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Wang S, Liu S, Wang J, Yokosho K, Zhou B, Yu YC, Liu Z, Frommer WB, Ma JF, Chen LQ, Guan Y, Shou H, Tian Z. Simultaneous changes in seed size, oil content and protein content driven by selection of SWEET homologues during soybean domestication. Natl Sci Rev 2020; 7:1776-1786. [PMID: 34691511 PMCID: PMC8290959 DOI: 10.1093/nsr/nwaa110] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 02/02/2023] Open
Abstract
Soybean accounts for more than half of the global production of oilseed and more than a quarter of the protein used globally for human food and animal feed. Soybean domestication involved parallel increases in seed size and oil content, and a concomitant decrease in protein content. However, science has not yet discovered whether these effects were due to selective pressure on a single gene or multiple genes. Here, re-sequencing data from >800 genotypes revealed a strong selection during soybean domestication on GmSWEET10a. The selection of GmSWEET10a conferred simultaneous increases in soybean-seed size and oil content as well as a reduction in the protein content. The result was validated using both near-isogenic lines carrying substitution of haplotype chromosomal segments and transgenic soybeans. Moreover, GmSWEET10b was found to be functionally redundant with its homologue GmSWEET10a and to be undergoing selection in current breeding, leading the the elite allele GmSWEET10b, a potential target for present-day soybean breeding. Both GmSWEET10a and GmSWEET10b were shown to transport sucrose and hexose, contributing to sugar allocation from seed coat to embryo, which consequently determines oil and protein contents and seed size in soybean. We conclude that past selection of optimal GmSWEET10a alleles drove the initial domestication of multiple soybean-seed traits and that targeted selection of the elite allele GmSWEET10b may further improve the yield and seed quality of modern soybean cultivars.
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Affiliation(s)
- Shoudong Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life sciences, Zhejiang University, Hangzhou 310058, China
| | - Shulin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Wang
- College of Resources and Environment, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Kengo Yokosho
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Bin Zhou
- Institute of Crop Science, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Ya-Chi Yu
- Department of Plant Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Zhi Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wolf B Frommer
- Institute for Molecular Physiology and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Jian Feng Ma
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Li-Qing Chen
- Department of Plant Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yuefeng Guan
- FAFU-UCR Joint Center for Horticultural Plant Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Huixia Shou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Aguirre M, Kiegle E, Leo G, Ezquer I. Carbohydrate reserves and seed development: an overview. PLANT REPRODUCTION 2018; 31:263-290. [PMID: 29728792 DOI: 10.1007/s00497-018-0336-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 04/23/2018] [Indexed: 06/08/2023]
Abstract
Seeds are one of the most important food sources, providing humans and animals with essential nutrients. These nutrients include carbohydrates, lipids, proteins, vitamins and minerals. Carbohydrates are one of the main energy sources for both plant and animal cells and play a fundamental role in seed development, human nutrition and the food industry. Many studies have focused on the molecular pathways that control carbohydrate flow during seed development in monocot and dicot species. For this reason, an overview of seed biodiversity focused on the multiple metabolic and physiological mechanisms that govern seed carbohydrate storage function in the plant kingdom is required. A large number of mutants affecting carbohydrate metabolism, which display defective seed development, are currently available for many plant species. The physiological, biochemical and biomolecular study of such mutants has led researchers to understand better how metabolism of carbohydrates works in plants and the critical role that these carbohydrates, and especially starch, play during seed development. In this review, we summarize and analyze the newest findings related to carbohydrate metabolism's effects on seed development, pointing out key regulatory genes and enzymes that influence seed sugar import and metabolism. Our review also aims to provide guidelines for future research in the field and in this way to assist seed quality optimization by targeted genetic engineering and classical breeding programs.
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Affiliation(s)
- Manuel Aguirre
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133, Milan, Italy
- FNWI, University of Amsterdam, 1098 XH, Amsterdam, The Netherlands
| | - Edward Kiegle
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Giulia Leo
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133, Milan, Italy
| | - Ignacio Ezquer
- Dipartimento di BioScienze, Università degli Studi di Milano, 20133, Milan, Italy.
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3
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Milne RJ, Grof CP, Patrick JW. Mechanisms of phloem unloading: shaped by cellular pathways, their conductances and sink function. CURRENT OPINION IN PLANT BIOLOGY 2018; 43:8-15. [PMID: 29248828 DOI: 10.1016/j.pbi.2017.11.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/24/2017] [Accepted: 11/30/2017] [Indexed: 05/03/2023]
Abstract
Phloem unloading represents a series of cell-to-cell transport steps transferring phloem-mobile constituents from phloem to sink tissues/organs to fuel their development or resource storage. Our analysis focuses on unloading of two major phloem-mobile constituents, sugars and water. Their unloading can occur across phloem plasma membranes (apoplasmic unloading), through plasmodesmata interconnecting phloem and sink cells (symplasmic unloading) or predominately symplasmically with an intervening post-phloem apoplasmic step. In planta studies of phloem unloading encounter substantial technical challenges in accessing phloem within a meshwork of vascular/ground tissues. Thus, current understanding of phloem-unloading mechanisms largely has been deduced from indirect experimental measures or modelling. Here we highlight recent advances in understanding phloem unloading mechanisms and identify where important knowledge gaps remain.
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Affiliation(s)
- Ricky J Milne
- CSIRO Agriculture and Food, Canberra, Australian Capital Territory 2601, Australia
| | - Christopher Pl Grof
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - John W Patrick
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia.
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4
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Abstract
The phloem plays a central role in transporting resources and signalling molecules from fully expanded leaves to provide precursors for, and to direct development of, heterotrophic organs located throughout the plant body. We review recent advances in understanding mechanisms regulating loading and unloading of resources into, and from, the phloem network; highlight unresolved questions regarding the physiological significance of the vast array of proteins and RNAs found in phloem saps; and evaluate proposed structure/function relationships considered to account for bulk flow of sap, sustained at high rates and over long distances, through the transport phloem.
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Affiliation(s)
- Johannes Liesche
- Biomass Energy Center for Arid and Semi-arid lands, Northwest A&F University, Yangling, China
- College of Life Science, Northwest A&F University, Yangling , China
| | - John Patrick
- Department of Biological Sciences, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, Australia
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5
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Millar JL, Khan D, Becker MG, Chan A, Dufresne A, Sumner M, Belmonte MF. Chalazal seed coat development in Brassica napus. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2015; 241:45-54. [PMID: 26706057 DOI: 10.1016/j.plantsci.2015.09.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 09/16/2015] [Accepted: 09/22/2015] [Indexed: 05/03/2023]
Abstract
The chalazal seed coat (CZSC) is a maternal subregion adjacent to the funiculus which serves as the first point of entry into the developing seed. This subregion is of particular interest in Brassica napus (canola) because of its location within the seed and its putative contribution to seed filling processes. In this study, the CZSC of canola was characterized at an anatomical and molecular level to (i) describe the cellular and subcellular features of the CZSC throughout seed development, (ii) reveal cellular features of the CZSC that relate to transport processes, (iii) study gene activity of transporters and transcriptional regulators in the CZSC subregion over developmental time, and (iv) briefly investigate the contribution of the A and C constituent genomes to B. napus CZSC gene activity. We found that the CZSC contains terminating ends of xylem and phloem as well as a mosaic of endomembrane and plasmodesmatal connections, suggesting that this subregion is likely involved in the transport of material and information from the maternal tissues of the plant to other regions of the seed. Laser microdissection coupled with quantitative RT-PCR identified the relative abundance of sugar, water, auxin and amino acid transporter homologs inherited from the constituent genomes of this complex polyploid. We also studied the expression of three transcription factors that were shown to co-express with these biological processes providing a preliminary framework for the regulatory networks responsible for seed filling in canola and discuss the relationship of the CZSC to other regions and subregions of the seed and its role in seed development.
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Affiliation(s)
- Jenna L Millar
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Deirdre Khan
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Michael G Becker
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Ainsley Chan
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - André Dufresne
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Michael Sumner
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada
| | - Mark F Belmonte
- University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB R3T 2N2, Canada.
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6
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Sánchez-Linares L, Gavilanes-Ruíz M, Díaz-Pontones D, Guzmán-Chávez F, Calzada-Alejo V, Zurita-Villegas V, Luna-Loaiza V, Moreno-Sánchez R, Bernal-Lugo I, Sánchez-Nieto S. Early carbon mobilization and radicle protrusion in maize germination. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:4513-26. [PMID: 22611232 PMCID: PMC3421986 DOI: 10.1093/jxb/ers130] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Considerable amounts of information is available on the complex carbohydrates that are mobilized and utilized by the seed to support early seedling development. These events occur after radicle has protruded from the seed. However, scarce information is available on the role of the endogenous soluble carbohydrates from the embryo in the first hours of germination. The present work analysed how the soluble carbohydrate reserves in isolated maize embryos are mobilized during 6-24 h of water imbibition, an interval that exclusively embraces the first two phases of the germination process. It was found that sucrose constitutes a very significant reserve in the scutellum and that it is efficiently consumed during the time in which the adjacent embryo axis is engaged in an active metabolism. Sucrose transporter was immunolocalized in the scutellum and in vascular elements. In parallel, a cell-wall invertase activity, which hydrolyses sucrose, developed in the embryo axis, which favoured higher glucose uptake. Sucrose and hexose transporters were active in the embryo tissues, together with the plasma membrane H(+)-ATPase, which was localized in all embryo regions involved in both nutrient transport and active cell elongation to support radicle extension. It is proposed that, during the initial maize germination phases, a net flow of sucrose takes place from the scutellum towards the embryo axis and regions that undergo elongation. During radicle extension, sucrose and hexose transporters, as well as H(+)-ATPase, become the fundamental proteins that orchestrate the transport of nutrients required for successful germination.
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Affiliation(s)
- Luis Sánchez-Linares
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
| | - Marina Gavilanes-Ruíz
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
| | - David Díaz-Pontones
- Departamento de Ciencias de la Salud, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana Iztapalapa. Apartado Postal 55535, 09340, DF, México
| | - Fernando Guzmán-Chávez
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
| | - Viridiana Calzada-Alejo
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
| | - Viridiana Zurita-Villegas
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
| | - Viridiana Luna-Loaiza
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
| | - Rafael Moreno-Sánchez
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Tlalpan, 14080, DF, México
| | - Irma Bernal-Lugo
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
| | - Sobeida Sánchez-Nieto
- Departamento de Bioquímica, Facultad de Química, Conjunto E. Universidad Nacional Autónoma de México, Cd. Universitaria, Coyoacán, 04510, DF, México
- To whom correspondence should be addressed. E-mail:
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7
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Lahuta LB, Dzik T. D-chiro-inositol affects accumulation of raffinose family oligosaccharides in developing embryos of Pisum sativum. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:352-8. [PMID: 20947202 DOI: 10.1016/j.jplph.2010.07.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 07/28/2010] [Accepted: 07/28/2010] [Indexed: 05/30/2023]
Abstract
Developing garden pea embryos are able to take up exogenously applied cyclitols: myo-inositol, which naturally occurs in pea, and two cyclitols absent in pea plants: d-chiro-inositol and d-pinitol. The competition in the uptake of cyclitols by pea embryo, insensitivity to glucose and sucrose, and susceptibility to inhibitor(s) of H(+)-symporters (e.g. CCCP and antimycin A) suggest that a common cyclitol transporter is involved. Both d-chiro-inositol and d-pinitol can be translocated through the pea plant to developing embryos. During seed maturation drying, they are used for synthesis of mainly mono-galactosides, such as fagopyritol B1 and galactosyl pinitol A. Accumulation of d-chiro-inositol (and formation of fagopyritols), but not d-pinitol, strongly reduces accumulation of verbascose, the main raffinose oligosaccharide in pea seeds. The reasons for the observed changes are discussed.
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Affiliation(s)
- Lesław B Lahuta
- Department of Plant Physiology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Oczapowskiego, Poland.
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8
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Cho JI, Burla B, Lee DW, Ryoo N, Hong SK, Kim HB, Eom JS, Choi SB, Cho MH, Bhoo SH, Hahn TR, Neuhaus HE, Martinoia E, Jeon JS. Expression analysis and functional characterization of the monosaccharide transporters, OsTMTs, involving vacuolar sugar transport in rice (Oryza sativa). THE NEW PHYTOLOGIST 2010; 186:657-68. [PMID: 20202129 DOI: 10.1111/j.1469-8137.2010.03194.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
In Arabidopsis, the compartmentation of sugars into vacuoles is known to be facilitated by sugar transporters. However, vacuolar sugar transporters have not been studied in detail in other plant species. To characterize the rice (Oryza sativa) tonoplast monosaccharide transporters, OsTMT1 and OsTMT2, we analysed their subcellular localization using green fluorescent protein (GFP) and expression patterns using reverse-transcription polymerase chain reaction (RT-PCR), performed histochemical beta-glucuronidase (GUS) assay and in situ hybridization analysis, and assessed sugar transport ability using isolated vacuoles. Expression of OsTMT-GFP fusion protein in rice and Arabidopsis revealed that the OsTMTs localize at the tonoplast. Analyses of OsTMT promoter-GUS transgenic rice indicated that OsTMT1 and OsTMT2 are highly expressed in bundle sheath cells, and in vascular parenchyma and companion cells in leaves, respectively. Both genes were found to be preferentially expressed in the vascular tissues of roots, the palea/lemma of spikelets, and in the main vascular tissues and nucellar projections on the dorsal side of the seed coats. Glucose uptake studies using vacuoles isolated from transgenic mutant Arabidopsis (tmt1-2-3) expressing OsTMT1 demonstrated that OsTMTs are capable of transporting glucose into vacuoles. Based on expression analysis and functional characterization, our present findings suggest that the OsTMTs play a role in vacuolar glucose storage in rice.
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Affiliation(s)
- Jung-Il Cho
- Graduate School of Biotechnology and Plant Metabolism Research Center, Kyung Hee University, Yongin 446-701, Korea
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9
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Tegeder M, Tan Q, Grennan AK, Patrick JW. Amino acid transporter expression and localisation studies in pea (Pisum sativum). FUNCTIONAL PLANT BIOLOGY : FPB 2007; 34:1019-1028. [PMID: 32689430 DOI: 10.1071/fp07107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 09/07/2007] [Indexed: 05/03/2023]
Abstract
Expression of the amino acid permeases PsAAP1 and PsAAP2 was analysed in developing pea (Pisum sativum L.) plants. Both transporters were expressed in seed coats and cotyledon epidermal transfer cells and storage parenchyma cells. AAP expression is developmentally regulated and coincides with the onset of storage protein synthesis. Nitrogen was shown to induce AAP expression and AAP transcript levels were upregulated during the photoperiod. Analysis of Arabidopsis thaliana AAP1 promoter activity in pea, using promoter-β-glucuronidase (promotor-GUS) studies, revealed targeting of GUS to seed coats and cotyledon epidermal transfer cells. Expression was found in the nutritious endosperm during the early stages of seed development, whereas GUS staining in embryos was detected from the heart stage onward. In addition, AAP1 expression was observed in the phloem throughout the plant. This finding equally applied to PsAAP1 expression as shown by in situ mRNA hybridisation, which also demonstrated that PsAAP1 expression was localised to companion cells. Overall, PsAAP1 expression patterns and cellular localisation point to a function of the transporter in phloem loading of amino acids for translocation to sinks and in seed loading for development and storage protein accumulation.
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Affiliation(s)
- Mechthild Tegeder
- School of Biological Sciences, Centre for Integrated Biotechnology, Centre for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
| | - Qiumin Tan
- School of Biological Sciences, Centre for Integrated Biotechnology, Centre for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
| | - Aleel K Grennan
- School of Biological Sciences, Centre for Integrated Biotechnology, Centre for Reproductive Biology, Washington State University, Pullman, WA 99164, USA
| | - John W Patrick
- School of Environmental and Life Sciences, The University of Newcastle, NSW 2308, Australia
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10
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Zhang WH, Zhou Y, Dibley KE, Tyerman SD, Furbank RT, Patrick JW. Review: Nutrient loading of developing seeds. FUNCTIONAL PLANT BIOLOGY : FPB 2007; 34:314-331. [PMID: 32689358 DOI: 10.1071/fp06271] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2006] [Accepted: 01/30/2007] [Indexed: 05/03/2023]
Abstract
Interest in nutrient loading of seeds is fuelled by its central importance to plant reproductive success and human nutrition. Rates of nutrient loading, imported through the phloem, are regulated by transport and transfer processes located in sources (leaves, stems, reproductive structures), phloem pathway and seed sinks. During the early phases of seed development, most control is likely to be imposed by a low conductive pathway of differentiating phloem cells serving developing seeds. Following the onset of storage product accumulation by seeds, and, depending on nutrient species, dominance of path control gives way to regulation by processes located in sources (nitrogen, sulfur, minor minerals), phloem path (transition elements) or seed sinks (sugars and major mineral elements, such as potassium). Nutrients and accompanying water are imported into maternal seed tissues and unloaded from the conducting sieve elements into an extensive post-phloem symplasmic domain. Nutrients are released from this symplasmic domain into the seed apoplasm by poorly understood membrane transport mechanisms. As seed development progresses, increasing volumes of imported phloem water are recycled back to the parent plant by process(es) yet to be discovered. However, aquaporins concentrated in vascular and surrounding parenchyma cells of legume seed coats could provide a gated pathway of water movement in these tissues. Filial cells, abutting the maternal tissues, take up nutrients from the seed apoplasm by membrane proteins that include sucrose and amino acid/H+ symporters functioning in parallel with non-selective cation channels. Filial demand for nutrients, that comprise the major osmotic species, is integrated with their release and phloem import by a turgor-homeostat mechanism located in maternal seed tissues. It is speculated that turgors of maternal unloading cells are sensed by the cytoskeleton and transduced by calcium signalling cascades.
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Affiliation(s)
- Wen-Hao Zhang
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, The Chinese Academy of Sciences, Beijing 100093, China
| | - Yuchan Zhou
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2238, Australia
| | - Katherine E Dibley
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2238, Australia
| | - Stephen D Tyerman
- School of Agriculture, Food and Wine, Adelaide University, Waite Campus, PMB #1, Glen Osmond, SA 5064, Australia
| | - Robert T Furbank
- CSIRO Plant Industry, GPO Box 1600, Canberra, ACT 2601, Australia
| | - John W Patrick
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2238, Australia
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11
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Zhou Y, Qu H, Dibley KE, Offler CE, Patrick JW. A suite of sucrose transporters expressed in coats of developing legume seeds includes novel pH-independent facilitators. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 49:750-64. [PMID: 17253986 DOI: 10.1111/j.1365-313x.2006.03000.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
A suite of newly discovered sucrose transporter genes, PsSUF1, PsSUF4, PvSUT1 and PvSUF1, were isolated from the coats of developing pea (Pisum sativum L.) and bean (Phaseolus vulgaris L.) seeds. Sequence analysis indicated that deduced proteins encoded by PsSUF1, PvSUT1 and PvSUF1 clustered in a separate sub-group under sucrose transporter Clade I, whereas the deduced protein encoded by PsSUF4 clustered in Clade II. When expressed in yeast, these genes were shown to encode sucrose transporters with apparent Michaelis Menten constant (Km) values ranging from 8.9 to 99.8 mm. PvSUT1 exhibited functional characteristics of a sucrose/H+ symporter. In contrast, PsSUF1, PvSUF1 and PsSUF4 supported the pH- and energy independent transport of sucrose that was shown to be bi-directional. These transport properties, together with that of counter transport, indicated that PsSUF1, PvSUF1 and PsSUF4 function as carriers that support the facilitated diffusion of sucrose. Carrier function was unaffected by diethylpyrocarbonate and by maltose competition, suggesting that the sucrose binding sites of these transporters differed from those of known sucrose/H+ symporters. All sucrose transporters were expressed throughout the plant and, of greatest interest, were co-expressed in cells considered responsible for sucrose efflux from seed coats. The possible roles played by the novel facilitators in sucrose efflux from seed coats are discussed.
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Affiliation(s)
- Yuchan Zhou
- School of Environmental & Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
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12
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Harrington GN, Dibley KE, Ritchie RJ, Offler CE, Patrick JW. Hexose uptake by developing cotyledons of Vicia faba: physiological evidence for transporters of differing affinities and specificities. FUNCTIONAL PLANT BIOLOGY : FPB 2005; 32:987-995. [PMID: 32689194 DOI: 10.1071/fp05081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2005] [Accepted: 05/31/2005] [Indexed: 06/11/2023]
Abstract
Cotyledons of broad bean (Vicia faba L.) develop in an apoplasmic environment that shifts in composition from one dominated by hexoses to one dominated by sucrose. During the latter phase of development, sucrose / H+ symporter activity and expression is restricted to cotyledon epidermal transfer cell complexes that support sucrose fluxes that are 8.5-fold higher than those exhibited by the storage parenchyma. In contrast, the flux difference between these cotyledon tissues is only 1.7-fold for hexoses. Glucose and fructose uptake was shown to be sensitive to PCMBS and phloridzin, both of which slow H+-sugar transport. A low Km (or high affinity transporter, HAT) mechanism transports glucose and glucose-analogues exclusively. No HAT system for fructose could be found. A high Km (low affinity transporter, LAT) mechanism transports a broader range of hexoses, including glucose and fructose. Consistent with glucose and fructose transport being H+-coupled, their uptake was inhibited by dissipating the proton motive force (pmf) by treating cotyledons with carbonyl cyanide m-chlorophenol hydrazone, propionic acid or tetraphenylphosphonium ion. Erythrosin B inhibited hexose uptake, indicating a role for the P-type H+-ATPase in establishing the pmf. It is concluded that H+-coupled glucose and fructose transport mechanisms occur at plasma membranes of dermal transfer cell complexes and storage parenchyma cells. These transport mechanisms are active during pre- and storage phases of cotyledon development. However, hexose symport only makes a quantitative contribution to cotyledon biomass gain during the pre-storage stage of development.
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Affiliation(s)
- Gregory N Harrington
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - Katherine E Dibley
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | | | - Christina E Offler
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
| | - John W Patrick
- School of Environmental and Life Sciences, The University of Newcastle, Callaghan, NSW 2308, Australia
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Lalonde S, Wipf D, Frommer WB. Transport mechanisms for organic forms of carbon and nitrogen between source and sink. ANNUAL REVIEW OF PLANT BIOLOGY 2004; 55:341-72. [PMID: 15377224 DOI: 10.1146/annurev.arplant.55.031903.141758] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Sugars and amino acids are generated in plants by assimilation from inorganic forms. Assimilated forms cross multiple membranes on their way from production sites to storage or use locations. Specific transport systems are responsible for vacuolar uptake and release, for efflux from the cells, and for uptake into the vasculature. Detailed phylogenetic analyses suggest that only proton-coupled cotransporters involved in phloem loading have been identified to date, whereas systems for vacuolar transport and efflux still await identification. Novel imaging approaches may provide the means to characterize the cellular events and elucidate whole plant control of assimilate partitioning and allocation.
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