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Valero-Rubira I, Vallés MP, Echávarri B, Fustero P, Costar MA, Castillo AM. New Epigenetic Modifier Inhibitors Enhance Microspore Embryogenesis in Bread Wheat. PLANTS (BASEL, SWITZERLAND) 2024; 13:772. [PMID: 38592809 PMCID: PMC10975478 DOI: 10.3390/plants13060772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/05/2024] [Accepted: 03/05/2024] [Indexed: 04/11/2024]
Abstract
The use of doubled haploid (DH) technology enables the development of new varieties of plants in less time than traditional breeding methods. In microspore embryogenesis (ME), stress treatment triggers microspores towards an embryogenic pathway, resulting in the production of DH plants. Epigenetic modifiers have been successfully used to increase ME efficiency in a number of crops. In wheat, only the histone deacetylase inhibitor trichostatin A (TSA) has been shown to be effective. In this study, inhibitors of epigenetic modifiers acting on histone methylation (chaetocin and CARM1 inhibitor) and histone phosphorylation (aurora kinase inhibitor II (AUKI-II) and hesperadin) were screened to determine their potential in ME induction in high- and mid-low-responding cultivars. The use of chaetocin and AUKI-II resulted in a higher percentage of embryogenic structures than controls in both cultivars, but only AUKI-II was superior to TSA. In order to evaluate the potential of AUKI-II in terms of increasing the number of green DH plants, short and long application strategies were tested during the mannitol stress treatment. The application of 0.8 µM AUKI-II during a long stress treatment resulted in a higher percentage of chromosome doubling compared to control DMSO in both cultivars. This concentration produced 33% more green DH plants than the control in the mid-low-responding cultivar, but did not affect the final ME efficiency in a high-responding cultivar. This study has identified new epigenetic modifiers whose use could be promising for increasing the efficiency of other systems that require cellular reprogramming.
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Affiliation(s)
| | | | | | | | | | - Ana María Castillo
- Department of Genetics and Plant Breeding, Aula Dei Experimental Station, Spanish National Research Council (EEAD-CSIC), 50059 Zaragoza, Spain; (I.V.-R.); (M.P.V.); (B.E.); (P.F.); (M.A.C.)
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2
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Broughton S, Castello M, Liu L, Killen J, McMullan C. Anther Culture Protocols for Barley and Wheat. Methods Mol Biol 2024; 2827:243-266. [PMID: 38985275 DOI: 10.1007/978-1-0716-3954-2_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Doubled haploid (DH) techniques remain valuable tools for wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) genetic improvement, and DH populations are used extensively in breeding and research endeavors. Several techniques are available for DH production in wheat and barley. Here, we describe two simple, robust anther culture methods used to produce more than 15,000 DH wheat and barley lines annually in Australia.
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Affiliation(s)
- Sue Broughton
- Department of Primary Industries and Regional Development, South Perth, WA, Australia.
| | - Marieclaire Castello
- Department of Primary Industries and Regional Development, South Perth, WA, Australia
| | - Li Liu
- Department of Primary Industries and Regional Development, South Perth, WA, Australia
| | - Julie Killen
- Department of Primary Industries and Regional Development, South Perth, WA, Australia
| | - Christopher McMullan
- Department of Primary Industries and Regional Development, South Perth, WA, Australia
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3
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Valero-Rubira I, Castillo AM, Burrell MÁ, Vallés MP. Microspore embryogenesis induction by mannitol and TSA results in a complex regulation of epigenetic dynamics and gene expression in bread wheat. FRONTIERS IN PLANT SCIENCE 2023; 13:1058421. [PMID: 36699843 PMCID: PMC9868772 DOI: 10.3389/fpls.2022.1058421] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 12/07/2022] [Indexed: 06/17/2023]
Abstract
Reprogramming of microspores development towards embryogenesis mediated by stress treatment constitutes the basis of doubled haploid production. Recently, compounds that alter histone post-translational modifications (PTMs) have been reported to enhance microspore embryogenesis (ME), by altering histones acetylation or methylation. However, epigenetic mechanisms underlying ME induction efficiency are poorly understood. In this study, the epigenetic dynamics and the expression of genes associated with histone PTMs and ME induction were studied in two bread wheat cultivars with different ME response. Microspores isolated at 0, 3 and 5 days, treated with 0.7M mannitol (MAN) and 0.7M mannitol plus 0.4µM trichostatin A (TSA), which induced ME more efficiently, were analyzed. An additional control of gametophytic development was included. Microspores epigenetic state at the onset of ME induction was distinctive between cultivars by the ratio of H3 variants and their acetylated forms, the localization and percentage of labeled microspores with H3K9ac, H4K5ac, H4K16ac, H3K9me2 and H3K27me3, and the expression of genes related to pollen development. These results indicated that microspores of the high responding cultivar could be at a less advanced stage in pollen development. MAN and TSA resulted in a hyperacetylation of H3.2, with a greater effect of TSA. Histone PTMs were differentially affected by both treatments, with acetylation being most concerned. The effect of TSA was observed in the H4K5ac localization pattern at 3dT in the mid-low responding cultivar. Three gene networks linked to ME response were identified. TaHDT1, TaHAG2, TaYAO, TaNFD6-A, TabZIPF1 and TaAGO802-B, associated with pollen development, were down-regulated. TaHDA15, TaHAG3, TaHAM, TaYUC11D, Ta-2B-LBD16 TaMS1 and TaDRM3 constituted a network implicated in morphological changes by auxin signaling and cell wall modification up-regulated at 3dT. The last network included TaHDA18, TaHAC1, TaHAC4, TaABI5, TaATG18fD, TaSDG1a-7A and was related to ABA and ethylene hormone signaling pathways, DNA methylation and autophagy processes, reaching the highest expression at 5dT. The results indicated that TSA mainly modified the regulation of genes related to pollen and auxin signaling. This study represents a breakthrough in identifying the epigenetic dynamics and the molecular mechanisms governing ME induction efficiency, with relevance to recalcitrant wheat genotypes and other crops.
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Affiliation(s)
- Isabel Valero-Rubira
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Zaragoza, Spain
| | - Ana María Castillo
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Zaragoza, Spain
| | - María Ángela Burrell
- Departamento de Patología, Anatomía y Fisiología, Facultad de Ciencias, Universidad de Navarra, Pamplona, Spain
| | - Maria Pilar Vallés
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Zaragoza, Spain
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4
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Shen K, Qu M, Zhao P. The Roads to Haploid Embryogenesis. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12020243. [PMID: 36678955 PMCID: PMC9865920 DOI: 10.3390/plants12020243] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/19/2022] [Accepted: 12/30/2022] [Indexed: 05/31/2023]
Abstract
Although zygotic embryogenesis is usually studied in the field of seed biology, great attention has been paid to the methods used to generate haploid embryos due to their applications in crop breeding. These mainly include two methods for haploid embryogenesis: in vitro microspore embryogenesis and in vivo haploid embryogenesis. Although microspore culture systems and maize haploid induction systems were discovered in the 1960s, little is known about the molecular mechanisms underlying haploid formation. In recent years, major breakthroughs have been made in in vivo haploid induction systems, and several key factors, such as the matrilineal (MTL), baby boom (BBM), domain of unknown function 679 membrane protein (DMP), and egg cell-specific (ECS) that trigger in vivo haploid embryo production in both the crops and Arabidopsis models have been identified. The discovery of these haploid inducers indicates that haploid embryogenesis is highly related to gamete development, fertilization, and genome stability in ealry embryos. Here, based on recent efforts to identify key players in haploid embryogenesis and to understand its molecular mechanisms, we summarize the different paths to haploid embryogenesis, and we discuss the mechanisms of haploid generation and its potential applications in crop breeding. Although these haploid-inducing factors could assist egg cells in bypassing fertilization to initiate embryogenesis or trigger genome elimination in zygotes after fertilization to form haploid embryos, the fertilization of central cells to form endosperms is a prerequisite step for haploid formation. Deciphering the molecular and cellular mechanisms for haploid embryogenesis, increasing the haploid induction efficiency, and establishing haploid induction systems in other crops are critical for promoting the application of haploid technology in crop breeding, and these should be addressed in further studies.
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Affiliation(s)
- Kun Shen
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Mengxue Qu
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Peng Zhao
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan 430072, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
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5
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Generation of Doubled Haploid Barley by Interspecific Pollination with Hordeum bulbosum. Methods Mol Biol 2021; 2287:215-226. [PMID: 34270032 DOI: 10.1007/978-1-0716-1315-3_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
The generation of doubled haploid barley plants by means of the so-called "Bulbosum" method has been practiced for meanwhile five decades. It rests upon the pollination of barley by its wild relative Hordeum bulbosum. This can result in the formation of hybrid embryos whose further development is typically associated with the loss of the pollinator's chromosomes. In recent years, this principle has, however, only rarely been used owing to the availability of efficient methods of anther and microspore culture. On the other hand, immature pollen-derived embryogenesis is to some extent prone to segregation bias in the resultant populations of haploids, which is due to its genotype dependency. Therefore, the principle of uniparental genome elimination has more recently regained increasing interest within the plant research and breeding community. The development of the present protocol relied on the use of the spring-type barley cultivar Golden Promise. The protocol is the result of a series of comparative experiments, which have addressed various methodological facets. The most influential ones included the method of emasculation, the temperature at flowering and early embryo development, the method, point in time and concentration of auxin administration for the stimulation of caryopsis development, the developmental stage at embryo dissection, as well as the nutrient medium used for embryo rescue. The present protocol allows the production of haploid barley plants at an efficiency of ca. 25% of the pollinated florets.
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Hoffie RE, Otto I, Hisano H, Kumlehn J. Site-Directed Mutagenesis in Barley Using RNA-Guided Cas Endonucleases During Microspore-Derived Generation of Doubled Haploids. Methods Mol Biol 2021; 2287:199-214. [PMID: 34270031 DOI: 10.1007/978-1-0716-1315-3_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
In plant research and breeding, haploid technology is employed upon crossing, induced mutagenesis or genetic engineering to generate populations of meiotic recombinants that are themselves genetically fixed. Thanks to the speed and efficiency in producing true-breeding lines, haploid technology has become a major driver of modern crop improvement. In the present study, we used embryogenic pollen cultures of winter barley ( Hordeum vulgare ) for Cas9 endonuclease-mediated targeted mutagenesis in haploid cells, which facilitates the generation of homozygous primary mutant plants. To this end, microspores were extracted from immature anthers, induced to undergo cell proliferation and embryogenic development in vitro, and were then inoculated with Agrobacterium for the delivery of T-DNAs comprising expression units for Cas9 endonuclease and target gene-specific guide RNAs (gRNAs). Amongst the regenerated plantlets, mutants were identified by PCR amplification of the target regions followed by sequencing of the amplicons. This approach also enabled us to discriminate between homozygous and heterozygous or chimeric mutants. The heritability of induced mutations and their homozygous state were experimentally confirmed by progeny analyses. The major advantage of the method lies in the preferential production of genetically fixed primary mutants, which facilitates immediate phenotypic analyses and, relying on that, a particularly efficient preselection of valuable lines for detailed investigations using their progenies.
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Affiliation(s)
- Robert Eric Hoffie
- Plant Reproductive Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Ingrid Otto
- Plant Reproductive Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Hiroshi Hisano
- Institute of Plant Science and Resources, Okayama University, Kurashiki, Okayama, Japan
| | - Jochen Kumlehn
- Plant Reproductive Biology, Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany.
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Corral-Martínez P, Siemons C, Horstman A, Angenent GC, de Ruijter N, Boutilier K. Live Imaging of embryogenic structures in Brassica napus microspore embryo cultures highlights the developmental plasticity of induced totipotent cells. PLANT REPRODUCTION 2020; 33:143-158. [PMID: 32651727 PMCID: PMC7648746 DOI: 10.1007/s00497-020-00391-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/29/2020] [Indexed: 05/10/2023]
Abstract
In vitro embryo development is highly plastic; embryo cell fate can be re-established in tissue culture through different pathways. In most angiosperms, embryo development from the single-celled zygote follows a defined pattern of cell divisions in which apical (embryo proper) and basal (root and suspensor) cell fates are established within the first cell divisions. By contrast, embryos that are induced in vitro in the absence of fertilization show a less regular initial cell division pattern yet develop into histodifferentiated embryos that can be converted into seedlings. We used the Brassica napus microspore embryogenesis system, in which the male gametophyte is reprogrammed in vitro to form haploid embryos, to identify the developmental fates of the different types of embryogenic structures found in culture. Using time-lapse imaging of LEAFY COTYLEDON1-expressing cells, we show that embryogenic cell clusters with very different morphologies are able to form haploid embryos. The timing of surrounding pollen wall (exine) rupture is a major determinant of cell fate in these clusters, with early exine rupture leading to the formation of suspensor-bearing embryos and late rupture to suspensorless embryos. In addition, we show that embryogenic callus, which develops into suspensor-bearing embryos, initially expresses transcripts associated with both basal- and apical-embryo cell fates, suggesting that these two cell fates are fixed later in development. This study reveals the inherent plasticity of in vitro embryo development and identifies new pathways by which embryo cell fate can be established.
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Affiliation(s)
- Patricia Corral-Martínez
- Plant Development Systems, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University and Research, P.O. Box 633, 6700 AP, Wageningen, The Netherlands
- Cell Biology Group, COMAV Institute, Universitat Politècnica de València (UPV), Camino de Vera, s/n. 46022, València, Spain
| | - Charlotte Siemons
- Plant Development Systems, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University and Research, P.O. Box 633, 6700 AP, Wageningen, The Netherlands
| | - Anneke Horstman
- Plant Development Systems, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University and Research, P.O. Box 633, 6700 AP, Wageningen, The Netherlands
| | - Gerco C Angenent
- Plant Development Systems, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University and Research, P.O. Box 633, 6700 AP, Wageningen, The Netherlands
| | - Norbert de Ruijter
- Laboratory of Cell Biology, Wageningen University and Research, P.O. Box 633, 6700 AP, Wageningen, The Netherlands
- Wageningen Light Microscopy Centre, Wageningen University and Research, P.O. Box 633, 6700 AP, Wageningen, The Netherlands
| | - Kim Boutilier
- Plant Development Systems, Wageningen University and Research, P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
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Bie XM, Dong L, Li XH, Wang H, Gao XQ, Li XG. Trichostatin A and sodium butyrate promotes plant regeneration in common wheat. PLANT SIGNALING & BEHAVIOR 2020; 15:1820681. [PMID: 32962515 PMCID: PMC7671042 DOI: 10.1080/15592324.2020.1820681] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Histone acetylation modification plays a vital role in plant cell division and differentiation. However, the function on wheat mature embryo culture has not been reported. Here, we used the mature embryo of wheat genotypes including CB037, Fielder, and Chinese Spring (CS) as materials to analyze the effects of different concentrations of trichostatin A (TSA) and sodium butyrate (SB) on plant regeneration efficiency. The results showed that, compared with the control group, the induction rates of embryogenic callus and green shoot were significantly increased with the addition of 0.5 µM TSA, while they were reduced under treatment of 2.5 µM TSA on wheat mature embryo. With the respective addition of 200 µM and 1000 µM SB, regeneration frequency of three genotypes was enhanced, especially in Fielder, which reached significant difference compared with the control group. Unfortunately, 0.5 µM TSA and 200 µM SB combination had no apparent effect on wheat regeneration frequency. The results indicated that TSA and SB increase plant regeneration in common wheat. In addition, TSA had a common effect and SB had different effect among genotypes on wheat regeneration frequency. The mechanism of action needs further investigation.
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Affiliation(s)
- Xiao Min Bie
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai′an, Shandong, China
- CONTACT Xiao Min Bie
| | - Luhao Dong
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai′an, Shandong, China
| | - Xiao Hui Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai′an, Shandong, China
| | - He Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai′an, Shandong, China
| | - Xi-Qi Gao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai′an, Shandong, China
| | - Xing Guo Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai′an, Shandong, China
- Xing Guo Li State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai′an, Shandong271018, China
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9
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Castillo AM, Valero-Rubira I, Burrell MÁ, Allué S, Costar MA, Vallés MP. Trichostatin A Affects Developmental Reprogramming of Bread Wheat Microspores towards an Embryogenic Route. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1442. [PMID: 33114625 PMCID: PMC7693754 DOI: 10.3390/plants9111442] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/17/2020] [Accepted: 10/21/2020] [Indexed: 12/24/2022]
Abstract
Microspores can be developmentally reprogrammed by the application of different stress treatments to initiate an embryogenic pathway leading to the production of doubled haploid (DH) plants. Epigenetic modifications are involved in cell reprogramming and totipotency in response to stress. To increase microspore embryogenesis (ME) efficiency in bread wheat, the effect of the histone deacetylase inhibitor trichostatin A (TSA) has been examined in two cultivars of wheat with different microspore embryogenesis response. Diverse strategies were assayed using 0-0.4 µM TSA as a single induction treatment and after or simultaneously with cold or mannitol stresses. The highest efficiency was achieved when 0.4 µM TSA was applied to anthers for 5 days simultaneously with a 0.7 M mannitol treatment, producing a four times greater number of green DH plants than mannitol. Ultrastructural studies by transmission electron microscopy indicated that mannitol with TSA and mannitol treatments induced similar morphological changes in early stages of microspore reprogramming, although TSA increased the number of microspores with 'star-like' morphology and symmetric divisions. The effect of TSA on the transcript level of four ME marker genes indicated that the early signaling pathways in ME, involving the TaTDP1 and TAA1b genes, may be mediated by changes in acetylation patterns of histones and/or other proteins.
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Affiliation(s)
- Ana María Castillo
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Avda Montañana 1005, 50059 Zaragoza, Spain; (A.M.C.); (I.V.-R.); (S.A.); (M.A.C.)
| | - Isabel Valero-Rubira
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Avda Montañana 1005, 50059 Zaragoza, Spain; (A.M.C.); (I.V.-R.); (S.A.); (M.A.C.)
| | - María Ángela Burrell
- Departamento de Patología, Anatomía y Fisiología, Facultad de Ciencias, Universidad de Navarra, C/Irrunlarrea s/n, 31008 Pamplona, Spain;
| | - Sandra Allué
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Avda Montañana 1005, 50059 Zaragoza, Spain; (A.M.C.); (I.V.-R.); (S.A.); (M.A.C.)
| | - María Asunción Costar
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Avda Montañana 1005, 50059 Zaragoza, Spain; (A.M.C.); (I.V.-R.); (S.A.); (M.A.C.)
| | - María Pilar Vallés
- Departamento de Genética y Producción Vegetal, Estación Experimental de Aula Dei, Consejo Superior de Investigaciones Científicas (EEAD-CSIC), Avda Montañana 1005, 50059 Zaragoza, Spain; (A.M.C.); (I.V.-R.); (S.A.); (M.A.C.)
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10
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Wu DD, Ruban A, Rutten T, Zhou YH, Houben A. Analysis of Pollen Grains by Immunostaining and FISH in Triticeae Species. Methods Mol Biol 2020; 2061:347-358. [PMID: 31583671 DOI: 10.1007/978-1-4939-9818-0_24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this chapter we describe protocols for immunolabeling and FISH of pollen grains undergoing postmeiotic mitosis using Aegilops speltoides, Secale cereale, and Hordeum vulgare as models. Tissue sectioning of pollen overcomes the problem of the pollen grain wall impermeability that interferes with immunolocalization and in situ hybridization. The crucial element of the protocol is the generation and immobilization of tissue sections. Our method facilitates the investigation of the microspore cell divisions and pollen grain maturation.
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Affiliation(s)
- Dan D Wu
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Stadt Seeland, Germany
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, China
| | - Alevtina Ruban
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Stadt Seeland, Germany
| | - Twan Rutten
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Stadt Seeland, Germany
| | - Yong H Zhou
- Triticeae Research Institute, Sichuan Agricultural University, Wenjiang, China
| | - Andreas Houben
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Stadt Seeland, Germany.
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11
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Testillano PS. Microspore embryogenesis: targeting the determinant factors of stress-induced cell reprogramming for crop improvement. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:2965-2978. [PMID: 30753698 DOI: 10.1093/jxb/ery464] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 12/17/2018] [Indexed: 05/17/2023]
Abstract
Under stress, isolated microspores are reprogrammed in vitro towards embryogenesis, producing doubled haploid plants that are useful biotechnological tools in plant breeding as a source of new genetic variability, fixed in homozygous plants in only one generation. Stress-induced cell death and low rates of cell reprogramming are major factors that reduce yield. Knowledge gained in recent years has revealed that initiation and progression of microspore embryogenesis involve a complex network of factors, whose roles are not yet well understood. Here, I review recent findings on the determinant factors underlying stress-induced microspore embryogenesis, focusing on the role of autophagy, cell death, auxin, chromatin modifications, and the cell wall. Autophagy and cell death proteases are crucial players in the response to stress, while cell reprogramming and acquisition of totipotency are regulated by hormonal and epigenetic mechanisms. Auxin biosynthesis, transport, and action are required for microspore embryogenesis. Initial stages involve DNA hypomethylation, H3K9 demethylation, and H3/H4 acetylation. Cell wall remodelling, with pectin de-methylesterification and arabinogalactan protein expression, is necessary for embryo development. Recent reports show that treatments with small modulators of autophagy, proteases, and epigenetic marks reduce cell death and enhance embryogenesis initiation in several crops, opening up new possibilities for improving in vitro embryo production in breeding programmes.
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Affiliation(s)
- Pilar S Testillano
- Pollen Biotechnology of Crop Plants group, Biological Research Center, CIB-CSIC, Ramiro de Maeztu, Madrid, Spain
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12
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Good KV, Martínez de Paz A, Tyagi M, Cheema MS, Thambirajah AA, Gretzinger TL, Stefanelli G, Chow RL, Krupke O, Hendzel M, Missiaen K, Underhill A, Landsberger N, Ausió J. Trichostatin A decreases the levels of MeCP2 expression and phosphorylation and increases its chromatin binding affinity. Epigenetics 2017; 12:934-944. [PMID: 29099289 DOI: 10.1080/15592294.2017.1380760] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
MeCP2 binds to methylated DNA in a chromatin context and has an important role in cancer and brain development and function. Histone deacetylase (HDAC) inhibitors are currently being used to palliate many cancer and neurological disorders. Yet, the molecular mechanisms involved are not well known for the most part and, in particular, the relationship between histone acetylation and MeCP2 is not well understood. In this paper, we study the effect of the HDAC inhibitor trichostatin A (TSA) on MeCP2, a protein whose dysregulation plays an important role in these diseases. We find that treatment of cells with TSA decreases the phosphorylation state of this protein and appears to result in a higher MeCP2 chromatin binding affinity. Yet, the binding dynamics with which the protein binds to DNA appear not to be significantly affected despite the chromatin reorganization resulting from the high levels of acetylation. HDAC inhibition also results in an overall decrease in MeCP2 levels of different cell lines. Moreover, we show that miR132 increases upon TSA treatment, and is one of the players involved in the observed downregulation of MeCP2.
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Affiliation(s)
- Katrina V Good
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
| | - Alexia Martínez de Paz
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
| | - Monica Tyagi
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
| | - Manjinder S Cheema
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
| | - Anita A Thambirajah
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , BC , V8W 3P6 , Canada.,b Douglas Hospital Research Center , Department of Psychiatry , McGill University , Montréal , Québec H3G 1Y6 , Canada
| | - Taylor L Gretzinger
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
| | - Gilda Stefanelli
- c Department of Medical Biotechnology and Translational Medicine , University of Milan , Milan , Italy
| | - Robert L Chow
- d Department of Biology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
| | - Oliver Krupke
- d Department of Biology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
| | - Michael Hendzel
- e Department of Cell Biology , Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta , Canada.,f Department of Oncology and Department of Cell Biology , Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta , Canada
| | - Kristal Missiaen
- f Department of Oncology and Department of Cell Biology , Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta , Canada
| | - Alan Underhill
- f Department of Oncology and Department of Cell Biology , Faculty of Medicine and Dentistry , University of Alberta , Edmonton , Alberta , Canada
| | - Nicoletta Landsberger
- c Department of Medical Biotechnology and Translational Medicine , University of Milan , Milan , Italy
| | - Juan Ausió
- a Department of Biochemistry and Microbiology , University of Victoria , Victoria , BC , V8W 3P6 , Canada
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