1
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Gómez-Páez DM, Magnani E. Confocal Imaging of Seeds. Methods Mol Biol 2024; 2830:93-104. [PMID: 38977571 DOI: 10.1007/978-1-0716-3965-8_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: 07/10/2024]
Abstract
In flowering plants, proper seed development is achieved through the constant interplay of fertilization products, embryo and endosperm, and maternal tissues. Understanding such a complex biological process requires microscopy techniques able to unveil the seed internal morphological structure. Seed thickness and relatively low permeability make conventional tissue staining techniques impractical unless combined with time-consuming dissecting methods. Here, we describe two techniques to imaging the three-dimensional structure of Arabidopsis seeds by confocal laser scanning microscopy. Both procedures, while differing in their time of execution and resolution, are based on cell wall staining of seed tissues with fluorescent dyes.
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Affiliation(s)
- Dennys-Marcela Gómez-Páez
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France
| | - Enrico Magnani
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), Versailles, France.
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2
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Harnvanichvech Y, Borassi C, Daghma DES, van der Kooij HM, Sprakel J, Weijers D. An elastic proteinaceous envelope encapsulates the early Arabidopsis embryo. Development 2023; 150:dev201943. [PMID: 37869985 PMCID: PMC10651100 DOI: 10.1242/dev.201943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 10/09/2023] [Indexed: 10/24/2023]
Abstract
Plant external surfaces are often covered by barriers that control the exchange of molecules, protect from pathogens and offer mechanical integrity. A key question is when and how such surface barriers are generated. Post-embryonic surfaces have well-studied barriers, including the cuticle, and it has been previously shown that the late Arabidopsis thaliana embryo is protected by an endosperm-derived sheath deposited onto a primordial cuticle. Here, we show that both cuticle and sheath are preceded by another structure during the earliest stages of embryogenesis. This structure, which we named the embryonic envelope, is tightly wrapped around the embryonic surface but can be physically detached by cell wall digestion. We show that this structure is composed primarily of extensin and arabinogalactan O-glycoproteins and lipids, which appear to form a dense and elastic crosslinked embryonic envelope. The envelope forms in cuticle-deficient mutants and in a mutant that lacks endosperm. This embryo-derived envelope is therefore distinct from previously described cuticle and sheath structures. We propose that it acts as an expandable diffusion barrier, as well as a means to mechanically confine the embryo to maintain its tensegrity during early embryogenesis.
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Affiliation(s)
- Yosapol Harnvanichvech
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen 6708 WE, The Netherlands
- Physical Chemistry and Soft Matter, Wageningen University and Research, Wageningen 6708 WE, The Netherlands
| | - Cecilia Borassi
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen 6708 WE, The Netherlands
| | - Diaa Eldin S. Daghma
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen 6708 WE, The Netherlands
| | - Hanne M. van der Kooij
- Physical Chemistry and Soft Matter, Wageningen University and Research, Wageningen 6708 WE, The Netherlands
| | - Joris Sprakel
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen 6708 WE, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University and Research, Wageningen 6708 WE, The Netherlands
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3
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Baud S, Corso M, Debeaujon I, Dubreucq B, Job D, Marion-Poll A, Miquel M, North H, Rajjou L, Lepiniec L. Recent progress in molecular genetics and omics-driven research in seed biology. C R Biol 2023; 345:61-110. [PMID: 36847120 DOI: 10.5802/crbiol.104] [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: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 01/11/2023]
Abstract
Elucidating the mechanisms that control seed development, metabolism, and physiology is a fundamental issue in biology. Michel Caboche had long been a catalyst for seed biology research in France up until his untimely passing away last year. To honour his memory, we have updated a review written under his coordination in 2010 entitled "Arabidopsis seed secrets unravelled after a decade of genetic and omics-driven research". This review encompassed different molecular aspects of seed development, reserve accumulation, dormancy and germination, that are studied in the lab created by M. Caboche. We have extended the scope of this review to highlight original experimental approaches implemented in the field over the past decade such as omics approaches aimed at investigating the control of gene expression, protein modifications, primary and specialized metabolites at the tissue or even cellular level, as well as seed biodiversity and the impact of the environment on seed quality.
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4
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Shin S, Chairattanawat C, Yamaoka Y, Yang Q, Lee Y, Hwang JU. Early seed development requires the A-type ATP-binding cassette protein ABCA10. PLANT PHYSIOLOGY 2022; 189:360-374. [PMID: 35166840 PMCID: PMC9070825 DOI: 10.1093/plphys/kiac062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 01/06/2022] [Indexed: 05/11/2023]
Abstract
A-type ATP-binding cassette (ABCA) proteins transport lipids and lipid-based molecules in humans, and their malfunction is associated with various inherited diseases. Although plant genomes encode many ABCA transporters, their molecular and physiological functions remain largely unknown. Seeds are rapidly developing organs that rely on the biosynthesis and transport of large quantities of lipids to generate new membranes and storage lipids. In this study, we characterized the Arabidopsis (Arabidopsis thaliana) ABCA10 transporter, which is selectively expressed in female gametophytes and early developing seeds. By 3 d after flowering (DAF), seeds from the abca10 loss-of-function mutant exhibited a smaller chalazal endosperm than those of the wild-type. By 4 DAF, their endosperm nuclei occupied a smaller area than those of the wild-type. The endosperm nuclei of the mutants also failed to distribute evenly inside the seed coat and stayed aggregated instead, possibly due to inadequate expansion of abca10 endosperm. This endosperm defect might have retarded abca10 embryo development. At 7 DAF, a substantial portion of abca10 embryos remained at the globular or earlier developmental stages, whereas wild-type embryos were at the torpedo or later stages. ABCA10 is likely involved in lipid metabolism, as ABCA10 overexpression induced the overaccumulation of triacylglycerol but did not change the carbohydrate or protein contents in seeds. In agreement, ABCA10 localized to the endoplasmic reticulum (ER), the major site of lipid biosynthesis. Our results reveal that ABCA10 plays an essential role in early seed development, possibly by transporting substrates for lipid metabolism to the ER.
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Affiliation(s)
- Seungjun Shin
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | | | - Yasuyo Yamaoka
- Division of Biotechnology, The Catholic University of Korea, Bucheon 14662, Republic of Korea
| | - Qianying Yang
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Youngsook Lee
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
- Department of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
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5
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Wehbi H, Soulhat C, Morin H, Bendahmane A, Hilson P, Bouchabké-Coussa O. One-Week Scutellar Somatic Embryogenesis in the Monocot Brachypodium distachyon. PLANTS 2022; 11:plants11081068. [PMID: 35448796 PMCID: PMC9025947 DOI: 10.3390/plants11081068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/06/2022] [Accepted: 04/11/2022] [Indexed: 11/16/2022]
Abstract
Plant somatic embryogenesis (SE) is a natural process of vegetative propagation. It can be induced in tissue cultures to investigate developmental transitions, to create transgenic or edited lines, or to multiply valuable crops. We studied the induction of SE in the scutellum of monocots with Brachypodium distachyon as a model system. Towards the in-depth analysis of SE initiation, we determined the earliest stages at which somatic scutellar cells acquired an embryogenic fate, then switched to a morphogenetic mode in a regeneration sequence involving treatments with exogenous hormones: first an auxin (2,4-D) then a cytokinin (kinetin). Our observations indicated that secondary somatic embryos could already develop in the proliferative calli derived from immature zygotic embryo tissues within one week from the start of in vitro culture. Cell states and tissue identity were deduced from detailed histological examination, and in situ hybridization was performed to map the expression of key developmental genes. The fast SE induction method we describe here facilitates the mechanistic study of the processes involved and may significantly shorten the production of transgenic or gene-edited plants.
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Affiliation(s)
- Houssein Wehbi
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (H.W.); (C.S.); (O.B.-C.)
| | - Camille Soulhat
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (H.W.); (C.S.); (O.B.-C.)
| | - Halima Morin
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France; (H.M.); (A.B.)
| | - Abdelhafid Bendahmane
- Université Paris-Saclay, CNRS, INRAE, Univ Evry, Institute of Plant Sciences Paris-Saclay (IPS2), 91190 Gif-sur-Yvette, France; (H.M.); (A.B.)
| | - Pierre Hilson
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (H.W.); (C.S.); (O.B.-C.)
- Correspondence:
| | - Oumaya Bouchabké-Coussa
- Université Paris-Saclay, INRAE, AgroParisTech, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France; (H.W.); (C.S.); (O.B.-C.)
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6
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MYB70 modulates seed germination and root system development in Arabidopsis. iScience 2021; 24:103228. [PMID: 34746697 PMCID: PMC8551079 DOI: 10.1016/j.isci.2021.103228] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/25/2021] [Accepted: 10/01/2021] [Indexed: 12/03/2022] Open
Abstract
Crosstalk among ABA, auxin, and ROS plays critical roles in modulating seed germination, root growth, and suberization. However, the underlying molecular mechanisms remain largely elusive. Here, MYB70, a R2R3-MYB transcription factor was shown to be a key component of these processes in Arabidopsis thaliana. myb70 seeds displayed decreased sensitivity, while MYB70-overexpressing OX70 seeds showed increased sensitivity in germination in response to exogenous ABA through MYB70 physical interaction with ABI5 protein, leading to enhanced stabilization of ABI5. Furthermore, MYB70 modulates root system development (RSA) which is associated with increased conjugated IAA content and H2O2/O2⋅− ratio but reduced root suberin deposition, consequently affecting nutrient uptake. In support of these data, MYB70 positively regulates the expression of auxin conjugation-related GH3, while negatively peroxidase-encoding and suberin biosynthesis-related genes. Our findings collectively revealed a previously uncharacterized component that modulates ABA and auxin signaling pathways, H2O2/O2⋅− balance, and suberization, consequently regulating RSA and seed germination. MYB70 regulates seed germination by enhancing ABA signaling via interaction with ABI5 MYB70 activates the IAA conjugation process by upregulating GH3 genes expression MYB70 mediates root growth via repression of PER genes MYB70 negatively regulates suberin biosynthesis in roots
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Nath M, Chowdhury FT, Ahmed S, Das A, Islam MR, Khan H. Value addition to jute: assessing the effect of artificial reduction of lignin on jute diversification. Heliyon 2021; 7:e06353. [PMID: 33748456 PMCID: PMC7969331 DOI: 10.1016/j.heliyon.2021.e06353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/05/2020] [Accepted: 02/19/2021] [Indexed: 11/18/2022] Open
Abstract
In the backdrop of an abundance of lignin in jute, the main focus of the present study was to conduct a quality assessment of four delignified jute lines (in which four lignin biosynthetic genes were individually downregulated) across advanced generations for industrial applications. To this end, the transgenic lines were advanced to 7th (COMT and C4H lines) and 5th (C3H and F5H lines) transformed generations. The results exhibit approximately 16–25% reduction in acid-insoluble lignin for the whole stem and 13–14% reduction in fiber lignin content for all four transgenic lines compared to the control. The altered lignin composition led to a 3–6% increase in the cellulose content and a small improvement in the enzymatic release of glucose. Lignin reduction led to an exposure of the underlying fibrils in transgenic lines as observed through a scanning electron microscope whereas, it was undiscernible in the control fiber. Furthermore, an analysis of the mechanical properties appears almost similar to that of the control with no morphological deformities. Jute fibers from the transgenic lines offer tremendous cost-effective implications from an economic perspective.
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Affiliation(s)
- Mousumi Nath
- Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh.,University of Science and Technology Chittagong, Chattogram, 4202, Bangladesh
| | | | - Shabbir Ahmed
- Intelligent Structural Systems Laboratory (ISSL), Rensselaer Polytechnic Institute, New York, USA
| | - Avizit Das
- Jashore University of Science and Technology, Jashore, 7408, Bangladesh
| | - Mohammad Riazul Islam
- Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Haseena Khan
- Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
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8
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Lu J, Le Hir R, Gómez-Páez DM, Coen O, Péchoux C, Jasinski S, Magnani E. The nucellus: between cell elimination and sugar transport. PLANT PHYSIOLOGY 2021; 185:478-490. [PMID: 33721907 PMCID: PMC8133628 DOI: 10.1093/plphys/kiaa045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 11/10/2020] [Indexed: 05/29/2023]
Abstract
The architecture of the seed is shaped by the processes of tissue partitioning, which determines the volume ratio of maternal and zygotic tissues, and nutrient partitioning, which regulates nutrient distribution among tissues. In angiosperms, early seed development is characterized by antagonistic development of the nucellus maternal tissue and the endosperm fertilization product to become the main sugar sink. This process marked the evolution of angiosperms and outlines the most ancient seed architectures. In Arabidopsis, the endosperm partially eliminates the nucellus and imports sugars from the seed coat. Here, we show that the nucellus is symplasmically connected to the chalaza, the seed nutrient unloading zone, and works as both a sugar sink and source alongside the seed coat. After fertilization, the transient nucellus accumulates starch early on and releases it in the apoplasmic space during its elimination. By contrast, the persistent nucellus exports sugars toward the endosperm through the SWEET4 hexose facilitator. Finally, we analyzed sugar metabolism and transport in the transparent testa 16 mutant, which fails to undergo nucellus cell elimination, which shed light on the coordination between tissue and nutrient partitioning. Overall, this study identifies a path of sugar transport in the Arabidopsis seed and describes a link between sugar redistribution and the nucellus cell-elimination program.
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Affiliation(s)
- Jing Lu
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, University of Paris-Saclay, Route de St-Cyr (RD10), 78026 Versailles Cedex, France
- École Doctorale 567 Sciences du Végétal, University Paris-Sud, University of Paris-Saclay, bat 360, 91405 Orsay Cedex, France
| | - Rozenn Le Hir
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, University of Paris-Saclay, Route de St-Cyr (RD10), 78026 Versailles Cedex, France
| | - Dennys-Marcela Gómez-Páez
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, University of Paris-Saclay, Route de St-Cyr (RD10), 78026 Versailles Cedex, France
| | - Olivier Coen
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, University of Paris-Saclay, Route de St-Cyr (RD10), 78026 Versailles Cedex, France
- École Doctorale 567 Sciences du Végétal, University Paris-Sud, University of Paris-Saclay, bat 360, 91405 Orsay Cedex, France
| | - Christine Péchoux
- INRAE, Génétique Animale et Biologie Intégrative, Domaine de Vilvert, 78352 Jouy-en-Josas Cedex, France
| | - Sophie Jasinski
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, University of Paris-Saclay, Route de St-Cyr (RD10), 78026 Versailles Cedex, France
| | - Enrico Magnani
- Institut Jean-Pierre Bourgin, INRAE, AgroParisTech, CNRS, University of Paris-Saclay, Route de St-Cyr (RD10), 78026 Versailles Cedex, France
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9
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Gomez MD, Barro-Trastoy D, Fuster-Almunia C, Tornero P, Alonso JM, Perez-Amador MA. Gibberellin-mediated RGA-LIKE1 degradation regulates embryo sac development in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:7059-7072. [PMID: 32845309 PMCID: PMC7906783 DOI: 10.1093/jxb/eraa395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/21/2020] [Indexed: 05/03/2023]
Abstract
Ovule development is essential for plant survival, as it allows correct embryo and seed development upon fertilization. The female gametophyte is formed in the central area of the nucellus during ovule development, in a complex developmental programme that involves key regulatory genes and the plant hormones auxins and brassinosteroids. Here we provide novel evidence of the role of gibberellins (GAs) in the control of megagametogenesis and embryo sac development, via the GA-dependent degradation of RGA-LIKE1 (RGL1) in the ovule primordia. YPet-rgl1Δ17 plants, which express a dominant version of RGL1, showed reduced fertility, mainly due to altered embryo sac formation that varied from partial to total ablation. YPet-rgl1Δ17 ovules followed normal development of the megaspore mother cell, meiosis, and formation of the functional megaspore, but YPet-rgl1Δ17 plants had impaired mitotic divisions of the functional megaspore. This phenotype is RGL1-specific, as it is not observed in any other dominant mutants of the DELLA proteins. Expression analysis of YPet-rgl1Δ17 coupled to in situ localization of bioactive GAs in ovule primordia led us to propose a mechanism of GA-mediated RGL1 degradation that allows proper embryo sac development. Taken together, our data unravel a novel specific role of GAs in the control of female gametophyte development.
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Affiliation(s)
- Maria Dolores Gomez
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV)–Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación, Ed. 8E, Ingeniero Fausto Elio s/n, Valencia, Spain
| | - Daniela Barro-Trastoy
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV)–Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación, Ed. 8E, Ingeniero Fausto Elio s/n, Valencia, Spain
| | - Clara Fuster-Almunia
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV)–Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación, Ed. 8E, Ingeniero Fausto Elio s/n, Valencia, Spain
| | - Pablo Tornero
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV)–Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación, Ed. 8E, Ingeniero Fausto Elio s/n, Valencia, Spain
| | - Jose M Alonso
- Department of Plant and Microbial Biology, Program in Genetics, North Carolina State University, Raleigh, NC, USA
| | - Miguel A Perez-Amador
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universidad Politécnica de Valencia (UPV)–Consejo Superior de Investigaciones Científicas (CSIC), Ciudad Politécnica de la Innovación, Ed. 8E, Ingeniero Fausto Elio s/n, Valencia, Spain
- Correspondence:
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10
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Molecular and environmental factors regulating seed longevity. Biochem J 2020; 477:305-323. [PMID: 31967650 DOI: 10.1042/bcj20190165] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 12/20/2019] [Accepted: 01/03/2020] [Indexed: 12/18/2022]
Abstract
Seed longevity is a central pivot of the preservation of biodiversity, being of main importance to face the challenges linked to global climate change and population growth. This complex, quantitative seed quality trait is acquired on the mother plant during the second part of seed development. Understanding what factors contribute to lifespan is one of the oldest and most challenging questions in plant biology. One of these challenges is to recognize that longevity depends on the storage conditions that are experimentally used because they determine the type and rate of deleterious conditions that lead to cell death and loss of viability. In this review, we will briefly review the different storage methods that accelerate the deteriorative reactions during storage and argue that a minimum amount of information is necessary to interpret the longevity data. Next, we will give an update on recent discoveries on the hormonal factors regulating longevity, both from the ABA signaling pathway but also other hormonal pathways. In addition, we will review the effect of both maternal and abiotic factors that influence longevity. In the last section of this review, we discuss the problems in unraveling cause-effect relationship between the time of death during storage and deteriorative reactions leading to seed ageing. We focus on the three major types of cellular damage, namely membrane permeability, lipid peroxidation and RNA integrity for which germination data on seed stored in dedicated seed banks for long period times are now available.
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11
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Li SF, Allen PJ, Napoli RS, Browne RG, Pham H, Parish RW. MYB-bHLH-TTG1 Regulates Arabidopsis Seed Coat Biosynthesis Pathways Directly and Indirectly via Multiple Tiers of Transcription Factors. PLANT & CELL PHYSIOLOGY 2020; 61:1005-1018. [PMID: 32154880 DOI: 10.1093/pcp/pcaa027] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/02/2020] [Indexed: 06/10/2023]
Abstract
MYB-bHLH-WDR (MBW) transcription factor (TF) complexes regulate Arabidopsis seed coat development including mucilage and tannin biosynthesis. The R2R3 MYBs MYB5, MYB23 and TRANSPARENT TESTA2 (TT2) participate in the MBW complexes with the WD-repeat protein TRANSPARENT TESTA GLABRA1 (TTG1). These complexes regulate GLABRA2 (GL2) and TTG2 expression in developing seeds. Microarray transcriptome analysis of ttg1-1- and wild-type (Ler) developing seeds identified 246 TTG1-regulated genes, which include all known metabolic genes of the tannin biosynthetic pathway. The first detailed TTG1-dependent metabolic pathways could be proposed for the biosynthesis of mucilage, jasmonic acid (JA) and cuticle including wax ester in developing seeds. We also assigned many known and previously uncharacterized genes to the activation/inactivation of hormones, plant immunity and nutrient transport. The promoters of six cuticle pathway genes were active in developing seeds. Expression of 11 genes was determined in the developing seeds of the combinatorial mutants of MYB5, MYB23 and TT2, and in the combinatorial mutants of GL2, HOMEODOMAIN GLABROUS2 (HDG2) and TTG2. These six TFs positively co-regulated the expression of four repressor genes while three of the six TFs repressed the wax biosynthesis genes examined, suggesting that the three TFs upregulate the expression of these repressor genes, which, in turn, repress the wax biosynthesis genes. Chromatin immunoprecipitation analysis identified 21 genes directly regulated by MYB5 including GL2, HDG2, TTG2, four repressor genes and various metabolic genes. We propose a multi-tiered regulatory mechanism by which MBWs regulate tannin, mucilage, JA and cuticle biosynthetic pathways.
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Affiliation(s)
- Song Feng Li
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBioscience, La Trobe University, Bundoora, Melbourne, VIC 3086, Australia
| | - Patrick J Allen
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBioscience, La Trobe University, Bundoora, Melbourne, VIC 3086, Australia
| | - Ross S Napoli
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBioscience, La Trobe University, Bundoora, Melbourne, VIC 3086, Australia
| | - Richard G Browne
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBioscience, La Trobe University, Bundoora, Melbourne, VIC 3086, Australia
| | - Hanh Pham
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBioscience, La Trobe University, Bundoora, Melbourne, VIC 3086, Australia
| | - Roger W Parish
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBioscience, La Trobe University, Bundoora, Melbourne, VIC 3086, Australia
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12
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Coen O, Lu J, Xu W, Pateyron S, Grain D, Péchoux C, Lepiniec L, Magnani E. A TRANSPARENT TESTA Transcriptional Module Regulates Endothelium Polarity. FRONTIERS IN PLANT SCIENCE 2019; 10:1801. [PMID: 32117351 PMCID: PMC7015901 DOI: 10.3389/fpls.2019.01801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/23/2019] [Indexed: 05/06/2023]
Abstract
Seeds have greatly contributed to the successful colonization of land by plants. Compared to spores, seeds carry nutrients, rely less on water for germination, provide a higher degree of protection against biotic and abiotic stresses, and can disperse in different ways. Such advantages are, to a great extent, provided by the seed coat. The evolution of a multi-function seed-coat is inheritably linked to the evolution of tissue polarity, which allows the development of morphologically and functionally distinct domains. Here, we show that the endothelium, the innermost cell layer of the seed coat, displays distinct morphological features along the proximal-distal axis. Furthermore, we identified a TRANSPARENT TESTA transcriptional module that contributes to establishing endothelium polarity and responsiveness to fertilization. Finally, we characterized its downstream gene pathway by whole-genome transcriptional analyses. We speculate that such a regulatory module might have been responsible for the evolution of morphological diversity in seed shape, micropylar pore formation, and cuticle deposition.
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Affiliation(s)
- Olivier Coen
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, University of Paris-Saclay, Versailles, France
- École Doctorale 567 Sciences du Végétal, University Paris-Sud, University of Paris-Saclay, Orsay, France
| | - Jing Lu
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, University of Paris-Saclay, Versailles, France
- École Doctorale 567 Sciences du Végétal, University Paris-Sud, University of Paris-Saclay, Orsay, France
| | - Wenjia Xu
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, University of Paris-Saclay, Versailles, France
| | - Stéphanie Pateyron
- TranscriptOmic Platform of IPS2, Institute of Plant Sciences Paris Saclay IPS2, CNRS, INRA, Université Paris-Sud, Université Evry, Université Paris-Saclay, Orsay, France
| | - Damaris Grain
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, University of Paris-Saclay, Versailles, France
| | - Christine Péchoux
- INRA, Génétique Animale et Biologie Intégrative, Jouy-en-Josas, France
| | - Loïc Lepiniec
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, University of Paris-Saclay, Versailles, France
| | - Enrico Magnani
- Institut Jean-Pierre Bourgin, INRA, AgroParisTech, CNRS, University of Paris-Saclay, Versailles, France
- *Correspondence: Enrico Magnani,
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