. Rapeseed seedlings overexpressing BnMRD107 showed improved resistance to osmotic stress. Our findings not only lay a foundation for further functional characterization of BnMYB-related genes, but also provide valuable clues to determine candidate genes for future genetic improvement of B. napus.
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Affiliation(s)
- Jian Li
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China
| | - Keyun Lin
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China
| | - Shuai Zhang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China
| | - Jian Wu
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Yujie Fang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
| | - Youping Wang
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Yangzhou University, Yangzhou, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou, China
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Thomson G, Zhang L, Wen J, Mysore KS, Putterill J. The Candidate Photoperiod Gene MtFE Promotes Growth and Flowering in Medicago truncatula. FRONTIERS IN PLANT SCIENCE 2021; 12:634091. [PMID: 33841463 PMCID: PMC8032900 DOI: 10.3389/fpls.2021.634091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/01/2021] [Indexed: 05/04/2023]
Abstract
Flowering time influences the yield and productivity of legume crops. Medicago truncatula is a reference temperate legume that, like the winter annual Arabidopsis thaliana, shows accelerated flowering in response to vernalization (extended cold) and long-day (LD) photoperiods (VLD). However, unlike A. thaliana, M. truncatula appears to lack functional homologs of core flowering time regulators CONSTANS (CO) and FLOWERING LOCUS C (FLC) which act upstream of the mobile florigen FLOWERING LOCUS T (FT). Medicago truncatula has three LD-induced FT-like genes (MtFTa1, MtFTb1, and MtFTb2) with MtFTa1 promoting M. truncatula flowering in response to VLD. Another photoperiodic regulator in A. thaliana, FE, acts to induce FT expression. It also regulates the FT transport pathway and is required for phloem development. Our study identifies a M. truncatula FE homolog Medtr6g444980 (MtFE) which complements the late flowering fe-1 mutant when expressed from the phloem-specific SUCROSE-PROTON SYMPORTER 2 (SUC2) promoter. Analysis of two M. truncatula Tnt1 insertional mutants indicate that MtFE promotes flowering in LD and VLD and growth in all conditions tested. Expression of MtFTa1, MtFTb1, and MtFTb2 are reduced in Mtfe mutant (NF5076), correlating with its delayed flowering. The NF5076 mutant plants are much smaller than wild type indicating that MtFE is important for normal plant growth. The second mutant (NF18291) displays seedling lethality, like strong fe mutants. We searched for mutants in MtFTb1 and MtFTb2 identifying a Mtftb2 knock out Tnt1 mutant (NF20803). However, it did not flower significantly later than wild type. Previously, yeast-two-hybrid assays (Y2H) suggested that Arabidopsis FE interacted with CO and NUCLEAR FACTOR-Y (NF-Y)-like proteins to regulate FT. We found that MtFE interacts with CO and also M. truncatula NF-Y-like proteins in Y2H experiments. Our study indicates that despite the apparent absence of a functional MtCO-like gene, M. truncatula FE likely influences photoperiodic FT expression and flowering time in M. truncatula via a partially conserved mechanism with A. thaliana.
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Affiliation(s)
- Geoffrey Thomson
- The Flowering Lab, School of Biological Sciences, University of Auckland, Auckland, New Zealand
- *Correspondence: Geoffrey Thomson, ;
| | - Lulu Zhang
- The Flowering Lab, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Jiangqi Wen
- Noble Research Institute, Ardmore, OK, United States
| | | | - Joanna Putterill
- The Flowering Lab, School of Biological Sciences, University of Auckland, Auckland, New Zealand
- *Correspondence: Geoffrey Thomson, ;
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Kinoshita A, Richter R. Genetic and molecular basis of floral induction in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2490-2504. [PMID: 32067033 PMCID: PMC7210760 DOI: 10.1093/jxb/eraa057] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 02/03/2020] [Indexed: 05/18/2023]
Abstract
Many plants synchronize their life cycles in response to changing seasons and initiate flowering under favourable environmental conditions to ensure reproductive success. To confer a robust seasonal response, plants use diverse genetic programmes that integrate environmental and endogenous cues and converge on central floral regulatory hubs. Technological advances have allowed us to understand these complex processes more completely. Here, we review recent progress in our understanding of genetic and molecular mechanisms that control flowering in Arabidopsis thaliana.
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Affiliation(s)
- Atsuko Kinoshita
- Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, Japan
- Correspondence: or
| | - René Richter
- School of Agriculture and Food, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Melbourne, Australia
- Correspondence: or
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Ke YT, Lin KF, Gu CH, Yeh CH. Molecular Characterization and Expression Profile of PaCOL1, a CONSTANS-like Gene in Phalaenopsis Orchid. PLANTS (BASEL, SWITZERLAND) 2020; 9:plants9010068. [PMID: 31947959 PMCID: PMC7020484 DOI: 10.3390/plants9010068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
CONSTANS (CO) and CONSTANS-like (COL) genes play important roles in coalescing signals from photoperiod and temperature pathways. However, the mechanism of CO and COLs involved in regulating the developmental stage transition and photoperiod/temperature senescing remains unclear. In this study, we identified a COL ortholog gene from the Taiwan native orchid Phalaenopsis aphrodite. The Phalaenopsis aphrodite CONSTANS-like 1 (PaCOL1) belongs to the B-box protein family and functions in the nucleus and cytosol. Expression profile analysis of Phalaenopsis aphrodite revealed that PaCOL1 was significantly expressed in leaves, but its accumulation was repressed during environmental temperature shifts. We found a differential profile for PaCOL1 accumulation, with peak accumulation at late afternoon and at the middle of the night. Arabidopsis with PaCOL1 overexpression showed earlier flowering under short-day (SD) conditions (8 h/23 °C light and 16 h/23 °C dark) but similar flowering time under long-day (LD) conditions (16 h/23 °C light and 8 h/23 °C dark). Transcriptome sequencing revealed several genes upregulated in PaCOL1-overexpressing Arabidopsis plants that were previously involved in flowering regulation of the photoperiod pathway. Yeast two-hybrid (Y2H) analysis and bimolecular fluorescence complementation (BiFC) analysis revealed that PaCOL1 could interact with a crucial clock-associated regulator, AtCCA1, and a flowering repressor, AtFLC. Furthermore, expressing PaCOL1 in cca1.lhy partially reversed the mutant flowering time under photoperiod treatment, which confirms the role of PaCOL1 function in the rhythmic associated factors for modulating flowering.
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10
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Endo M, Yoshida M, Sasaki Y, Negishi K, Horikawa K, Daimon Y, Kurotani KI, Notaguchi M, Abe M, Araki T. Re-Evaluation of Florigen Transport Kinetics with Separation of Functions by Mutations That Uncouple Flowering Initiation and Long-Distance Transport. PLANT & CELL PHYSIOLOGY 2018; 59:1621-1629. [PMID: 29562349 DOI: 10.1093/pcp/pcy063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 03/15/2018] [Indexed: 06/08/2023]
Abstract
In many plants, timing of flowering is regulated by day length. In Arabidopsis, florigen, FLOWERING LOCUS T (FT) protein, is synthesized in leaf phloem companion cells in response to long days and is transported to the shoot apical meristem (SAM) through the phloem. The temporal aspects of florigen transportation have been studied in various plants by physiological experiments. Nevertheless, little is known about how FT protein transportation is regulated in Arabidopsis. In this study, we performed heat shock-based transient FT induction in a single leaf blade and detected the FT protein in the shoot apex by 2D-PAGE. We demonstrated that detectable amounts of FT were transported from the leaf to the shoot apex within 8 h, and subsequent FT-induced target gene expression was detected within 8-12 h. Furthermore, we identified three amino acid residues (V70, S76 and R83) where missense mutations led to reduced mobility. Interestingly, these FT variants lost only their transportation ability, but retained their flowering promotion capacity, suggesting that discrete amino acids are involved in flowering regulation and transport regulation. Since the interaction with FT-INTERACTING PROTEIN 1 (FTIP1) was not affected in these FT variants, we hypothesize that the three amino acid residues are not involved in the FTIP1-mediated pathway of uploading, but rather in the subsequent step(s) of FT transport.
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Affiliation(s)
- Motomu Endo
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
- Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho Kawaguchi, Saitama, Japan
| | | | - Youhei Sasaki
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Katsuya Negishi
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kobo Horikawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Yasufumi Daimon
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | | | | | - Mitsutomo Abe
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
| | - Takashi Araki
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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Negishi K, Endo M, Abe M, Araki T. SODIUM POTASSIUM ROOT DEFECTIVE1 regulates FLOWERING LOCUS T expression via the microRNA156-SQUAMOSA PROMOTER BINDING PROTEIN-LIKE3 module in response to potassium conditions. PLANT & CELL PHYSIOLOGY 2018; 59:404-413. [PMID: 29253219 DOI: 10.1093/pcp/pcx199] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/09/2017] [Indexed: 06/07/2023]
Abstract
To determine flowering time, plants perceive multiple environmental stimuli and integrate these signals in the regulation of a florigen gene, FLOWERING LOCUS T (FT). It has been known that nutrient availability affects flowering time in both laboratories and fields. Nitrogen (N), phosphorus (P) and potassium (K) are the three major macronutrients which are important for plant growth and development. Although N and P stimuli can alter the expression of regulators of FT including microRNA156 (miR156) and miR156-targeted transcription factors of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) family, how K+ conditions affect flowering is still unclear. We focused on SODIUM POTASSUIM ROOT DEFECTIVE1 (NaKR1) whose mutant plants showed Na+ and K+ overaccumulation and late flowering. It was reported that NaKR1 is involved in the phloem transport of FT protein. Here we report that NaKR1 is also required for the promotion of FT expression in long-day conditions. NaKR1 affects the accumulation of miR156 and SPL3 expression, suggesting that NaKR1 regulates FT expression in part through the miR156-SPL3 module. The late-flowering phenotype of the nakr1-1 mutant was partially suppressed under low K+ conditions, and miR156 abundance and SPL3 expression in the nakr1-1 mutant and, to a lesser extent, in wild-type plants responded to K+ conditions. Taken together, our findings suggest that the miR156-SPL3 module mediates regulation of FT expression by NaKR1 in response to K+ conditions. Finally, we propose a model in which NaKR1 plays dual roles in regulation of flowering, one in the regulation of florigen production, the other in that of florigen transport.
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Affiliation(s)
- Katsuya Negishi
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8501 Japan
| | - Motomu Endo
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8501 Japan
| | - Mitsutomo Abe
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Takashi Araki
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8501 Japan
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