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Pavani G, Malhotra PK, Verma SK. Flowering in sugarcane-insights from the grasses. 3 Biotech 2023; 13:154. [PMID: 37138783 PMCID: PMC10149435 DOI: 10.1007/s13205-023-03573-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 04/19/2023] [Indexed: 05/05/2023] Open
Abstract
Flowering is a crucial phase for angiosperms to continue their species propagation and is highly regulated. In the current review, flowering in sugarcane and the associated mechanisms are elaborately presented. In sugarcane, flowering has two effects, wherein it is a beneficial factor from the breeder's perspective and crucial for crop improvement, but commercially, it depletes the sucrose reserves from the stalks; hence, less value is assigned. Different species of Saccharum genus are spread across geographical latitudes, thereby proving their ability to grow in multiple inductive daylengths of different locations according in the habituated zone. In general, sugarcane is termed an intermediate daylength plant with quantitative short-day behaviour as it requires reduction in daylength from 12 h 55 min to 12 h or 12 h 30 min. The prime concern in sugarcane flowering is its erratic flowering nature. The transition to reproductive stage which reverts to vegetative stage if there is any deviation from ambient temperature and light is also an issue. Spatial and temporal gene expression patterns during vegetative to reproductive stage transition and after reverting to vegetative state could possibly reveal how the genetic circuits are being governed. This review will also shed a light on potential roles of genes and/or miRNAs in flowering in sugarcane. Knowledge of transcriptomic background of circadian, photoperiod, and gibberellin pathways in sugarcane will enable us to better understand of variable response in floral development.
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Affiliation(s)
- Gongati Pavani
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, 141004 India
| | - Pawan Kumar Malhotra
- School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana, 141004 India
| | - Sandeep Kumar Verma
- Institute of Biological Science, SAGE University, Bypass Road, Kailod Kartal, Indore, Madhya Pradesh 452020 India
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Cho LH, Yoon J, Tun W, Baek G, Peng X, Hong WJ, Mori IC, Hojo Y, Matsuura T, Kim SR, Kim ST, Kwon SW, Jung KH, Jeon JS, An G. Cytokinin increases vegetative growth period by suppressing florigen expression in rice and maize. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 110:1619-1635. [PMID: 35388561 DOI: 10.1111/tpj.15760] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/17/2022] [Accepted: 03/28/2022] [Indexed: 05/12/2023]
Abstract
Increasing the vegetative growth period of crops can increase biomass and grain yield. In rice (Oryza sativa), the concentration of trans -zeatin, an active cytokinin, was high in the leaves during vegetative growth and decreased rapidly upon induction of florigen expression, suggesting that this hormone is involved in the regulation of the vegetative phase. To elucidate whether exogenous cytokinin application influences the length of the vegetative phase, we applied 6-benzylaminopurine (BAP) to rice plants at various developmental stages. Our treatment delayed flowering time by 8-9 days when compared with mock-treated rice plants, but only at the transition stage when the flowering signals were produced. Our observations also showed that flowering in the paddy field is delayed by thidiazuron, a stable chemical that mimics the effects of cytokinin. The transcript levels of florigen genes Heading date 3a (Hd3a) and Rice Flowering locus T1 (RFT1) were significantly reduced by the treatment, but the expression of Early heading date 1 (Ehd1), a gene found directly upstream of the florigen genes, was not altered. In maize (Zea mays), similarly, BAP treatment increased the vegetative phage by inhibiting the expression of ZCN8, an ortholog of Hd3a. We showed that cytokinin treatment induced the expression of two type-A response regulators (OsRR1 and OsRR2) which interacted with Ehd1, a type-B response regulator. We also observed that cytokinin did not affect flowering time in ehd1 knockout mutants. Our study indicates that cytokinin application increases the duration of the vegetative phase by delaying the expression of florigen genes in rice and maize by inhibiting Ehd1.
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Affiliation(s)
- Lae-Hyeon Cho
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang, 50463, Republic of Korea
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
| | - Jinmi Yoon
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang, 50463, Republic of Korea
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
| | - Win Tun
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
| | - Gibeom Baek
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang, 50463, Republic of Korea
| | - Xin Peng
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
- Institute of Genomics and Bioinformatics, South China Agricultural University, Guangzhou, 510642, China
| | - Woo-Jong Hong
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
| | - Izumi C Mori
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Yuko Hojo
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Takakazu Matsuura
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, 710-0046, Japan
| | - Sung-Ryul Kim
- Novel Gene Resources Laboratory, Strategic Innovation Platform, International Rice Research Institute (IRRI), DAPO Box 7777, Metro Manila, Philippines
| | - Sun-Tae Kim
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang, 50463, Republic of Korea
| | - Soon-Wook Kwon
- Department of Plant Bioscience, Life and Industry Convergence Research Institute, Pusan National University, Miryang, 50463, Republic of Korea
| | - Ki-Hong Jung
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
| | - Jong-Seong Jeon
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
| | - Gynheung An
- Crop Biotech Institute and Graduate School of Biotechnology, Kyung Hee University, Yongin, 17104, South Korea
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Venail J, da Silva Santos PH, Manechini JR, Alves LC, Scarpari M, Falcão T, Romanel E, Brito M, Vicentini R, Pinto L, Jackson SD. Analysis of the PEBP gene family and identification of a novel FLOWERING LOCUS T orthologue in sugarcane. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2035-2049. [PMID: 34893811 PMCID: PMC8982381 DOI: 10.1093/jxb/erab539] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/09/2021] [Indexed: 05/21/2023]
Abstract
Sugarcane (Saccharum spp.) is an important economic crop for both sugar and biomass, the yields of which are negatively affected by flowering. The molecular mechanisms controlling flowering in sugarcane are nevertheless poorly understood. RNA-seq data analysis and database searches have enabled a comprehensive description of the PEBP gene family in sugarcane. It is shown to consist of at least 13 FLOWERING LOCUS T (FT)-like genes, two MOTHER OF FT AND TFL (MFT)-like genes, and four TERMINAL FLOWER (TFL)-like genes. As expected, these genes all show very high homology to their corresponding genes in Sorghum, and also to FT-like, MFT-like, and TFL-like genes in maize, rice, and Arabidopsis. Functional analysis in Arabidopsis showed that the sugarcane ScFT3 gene can rescue the late flowering phenotype of the Arabidopsis ft-10 mutant, whereas ScFT5 cannot. High expression levels of ScFT3 in leaves of short day-induced sugarcane plants coincided with initial stages of floral induction in the shoot apical meristem as shown by histological analysis of meristem dissections. This suggests that ScFT3 is likely to play a role in floral induction in sugarcane; however, other sugarcane FT-like genes may also be involved in the flowering process.
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Affiliation(s)
- Julien Venail
- School of Life Sciences, University of Warwick, Gibbet Hill, Coventry CV4 7AL, UK
| | | | - Joao Ricardo Manechini
- Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | | | - Maximiliano Scarpari
- Centro de Cana, Instituto Agronômico de Campinas (IAC), Ribeirão Preto, São Paulo, Brazil
| | - Thais Falcão
- Departamento de Biotecnologia, Escola de Engenharia de Lorena (EEL), Universidade de São Paulo (USP), São Paulo, Brazil
| | - Elisson Romanel
- Departamento de Biotecnologia, Escola de Engenharia de Lorena (EEL), Universidade de São Paulo (USP), São Paulo, Brazil
| | - Michael Brito
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo (UNIFESP), São José dos Campos, São Paulo, Brazil
| | - Renato Vicentini
- Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, São Paulo, Brazil
| | - Lucia Pinto
- Centro de Cana, Instituto Agronômico de Campinas (IAC), Ribeirão Preto, São Paulo, Brazil
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Manechini JRV, Santos PHDS, Romanel E, Brito MDS, Scarpari MS, Jackson S, Pinto LR, Vicentini R. Transcriptomic Analysis of Changes in Gene Expression During Flowering Induction in Sugarcane Under Controlled Photoperiodic Conditions. FRONTIERS IN PLANT SCIENCE 2021; 12:635784. [PMID: 34211482 PMCID: PMC8239368 DOI: 10.3389/fpls.2021.635784] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 04/12/2021] [Indexed: 05/11/2023]
Abstract
Flowering is of utmost relevance for the agricultural productivity of the sugarcane bioeconomy, but data and knowledge of the genetic mechanisms underlying its photoperiodic induction are still scarce. An understanding of the molecular mechanisms that regulate the transition from vegetative to reproductive growth in sugarcane could provide better control of flowering for breeding. This study aimed to investigate the transcriptome of +1 mature leaves of a sugarcane cultivar subjected to florally inductive and non-inductive photoperiodic treatments to identify gene expression patterns and molecular regulatory modules. We identified 7,083 differentially expressed (DE) genes, of which 5,623 showed significant identity to other plant genes. Functional group analysis showed differential regulation of important metabolic pathways involved in plant development, such as plant hormones (i.e., cytokinin, gibberellin, and abscisic acid), light reactions, and photorespiration. Gene ontology enrichment analysis revealed evidence of upregulated processes and functions related to the response to abiotic stress, photoprotection, photosynthesis, light harvesting, and pigment biosynthesis, whereas important categories related to growth and vegetative development of plants, such as plant organ morphogenesis, shoot system development, macromolecule metabolic process, and lignin biosynthesis, were downregulated. Also, out of 76 sugarcane transcripts considered putative orthologs to flowering genes from other plants (such as Arabidopsis thaliana, Oryza sativa, and Sorghum bicolor), 21 transcripts were DE. Nine DE genes related to flowering and response to photoperiod were analyzed either at mature or spindle leaves at two development stages corresponding to the early stage of induction and inflorescence primordia formation. Finally, we report a set of flowering-induced long non-coding RNAs and describe their level of conservation to other crops, many of which showed expression patterns correlated against those in the functionally grouped gene network.
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Affiliation(s)
- João Ricardo Vieira Manechini
- Laboratório de Biologia de Sistemas, Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
| | - Paulo Henrique da Silva Santos
- Departamento de Genética e Melhoramento de Plantas, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual de São Paulo (UNESP), Jaboticabal, Brazil
| | - Elisson Romanel
- Laboratório de Genômica de Plantas e Bioenergia (PGEMBL), Departamento de Biotecnologia, Escola de Engenharia de Lorena (EEL), Universidade de São Paulo (USP), Lorena, Brazil
| | - Michael dos Santos Brito
- Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo (UNIFESP), São José dos Campos, Brazil
| | | | - Stephen Jackson
- School of Life Sciences, The University of Warwick, Coventry, United Kingdom
| | - Luciana Rossini Pinto
- Departamento de Genética e Melhoramento de Plantas, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual de São Paulo (UNESP), Jaboticabal, Brazil
- Centro de Cana, Instituto Agronômico de Campinas (IAC), Ribeirão Preto, Brazil
| | - Renato Vicentini
- Laboratório de Biologia de Sistemas, Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
- *Correspondence: Renato Vicentini,
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Glassop D, Rae AL. Expression of sugarcane genes associated with perception of photoperiod and floral induction reveals cycling over a 24-hour period. FUNCTIONAL PLANT BIOLOGY : FPB 2019; 46:314-327. [PMID: 32172741 DOI: 10.1071/fp18136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 11/19/2018] [Indexed: 05/25/2023]
Abstract
The genetic network resulting in the production of an inflorescence is complex, involving one or more pathways including the photoperiod, maturity, gibberellin and autonomous pathways, and induction and repression of genes along the pathways. Understanding the cyclic expression profile of genes involved with photoperiod perception and floral pathway induction in sugarcane, an intermediate-short day plant (ISD), is crucial for identifying key genes and understanding how the profile changes in response to floral induction signals under decreasing daylengths. Homologues of 21 genes, and some gene alleles, associated with photoperiod perception and the flower induction pathway were examined in sugarcane variety Q174 over a 24-h light-dark cycle. The strongest expression of these genes was seen in the immature spindle leaves and levels of expression generally decreased with increasing leaf age. Significant changes in gene expression levels during a 24-h cycle were observed for 16 of the 21 genes tested. We have now defined an important baseline for expression patterns over a 24-h cycle in non-inductive conditions in sugarcane. These results can be utilised to select the optimal time for detecting changes during floral induction, differences between varieties that are responsive/non-responsive to photoperiod induction, and to identify genes that may be manipulated to enhance or inhibit flowering.
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Affiliation(s)
- Donna Glassop
- CSIRO Agriculture and Food, 306 Carmody Road, St Lucia, Qld 4067, Australia
| | - Anne L Rae
- CSIRO Agriculture and Food, 306 Carmody Road, St Lucia, Qld 4067, Australia
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Goretti D, Martignago D, Landini M, Brambilla V, Gómez-Ariza J, Gnesutta N, Galbiati F, Collani S, Takagi H, Terauchi R, Mantovani R, Fornara F. Transcriptional and Post-transcriptional Mechanisms Limit Heading Date 1 (Hd1) Function to Adapt Rice to High Latitudes. PLoS Genet 2017; 13:e1006530. [PMID: 28068345 PMCID: PMC5221825 DOI: 10.1371/journal.pgen.1006530] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 12/08/2016] [Indexed: 11/24/2022] Open
Abstract
Rice flowering is controlled by changes in the photoperiod that promote the transition to the reproductive phase as days become shorter. Natural genetic variation for flowering time has been largely documented and has been instrumental to define the genetics of the photoperiodic pathway, as well as providing valuable material for artificial selection of varieties better adapted to local environments. We mined genetic variation in a collection of rice varieties highly adapted to European regions and isolated distinct variants of the long day repressor HEADING DATE 1 (Hd1) that perturb its expression or protein function. Specific variants allowed us to define novel features of the photoperiodic flowering pathway. We demonstrate that a histone fold domain scaffold formed by GRAIN YIELD, PLANT HEIGHT AND HEADING DATE 8 (Ghd8) and several NF-YC subunits can accommodate distinct proteins, including Hd1 and PSEUDO RESPONSE REGULATOR 37 (PRR37), and that the resulting OsNF-Y complex containing Hd1 can bind a specific sequence in the promoter of HEADING DATE 3A (Hd3a). Artificial selection has locally favored an Hd1 variant unable to assemble in such heterotrimeric complex. The causal polymorphism was defined as a single conserved lysine in the CCT domain of the Hd1 protein. Our results indicate how genetic variation can be stratified and explored at multiple levels, and how its description can contribute to the molecular understanding of basic developmental processes. Many plant species flower in response to changes in day length and can be categorized depending on their requirements for long or short days. Rice has tropical origins and normally flowers in response to shortening days. However, artificial selection operated by ancient farmers or modern breeders adapted rice cultivation to several environments, including those typical of temperate regions characterized by long days during the cropping season. Modifications of the genetic network controlling flowering that are causal to such expansion have been the subject of extensive studies, but the full complement of genes that regulate it and the molecular bases of their activity remains unknown. We took advantage of germplasm cultivated in Europe—and highly adapted to flower under long days–to isolate widespread variants of the HEADING DATE 1 (Hd1) gene that limits flowering in temperate areas, and showed that such variants are non-functional and unable to prevent long day flowering. We identified the DNA changes causing the gene to be non-functional and used such mutant alleles as tools to demonstrate that Hd1 can bind a specific DNA sequence in the promoter of a florigenic rice gene. Mining genetic diversity becomes thus instrumental to define the molecular properties of regulatory pathways.
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Affiliation(s)
- Daniela Goretti
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Damiano Martignago
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, United Kingdom
| | - Martina Landini
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
| | - Vittoria Brambilla
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
- Department of Agricultural and Environmental Sciences–Production, Territory, Agroenergy, University of Milan, Via Celoria 2, Milan, Italy
| | - Jorge Gómez-Ariza
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
| | - Nerina Gnesutta
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
| | - Francesca Galbiati
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
| | - Silvio Collani
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, Umeå, Sweden
| | - Hiroki Takagi
- Iwate Biotechnology Research Center and Laboratory of Crop Evolution, Graduate School of Agricultural Sciences, Kyoto University, Mozume, Muko, Kyoto, Japan
| | - Ryohei Terauchi
- Iwate Biotechnology Research Center and Laboratory of Crop Evolution, Graduate School of Agricultural Sciences, Kyoto University, Mozume, Muko, Kyoto, Japan
| | - Roberto Mantovani
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
| | - Fabio Fornara
- Department of Biosciences, University of Milan, Via Celoria 26, Milan, Italy
- * E-mail:
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Song K, Kim HC, Shin S, Kim KH, Moon JC, Kim JY, Lee BM. Transcriptome Analysis of Flowering Time Genes under Drought Stress in Maize Leaves. FRONTIERS IN PLANT SCIENCE 2017; 8:267. [PMID: 28298916 PMCID: PMC5331056 DOI: 10.3389/fpls.2017.00267] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 02/14/2017] [Indexed: 05/20/2023]
Abstract
Flowering time is an important factor determining yield and seed quality in maize. A change in flowering time is a strategy used to survive abiotic stresses. Among abiotic stresses, drought can increase anthesis-silking intervals (ASI), resulting in negative effects on maize yield. We have analyzed the correlation between flowering time and drought stress using RNA-seq and bioinformatics tools. Our results identified a total of 619 genes and 126 transcripts whose expression was altered by drought stress in the maize B73 leaves under short-day condition. Among drought responsive genes, we also identified 20 genes involved in flowering times. Gene Ontology (GO) enrichment analysis was used to predict the functions of the drought-responsive genes and transcripts. GO categories related to flowering time included reproduction, flower development, pollen-pistil interaction, and post-embryonic development. Transcript levels of several genes that have previously been shown to affect flowering time, such as PRR37, transcription factor HY5, and CONSTANS, were significantly altered by drought conditions. Furthermore, we also identified several drought-responsive transcripts containing C2H2 zinc finger, CCCH, and NAC domains, which are frequently involved in transcriptional regulation and may thus have potential to alter gene expression programs to change maize flowering time. Overall, our results provide a genome-wide analysis of differentially expressed genes (DEGs), novel transcripts, and isoform variants expressed during the reproductive stage of maize plants subjected to drought stress and short-day condition. Further characterization of the drought-responsive transcripts identified in this study has the potential to advance our understanding of the mechanisms that regulate flowering time under drought stress.
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Affiliation(s)
- Kitae Song
- Department of Life Science, Dongguk University-SeoulSeoul, South Korea
| | - Hyo Chul Kim
- Department of Life Science, Dongguk University-SeoulSeoul, South Korea
| | - Seungho Shin
- Department of Life Science, Dongguk University-SeoulSeoul, South Korea
| | - Kyung-Hee Kim
- Department of Life Science, Dongguk University-SeoulSeoul, South Korea
| | - Jun-Cheol Moon
- Agriculture and Life Sciences Research Institute, Kangwon National UniversityChuncheon, South Korea
| | - Jae Yoon Kim
- Department of Plant Resources, College of Industrial Science, Kongju National UniversityYesan, South Korea
| | - Byung-Moo Lee
- Department of Life Science, Dongguk University-SeoulSeoul, South Korea
- *Correspondence: Byung-Moo Lee
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Cho LH, Yoon J, Pasriga R, An G. Homodimerization of Ehd1 Is Required to Induce Flowering in Rice. PLANT PHYSIOLOGY 2016; 170:2159-71. [PMID: 26864016 PMCID: PMC4825144 DOI: 10.1104/pp.15.01723] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/02/2016] [Indexed: 05/20/2023]
Abstract
In plants, flowering time is elaborately controlled by various environment factors. Ultimately, florigens such as FLOWERING LOCUS T (FT) or FT-like molecules induce flowering. In rice (Oryza sativa), Early heading date 1 (Ehd1) is a major inducer of florigen gene expression. Although Ehd1 is highly homologous to the type-B response regulator (RR) family in the cytokinin signaling pathway, its precise molecular mechanism is not well understood. In this study, we showed that the C-terminal portion of the protein containing the GARP DNA-binding (G) domain can promote flowering when overexpressed. We also observed that the N-terminal portion of Ehd1, carrying the receiver (R) domain, delays flowering by inhibiting endogenous Ehd1 activity. Ehd1 protein forms a homomer via a 16-amino acid region in the inter domain between R and G. From the site-directed mutagenesis analyses, we demonstrated that phosphorylation of the Asp-63 residue within the R domain induces the homomerization of Ehd1, which is crucial for Ehd1 activity. A type-A RR, OsRR1, physically interacts with Ehd1 to form a heterodimer. In addition, OsRR1-overexpressing plants show a late-flowering phenotype. Based on these observations, we conclude that OsRR1 inhibits Ehd1 activity by binding to form an inactive complex.
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Affiliation(s)
- Lae-Hyeon Cho
- Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea (L.-H.C., J.Y., R.P., G.A.);Department of Life Science, Pohang University of Science and Technology, Pohang 790-784, Korea (L.-H.C., J.Y.); andGraduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea (R.P., G.A.)
| | - Jinmi Yoon
- Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea (L.-H.C., J.Y., R.P., G.A.);Department of Life Science, Pohang University of Science and Technology, Pohang 790-784, Korea (L.-H.C., J.Y.); andGraduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea (R.P., G.A.)
| | - Richa Pasriga
- Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea (L.-H.C., J.Y., R.P., G.A.);Department of Life Science, Pohang University of Science and Technology, Pohang 790-784, Korea (L.-H.C., J.Y.); andGraduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea (R.P., G.A.)
| | - Gynheung An
- Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea (L.-H.C., J.Y., R.P., G.A.);Department of Life Science, Pohang University of Science and Technology, Pohang 790-784, Korea (L.-H.C., J.Y.); andGraduate School of Biotechnology, Kyung Hee University, Yongin 446-701, Korea (R.P., G.A.)
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Coelho CP, Minow MAA, Chalfun-Júnior A, Colasanti J. Putative sugarcane FT/TFL1 genes delay flowering time and alter reproductive architecture in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2014; 5:221. [PMID: 24904616 PMCID: PMC4033272 DOI: 10.3389/fpls.2014.00221] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 05/03/2014] [Indexed: 05/05/2023]
Abstract
Agriculturally important grasses such as rice, maize, and sugarcane are evolutionarily distant from Arabidopsis, yet some components of the floral induction process are highly conserved. Flowering in sugarcane is an important factor that negatively affects cane yield and reduces sugar/ethanol production from this important perennial bioenergy crop. Comparative studies have facilitated the identification and characterization of putative orthologs of key flowering time genes in sugarcane, a complex polyploid plant whose genome has yet to be sequenced completely. Using this approach we identified phosphatidylethanolamine-binding protein (PEBP) gene family members in sugarcane that are similar to the archetypical FT and TFL1 genes of Arabidopsis that play an essential role in controlling the transition from vegetative to reproductive growth. Expression analysis of ScTFL1, which falls into the TFL1-clade of floral repressors, showed transcripts in developing leaves surrounding the shoot apex but not at the apex itself. ScFT1 was detected in immature leaves and apical regions of vegetatively growing plants and, after the floral transition, expression also occurred in mature leaves. Ectopic over-expression of ScTFL1 in Arabidopsis caused delayed flowering in Arabidopsis, as might be expected for a gene related to TFL1. In addition, lines with the latest flowering phenotype exhibited aerial rosette formation. Unexpectedly, over-expression of ScFT1, which has greatest similarity to the florigen-encoding FT, also caused a delay in flowering. This preliminary analysis of divergent sugarcane FT and TFL1 gene family members from Saccharum spp. suggests that their expression patterns and roles in the floral transition has diverged from the predicted role of similar PEBP family members.
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Affiliation(s)
- Carla P. Coelho
- Setor de Fisiologia Vegetal, Departamento de Biologia, Universidade Federal de LavrasLavras, Brazil
- Department of Molecular and Cellular Biology, University of GuelphGuelph, ON, Canada
| | - Mark A. A. Minow
- Department of Molecular and Cellular Biology, University of GuelphGuelph, ON, Canada
| | - Antonio Chalfun-Júnior
- Setor de Fisiologia Vegetal, Departamento de Biologia, Universidade Federal de LavrasLavras, Brazil
| | - Joseph Colasanti
- Department of Molecular and Cellular Biology, University of GuelphGuelph, ON, Canada
- *Correspondence: Joseph Colasanti, Department of Molecular and Cellular Biology, University of Guelph, 50 Stone Road East, Guelph, ON, N1G 2W1, Canada e-mail:
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