1
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Lee K, Yoon H, Seo PJ. The AGL6-ELF3-FT circuit controls flowering time in Arabidopsis. PLANT SIGNALING & BEHAVIOR 2024; 19:2358684. [PMID: 38805453 PMCID: PMC11135843 DOI: 10.1080/15592324.2024.2358684] [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: 02/22/2024] [Accepted: 05/13/2024] [Indexed: 05/30/2024]
Abstract
Adjusting the timing of floral transition is essential for reproductive success in plants. A number of flowering regulators integrate internal and external signals to precisely determine the time to flower. We here report that the AGAMOUS-LIKE 6 (AGL6) - EARLY FLOWERING 3 (ELF3) module regulates flowering in the FLOWERING LOCUS T (FT)-dependent pathway in Arabidopsis. The AGL6 transcriptional repressor promotes floral transition by directly suppressing ELF3, which in turn directly represses FT expression that acts as a floral integrator. Indeed, ELF3 is epistatic to AGL6 in the control of floral transition. Overall, our findings propose that the AGL6-ELF3 module contributes to fine-tuning flowering time in plants.
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Affiliation(s)
- Kyounghee Lee
- Department of Chemistry, Seoul National University, Seoul, Republic of Korea
- Research Institute of Basic Sciences, Seoul National University, Seoul, Republic of Korea
| | - Hobin Yoon
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, Republic of Korea
| | - Pil Joon Seo
- Department of Chemistry, Seoul National University, Seoul, Republic of Korea
- Research Institute of Basic Sciences, Seoul National University, Seoul, Republic of Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, Republic of Korea
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2
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Genomewide Identification and Characterization of the Genes Involved in the Flowering of Cotton. Int J Mol Sci 2022; 23:ijms23147940. [PMID: 35887288 PMCID: PMC9323069 DOI: 10.3390/ijms23147940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/12/2022] [Accepted: 07/16/2022] [Indexed: 01/27/2023] Open
Abstract
Flowering is a prerequisite for flowering plants to complete reproduction, and flowering time has an important effect on the high and stable yields of crops. However, there are limited reports on flowering-related genes at the genomic level in cotton. In this study, genomewide analysis of the evolutionary relationship of flowering-related genes in different cotton species shows that the numbers of flowering-related genes in the genomes of tetraploid cotton species Gossypium hirsutum and Gossypium barbadense were similar, and that these numbers were approximately twice as much as the number in diploid cotton species Gossypium arboretum. The classification of flowering-related genes shows that most of them belong to the photoperiod and circadian clock flowering pathway. The distribution of flowering-related genes on the chromosomes of the At and Dt subgenomes was similar, with no subgenomic preference detected. In addition, most of the flowering-related core genes in Arabidopsis thaliana had homologs in the cotton genome, but the copy numbers and expression patterns were disparate; moreover, flowering-related genes underwent purifying selection throughout the evolutionary and selection processes. Although the differentiation and reorganization of many key genes of the cotton flowering regulatory network occurred throughout the evolutionary and selection processes, most of them, especially those involved in the important flowering regulatory networks, have been relatively conserved and preferentially selected.
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3
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Bischof S. Dissecting the response to photoperiod at the cell-type level. THE PLANT CELL 2021; 33:1083-1084. [PMID: 35234974 PMCID: PMC8889999 DOI: 10.1093/plcell/koab037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 01/22/2021] [Indexed: 06/14/2023]
Affiliation(s)
- Sylvain Bischof
- Department of Plant and Microbial Biology, University of Z�rich, 8006 Z�rich, Switzerland
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4
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Lu J, Sun J, Jiang A, Bai M, Fan C, Liu J, Ning G, Wang C. Alternate expression of CONSTANS-LIKE 4 in short days and CONSTANS in long days facilitates day-neutral response in Rosa chinensis. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:4057-4068. [PMID: 32227095 PMCID: PMC7475255 DOI: 10.1093/jxb/eraa161] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 03/26/2020] [Indexed: 05/08/2023]
Abstract
Photoperiodic flowering responses are classified into three major types: long day (LD), short day (SD), and day neutral (DN). The inverse responses to daylength of LD and SD plants have been partly characterized in Arabidopsis and rice; however, the molecular mechanism underlying the DN response is largely unknown. Modern roses are economically important ornamental plants with continuous flowering (CF) features, and are generally regarded as DN plants. Here, RcCO and RcCOL4 were identified as floral activators up-regulated under LD and SD conditions, respectively, in the CF cultivar Rosa chinensis 'Old-Blush'. Diminishing the expression of RcCO or/and RcCOL4 by virus-induced gene silencing (VIGS) delayed flowering time under both SDs and LDs. Interestingly, in contrast to RcCO-silenced plants, the flowering time of RcCOL4-silenced plants was more delayed under SD than under LD conditions, indicating perturbed plant responses to day neutrality. Further analyses revealed that physical interaction between RcCOL4 and RcCO facilitated binding of RcCO to the CORE motif in the promoter of RcFT and induction of RcFT. Taken together, the complementary expression of RcCO in LDs and of RcCOL4 in SDs guaranteed flowering under favorable growth conditions regardless of the photoperiod. This finding established the molecular foundation of CF in roses and further shed light on the underlying mechanisms of DN responses.
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Affiliation(s)
- Jun Lu
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Jingjing Sun
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Anqi Jiang
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Mengjuan Bai
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Chunguo Fan
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Jinyi Liu
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Guogui Ning
- College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Changquan Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
- Correspondence:
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5
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Lee C, Kim SJ, Jin S, Susila H, Youn G, Nasim Z, Alavilli H, Chung KS, Yoo SJ, Ahn JH. Genetic interactions reveal the antagonistic roles of FT/TSF and TFL1 in the determination of inflorescence meristem identity in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 99:452-464. [PMID: 30943325 DOI: 10.1111/tpj.14335] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 02/26/2019] [Accepted: 03/26/2019] [Indexed: 05/10/2023]
Abstract
During the transition to the reproductive phase, the shoot apical meristem switches from the developmental program that generates vegetative organs to instead produce flowers. In this study, we examined the genetic interactions of FLOWERING LOCUS T (FT)/TWIN SISTER OF FT (TSF) and TERMINAL FLOWER 1 (TFL1) in the determination of inflorescence meristem identity in Arabidopsis thaliana. The ft-10 tsf-1 mutants produced a compact inflorescence surrounded by serrated leaves (hyper-vegetative shoot) at the early bolting stage, as did plants overexpressing TFL1. Plants overexpressing FT or TSF (or both FT and TFL1) generated a terminal flower, as did tfl1-20 mutants. The terminal flower formed in tfl1-20 mutants converted to a hyper-vegetative shoot in ft-10 tsf-1 mutants. Grafting ft-10 tsf-1 or ft-10 tsf-1 tfl1-20 mutant scions to 35S::FT rootstock plants produced a normal inflorescence and a terminal flower in the scion plants, respectively, although both scions showed similar early flowering. Misexpression of FT in the vasculature and in the shoot apex in wild-type plants generated a normal inflorescence and a terminal flower, respectively. By contrast, in ft-10 tsf-1 mutants the vasculature-specific misexpression of FT converted the hyper-vegetative shoot to a normal inflorescence, and in the ft-10 tsf-1 tfl1-20 mutants converted the shoot to a terminal flower. TFL1 levels did not affect the inflorescence morphology caused by FT/TSF overexpression at the early bolting stage. Taking these results together, we proposed that FT/TSF and TFL1 play antagonistic roles in the determination of inflorescence meristem identity, and that FT/TSF are more important than TFL1 in this process.
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Affiliation(s)
- Chunghee Lee
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Soo-Jin Kim
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Suhyun Jin
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Hendry Susila
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Geummin Youn
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Zeeshan Nasim
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Hemasundar Alavilli
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Kyung-Sook Chung
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Seong Jeon Yoo
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
| | - Ji Hoon Ahn
- Department of Life Sciences, Korea University, 145 Anamro, Seongbuk-Gu, Seoul, 02841, South Korea
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Miao XY, Qu HP, Han YL, He CF, Qiu DW, Cheng ZW. The protein elicitor Hrip1 enhances resistance to insects and early bolting and flowering in Arabidopsis thaliana. PLoS One 2019; 14:e0216082. [PMID: 31022256 PMCID: PMC6483360 DOI: 10.1371/journal.pone.0216082] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 04/12/2019] [Indexed: 11/19/2022] Open
Abstract
The elicitor Hrip1 isolated from necrotrophic fungus Alternaria tenuissima, could induce systemic acquired resistance in tobacco to enhance resistance to tobacco mosaic virus. In the present study, we found that the transgenic lines of Hrip1-overexpression in wild type (WT) Arabidopsis thaliana were more resistant to Spodoptera exigua and were early bolting and flowering than the WT. A profiling of transcription assay using digital gene expression profiling was used for transgenic and WT Arabidopsis thaliana. Differentially expressed genes including 40 upregulated and three downregulated genes were identified. In transgenic lines of Hrip1-overexpression, three genes related to jasmonate (JA) biosynthesis were significantly upregulated, and the JA level was found to be higher than WT. Two GDSL family members (GLIP1 and GLIP4) and pathogen-related gene, which participated in pathogen defense action, were upregulated in the transgenic line of Hrip1-overexpression. Thus, Hrip1 is involved in affecting the flower bolting time and regulating endogenous JA biosynthesis and regulatory network to enhance resistance to insect.
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Affiliation(s)
- Xin-yue Miao
- Beijing Key Laboratory of Plants Resource Research and Development, School of Sciences, Beijing Technology and Business University, Beijing, China
| | - Hong-pan Qu
- Beijing Key Laboratory of Plants Resource Research and Development, School of Sciences, Beijing Technology and Business University, Beijing, China
| | - Ya-lei Han
- Aerospace Center Hospital, Cardiovascular Department, Beijing, China
| | - Cong-fen He
- Beijing Key Laboratory of Plants Resource Research and Development, School of Sciences, Beijing Technology and Business University, Beijing, China
| | - De-wen Qiu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhi-wei Cheng
- Beijing Key Laboratory of Plants Resource Research and Development, School of Sciences, Beijing Technology and Business University, Beijing, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- * E-mail:
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7
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Song GQ, Walworth A, Lin T, Chen Q, Han X, Irina Zaharia L, Zhong GY. VcFT-induced mobile florigenic signals in transgenic and transgrafted blueberries. HORTICULTURE RESEARCH 2019; 6:105. [PMID: 31645960 PMCID: PMC6804590 DOI: 10.1038/s41438-019-0188-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/26/2019] [Accepted: 07/29/2019] [Indexed: 05/03/2023]
Abstract
FLOWERING LOCUS T (FT) can promote early flowering in annual species, but such role has not been well demonstrated in woody species. We produced self and reciprocal grafts involving non-transgenic blueberry (NT) and transgenic blueberry (T) carrying a 35S-driven blueberry FT (VcFT-OX). We demonstrated that the transgenic VcFT-OX rootstock promoted flowering of non-transgenic blueberry scions in the NT (scion):T (rootstock) grafts. We further analyzed RNA-Seq profiles and six groups of phytohormones in both NT:T and NT:NT plants. We observed content changes of several hormone metabolites, in a descending order, in the transgenic NT:T, non-transgenic NT:T, and non-transgenic NT:NT leaves. By comparing differential expression transcripts (DETs) of these tissues in relative to their control, we found that the non-transgenic NT:T leaves had many DETs shared with the transgenic NT:T leaves, but very few with the transgenic NT:T roots. Interestingly, a number of these shared DETs belong to hormone pathway genes, concurring with the content changes of hormone metabolites in both transgenic and non-transgenic leaves of the NT:T plants. These results suggest that phytohormones induced by VcFT-OX in the transgenic leaves might serve as part of the signals that resulted in early flowering in both transgenic plants and the non-transgenic NT:T scions.
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Affiliation(s)
- Guo-qing Song
- Plant Biotechnology Resource and Outreach Center, Department of Horticulture, Michigan State University, East Lansing, MI 48824 USA
| | - Aaron Walworth
- Plant Biotechnology Resource and Outreach Center, Department of Horticulture, Michigan State University, East Lansing, MI 48824 USA
| | - Tianyi Lin
- Plant Biotechnology Resource and Outreach Center, Department of Horticulture, Michigan State University, East Lansing, MI 48824 USA
| | - Qiuxia Chen
- Plant Biotechnology Resource and Outreach Center, Department of Horticulture, Michigan State University, East Lansing, MI 48824 USA
| | - Xiumei Han
- Aquatic and Crop Resource Development, National Research Council of Canada, Saskatoon, SK S7N 0W9 Canada
| | - L. Irina Zaharia
- Aquatic and Crop Resource Development, National Research Council of Canada, Saskatoon, SK S7N 0W9 Canada
| | - Gan-yuan Zhong
- Grape Genetics Research Unit, USDA-ARS, Geneva, NY 14456 USA
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8
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Silva Souza L, Diniz RP, Neves RDJ, Alves AAC, Oliveira EJD. Grafting as a strategy to increase flowering of cassava. SCIENTIA HORTICULTURAE 2018; 240:544-551. [PMID: 30349150 PMCID: PMC6039848 DOI: 10.1016/j.scienta.2018.06.070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 06/12/2018] [Accepted: 06/20/2018] [Indexed: 05/22/2023]
Abstract
In cassava (Manihot esculenta Crantz), transferring genes via genetic breeding depends on crosses between contrasting progenitors, which is often limited by the low flowering rate of many genotypes. The main purpose of this work was to evaluate the effect of grafting on floral induction of cassava. For this, three genotypes were used: 1) BRS Formosa: a genotype with low flowering rate; 2) BGM0823: a genotype with high flowering rate; and 3) FLA05-02: a genotype of M. esculenta ssp. flabellifolia with high flowering rate. Cleft grafting was performed to generate the following treatments: Self-grafting of: 1) BGM0823 (Self-0823); 2) BRS Formosa (Self-Formosa); and 3) FLA05-02 (Self-FLA); and grafting of the genotypes, with the first being the scion and the second the rootstock: 4) BGM0823 × BRS Formosa; 5) BGM0823 × FLA05-02; 6) FLA05-02 × BRS Formosa; 7) FLA05-02 × BGM0823; 8) BRS Formosa × BGM0823; 9) BRS Formosa × FLA05-02; and also ungrafted treatments: 10) BGM0823; 11) BRS Formosa; and 12) FLA05-02. The results showed a 201% increase in the production of male flowers, 560% of female flowers and 400% of fruits in BRS Formosa grafted on BGM0823. BGM0823 (rootstock) also increased fruit production by 190% of FLA05-02. The grafted cassava plants exhibited an increase on the shoot production, although there was no change in the fresh root yield. The grafting of genotypes with high flowering rates can induce flowering in genotypes with low flowering rates.
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Affiliation(s)
- Leonardo Silva Souza
- Universidade Federal do Recôncavo da Bahia, Campus Cruz das Almas, 44380-000 Cruz das Almas, BA, Brazil
| | - Rafael Parreira Diniz
- Universidade Federal do Recôncavo da Bahia, Campus Cruz das Almas, 44380-000 Cruz das Almas, BA, Brazil
- Embrapa Mandioca e Fruticultura, Rua da Embrapa, Caixa Postal 007, 44380-000 Cruz das Almas, BA, Brazil
| | | | | | - Eder Jorge de Oliveira
- Embrapa Mandioca e Fruticultura, Rua da Embrapa, Caixa Postal 007, 44380-000 Cruz das Almas, BA, Brazil
- Corresponding author.
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9
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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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10
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Pasriga R, Cho LH, Yoon J, An G. Identification of the Regulatory Region Responsible for Vascular Tissue-Specific Expression in the Rice Hd3a Promoter. Mol Cells 2018; 41:342-350. [PMID: 29487275 PMCID: PMC5935103 DOI: 10.14348/molcells.2018.2320] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Revised: 01/01/2018] [Accepted: 01/08/2018] [Indexed: 12/22/2022] Open
Abstract
Flowering time is determined by florigens. These genes include, Heading date 3a (Hd3a) and Rice FT 1 (RFT1) in rice, which are specifically expressed in the vascular tissues of leaves at the floral transition stage. To study the cis-regulatory elements present in the promoter region of Hd3a, we generated transgenic plants carrying the 1.75-kb promoter fragment of Hd3a that was fused to the β-glucuronidase (GUS) reporter gene. Plants expressing this construct conferred a vascular cell-specific expression pattern for the reporter gene. However, GUS was expressed in leaves at all developmental stages, including the early seedling stage when Hd3a was not detected. Furthermore, the reporter was expressed in roots at all stages. This suggests that the 1.75-kb region lackings cis-elements that regulate leaf-specific expression at the appropriate developmental stages. Deletion analyses of the promoter region indicated that regulatory elements determining vascular cell-specific expression are present in the 200-bp region between -245 bp and -45 bp from the transcription initiation site. By transforming the Hd3a-GUS construct to rice cultivar 'Taichung 65' which is defective in Ehd1, we observed that Ehd1 is the major regulatory element that controls Hd3a promoter activity.
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Affiliation(s)
- Richa Pasriga
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 17104,
Korea
| | - Lae-Hyeon Cho
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 17104,
Korea
| | - Jinmi Yoon
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 17104,
Korea
| | - Gynheung An
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 17104,
Korea
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11
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Gras DE, Vidal EA, Undurraga SF, Riveras E, Moreno S, Dominguez-Figueroa J, Alabadi D, Blázquez MA, Medina J, Gutiérrez RA. SMZ/SNZ and gibberellin signaling are required for nitrate-elicited delay of flowering time in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:619-631. [PMID: 29309650 PMCID: PMC5853263 DOI: 10.1093/jxb/erx423] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 11/15/2017] [Indexed: 05/04/2023]
Abstract
The reproductive success of plants largely depends on the correct programming of developmental phase transitions, particularly the shift from vegetative to reproductive growth. The timing of this transition is finely regulated by the integration of an array of environmental and endogenous factors. Nitrogen is the mineral macronutrient that plants require in the largest amount, and as such its availability greatly impacts on many aspects of plant growth and development, including flowering time. We found that nitrate signaling interacts with the age-related and gibberellic acid pathways to control flowering time in Arabidopsis thaliana. We revealed that repressors of flowering time belonging to the AP2-type transcription factor family including SCHLAFMUTZE (SMZ) and SCHNARCHZAPFEN (SNZ) are important regulators of flowering time in response to nitrate. Our results support a model whereby nitrate activates SMZ and SNZ via the gibberellin pathway to repress flowering time in Arabidopsis thaliana.
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Affiliation(s)
- Diana E Gras
- FONDAP Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Instituto de Agrobiotecnología del Litoral (CONICET-UNL), Cátedra de Biología Celular y Molecular, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Paraje El Pozo, Santa Fe, Argentina
| | - Elena A Vidal
- FONDAP Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Centro de Genómica y Bioinformática, Universidad Mayor, Santiago, Chile
| | - Soledad F Undurraga
- FONDAP Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Eleodoro Riveras
- FONDAP Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Sebastián Moreno
- FONDAP Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - José Dominguez-Figueroa
- Centro de Biotecnología y Genómica de Plantas, (UPM-INIA) Campus de Montegancedo, Madrid, Spain
| | - David Alabadi
- Instituto de Biología Molecular y Celular de Plantas (CSIC-Universidad Politécnica de Valencia), Valencia, Spain
| | - Miguel A Blázquez
- Instituto de Biología Molecular y Celular de Plantas (CSIC-Universidad Politécnica de Valencia), Valencia, Spain
| | - Joaquín Medina
- Centro de Biotecnología y Genómica de Plantas, (UPM-INIA) Campus de Montegancedo, Madrid, Spain
| | - Rodrigo A Gutiérrez
- FONDAP Center for Genome Regulation, Millennium Nucleus Center for Plant Systems and Synthetic Biology, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Correspondence:
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12
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Gao C, Qi S, Liu K, Li D, Jin C, Duan S, Zhang M, Chen M. Functional characterization of Brassica napus DNA topoisomerase Iα-1 and its effect on flowering time when expressed in Arabidopsis thaliana. Biochem Biophys Res Commun 2017; 486:124-129. [PMID: 28283390 DOI: 10.1016/j.bbrc.2017.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 03/06/2017] [Indexed: 01/17/2023]
Abstract
Previous studies have shown that DNA topoisomerase Iα (AtTOP1α) has specific developmental functions during growth and development in Arabidopsis thaliana. However, little is known about the roles of DNA topoisomerases in the closely related and commercially important plant, rapeseed (Brassica napus). Here, the full-length BnTOP1α-1 coding sequence was cloned from the A2 subgenome of the Brassica napus inbred line L111. We determine that all BnTOP1α paralogs showed differing patterns of expression in different organs of L111, and that when expressed in tobacco leaves as a fusion protein with green fluorescent protein, BnTOP1α-1 localized to the nucleus. We further showed that ectopic expression of BnTOP1α-1 in the A. thaliana top1α-7 mutant fully complemented the early flowering phenotype of the mutant. Moreover, altered expression levels in top1α-7 seedlings of several key genes controlling flowering time were restored to wild type levels by ectopic expression of BnTOP1α-1. These results provide valuable insights into the roles of rapeseed DNA topoisomerases in flowering time, and provide a promising target for genetic manipulation of this commercially significant process in rapeseed.
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Affiliation(s)
- Chenhao Gao
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Shuanghui Qi
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Kaige Liu
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Dong Li
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Changyu Jin
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Shaowei Duan
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Meng Zhang
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Mingxun Chen
- College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China.
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13
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Wolabu TW, Zhang F, Niu L, Kalve S, Bhatnagar-Mathur P, Muszynski MG, Tadege M. Three FLOWERING LOCUS T-like genes function as potential florigens and mediate photoperiod response in sorghum. THE NEW PHYTOLOGIST 2016; 210:946-59. [PMID: 26765652 DOI: 10.1111/nph.13834] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/30/2015] [Indexed: 05/06/2023]
Abstract
Sorghum is a typical short-day (SD) plant and its use in grain or biomass production in temperate regions depends on its flowering time control, but the underlying molecular mechanism of floral transition in sorghum is poorly understood. Here we characterized sorghum FLOWERING LOCUS T (SbFT) genes to establish a molecular road map for mechanistic understanding. Out of 19 PEBP genes, SbFT1, SbFT8 and SbFT10 were identified as potential candidates for encoding florigens using multiple approaches. Phylogenetic analysis revealed that SbFT1 clusters with the rice Hd3a subclade, while SbFT8 and SbFT10 cluster with the maize ZCN8 subclade. These three genes are expressed in the leaf at the floral transition initiation stage, expressed early in grain sorghum genotypes but late in sweet and forage sorghum genotypes, induced by SD treatment in photoperiod-sensitive genotypes, cooperatively repressed by the classical sorghum maturity loci, interact with sorghum 14-3-3 proteins and activate flowering in transgenic Arabidopsis plants, suggesting florigenic potential in sorghum. SD induction of these three genes in sensitive genotypes is fully reversed by 1 wk of long-day treatment, and yet, some aspects of the SD treatment may still make a small contribution to flowering in long days, indicating a complex photoperiod response mediated by SbFT genes.
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Affiliation(s)
- Tezera W Wolabu
- Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Fei Zhang
- Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Lifang Niu
- Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Shweta Kalve
- Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA
| | - Pooja Bhatnagar-Mathur
- International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, 502324, India
| | - Michael G Muszynski
- Department of Genetics, Development and Cell Biology, Iowa State University, 2156 Molecular Biology, Ames, IA, 50011, USA
| | - Million Tadege
- Department of Plant and Soil Sciences, Institute for Agricultural Biosciences, Oklahoma State University, 3210 Sam Noble Parkway, Ardmore, OK, 73401, USA
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14
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Leal Valentim F, van Mourik S, Posé D, Kim MC, Schmid M, van Ham RCHJ, Busscher M, Sanchez-Perez GF, Molenaar J, Angenent GC, Immink RGH, van Dijk ADJ. A quantitative and dynamic model of the Arabidopsis flowering time gene regulatory network. PLoS One 2015; 10:e0116973. [PMID: 25719734 PMCID: PMC4342252 DOI: 10.1371/journal.pone.0116973] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 12/16/2014] [Indexed: 01/14/2023] Open
Abstract
Various environmental signals integrate into a network of floral regulatory genes leading to the final decision on when to flower. Although a wealth of qualitative knowledge is available on how flowering time genes regulate each other, only a few studies incorporated this knowledge into predictive models. Such models are invaluable as they enable to investigate how various types of inputs are combined to give a quantitative readout. To investigate the effect of gene expression disturbances on flowering time, we developed a dynamic model for the regulation of flowering time in Arabidopsis thaliana. Model parameters were estimated based on expression time-courses for relevant genes, and a consistent set of flowering times for plants of various genetic backgrounds. Validation was performed by predicting changes in expression level in mutant backgrounds and comparing these predictions with independent expression data, and by comparison of predicted and experimental flowering times for several double mutants. Remarkably, the model predicts that a disturbance in a particular gene has not necessarily the largest impact on directly connected genes. For example, the model predicts that SUPPRESSOR OF OVEREXPRESSION OF CONSTANS (SOC1) mutation has a larger impact on APETALA1 (AP1), which is not directly regulated by SOC1, compared to its effect on LEAFY (LFY) which is under direct control of SOC1. This was confirmed by expression data. Another model prediction involves the importance of cooperativity in the regulation of APETALA1 (AP1) by LFY, a prediction supported by experimental evidence. Concluding, our model for flowering time gene regulation enables to address how different quantitative inputs are combined into one quantitative output, flowering time.
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Affiliation(s)
- Felipe Leal Valentim
- Bioscience, Plant Research International, Wageningen UR, Wageningen, The Netherlands
| | - Simon van Mourik
- Biometris, Wageningen UR, Wageningen, The Netherlands
- Netherlands Consortium for Systems Biology, Amsterdam, The Netherlands
| | - David Posé
- Max Planck Institute for Developmental Biology, Molecular Biology, Tübingen, Germany
| | - Min C. Kim
- Max Planck Institute for Developmental Biology, Molecular Biology, Tübingen, Germany
| | - Markus Schmid
- Max Planck Institute for Developmental Biology, Molecular Biology, Tübingen, Germany
| | | | - Marco Busscher
- Bioscience, Plant Research International, Wageningen UR, Wageningen, The Netherlands
| | - Gabino F. Sanchez-Perez
- Bioscience, Plant Research International, Wageningen UR, Wageningen, The Netherlands
- Chair group Bioinformatics, Wageningen University, Wageningen, The Netherlands
| | - Jaap Molenaar
- Biometris, Wageningen UR, Wageningen, The Netherlands
| | - Gerco C. Angenent
- Bioscience, Plant Research International, Wageningen UR, Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University, Wageningen, The Netherlands
| | - Richard G. H. Immink
- Bioscience, Plant Research International, Wageningen UR, Wageningen, The Netherlands
| | - Aalt D. J. van Dijk
- Bioscience, Plant Research International, Wageningen UR, Wageningen, The Netherlands
- Biometris, Wageningen UR, Wageningen, The Netherlands
- Netherlands Consortium for Systems Biology, Amsterdam, The Netherlands
- * E-mail:
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15
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Song YH, Shim JS, Kinmonth-Schultz HA, Imaizumi T. Photoperiodic flowering: time measurement mechanisms in leaves. ANNUAL REVIEW OF PLANT BIOLOGY 2015; 66:441-64. [PMID: 25534513 PMCID: PMC4414745 DOI: 10.1146/annurev-arplant-043014-115555] [Citation(s) in RCA: 398] [Impact Index Per Article: 44.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Many plants use information about changing day length (photoperiod) to align their flowering time with seasonal changes to increase reproductive success. A mechanism for photoperiodic time measurement is present in leaves, and the day-length-specific induction of the FLOWERING LOCUS T (FT) gene, which encodes florigen, is a major final output of the pathway. Here, we summarize the current understanding of the molecular mechanisms by which photoperiodic information is perceived in order to trigger FT expression in Arabidopsis as well as in the primary cereals wheat, barley, and rice. In these plants, the differences in photoperiod are measured by interactions between circadian-clock-regulated components, such as CONSTANS (CO), and light signaling. The interactions happen under certain day-length conditions, as previously predicted by the external coincidence model. In these plants, the coincidence mechanisms are governed by multilayered regulation with numerous conserved as well as unique regulatory components, highlighting the breadth of photoperiodic regulation across plant species.
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Affiliation(s)
- Young Hun Song
- Department of Biology, University of Washington, Seattle, Washington 98195-1800;
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16
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Li L, Hu L, Han LP, Ji H, Zhu Y, Wang X, Ge J, Xu M, Shen D, Dong H. Expression of turtle riboflavin-binding protein represses mitochondrial electron transport gene expression and promotes flowering in Arabidopsis. BMC PLANT BIOLOGY 2014; 14:381. [PMID: 25547226 PMCID: PMC4310184 DOI: 10.1186/s12870-014-0381-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 12/11/2014] [Indexed: 05/12/2023]
Abstract
BACKGROUND Recently we showed that de novo expression of a turtle riboflavin-binding protein (RfBP) in transgenic Arabidopsis increased H2O2 concentrations inside leaf cells, enhanced the expression of floral regulatory gene FD and floral meristem identity gene AP1 at the shoot apex, and induced early flowering. Here we report that RfBP-induced H2O2 presumably results from electron leakage at the mitochondrial electron transport chain (METC) and this source of H2O2 contributes to the early flowering phenotype. RESULTS While enhanced expression of FD and AP1 at the shoot apex was correlated with early flowering, the foliar expression of 13 of 19 METC genes was repressed in RfBP-expressing (RfBP+) plants. Inside RfBP+ leaf cells, cytosolic H2O2 concentrations were increased possibly through electron leakage because similar responses were also induced by a known inducer of electron leakage from METC. Early flowering no longer occurred when the repression on METC genes was eliminated by RfBP gene silencing, which restored RfBP+ to wild type in levels of FD and AP1 expression, H2O2, and flavins. Flowering was delayed by the external riboflavin application, which brought gene expression and flavins back to the steady-state levels but only caused 55% reduction of H2O2 concentrations in RfBP+ plants. RfBP-repressed METC gene expression remedied the cytosolic H2O2 diminution by genetic disruption of transcription factor NFXLl and compensated for compromises in FD and AP1 expression and flowering time. By contrast, RfBP resembled a peroxisomal catalase mutation, which augments the cytosolic H2O2, to enhance FD and AP1 expression and induce early flowering. CONCLUSIONS RfBP-repressed METC gene expression potentially causes electron leakage as one of cellular sources for the generation of H2O2 with the promoting effect on flowering. The repressive effect on METC gene expression is not the only way by which RfBP induces H2O2 and currently unappreciated factors may also function under RfBP+ background.
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Affiliation(s)
- Liang Li
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Li Hu
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Li-Ping Han
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Hongtao Ji
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Yueyue Zhu
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Xiaobing Wang
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Jun Ge
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Manyu Xu
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Dan Shen
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
| | - Hansong Dong
- Department of Plant Pathology, Nanjing Agricultural University and State Ministry of Education Key Laboratory of Integrated Management of Crop Pathogens and Insect Pests, Nanjing, 210095 China
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17
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Shim JS, Imaizumi T. Circadian clock and photoperiodic response in Arabidopsis: from seasonal flowering to redox homeostasis. Biochemistry 2014; 54:157-70. [PMID: 25346271 PMCID: PMC4303289 DOI: 10.1021/bi500922q] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Many of the developmental responses
and behaviors in plants that
occur throughout the year are controlled by photoperiod; among these,
seasonal flowering is the most characterized. Molecular genetic and
biochemical analyses have revealed the mechanisms by which plants
sense changes in day length to regulate seasonal flowering. In Arabidopsis thaliana, induction of the expression of a florigen,
FLOWERING LOCUS T (FT) protein, is a major output of the photoperiodic
flowering pathway. The circadian clock coordinates the expression
profiles and activities of the components in this pathway. Light-dependent
control of CONSTANS (CO) transcription factor activity is a crucial
part of the induction of the photoperiodic expression of FT. CO protein is stabilized only in the long day afternoon, which
is when FT is induced. In this review, we summarize
recent progress in the determination of the molecular architecture
of the circadian clock and mechanisms underlying photoperiodic flowering.
In addition, we introduce the molecular mechanisms of other biological
processes, such as hypocotyl growth and reactive oxygen species production,
which are also controlled by alterations in photoperiod.
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Affiliation(s)
- Jae Sung Shim
- Department of Biology, University of Washington , Seattle, Washington 98195-1800, United States
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18
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Bernier G. My favourite flowering image: the role of cytokinin as a flowering signal. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:5795-9. [PMID: 21586428 DOI: 10.1093/jxb/err114] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
My favourite flowering image shows a section in a shoot apical meristem of Sinapis alba undertaking the very first step of its transition to flowering. This step is the activation of the SaSOC1 gene, the Sinapis orthologue of Arabidopsis SUPPRESSOR OF OVEREXPRESSION OF CO1 (SOC1), in a few central cells of the meristem. Hidden behind this picture is my long quest of physiological signals controlling flowering. Milestones of this story are briefly recounted here and this gives me an opportunity to raise a number of questions about the nature and function of florigen.
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Affiliation(s)
- Georges Bernier
- Laboratory of Plant Physiology, University of Liège, B-4000 Liège, Belgium
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19
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Winterhagen P, Tiyayon P, Samach A, Hegele M, Wünsche JN. Isolation and characterization of FLOWERING LOCUS T subforms and APETALA1 of the subtropical fruit tree Dimocarpus longan. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 71:184-90. [PMID: 23954797 DOI: 10.1016/j.plaphy.2013.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 07/24/2013] [Indexed: 05/04/2023]
Abstract
Longan (Dimocarpus longan Lour.) is a subtropical evergreen fruit tree, mainly cultivated in Asia. Two putative floral integrator genes, D. longan FLOWERING LOCUS T1 and 2 (DlFT1 and DlFT2) were isolated and both translated sequences revealed a high homology to FT sequences from other plants. Moreover, two APETALA1-like (DlAP1-1 and DlAP1-2) sequences from longan were isolated and characterized. Results indicate that the sequences of these genes are highly conserved, suggesting functions in the longan flowering pathway. Ectopic expression of the longan genes in arabidopsis resulted in different flowering time phenotypes of transgenic plants. Expression experiments reveal a different action of the longan FT genes and indicate that DlFT1 is a flowering promoter, while DlFT2 acts as flowering inhibitor. Overexpression of longan AP1 genes in transgenic arabidopsis results in a range of flowering time phenotypes also including early and late flowering individuals.
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Affiliation(s)
- Patrick Winterhagen
- Institute of Crop Science, Section Crop Physiology of Specialty Crops, Hohenheim University, Stuttgart, Germany.
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20
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Liu L, Zhu Y, Shen L, Yu H. Emerging insights into florigen transport. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:607-13. [PMID: 23810436 DOI: 10.1016/j.pbi.2013.06.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 06/01/2013] [Accepted: 06/05/2013] [Indexed: 05/19/2023]
Abstract
The photoperiodic control of flowering in plants begins with the perception of seasonal changes in day length and consequential induction of a mobile floral stimulus in leaves. This stimulus called florigen is transported from leaves to the shoot apical meristem to provoke the initiation of floral meristems. Decades of efforts have identified that the proteins encoded by FLOWERING LOCUS T (FT) in Arabidopsis and its orthologs in other plant species are part of the long-sought florigen. Emerging evidence suggests that long-distance transport of FT towards the shoot apical meristem occurs through the phloem in a regulated manner. This review summarizes the recent advances in understanding florigen transport and discusses the proven and potential regulators required for this process.
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Affiliation(s)
- Lu Liu
- Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, 10 Science Drive 4, 117543 Singapore, Singapore
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21
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Li XF, Jia LY, Xu J, Deng XJ, Wang Y, Zhang W, Zhang XP, Fang Q, Zhang DM, Sun Y, Xu L. FT-like NFT1 gene may play a role in flower transition induced by heat accumulation in Narcissus tazetta var. chinensis. PLANT & CELL PHYSIOLOGY 2013; 54:270-81. [PMID: 23303875 DOI: 10.1093/pcp/pcs181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The low-temperature flowering-response pathway, used as an inductive stimulus to induce flowering in plant species from temperate regions in response to cold temperature, has been extensively studied. However, limited information is available on the flower transition of several bulbous species, which require high temperature for flower differentiation. Narcissus tazetta var. chinensis (Chinese narcissus) exhibits a 2 year juvenile phase, and flower initiation within its bulbs occurs during summer dormancy. The genetic factors that control flower initiation are mostly unknown in Chinese narcissus. In the present study, we found that a high storage temperature is necessary for flower initiation. Flower initiation was advanced in bulbs previously exposed to extended high temperature. The heat accumulation required for flower transition was also determined. High temperature treatment rescued the low flower percentage resulting from short storage duration under natural conditions. In addition, extended high storage temperature was found to increase the flowering percentage of 2-year-old plants, which can be applied in breeding. Narcissus FLOWERING LOCUS T1 (NFT1), a homolog of the Arabidopsis thaliana gene FLOWERING LOCUS T, was isolated in this study. NFT1 transcripts were abundant during flower initiation in mature bulbs and were up-regulated by high temperature. The genetic experiments, coupled with an expression profiling assay, suggest that NFT1 possibly takes part in flower transition control in response to high temperature.
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MESH Headings
- Amino Acid Sequence
- Arabidopsis/genetics
- Arabidopsis/metabolism
- Cloning, Molecular
- DNA, Complementary/genetics
- DNA, Complementary/metabolism
- Flowers/genetics
- Flowers/growth & development
- Flowers/ultrastructure
- Gene Expression Regulation, Plant
- Genes, Plant
- Hot Temperature
- Meristem/genetics
- Meristem/metabolism
- Microscopy, Electron, Scanning
- Molecular Sequence Data
- Narcissus/anatomy & histology
- Narcissus/genetics
- Narcissus/growth & development
- Plant Proteins/genetics
- Plant Proteins/metabolism
- Plants, Genetically Modified/genetics
- Plants, Genetically Modified/growth & development
- Plants, Genetically Modified/metabolism
- Sequence Alignment
- Species Specificity
- Time Factors
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Affiliation(s)
- Xiao-Fang Li
- School of Life Science, East China Normal University, 500 Dongchuan Rd., Shanghai, PR China
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22
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Muñoz-Fambuena N, Mesejo C, González-Mas MC, Primo-Millo E, Agustí M, Iglesias DJ. Fruit load modulates flowering-related gene expression in buds of alternate-bearing 'Moncada' mandarin. ANNALS OF BOTANY 2012; 110:1109-18. [PMID: 22915579 PMCID: PMC3478051 DOI: 10.1093/aob/mcs190] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2012] [Accepted: 07/10/2012] [Indexed: 05/07/2023]
Abstract
BACKGROUND AND AIMS Gene determination of flowering is the result of complex interactions involving both promoters and inhibitors. In this study, the expression of flowering-related genes at the meristem level in alternate-bearing citrus trees is analysed, together with the interplay between buds and leaves in the determination of flowering. METHODS First defruiting experiments were performed to manipulate blossoming intensity in 'Moncada' mandarin, Citrus clementina. Further defoliation was performed to elucidate the role leaves play in the flowering process. In both cases, the activity of flowering-related genes was investigated at the flower induction (November) and differentiation (February) stages. KEY RESULTS Study of the expression pattern of flowering-genes in buds from on (fully loaded) and off (without fruits) trees revealed that homologues of FLOWERING LOCUS T (CiFT), TWIN SISTER OF FT (TSF), APETALA1 (CsAP1) and LEAFY (CsLFY) were negatively affected by fruit load. CiFT and TSF activities showed a marked increase in buds from off trees through the study period (ten-fold in November). By contrast, expression of the homologues of the flowering inhibitors of TERMINAL FLOWER 1 (CsTFL), TERMINAL FLOWER 2 (TFL2) and FLOWERING LOCUS C (FLC) was generally lower in off trees. Regarding floral identity genes, the increase in CsAP1 expression in off trees was much greater in buds than in leaves, and significant variations in CsLFY expression (approx. 20 %) were found only in February. Defoliation experiments further revealed that the absence of leaves completely abolished blossoming and severely affected the expression of most of the flowering-related genes, particularly decreasing the activity of floral promoters and of CsAP1 at the induction stage. CONCLUSIONS These results suggest that the presence of fruit affects flowering by greatly altering gene-expression not only at the leaf but also at the meristem level. Although leaves are required for flowering to occur, their absence strongly affects the activity of floral promoters and identity genes.
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Affiliation(s)
- Natalia Muñoz-Fambuena
- Instituto Agroforestal Mediterráneo, Universidad Politécnica de Valencia, E-46022 Valencia, Spain
| | - Carlos Mesejo
- Instituto Agroforestal Mediterráneo, Universidad Politécnica de Valencia, E-46022 Valencia, Spain
| | - M. Carmen González-Mas
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias, E-46113 Moncada, Valencia, Spain
| | - Eduardo Primo-Millo
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias, E-46113 Moncada, Valencia, Spain
| | - Manuel Agustí
- Instituto Agroforestal Mediterráneo, Universidad Politécnica de Valencia, E-46022 Valencia, Spain
| | - Domingo J. Iglesias
- Centro de Citricultura y Producción Vegetal, Instituto Valenciano de Investigaciones Agrarias, E-46113 Moncada, Valencia, Spain
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23
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Batailler B, Lemaître T, Vilaine F, Sanchez C, Renard D, Cayla T, Beneteau J, Dinant S. Soluble and filamentous proteins in Arabidopsis sieve elements. PLANT, CELL & ENVIRONMENT 2012; 35:1258-73. [PMID: 22292537 DOI: 10.1111/j.1365-3040.2012.02487.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Phloem sieve elements are highly differentiated cells involved in the long-distance transport of photoassimilates. These cells contain both aggregated phloem-proteins (P-proteins) and soluble proteins, which are also translocated by mass flow. We used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to carry out a proteomic survey of the phloem exudate of Arabidopsis thaliana, collected by the ethylenediaminetetraacetic acid (EDTA)-facilitated method. We identified 287 proteins, a large proportion of which were enzymes involved in the metabolic precursor generation and amino acid synthesis, suggesting that sieve tubes display high levels of metabolic activity. RNA-binding proteins, defence proteins and lectins were also found. No putative P-proteins were detected in the EDTA-exudate fraction, indicating a lack of long-distance translocation of such proteins in Arabidopsis. In parallel, we investigated the organization of P-proteins, by high-resolution transmission electron microscopy, and the localization of the phloem lectin PP2, a putative P-protein component, by immunolocalization with antibodies against PP2-A1. Transmission electron microscopy observations of P-proteins revealed bundles of filaments resembling strings of beads. PP2-A1 was found weakly associated with these structures in the sieve elements and bound to plastids. These observations suggest that PP2-A1 is anchored to P-proteins and organelles rather than being a structural component of P-proteins.
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Affiliation(s)
- Brigitte Batailler
- UMR1332, Biologie du Fruit et Pathologie, INRA, F-33140 Villenave d'Ornon, France
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Kooke R, Keurentjes JJB. Multi-dimensional regulation of metabolic networks shaping plant development and performance. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3353-65. [PMID: 22140247 DOI: 10.1093/jxb/err373] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The metabolome is an integral part of a plant's life cycle and determines for a large part its external phenotype. It is the final, internal product of chemical interactions, obtained through developmental, genetic, and environmental inputs, and as such, it defines the state of a plant in terms of development and performance. Understanding its regulation will provide knowledge and new insights into the biochemical pathways and genetic interactions that shape the plant and its surroundings. In this review, we will focus on four dimensions that contribute to the huge diversity of metabolomes and we will illustrate how this diversity shapes the plant in terms of development and performance: (i) temporal regulation: the metabolome is extremely dynamic and temporal changes in the environment can have an immense impact on its composition; (ii) spatial regulation: metabolites can be very specific, in both quantitative and qualitative terms, to specialized organs, tissues, and cell types; (iii) environmental regulation: the metabolic profile of plants is highly dependent on environmental signals, such as light, temperature, and nutrients, and very susceptible to biotic and abiotic stresses; and (iv) genetic regulation: the biosynthesis, structure, and accumulation of metabolites have a genetic origin, and there is quantitative and qualitative variation for metabolomes within a species. We will address the contribution of these dimensions to the wide diversity of metabolomes and highlight how the multi-dimensional regulation of metabolism defines the plant's phenotype.
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Affiliation(s)
- R Kooke
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, Wageningen, The Netherlands
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Berbel A, Ferrándiz C, Hecht V, Dalmais M, Lund OS, Sussmilch FC, Taylor SA, Bendahmane A, Ellis THN, Beltrán JP, Weller JL, Madueño F. VEGETATIVE1 is essential for development of the compound inflorescence in pea. Nat Commun 2012; 3:797. [PMID: 22531182 DOI: 10.1038/ncomms1801] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 03/22/2012] [Indexed: 11/09/2022] Open
Abstract
Unravelling the basis of variation in inflorescence architecture is important to understanding how the huge diversity in plant form has been generated. Inflorescences are divided between simple, as in Arabidopsis, with flowers directly formed at the main primary inflorescence axis, and compound, as in legumes, where they are formed at secondary or even higher order axes. The formation of secondary inflorescences predicts a novel genetic function in the development of the compound inflorescences. Here we show that in pea this function is controlled by VEGETATIVE1 (VEG1), whose mutation replaces secondary inflorescences by vegetative branches. We identify VEG1 as an AGL79-like MADS-box gene that specifies secondary inflorescence meristem identity. VEG1 misexpression in meristem identity mutants causes ectopic secondary inflorescence formation, suggesting a model for compound inflorescence development based on antagonistic interactions between VEG1 and genes conferring primary inflorescence and floral identity. Our study defines a novel mechanism to generate inflorescence complexity.
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Affiliation(s)
- Ana Berbel
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia, Valencia 46022, Spain
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Liu L, Liu C, Hou X, Xi W, Shen L, Tao Z, Wang Y, Yu H. FTIP1 is an essential regulator required for florigen transport. PLoS Biol 2012; 10:e1001313. [PMID: 22529749 PMCID: PMC3328448 DOI: 10.1371/journal.pbio.1001313] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 03/09/2012] [Indexed: 12/16/2022] Open
Abstract
The capacity to respond to day length, photoperiodism, is crucial for flowering plants to adapt to seasonal change. The photoperiodic control of flowering in plants is mediated by a long-distance mobile floral stimulus called florigen that moves from leaves to the shoot apex. Although the proteins encoded by FLOWERING LOCUS T (FT) in Arabidopsis and its orthologs in other plants are identified as the long-sought florigen, whether their transport is a simple diffusion process or under regulation remains elusive. Here we show that an endoplasmic reticulum (ER) membrane protein, FT-INTERACTING PROTEIN 1 (FTIP1), is an essential regulator required for FT protein transport in Arabidopsis. Loss of function of FTIP1 exhibits late flowering under long days, which is partly due to the compromised FT movement to the shoot apex. FTIP1 and FT share similar mRNA expression patterns and subcellular localization, and they interact specifically in phloem companion cells. FTIP1 is required for FT export from companion cells to sieve elements, thus affecting FT transport through the phloem to the SAM. Our results provide a mechanistic understanding of florigen transport, demonstrating that FT moves in a regulated manner and that FTIP1 mediates FT transport to induce flowering.
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Affiliation(s)
| | | | | | | | | | | | | | - Hao Yu
- Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, Singapore
- * E-mail:
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Schwab R. The Roles of miR156 and miR172 in Phase Change Regulation. MICRORNAS IN PLANT DEVELOPMENT AND STRESS RESPONSES 2012. [DOI: 10.1007/978-3-642-27384-1_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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Crane O, Halaly T, Pang X, Lavee S, Perl A, Vankova R, Or E. Cytokinin-induced VvTFL1A expression may be involved in the control of grapevine fruitfulness. PLANTA 2012; 235:181-192. [PMID: 21863250 DOI: 10.1007/s00425-011-1497-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Accepted: 08/02/2011] [Indexed: 05/31/2023]
Abstract
Grapevine bud fruitfulness is determined by the differentiation of uncommitted meristem (UCM) into either tendril or inflorescence. Since tendril and inflorescence differentiation have long been considered sequential steps in inflorescence development, factors that control the progression of floral meristem development may regulate the final outcome of UCM differentiation, and thus affect fruitfulness. A comparison of the expression profiles of the master regulators of floral meristem identity (FMI) during development of fruitful and non-fruitful buds along the same cane allowed associating the expression of a homolog of terminal flower 1 (TFL1, a negative regulator of FMI) to fruitful buds, and the expression of positive FMI regulators to non-fruitful buds. Combined with (a) cytokinin-induced upregulation of VvTFL1A expression in cultured tendrils, which accompanied cytokinin-derived tendril transformation into branched, inflorescence-like structures, (b) positive regulation of VvTFL1A expression by cytokinin, which was demonstrated in transgenic embryonic culture expressing GUS reporter under the control of VvTFL1A promoter, and (c) a significantly higher level of active cytokinins in fruitful positions, the data may support the assumption of cytokinin-regulated VvTFL1A activity's involvement in the control of inflorescence development. Such activity may delay acquisition of FMI and allow an extended branching period for the UCM, resulting in the differentiation of inflorescence primordia.
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Affiliation(s)
- Omer Crane
- Department of Fruit Tree Sciences, Institute of Horticulture, Agricultural Research Organization, Volcani Center, 50250, Bet Dagan, Israel
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Teaster ND, Keereetaweep J, Kilaru A, Wang YS, Tang Y, Tran CNQ, Ayre BG, Chapman KD, Blancaflor EB. Overexpression of Fatty Acid Amide Hydrolase Induces Early Flowering in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2012; 3:32. [PMID: 22645580 PMCID: PMC3355813 DOI: 10.3389/fpls.2012.00032] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 02/01/2012] [Indexed: 05/19/2023]
Abstract
N-acylethanolamines (NAEs) are bioactive lipids derived from the hydrolysis of the membrane phospholipid N-acylphosphatidylethanolamine (NAPE). In animal systems this reaction is part of the "endocannabinoid" signaling pathway, which regulates a variety of physiological processes. The signaling function of NAE is terminated by fatty acid amide hydrolase (FAAH), which hydrolyzes NAE to ethanolamine and free fatty acid. Our previous work in Arabidopsis thaliana showed that overexpression of AtFAAH (At5g64440) lowered endogenous levels of NAEs in seeds, consistent with its role in NAE signal termination. Reduced NAE levels were accompanied by an accelerated growth phenotype, increased sensitivity to abscisic acid (ABA), enhanced susceptibility to bacterial pathogens, and early flowering. Here we investigated the nature of the early flowering phenotype of AtFAAH overexpression. AtFAAH overexpressors flowered several days earlier than wild type and AtFAAH knockouts under both non-inductive short day (SD) and inductive long day (LD) conditions. Microarray analysis revealed that the FLOWERING LOCUS T (FT) gene, which plays a major role in regulating flowering time, and one target MADS box transcription factor, SEPATALLA3 (SEP3), were elevated in AtFAAH overexpressors. Furthermore, AtFAAH overexpressors, with the early flowering phenotype had lower endogenous NAE levels in leaves compared to wild type prior to flowering. Exogenous application of NAE 12:0, which was reduced by up to 30% in AtFAAH overexpressors, delayed the onset of flowering in wild type plants. We conclude that the early flowering phenotype of AtFAAH overexpressors is, in part, explained by elevated FT gene expression resulting from the enhanced NAE hydrolase activity of AtFAAH, suggesting that NAE metabolism may participate in floral signaling pathways.
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Affiliation(s)
- Neal D. Teaster
- Plant Biology Division, The Samuel Roberts Noble FoundationArdmore, OK, USA
| | - Jantana Keereetaweep
- Department of Biological Sciences, Center for Plant Lipid Research, University of North TexasDenton, TX, USA
| | - Aruna Kilaru
- Department of Biological Sciences, East Tennessee State UniversityJohnson City, TN, USA
| | - Yuh-Shuh Wang
- Plant Signal Research Group, Institute of Technology, University of TartuTartu, Estonia
| | - Yuhong Tang
- Plant Biology Division, The Samuel Roberts Noble FoundationArdmore, OK, USA
| | - Christopher N.-Q. Tran
- Department of Biological Sciences, Center for Plant Lipid Research, University of North TexasDenton, TX, USA
| | - Brian G. Ayre
- Department of Biological Sciences, Center for Plant Lipid Research, University of North TexasDenton, TX, USA
| | - Kent D. Chapman
- Department of Biological Sciences, Center for Plant Lipid Research, University of North TexasDenton, TX, USA
| | - Elison B. Blancaflor
- Plant Biology Division, The Samuel Roberts Noble FoundationArdmore, OK, USA
- *Correspondence: Elison B. Blancaflor, Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK, USA. e-mail:
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Lazakis CM, Coneva V, Colasanti J. ZCN8 encodes a potential orthologue of Arabidopsis FT florigen that integrates both endogenous and photoperiod flowering signals in maize. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:4833-42. [PMID: 21730358 PMCID: PMC3192997 DOI: 10.1093/jxb/err129] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 03/24/2011] [Accepted: 03/30/2011] [Indexed: 05/18/2023]
Abstract
Higher plants use multiple perceptive measures to coordinate flowering time with environmental and endogenous cues. Physiological studies show that florigen is a mobile factor that transmits floral inductive signals from the leaf to the shoot apex. Arabidopsis FT protein is widely regarded as the archetype florigen found in diverse plant species, particularly in plants that use inductive photoperiods to flower. Recently, a large family of FT homologues in maize, the Zea CENTRORADIALIS (ZCN) genes, was described, suggesting that maize also contains FT-related proteins that act as a florigen. The product of one member of this large family, ZCN8, has several attributes that make it a good candidate as a maize florigen. Mechanisms underlying the floral transition in maize are less well understood than those of other species, partly because flowering in temperate maize is dependent largely on endogenous signals. The maize indeterminate1 (id1) gene is an important regulator of maize autonomous flowering that acts in leaves to mediate the transmission or production of florigenic signals. This study finds that id1 acts upstream of ZCN8 to control its expression, suggesting a possible new link to flowering in day-neutral maize. Moreover, in teosinte, a tropical progenitor of maize that requires short-day photoperiods to induce flowering, ZCN8 is highly up-regulated in leaves under inductive photoperiods. Finally, vascular-specific expression of ZCN8 in Arabidopsis complements the ft-1 mutation, demonstrating that leaf-specific expression of ZCN8 can induce flowering. These results suggest that ZCN8 may encode a florigen that integrates both endogenous and environmental signals in maize.
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Jarillo JA, Piñeiro M. Timing is everything in plant development. The central role of floral repressors. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2011; 181:364-78. [PMID: 21889042 DOI: 10.1016/j.plantsci.2011.06.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 06/20/2011] [Accepted: 06/21/2011] [Indexed: 05/07/2023]
Abstract
Progress in understanding the molecular basis of flowering time control has revealed that floral repressors play a central role in modulating the floral transition and are essential to prevent the precocious onset of flowering. A number of cellular processes including chromatin remodeling, selective protein degradation, and transcriptional regulation mediated by transcription factors are involved in repressing the initiation of flowering. Floral repressors interact at different levels with floral inductive pathways and prevent the premature onset of flowering that could impact negatively on the reproductive success of plants. Despite recent advances, further studies will be needed to understand how the interactions between floral repressors and the regulatory networks involved in the control of flowering time have evolved in different species. Recent data suggest that a diversity of regulatory proteins act as central floral repressors in different plants, and even in those species where regulatory modules are conserved new elements that modulate the function of these pathways have been recruited to mediate specific adaptive responses. The development of genomic tools and predictive models that can integrate large datasets related to the flowering behavior of plant species will facilitate the characterization of the repressor mechanisms underlying flowering responses, a trait with implications in the yield of crop species. In a scenario of global climate change, an in depth understanding of these gene circuits will be essential for the development of crop varieties with improved yield.
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Affiliation(s)
- Jose A Jarillo
- Centro de Biotecnología y Genómica de Plantas, INIA-UPM, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Campus de Montegancedo, Madrid, Spain
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Tsuwamoto R, Harada T. The Arabidopsis CORI3 promoter contains two cis-acting regulatory regions required for transcriptional activity in companion cells. PLANT CELL REPORTS 2011; 30:1723-33. [PMID: 21559970 DOI: 10.1007/s00299-011-1080-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/23/2011] [Accepted: 04/23/2011] [Indexed: 05/04/2023]
Abstract
Companion cells are metabolically active and functionally specialized cells that behave as terminals for the transport of materials between phloem and the surrounding tissue. Although previous research has clarified the distinct function of companion cells, it is still largely unknown how plants establish and maintain the special identity of these cells. To shed further light on this issue, we carried out expressed sequence tag (EST) analysis. To minimize the difficulty of dissociating and gathering intact companion cells, vascular strings with an abundant content of companion cells were excised from the petioles of Brassica napus. By random sequencing with a string-specific cDNA library derived by suppression subtractive hybridization between the string itself and the petiole from which it had been removed, we identified 377 ESTs and assembled them into 247 EST groups. The most frequent EST was ExBdl-102 (15 of 377 ESTs), which showed the highest sequence similarity to the Arabidopsis CORI3 (CORONATINE INDUCED 3) gene. The CORI3 promoter:GUS showed predominant expression in the vascular tissue of Arabidopsis. Through transient expression assay using Brassica vasculature and gene-gun-mediated transient assay, we found two integrated cis-regulatory regions of the CORI3 promoter. This work has provided not only string-specific EST information and shown that two novel cis-regulatory regions sustain transcriptional activity in companion cells, but also a series of procedures for efficiently examining the transcriptional framework of companion cells by exploiting the histochemical advantage of B. napus as an experimental material.
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Affiliation(s)
- Ryo Tsuwamoto
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan
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Benlloch R, Kim MC, Sayou C, Thévenon E, Parcy F, Nilsson O. Integrating long-day flowering signals: a LEAFY binding site is essential for proper photoperiodic activation of APETALA1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 67:1094-102. [PMID: 21623976 DOI: 10.1111/j.1365-313x.2011.04660.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The transition to flowering in Arabidopsis is characterized by the sharp and localized upregulation of APETALA1 (AP1) transcription in the newly formed floral primordia. Both the flower meristem-identity gene LEAFY (LFY) and the photoperiod pathway involving the FLOWERING LOCUS T (FT) and FD genes contribute to this upregulation. These pathways have been proposed to act independently but their respective contributions and mode of interaction have remained elusive. To address these questions, we studied the AP1 regulatory region. Combining in vitro and in vivo approaches, we identified which of the three putative LFY binding sites present in the AP1 promoter is essential for its activation by LFY. Interestingly, we found that this site is also important for the correct photoperiodic-dependent upregulation of AP1. In contrast, a previously proposed putative FD-binding site appears dispensable and unable to bind FD and we found no evidence for FD binding to other sites in the AP1 promoter, suggesting that the FT/FD-dependent activation of AP1 might be indirect. Altogether, our data give new insight into the interaction between the FT and LFY pathways in the upregulation of AP1 transcription under long-day conditions.
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Affiliation(s)
- Reyes Benlloch
- CEA, iRTSV, Laboratoire Physiologie Cellulaire et Végétale, F-38054 Grenoble, France
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Turnbull C. Long-distance regulation of flowering time. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:4399-413. [PMID: 21778182 DOI: 10.1093/jxb/err191] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
One of the great mysteries of plant science appears to have been resolved with the discovery that the protein FT can act as a phloem-mobile florigen hormone. The collective evidence from several laboratories, many from studies on photoperiod response, indicates that FT and its homologues are universal signalling molecules for flowering plants. Duplication and divergence of FT-like proteins reveals an increased complexity of function in certain taxonomic groups including grasses and legumes. There are additional components of long-distance flowering time control, such as a role for gibberellins in some species but probably not others. Cytokinins and sugars are further putative signals. Vernalization processes and responses are generally considered to occur in shoot meristems, but systemic responses to cold have been reported several times. Finally, there is increasing evidence that FT does not act purely to switch on flowering, but in addition, has broader roles in seasonal developmental switches such as bud dormancy and tuberization, and in the regulation of meristem determinacy and compound leaf development. This review seeks to highlight recent progress in systemic floral signalling, and to indicate areas in need of further research.
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Affiliation(s)
- Colin Turnbull
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK.
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Meng X, Muszynski MG, Danilevskaya ON. The FT-like ZCN8 Gene Functions as a Floral Activator and Is Involved in Photoperiod Sensitivity in Maize. THE PLANT CELL 2011; 23:942-60. [PMID: 21441432 PMCID: PMC3082274 DOI: 10.1105/tpc.110.081406] [Citation(s) in RCA: 206] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 02/08/2011] [Accepted: 03/04/2011] [Indexed: 05/18/2023]
Abstract
The mobile floral-promoting signal, florigen, is thought to consist of, in part, the FT protein named after the Arabidopsis thaliana gene FLOWERING LOCUS T. FT is transcribed and translated in leaves and its protein moves via the phloem to the shoot apical meristem where it promotes the transition from vegetative to reproductive development. In our search for a maize FT-like floral activator(s), seven Zea mays CENTRORADIALIS (ZCN) genes encoding FT homologous proteins were studied. ZCN8 stood out as the only ZCN having the requisite characteristics for possessing florigenic activity. In photoperiod sensitive tropical lines, ZCN8 transcripts were strongly upregulated in a diurnal manner under floral-inductive short days. In day-neutral temperate lines, ZCN8 mRNA level was independent of daylength and displayed only a weak cycling pattern. ZCN8 is normally expressed in leaf phloem, but ectopic expression of ZCN8 in vegetative stage shoot apices induced early flowering in transgenic plants. Silencing of ZCN8 by artificial microRNA resulted in late flowering. ZCN8 was placed downstream of indeterminate1 and upstream of delayed flowering1, two other floral activator genes. We propose a flowering model linking photoperiod sensitivity of tropical maize to diurnal regulation of ZCN8.
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Affiliation(s)
- Xin Meng
- Pioneer Hi-Bred International, a DuPont Business, Johnston, Iowa 50131-0552
| | - Michael G. Muszynski
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, Iowa 50011-3260
| | - Olga N. Danilevskaya
- Pioneer Hi-Bred International, a DuPont Business, Johnston, Iowa 50131-0552
- Address correspondence to
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Cellular factors in plant virus movement: at the leading edge of macromolecular trafficking in plants. Virology 2011; 411:237-43. [PMID: 21239029 DOI: 10.1016/j.virol.2010.12.021] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 12/14/2010] [Indexed: 11/22/2022]
Abstract
To establish systemic infection, plant viruses must be localized to the correct subcellular sites to accomplish replication and then traffic from initially infected cells into neighboring cells and even distant organs. Viruses have evolved various strategies to interact with pre-existing cellular factors to achieve these functions. In this review we discuss plant virus intracellular, intercellular and long-distance movement, focusing on the host cellular factors involved. We emphasize that elucidating viral movement mechanisms will not only shed light on the molecular mechanisms of infection, but will also contribute valuable insights into the regulation of endogenous macromolecular trafficking.
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Zhang C, Shi H, Chen L, Wang X, Lü B, Zhang S, Liang Y, Liu R, Qian J, Sun W, You Z, Dong H. Harpin-induced expression and transgenic overexpression of the phloem protein gene AtPP2-A1 in Arabidopsis repress phloem feeding of the green peach aphid Myzus persicae. BMC PLANT BIOLOGY 2011; 11:11. [PMID: 21226963 PMCID: PMC3030531 DOI: 10.1186/1471-2229-11-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 01/13/2011] [Indexed: 05/19/2023]
Abstract
BACKGROUND Treatment of plants with HrpNEa, a protein of harpin group produced by Gram-negative plant pathogenic bacteria, induces plant resistance to insect herbivores, including the green peach aphid Myzus persicae, a generalist phloem-feeding insect. Under attacks by phloem-feeding insects, plants defend themselves using the phloem-based defense mechanism, which is supposed to involve the phloem protein 2 (PP2), one of the most abundant proteins in the phloem sap. The purpose of this study was to obtain genetic evidence for the function of the Arabidopsis thaliana (Arabidopsis) PP2-encoding gene AtPP2-A1 in resistance to M. persicae when the plant was treated with HrpNEa and after the plant was transformed with AtPP2-A1. RESULTS The electrical penetration graph technique was used to visualize the phloem-feeding activities of apterous agamic M. persicae females on leaves of Arabidopsis plants treated with HrpNEa and an inactive protein control, respectively. A repression of phloem feeding was induced by HrpNEa in wild-type (WT) Arabidopsis but not in atpp2-a1/E/142, the plant mutant that had a defect in the AtPP2-A1 gene, the most HrpNEa-responsive of 30 AtPP2 genes. In WT rather than atpp2-a1/E/142, the deterrent effect of HrpNEa treatment on the phloem-feeding activity accompanied an enhancement of AtPP2-A1 expression. In PP2OETAt (AtPP2-A1-overexpression transgenic Arabidopsis thaliana) plants, abundant amounts of the AtPP2-A1 gene transcript were detected in different organs, including leaves, stems, calyces, and petals. All these organs had a deterrent effect on the phloem-feeding activity compared with the same organs of the transgenic control plant. When a large-scale aphid population was monitored for 24 hours, there was a significant decrease in the number of aphids that colonized leaves of HrpNEa-treated WT and PP2OETAt plants, respectively, compared with control plants. CONCLUSIONS The repression in phloem-feeding activities of M. persicae as a result of AtPP2-A1 overexpression, and as a deterrent effect of HrpNEa treatment in WT Arabidopsis rather than the atpp2-a1/E/142 mutant suggest that AtPP2-A1 plays a role in plant resistance to the insect, particularly at the phloem-feeding stage. The accompanied change of aphid population in leaf colonies suggests that the function of AtPP2-A1 is related to colonization of the plant.
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Affiliation(s)
- Chunling Zhang
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Haojie Shi
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Lei Chen
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
- Institute of Utilization of Nuclear Techniques, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, PR China
| | - Xiaomeng Wang
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Beibei Lü
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Shuping Zhang
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Yuan Liang
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Ruoxue Liu
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Jun Qian
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Weiwei Sun
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Zhenzhen You
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Hansong Dong
- Key Laboratory of Monitoring and Management of Crop Pathogens and Insect Pests, Ministry of Agriculture of R. P. China, Nanjing Agricultural University, Nanjing, 210095, PR China
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Takeda R, Petrov AI, Leontis NB, Ding B. A three-dimensional RNA motif in Potato spindle tuber viroid mediates trafficking from palisade mesophyll to spongy mesophyll in Nicotiana benthamiana. THE PLANT CELL 2011; 23:258-72. [PMID: 21258006 PMCID: PMC3051236 DOI: 10.1105/tpc.110.081414] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 12/13/2010] [Accepted: 12/25/2010] [Indexed: 05/04/2023]
Abstract
Cell-to-cell trafficking of RNA is an emerging biological principle that integrates systemic gene regulation, viral infection, antiviral response, and cell-to-cell communication. A key mechanistic question is how an RNA is specifically selected for trafficking from one type of cell into another type. Here, we report the identification of an RNA motif in Potato spindle tuber viroid (PSTVd) required for trafficking from palisade mesophyll to spongy mesophyll in Nicotiana benthamiana leaves. This motif, called loop 6, has the sequence 5'-CGA-3'...5'-GAC-3' flanked on both sides by cis Watson-Crick G/C and G/U wobble base pairs. We present a three-dimensional (3D) structural model of loop 6 that specifies all non-Watson-Crick base pair interactions, derived by isostericity-based sequence comparisons with 3D RNA motifs from the RNA x-ray crystal structure database. The model is supported by available chemical modification patterns, natural sequence conservation/variations in PSTVd isolates and related species, and functional characterization of all possible mutants for each of the loop 6 base pairs. Our findings and approaches have broad implications for studying the 3D RNA structural motifs mediating trafficking of diverse RNA species across specific cellular boundaries and for studying the structure-function relationships of RNA motifs in other biological processes.
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Affiliation(s)
- Ryuta Takeda
- Molecular, Cellular, and Developmental Biology Program, Ohio State University, Columbus, Ohio 43210
| | - Anton I. Petrov
- Department of Biological Sciences, Bowling Green State University, Bowling Green, Ohio 43403
| | - Neocles B. Leontis
- Department of Chemistry and Center for Biomolecular Sciences, Bowling Green State University, Bowling Green, Ohio 43403
| | - Biao Ding
- Molecular, Cellular, and Developmental Biology Program, Ohio State University, Columbus, Ohio 43210
- Department of Plant Cellular and Molecular Biology and Plant Biotechnology Center, Ohio State University, Columbus, Ohio 43210
- The Center for RNA Biology, Ohio State University, Columbus, Ohio 43210
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Abelenda JA, Navarro C, Prat S. From the model to the crop: genes controlling tuber formation in potato. Curr Opin Biotechnol 2010; 22:287-92. [PMID: 21168321 DOI: 10.1016/j.copbio.2010.11.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2010] [Revised: 11/25/2010] [Accepted: 11/25/2010] [Indexed: 12/15/2022]
Abstract
Photoperiod regulates many different developmental processes, including floral induction in several species and tuber formation in potato. Research in Arabidopsis led to the identification of FLOWERING LOCUS T (FT) as a main component of the florigen or mobile flowering promoting signal produced in the leaves. A similar mobile signal or tuberigen has been reported to induce tuber formation in potato, recent evidence obtained in our laboratory indicates that a potato homolog of FT encodes this signal. Flowering regulators, like CONSTANS and miR172, also play a role in tuberization, although it remains unclear whether these regulators function in identical pathways. Here, we highlight differential regulation of these genes in flowering and tuberization control and discuss on their possible tuberization-related function.
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Affiliation(s)
- José A Abelenda
- Dpto. de Genética Molecular de Plantas, Centro Nacional de Biotecnología-CSIC, Campus de Cantoblanco, c/Darwin 3, 28049 Madrid, Spain
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41
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Yoo SJ, Chung KS, Jung SH, Yoo SY, Lee JS, Ahn JH. BROTHER OF FT AND TFL1 (BFT) has TFL1-like activity and functions redundantly with TFL1 in inflorescence meristem development in Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 63:241-253. [PMID: 20409005 DOI: 10.1111/j.1365-313x.2010.04234.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The FLOWERING LOCUS T (FT)/TERMINAL FLOWER 1 (TFL1) family is a small gene family that encodes important regulators that control flower development in Arabidopsis. Here, we investigated the biological role of the product of BROTHER OF FT AND TFL1 (BFT), a member of this family, whose function remains unknown. Comparison of the critical residues that play a role in distinguishing FT- or TFL1-like activity revealed that BFT is more similar to FT. Similar to FT expression, BFT expression showed a diurnal oscillation pattern, peaking in the evening. In situ hybridization revealed BFT expression in the shoot apical meristem, young leaf and axillary inflorescence meristem. Transgenic plants over-expressing BFT exhibited delayed flowering and severe floral defects (floral indeterminacy and compact inflorescences surrounded by serrate leaves), similar to 35S::TFL1 plants. LEAFY (LFY) and APETALA1 (AP1) expression was significantly reduced in 35S::BFT plants. BFT over-expression failed to rescue the terminal flower phenotype of tfl1 mutants; however, it delayed both terminal flower formation in the primary inflorescence and axillary inflorescence development in the tfl1 mutant background. Consistent with this, the loss-of-function BFT alleles, bft-2 and an BFT RNAi line, accelerated termination of the primary inflorescence and formation of axillary inflorescences in the tfl1 mutant background. Taken together, our results suggest that, despite similarities in the critical residues of BFT and FT, BFT possesses a TFL1-like activity and functions redundantly with TFL1 in inflorescence meristem development, and possibly contributes to the regulation of plant architecture.
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Affiliation(s)
- Seong Jeon Yoo
- Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
| | - Kyung Sook Chung
- Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
| | - Seung Hye Jung
- Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
| | - So Yeon Yoo
- Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
| | - Jong Seob Lee
- School of Biological Sciences, Seoul National University, Seoul 151-742, Korea
| | - Ji Hoon Ahn
- Creative Research Initiative, School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea
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42
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Yant L, Mathieu J, Dinh TT, Ott F, Lanz C, Wollmann H, Chen X, Schmid M. Orchestration of the floral transition and floral development in Arabidopsis by the bifunctional transcription factor APETALA2. THE PLANT CELL 2010; 22:2156-70. [PMID: 20675573 PMCID: PMC2929098 DOI: 10.1105/tpc.110.075606] [Citation(s) in RCA: 347] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 07/07/2010] [Accepted: 07/14/2010] [Indexed: 05/17/2023]
Abstract
The Arabidopsis thaliana transcription factor APETALA2 (AP2) has numerous functions, including roles in seed development, stem cell maintenance, and specification of floral organ identity. To understand the relationship between these different roles, we mapped direct targets of AP2 on a genome-wide scale in two tissue types. We find that AP2 binds to thousands of loci in the developing flower, many of which exhibit AP2-dependent transcription. Opposing, logical effects are evident in AP2 binding to two microRNA genes that influence AP2 expression, with AP2 positively regulating miR156 and negatively regulating miR172, forming a complex direct feedback loop, which also included all but one of the AP2-like miR172 target clade members. We compare the genome-wide direct target repertoire of AP2 with that of SCHLAFMUTZE, a closely related transcription factor that also represses the transition to flowering. We detect clear similarities and important differences in the direct target repertoires that are also tissue specific. Finally, using an inducible expression system, we demonstrate that AP2 has dual molecular roles. It functions as both a transcriptional activator and repressor, directly inducing the expression of the floral repressor AGAMOUS-LIKE15 and directly repressing the transcription of floral activators like SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1.
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Affiliation(s)
- Levi Yant
- Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Johannes Mathieu
- Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Thanh Theresa Dinh
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside, California 92521
- ChemGen IGERT Program, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside, California 92521
| | - Felix Ott
- Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Christa Lanz
- Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Heike Wollmann
- Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Xuemei Chen
- Department of Botany and Plant Sciences, Center for Plant Cell Biology, Institute of Integrative Genome Biology, University of California, Riverside, California 92521
| | - Markus Schmid
- Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
- Address correspondence to
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43
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Lee YS, Jeong DH, Lee DY, Yi J, Ryu CH, Kim SL, Jeong HJ, Choi SC, Jin P, Yang J, Cho LH, Choi H, An G. OsCOL4 is a constitutive flowering repressor upstream of Ehd1 and downstream of OsphyB. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2010; 63:18-30. [PMID: 20409004 DOI: 10.1111/j.1365-313x.2010.04226.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Plants recognize environmental factors to determine flowering time. CONSTANS (CO) plays a central role in the photoperiod flowering pathway of Arabidopsis, and CO protein stability is modulated by photoreceptors. In rice, Hd1, an ortholog of CO, acts as a flowering promoter, and phytochromes repress Hd1 expression. Here, we investigated the functioning of OsCOL4, a member of the CONSTANS-like (COL) family in rice. OsCOL4 null mutants flowered early under short or long days. In contrast, OsCOL4 activation-tagging mutants (OsCOL4-D) flowered late in either environment. Transcripts of Ehd1, Hd3a, and RFT1 were increased in the oscol4 mutants, but reduced in the OsCOL4-D mutants. This finding indicates that OsCOL4 is a constitutive repressor functioning upstream of Ehd1. By comparison, levels of Hd1, OsID1, OsMADS50, OsMADS51, and OsMADS56 transcripts were not significantly changed in oscol4 or OsCOL4-D, suggesting that OsCOL4 functions independently from previously reported flowering pathways. In osphyB mutants, OsCOL4 expression was decreased and osphyB oscol4 double mutants flowered at the same time as the osphyB single mutants, indicating OsCOL4 functions downstream of OsphyB. We also present evidence for two independent pathways through which OsPhyB controls flowering time. These pathways are: (i) night break-sensitive, which does not need OsCOL4; and (ii) night break-insensitive, in which OsCOL4 functions between OsphyB and Ehd1.
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Affiliation(s)
- Yang-Seok Lee
- Department of Life Science, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea
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Danilevskaya ON, Meng X, Ananiev EV. Concerted modification of flowering time and inflorescence architecture by ectopic expression of TFL1-like genes in maize. PLANT PHYSIOLOGY 2010; 153:238-51. [PMID: 20200067 PMCID: PMC2862429 DOI: 10.1104/pp.110.154211] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 02/26/2010] [Indexed: 05/18/2023]
Abstract
TERMINAL FLOWER1 (TFL1)-like genes are highly conserved in plants and are thought to function in the maintenance of meristem indeterminacy. Recently, we described six maize (Zea mays) TFL1-related genes, named ZEA CENTRORADIALIS1 (ZCN1) to ZCN6. To gain insight into their functions, we generated transgenic maize plants overexpressing their respective cDNAs driven by a constitutive promoter. Overall, ectopic expression of the maize TFL1-like genes produced similar phenotypes, including delayed flowering and altered inflorescence architecture. We observed an apparent relationship between the magnitude of the transgenic phenotypes and the degree of homology between the ZCN proteins. ZCN2, -4, and -5 form a monophylogenetic clade, and their overexpression produced the strongest phenotypes. Along with very late flowering, these transgenic plants produced a "bushy" tassel with increased lateral branching and spikelet density compared with nontransgenic siblings. On the other hand, ZCN1, -3, and -6 produced milder effects. Among them, ZCN1 showed moderate effects on flowering time and tassel morphology, whereas ZCN3 and ZCN6 did not change flowering time but still showed effects on tassel morphology. In situ hybridizations of tissue from nontransgenic plants revealed that the expression of all ZCN genes was associated with vascular bundles, but each gene had a specific spatial and temporal pattern. Expression of four ZCN genes localized to the protoxylem, whereas ZCN5 was expressed in the protophloem. Collectively, our findings suggest that ectopic expression of the TFL1-like genes in maize modifies flowering time and inflorescence architecture through maintenance of the indeterminacy of the vegetative and inflorescence meristems.
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Affiliation(s)
- Olga N Danilevskaya
- Pioneer Hi-Bred International, a DuPont Business, Johnston, Iowa 50131, USA.
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45
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Busch W, Benfey PN. Information processing without brains--the power of intercellular regulators in plants. Development 2010; 137:1215-26. [PMID: 20332147 DOI: 10.1242/dev.034868] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Plants exhibit different developmental strategies than animals; these are characterized by a tight linkage between environmental conditions and development. As plants have neither specialized sensory organs nor a nervous system, intercellular regulators are essential for their development. Recently, major advances have been made in understanding how intercellular regulation is achieved in plants on a molecular level. Plants use a variety of molecules for intercellular regulation: hormones are used as systemic signals that are interpreted at the individual-cell level; receptor peptide-ligand systems regulate local homeostasis; moving transcriptional regulators act in a switch-like manner over small and large distances. Together, these mechanisms coherently coordinate developmental decisions with resource allocation and growth.
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Affiliation(s)
- Wolfgang Busch
- Department of Biology, Institute of Genome Sciences & Policy, Center for Systems Biology, Duke University, Durham, NC 27708, USA
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Kotoda N, Hayashi H, Suzuki M, Igarashi M, Hatsuyama Y, Kidou SI, Igasaki T, Nishiguchi M, Yano K, Shimizu T, Takahashi S, Iwanami H, Moriya S, Abe K. Molecular characterization of FLOWERING LOCUS T-like genes of apple (Malus x domestica Borkh.). PLANT & CELL PHYSIOLOGY 2010; 51:561-75. [PMID: 20189942 DOI: 10.1093/pcp/pcq021] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The two FLOWERING LOCUS T (FT)-like genes of apple (Malus x domestica Borkh.), MdFT1 and MdFT2, have been isolated and characterized. MdFT1 and MdFT2 were mapped, respectively, on distinct linkage groups (LGs) with partial homoeology, LG 12 and LG 4. The expression pattern of MdFT1 and MdFT2 differed in that MdFT1 was expressed mainly in apical buds of fruit-bearing shoots in the adult phase, with little expression in the juvenile tissues, whereas MdFT2 was expressed mainly in reproductive organs, including flower buds and young fruit. On the other hand, both genes had the potential to induce early flowering since transgenic Arabidopsis, which ectopically expressed MdFT1 or MdFT2, flowered earlier than wild-type plants. Furthermore, overexpression of MdFT1 conferred precocious flowering in apple, with altered expression of other endogenous genes, such as MdMADS12. These results suggest that MdFT1 could function to promote flowering by altering the expression of those genes and that, at least, other genes may play an important role as well in the regulation of flowering in apple. The long juvenile period of fruit trees prevents early cropping and efficient breeding. Our findings will be useful information to unveil the molecular mechanism of flowering and to develop methods to shorten the juvenile period in various fruit trees, including apple.
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Affiliation(s)
- Nobuhiro Kotoda
- Apple Breeding and Physiology Research Team, National Institute of Fruit Tree Science, 92-24 Nabe-yashiki, Shimo-kuriyagawa, Morioka, 020-0123 Japan. k
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Yant L, Mathieu J, Schmid M. Just say no: floral repressors help Arabidopsis bide the time. CURRENT OPINION IN PLANT BIOLOGY 2009; 12:580-6. [PMID: 19695946 DOI: 10.1016/j.pbi.2009.07.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 06/26/2009] [Accepted: 07/20/2009] [Indexed: 05/18/2023]
Abstract
Floral repressors ensure correct reproductive timing by safeguarding against premature flowering. In the past decade, several mechanisms of floral repression have come to light. Discrimination between direct and indirect repressors has been facilitated by increasing the use of chromatin immunoprecipitation assays. Certain MADS-domain transcription factors such as SHORT VEGETATIVE PHASE and FLOWERING LOCUS C bind directly to target euchromatin to repress specific loci including FLOWERING LOCUS T (FT) and FD. The AP2-domain transcription factor TEMPRANILLO 1 has also been shown to directly repress FT by binding its 5' UTR. We highlight emerging systems level approaches, including genome-scale direct binding studies (ChIP-chip and ChIP-Seq), which stand out in their promise to elucidate the complex network underlying the transition to flowering at an unprecedented level.
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Affiliation(s)
- Levi Yant
- Max Planck Institute for Developmental Biology, Department of Molecular Biology, Spemannstrasse 37-39, D-72076 Tübingen, Germany
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48
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D'Aloia M, Tamseddak K, Bonhomme D, Bonhomme F, Bernier G, Périlleux C. Gene activation cascade triggered by a single photoperiodic cycle inducing flowering in Sinapis alba. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 59:962-973. [PMID: 19473326 DOI: 10.1111/j.1365-313x.2009.03927.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Molecular genetic analyses in Arabidopsis disclosed a genetic pathway whereby flowering is induced by the photoperiod. This cascade is examined here within the time course of floral transition in the long-day (LD) plant Sinapis alba induced by a single photoperiodic cycle. In addition to previously available sequences, the cloning of CONSTANS (SaCO) and FLOWERING LOCUS T (SaFT) homologues allowed expression analyses to be performed to follow the flowering process step by step. A diurnal rhythm in SaCO expression in the leaves was observed and transcripts of SaFT were detected when light was given in phase with SaCO kinetics only. This occurred when day length was extended or when a short day was shifted towards a 'photophile phase'. The steady-state level of SaFT transcripts in the various physiological situations examined was found to correlate like a rheostat with floral induction strength. Kinetics of SaFT activation were also consistent with previous estimations of translocation of florigen out of leaves, which could actually occur after the inductive cycle. In response to one 22-h LD, initiation of floral meristems by the shoot apical meristem (SAM) started about 2 days after activation of SaFT and was marked by expression of APETALA1 (SaAP1). Meanwhile, LEAFY (SaLFY) was first up-regulated in leaf primordia and in the SAM. FRUITFULL (SaFUL) was later activated in the whole SAM but excluded from floral meristems. These patterns are integrated with previous observations concerning upregulation of SUPPRESSOR OF OVEREXPRESSION OF CO1 (SaSOC1) to provide a temporal and spatial map of floral transition in Sinapis.
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Affiliation(s)
- Maria D'Aloia
- Laboratory of Plant Physiology, University of Liège, B-4000 Liège, Belgium
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Abstract
How vernalization – exposure to a period of cold – induces flowering in Arabidopsis has been intensively investigated at the genetic and moleular levels. Recent papers, including one in BMC Plant Biology, shed light on changes in gene regulation that occur on vernalization in cereals.
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Abstract
As multicellular organisms, plants, like animals, use endogenous signaling molecules to coordinate their own physiology and development. To compensate for the absence of a cardiovascular system, plants have evolved specialized transport pathways to distribute signals and nutrients. The main transport streams include the xylem flow of the nutrients from the root to the shoot and the phloem flow of materials from the photosynthetic active tissues. These long-distance transport processes are complemented by several intercellular transport mechanisms (apoplastic, symplastic and transcellular transport). A prominent example of transcellular flow is transport of the phytohormone auxin within tissues. The process is mediated by influx and efflux carriers, whose polar localization in the plasma membrane determines the directionality of the flow. This polar auxin transport generates auxin maxima and gradients within tissues that are instrumental in the diverse regulation of various plant developmental processes, including embryogenesis, organogenesis, vascular tissue formation and tropisms.
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