101
|
Péron T, Candat A, Montiel G, Veronesi C, Macherel D, Delavault P, Simier P. New Insights into Phloem Unloading and Expression of Sucrose Transporters in Vegetative Sinks of the Parasitic Plant Phelipanche ramosa L. (Pomel). FRONTIERS IN PLANT SCIENCE 2016; 7:2048. [PMID: 28119724 PMCID: PMC5220101 DOI: 10.3389/fpls.2016.02048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 12/21/2016] [Indexed: 05/18/2023]
Abstract
The plant-parasitic plant interaction is a interesting model to study sink-source relationship and phloem unloading. The parasitic plants, such as the achlorophyllous plant Phelipanche ramosa, connect to the host phloem through the haustorium and act as supernumerary sinks for the host-derived photoassimilates, primarily sucrose. The application of the fluorescent symplastic tracer, carboxyfluorescein (CF) derived from carboxyfluorescein diacetate (CFDA), to the leaves of the host plant (Brassica napus) showed direct phloem connections at the host-parasite interface. These experiments also evidenced the dominant apoplastic pathway for phloem unloading in major vegetative sinks of the parasite, including tubercles and shoots, except the adventitious root apices. The CF experiments showed also the symplastic isolation of the phloem tissues from the sink tissues in tubercle and shoot of the parasite, then suggesting the pivotal role of sucrose transporters in sucrose unloading in P. ramosa sinks. Three cDNAs encoding sucrose transporters (PrSUT) were isolated from the parasitic plant. PrSUT1 transcripts accumulated at the same level in the tubercle throughout the parasite growth while a significant increase in transcript accumulation occurred after emergence in the flowering shoot, notably in the growing apical part. The in situ hybridization experiments revealed the PrSUT1 transcript accumulation in the mature phloem cells of both subterranean and flowering shoots, as well as in shoot terminal sinks corresponding to apical meristem, scale leaf primordia and immature vasculature. The transient expression experiments in Arabidopsis protoplasts showed that PrSUT1 was localized at the plasma membrane, suggesting its role in phloem functioning and sucrose uptake by the sink cells in P. ramosa. Conversely, the PrSUT2 transcript accumulation was constantly low in tubercles and shoots but PrSUT3 transcripts accumulated markedly in the subterranean and flowering shoots, in concordance with the PrSUT3 mRNA accumulation in multiple sink areas including apical meristem, scale-leaf primordia, immature vasculature and even storage parenchyma. However, the PrSUT3 transcripts did not accumulate in the mature phloem cells. The transient expression experiments in Arabidopsis protoplasts suggested a tonoplast localization of PrSUT3, for which nevertheless the involvement in intracellular sucrose transport needs clarification.
Collapse
Affiliation(s)
- Thomas Péron
- Laboratoire de Biologie et de Pathologie Végétales EA 1157, SFR 4207 QUASAV, Université de NantesNantes, France
| | - Adrien Candat
- UMR 1345 IRHS, SFR 4207 QUASAV, INRA, Agrocampus-Ouest, Université d'AngersBeaucouzé, France
| | - Grégory Montiel
- Laboratoire de Biologie et de Pathologie Végétales EA 1157, SFR 4207 QUASAV, Université de NantesNantes, France
| | - Christophe Veronesi
- Laboratoire de Biologie et de Pathologie Végétales EA 1157, SFR 4207 QUASAV, Université de NantesNantes, France
| | - David Macherel
- UMR 1345 IRHS, SFR 4207 QUASAV, INRA, Agrocampus-Ouest, Université d'AngersBeaucouzé, France
| | - Philippe Delavault
- Laboratoire de Biologie et de Pathologie Végétales EA 1157, SFR 4207 QUASAV, Université de NantesNantes, France
| | - Philippe Simier
- Laboratoire de Biologie et de Pathologie Végétales EA 1157, SFR 4207 QUASAV, Université de NantesNantes, France
- *Correspondence: Philippe Simier
| |
Collapse
|
102
|
Duan GL, Hu Y, Schneider S, McDermott J, Chen J, Sauer N, Rosen BP, Daus B, Liu Z, Zhu YG. Inositol transporters AtINT2 and AtINT4 regulate arsenic accumulation in Arabidopsis seeds. NATURE PLANTS 2016; 2:15202. [PMID: 27004129 PMCID: PMC4758254 DOI: 10.1038/nplants.2015.202] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 11/16/2015] [Indexed: 05/02/2023]
Abstract
Arsenic contamination of groundwater and soils threatens the health of tens of millions of people worldwide. Understanding the way in which arsenic is taken up by crops such as rice, which serve as a significant source of arsenic in the human diet, is therefore important. Membrane transport proteins that catalyse arsenic uptake by roots, and translocation through the xylem to shoots, have been characterized in a number of plants, including rice. The transporters responsible for loading arsenic from the xylem into the phloem and on into the seeds, however, are yet to be identified. Here, we show that transporters responsible for inositol uptake in the phloem in Arabidopsis also transport arsenic. Transformation of Saccharomyces cerevisiae with AtINT2 or AtINT4 led to increased arsenic accumulation and increased sensitivity to arsenite. Expression of AtINT2 in Xenopus laevis oocytes also induced arsenite import. Disruption of AtINT2 or AtINT4 in Arabidopsis thaliana led to a reduction in phloem, silique and seed arsenic concentrations in plants fed with arsenite through the roots, relative to wild-type plants. These plants also exhibited a large drop in silique and seed arsenic concentrations when fed with arsenite through the leaves. We conclude that in Arabidopsis, inositol transporters are responsible for arsenite loading into the phloem, the key source of arsenic in seeds.
Collapse
Affiliation(s)
- Gui-Lan Duan
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Ying Hu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Sabine Schneider
- Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
- Erlangen Center of Plant Science (ECROPS), Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - Joseph McDermott
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Jian Chen
- Department of Cellular Biology and Pharmacology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL 33199, USA
| | - Norbert Sauer
- Molekulare Pflanzenphysiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
- Erlangen Center of Plant Science (ECROPS), Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91058 Erlangen, Germany
| | - Barry P. Rosen
- Department of Cellular Biology and Pharmacology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL 33199, USA
| | - Birgit Daus
- Helmholtz Centre for Environmental Research GmbH – UFZ, Department Analytical Chemistry, Permoserstrasse 15/04318 Leipzig/Germany
| | - Zijuan Liu
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Yong-Guan Zhu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Science, Xiamen, China
| |
Collapse
|
103
|
Wang B, Ma M, Lu H, Meng Q, Li G, Yang X. Photosynthesis, sucrose metabolism, and starch accumulation in two NILs of winter wheat. PHOTOSYNTHESIS RESEARCH 2015; 126:363-73. [PMID: 25823798 DOI: 10.1007/s11120-015-0126-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 03/19/2015] [Indexed: 05/11/2023]
Abstract
The photosynthetic oxygen evolution rate, Hill reaction activity of seedlings and photosynthetic parameter, Pn-Ci curve and some source-sink metabolism-related enzyme activities, and substance content of flag leaves were measured by using two wheat near isogenic lines with significant differences in the photosynthetic rate of the 154 (high photosynthetic rate) and 212 (low photosynthetic rate) lines as materials. The results showed that the maximal carboxylation efficiency (Vcmax) and Hill reaction activity were higher in line 154 than that of line 212. The Pn in flag leaves of line 154 was significantly higher than that of line 212 during the anthesis to grain-filling stage. Higher leaf sucrose phosphate synthase activity, grain sucrose synthase activity, and grain ADPG pyrophosphorylase activity ensured that the photosynthate of line 154 could be transported to grains and translated into starch in a timely and effective manner, which also contributed to the maintenance of its high photosynthetic rate. Eventually, all of these factors of line 154 resulted in its higher grain yield compared with the low photosynthetic rate of line 212.
Collapse
Affiliation(s)
- Baoshan Wang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, People's Republic of China
| | - Mingyang Ma
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, People's Republic of China
| | - Haiguo Lu
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, People's Republic of China
| | - Qingwei Meng
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, People's Republic of China
| | - Gang Li
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, People's Republic of China
| | - Xinghong Yang
- State Key Laboratory of Crop Biology, Shandong Key Laboratory of Crop Biology, Shandong Agricultural University, Taian, 271018, People's Republic of China.
| |
Collapse
|
104
|
Seed filling in domesticated maize and rice depends on SWEET-mediated hexose transport. Nat Genet 2015; 47:1489-93. [PMID: 26523777 DOI: 10.1038/ng.3422] [Citation(s) in RCA: 279] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 09/23/2015] [Indexed: 12/20/2022]
Abstract
Carbohydrate import into seeds directly determines seed size and must have been increased through domestication. However, evidence of the domestication of sugar translocation and the identities of seed-filling transporters have been elusive. Maize ZmSWEET4c, as opposed to its sucrose-transporting homologs, mediates transepithelial hexose transport across the basal endosperm transfer layer (BETL), the entry point of nutrients into the seed, and shows signatures indicative of selection during domestication. Mutants of both maize ZmSWEET4c and its rice ortholog OsSWEET4 are defective in seed filling, indicating that a lack of hexose transport at the BETL impairs further transfer of sugars imported from the maternal phloem. In both maize and rice, SWEET4 was likely recruited during domestication to enhance sugar import into the endosperm.
Collapse
|
105
|
Bai H, Wang S, Liu J, Gao D, Jiang Y, Liu H, Cai Z. Localization of ginsenosides in Panax ginseng with different age by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry imaging. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 1026:263-271. [PMID: 26520809 DOI: 10.1016/j.jchromb.2015.09.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 08/31/2015] [Accepted: 09/17/2015] [Indexed: 01/15/2023]
Abstract
The root of Panax ginseng C.A. Mey. (P. ginseng) is one of the most popular traditional Chinese medicines, with ginsenosides as its main bioactive components. Because different ginsenosides have varied pharmacological effects, extraction and separation of ginsenosides are usually required for the investigation of pharmacological effects of different ginsenosides. However, the contents of ginsenosides vary with the ages and tissues of P. ginseng root. In this research, an efficient method to explore the distribution of ginsenosides and differentiate P. ginseng roots with different ages was developed based on matrix assisted laser desorption/ionization time-of-flight mass spectrometry imaging (MALDI-TOF-MSI). After a simple sample preparation, there were 18 peaks corresponding to 31 ginsenosides with distinct localization in the mass range of m/z 700-1400 identified by MALDI-TOF-MSI and MALDI-TOF-MS/MS. All the three types of ginsenosides were successfully detected and visualized in images, which could be correlated with anatomical features. The P. ginseng at the ages of 2, 4 and 6 could be differentiated finely through the principal component analysis of data collected from the cork based on the ion images but not data from the whole tissue. The experimental result implies that the established method for the direct analysis of metabolites in plant tissues has high potential for the rapid identification of metabolites and analysis of their localizations in medicinal herbs. Furthermore, this technique also provides valuable information for the component-specific extraction and pharmacological research of herbs.
Collapse
Affiliation(s)
- Hangrui Bai
- Department of Chemistry, Tsinghua University, Beijing 100084, China; State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Shujuan Wang
- State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Jianjun Liu
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, China
| | - Dan Gao
- State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China
| | - Yuyang Jiang
- School of Medicine, Tsinghua University, Beijing 100084, China
| | - Hongxia Liu
- State Key Laboratory Breeding Base-Shenzhen Key Laboratory of Chemical Biology, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China.
| | - Zongwei Cai
- State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China.
| |
Collapse
|
106
|
Gerbig S, Brunn HE, Spengler B, Schulz S. Spatially resolved investigation of systemic and contact pesticides in plant material by desorption electrospray ionization mass spectrometry imaging (DESI-MSI). Anal Bioanal Chem 2015; 407:7379-89. [DOI: 10.1007/s00216-015-8900-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 07/01/2015] [Accepted: 07/02/2015] [Indexed: 12/12/2022]
|
107
|
Bihmidine S, Baker RF, Hoffner C, Braun DM. Sucrose accumulation in sweet sorghum stems occurs by apoplasmic phloem unloading and does not involve differential Sucrose transporter expression. BMC PLANT BIOLOGY 2015; 15:186. [PMID: 26223524 PMCID: PMC4518677 DOI: 10.1186/s12870-015-0572-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 07/16/2015] [Indexed: 05/19/2023]
Abstract
BACKGROUND Sorghum (Sorghum bicolor L. Moench) cultivars store non-structural carbohydrates predominantly as either starch in seeds (grain sorghums) or sugars in stems (sweet sorghums). Previous research determined that sucrose accumulation in sweet sorghum stems was not correlated with the activities of enzymes functioning in sucrose metabolism, and that an apoplasmic transport step may be involved in stem sucrose accumulation. However, the sucrose unloading pathway from stem phloem to storage parenchyma cells remains unelucidated. Sucrose transporters (SUTs) transport sucrose across membranes, and have been proposed to function in sucrose partitioning differences between sweet and grain sorghums. The purpose of this study was to characterize the key differences in carbohydrate accumulation between a sweet and a grain sorghum, to define the path sucrose may follow for accumulation in sorghum stems, and to determine the roles played by sorghum SUTs in stem sucrose accumulation. RESULTS Dye tracer studies to determine the sucrose transport route revealed that, for both the sweet sorghum cultivar Wray and grain sorghum cultivar Macia, the phloem in the stem veins was symplasmically isolated from surrounding cells, suggesting sucrose was apoplasmically unloaded. Once in the phloem apoplasm, a soluble tracer diffused from the vein to stem parenchyma cell walls, indicating the lignified mestome sheath encompassing the vein did not prevent apoplasmic flux outside of the vein. To characterize carbohydrate partitioning differences between Wray and Macia, we compared the growth, stem juice volume, solute contents, SbSUTs gene expression, and additional traits. Contrary to previous findings, we detected no significant differences in SbSUTs gene expression within stem tissues. CONCLUSIONS Phloem sieve tubes within sweet and grain sorghum stems are symplasmically isolated from surrounding cells; hence, unloading from the phloem likely occurs apoplasmically, thereby defining the location of the previously postulated step for sucrose transport. Additionally, no changes in SbSUTs gene expression were detected in sweet vs. grain sorghum stems, suggesting alterations in SbSUT transcript levels do not account for the carbohydrate partitioning differences between cultivars. A model illustrating sucrose phloem unloading and movement to stem storage parenchyma, and highlighting roles for sucrose transport proteins in sorghum stems is discussed.
Collapse
Affiliation(s)
- Saadia Bihmidine
- Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA.
| | - R Frank Baker
- Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA.
- University of Missouri Molecular Cytology Core, 120 Bond Life Sciences Center, 1201 Rollins Street, Columbia, MO, 65211-7310, USA.
| | - Cassandra Hoffner
- Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA.
- Sigma-Aldrich Biotech, 545 S. Ewing, Saint Louis, MO, 63103, USA.
| | - David M Braun
- Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, 110 Tucker Hall, Columbia, MO, 65211, USA.
| |
Collapse
|
108
|
Pfautsch S, Hölttä T, Mencuccini M. Hydraulic functioning of tree stems--fusing ray anatomy, radial transfer and capacitance. TREE PHYSIOLOGY 2015; 35:706-22. [PMID: 26163488 DOI: 10.1093/treephys/tpv058] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 05/20/2015] [Indexed: 05/11/2023]
Abstract
Not long ago, textbooks on plant physiology divulged the view that phloem and xylem are separate transport systems with exclusive functions. Phloem was flowing downwards providing roots with carbohydrates. Xylem transported water upwards from roots to leaves. This simplified view has changed forever. Today we have a much-refined understanding of the complex transport mechanisms, regulatory functions and surprisingly ingenuous solutions trees have evolved to distribute carbohydrates and water internally to fuel growth and help mediate biotic and abiotic stresses. This review focuses on functional links between tissues of the inner bark region (i.e., more than just phloem) and the xylem, facilitated by radially aligned and interconnected parenchyma cells, called rays. Rays are usually found along the entire vertical axis of tree stems, mediating a number of transport processes. We use a top-down approach to unveil the role of rays in these processes. Due to the central role of rays in facilitating the coupling of inner bark and xylem we dedicate the first section to ray anatomy, pathways and control mechanisms involved in radial transport. In the second section, basic concepts and models for radial movement through rays are introduced and their impacts on water and carbon fluxes at the whole-tree level are discussed. This section is followed by a closer look at the capacitive function of composite tissues in stems where gradual changes in water potential generate a diurnal 'pulse'. We explain how this pulse can be measured and interpreted, and where the limitations of such analyses are. Towards the end of this review, we include a brief description of the role of radial transport during limited availability of water. By elucidating the strong hydraulic link between inner bark and xylem, the traditional view of two separate transport systems dissolves and the idea of one interconnected, yet highly segregated transport network for carbohydrates and water arises.
Collapse
Affiliation(s)
- Sebastian Pfautsch
- Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith 2751, NSW, Australia
| | - Teemu Hölttä
- Department of Forest Sciences, University of Helsinki, PO Box 27, FIN-00014, Finland
| | - Maurizio Mencuccini
- School of Geo-Science, University of Edinburgh, West Mains Road, Edinburgh EH9 3JN, UK ICREA at CREAF, Campus de UAB, Cerdanyola del Valles 08023, Barcelona, Spain
| |
Collapse
|
109
|
Rotsch D, Brossard T, Bihmidine S, Ying W, Gaddam V, Harmata M, Robertson JD, Swyers M, Jurisson SS, Braun DM. Radiosynthesis of 6'-Deoxy-6'[18F]Fluorosucrose via Automated Synthesis and Its Utility to Study In Vivo Sucrose Transport in Maize (Zea mays) Leaves. PLoS One 2015; 10:e0128989. [PMID: 26024520 PMCID: PMC4449027 DOI: 10.1371/journal.pone.0128989] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 05/01/2015] [Indexed: 01/08/2023] Open
Abstract
Sugars produced from photosynthesis in leaves are transported through the phloem tissues within veins and delivered to non-photosynthetic organs, such as roots, stems, flowers, and seeds, to support their growth and/or storage of carbohydrates. However, because the phloem is located internally within the veins, it is difficult to access and to study the dynamics of sugar transport. Radioactive tracers have been extensively used to study vascular transport in plants and have provided great insights into transport dynamics. To better study sucrose partitioning in vivo, a novel radioactive analog of sucrose was synthesized through a completely chemical synthesis route by substituting fluorine-18 (half-life 110 min) at the 6' position to generate 6'-deoxy-6'[(18)F]fluorosucrose ((18)FS). This radiotracer was then used to compare sucrose transport between wild-type maize plants and mutant plants lacking the Sucrose transporter1 (Sut1) gene, which has been shown to function in sucrose phloem loading. Our results demonstrate that (18)FS is transported in vivo, with the wild-type plants showing a greater rate of transport down the leaf blade than the sut1 mutant plants. A similar transport pattern was also observed for universally labeled [U-(14)C]sucrose ([U-(14)C]suc). Our findings support the proposed sucrose phloem loading function of the Sut1 gene in maize, and additionally demonstrate that the (18)FS analog is a valuable, new tool that offers imaging advantages over [U-(14)C]suc for studying phloem transport in plants.
Collapse
Affiliation(s)
- David Rotsch
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Tom Brossard
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Saadia Bihmidine
- Division of Biological Sciences, Interdisciplinary Plant Group and the Missouri Maize Center, University of Missouri, Columbia, Missouri, United States of America
| | - Weijiang Ying
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Vikram Gaddam
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - Michael Harmata
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - J. David Robertson
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
- University of Missouri Research Reactor, University of Missouri, Columbia, Missouri, United States of America
| | - Michael Swyers
- Division of Biological Sciences, Interdisciplinary Plant Group and the Missouri Maize Center, University of Missouri, Columbia, Missouri, United States of America
| | - Silvia S. Jurisson
- Department of Chemistry, University of Missouri, Columbia, Missouri, United States of America
| | - David M. Braun
- Division of Biological Sciences, Interdisciplinary Plant Group and the Missouri Maize Center, University of Missouri, Columbia, Missouri, United States of America
| |
Collapse
|
110
|
Abstract
Soluble sugars serve five main purposes in multicellular organisms: as sources of carbon skeletons, osmolytes, signals, and transient energy storage and as transport molecules. Most sugars are derived from photosynthetic organisms, particularly plants. In multicellular organisms, some cells specialize in providing sugars to other cells (e.g., intestinal and liver cells in animals, photosynthetic cells in plants), whereas others depend completely on an external supply (e.g., brain cells, roots and seeds). This cellular exchange of sugars requires transport proteins to mediate uptake or release from cells or subcellular compartments. Thus, not surprisingly, sugar transport is critical for plants, animals, and humans. At present, three classes of eukaryotic sugar transporters have been characterized, namely the glucose transporters (GLUTs), sodium-glucose symporters (SGLTs), and SWEETs. This review presents the history and state of the art of sugar transporter research, covering genetics, biochemistry, and physiology-from their identification and characterization to their structure, function, and physiology. In humans, understanding sugar transport has therapeutic importance (e.g., addressing diabetes or limiting access of cancer cells to sugars), and in plants, these transporters are critical for crop yield and pathogen susceptibility.
Collapse
Affiliation(s)
- Li-Qing Chen
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305;
| | | | | | | | | |
Collapse
|
111
|
Peuke AD, Gessler A, Trumbore S, Windt CW, Homan N, Gerkema E, VAN As H. Phloem flow and sugar transport in Ricinus communis L. is inhibited under anoxic conditions of shoot or roots. PLANT, CELL & ENVIRONMENT 2015; 38:433-47. [PMID: 24995994 DOI: 10.1111/pce.12399] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 06/25/2014] [Accepted: 06/27/2014] [Indexed: 06/03/2023]
Abstract
Anoxic conditions should hamper the transport of sugar in the phloem, as this is an active process. The canopy is a carbohydrate source and the roots are carbohydrate sinks. By fumigating the shoot with N2 or flooding the rhizosphere, anoxic conditions in the source or sink, respectively, were induced. Volume flow, velocity, conducting area and stationary water of the phloem were assessed by non-invasive magnetic resonance imaging (MRI) flowmetry. Carbohydrates and δ(13) C in leaves, roots and phloem saps were determined. Following flooding, volume flow and conducting area of the phloem declined and sugar concentrations in leaves and in phloem saps slightly increased. Oligosaccharides appeared in phloem saps and after 3 d, carbon transport was reduced to 77%. Additionally, the xylem flow declined and showed finally no daily rhythm. Anoxia of the shoot resulted within minutes in a reduction of volume flow, conductive area and sucrose in the phloem sap decreased. Sugar transport dropped to below 40% by the end of the N2 treatment. However, volume flow and phloem sap sugar tended to recover during the N2 treatment. Both anoxia treatments hampered sugar transport. The flow velocity remained about constant, although phloem sap sugar concentration changed during treatments. Apparently, stored starch was remobilized under anoxia.
Collapse
Affiliation(s)
- Andreas D Peuke
- ADP International Plant Science Consulting, Talstraße 8, Gundelfingen, D-79194, Germany; Institute for Landscape Biogeochemistry, Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e.V., Eberswalderstr. 84, Müncheberg, 15374, Germany
| | | | | | | | | | | | | |
Collapse
|
112
|
Lee Y, Nishizawa T, Yamashita K, Ishitani R, Nureki O. Structural basis for the facilitative diffusion mechanism by SemiSWEET transporter. Nat Commun 2015; 6:6112. [PMID: 25598322 PMCID: PMC4309421 DOI: 10.1038/ncomms7112] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 12/15/2014] [Indexed: 02/07/2023] Open
Abstract
SWEET family proteins mediate sugar transport across biological membranes and play crucial roles in plants and animals. The SWEETs and their bacterial homologues, the SemiSWEETs, are related to the PQ-loop family, which is characterized by highly conserved proline and glutamine residues (PQ-loop motif). Although the structures of the bacterial SemiSWEETs were recently reported, the conformational transition and the significance of the conserved motif in the transport cycle have remained elusive. Here we report crystal structures of SemiSWEET from Escherichia coli, in the both inward-open and outward-open states. A structural comparison revealed that SemiSWEET undergoes an intramolecular conformational change in each protomer. The conserved PQ-loop motif serves as a molecular hinge that enables the 'binder clip-like' motion of SemiSWEET. The present work provides the framework for understanding the overall transport cycles of SWEET and PQ-loop family proteins.
Collapse
Affiliation(s)
- Yongchan Lee
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Tomohiro Nishizawa
- 1] Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan [2] Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | | | - Ryuichiro Ishitani
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan
| |
Collapse
|
113
|
Jung B, Ludewig F, Schulz A, Meißner G, Wöstefeld N, Flügge UI, Pommerrenig B, Wirsching P, Sauer N, Koch W, Sommer F, Mühlhaus T, Schroda M, Cuin TA, Graus D, Marten I, Hedrich R, Neuhaus HE. Identification of the transporter responsible for sucrose accumulation in sugar beet taproots. NATURE PLANTS 2015; 1:14001. [PMID: 27246048 DOI: 10.1038/nplants.2014.1] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/24/2014] [Indexed: 05/21/2023]
Abstract
Sugar beet provides around one third of the sugar consumed worldwide and serves as a significant source of bioenergy in the form of ethanol. Sucrose accounts for up to 18% of plant fresh weight in sugar beet. Most of the sucrose is concentrated in the taproot, where it accumulates in the vacuoles. Despite 30 years of intensive research, the transporter that facilitates taproot sucrose accumulation has escaped identification. Here, we combine proteomic analyses of the taproot vacuolar membrane, the tonoplast, with electrophysiological analyses to show that the transporter BvTST2.1 is responsible for vacuolar sucrose uptake in sugar beet taproots. We show that BvTST2.1 is a sucrose-specific transporter, and present evidence to suggest that it operates as a proton antiporter, coupling the import of sucrose into the vacuole to the export of protons. BvTST2.1 exhibits a high amino acid sequence similarity to members of the tonoplast monosaccharide transporter family in Arabidopsis, prompting us to rename this group of proteins 'tonoplast sugar transporters'. The identification of BvTST2.1 could help to increase sugar yields from sugar beet and other sugar-storing plants in future breeding programs.
Collapse
Affiliation(s)
- Benjamin Jung
- Pflanzenphysiologie, University Kaiserslautern, Erwin Schrödinger Straße, D-67653 Kaiserslautern, Germany
| | - Frank Ludewig
- Biocenter Cologne, Botanical Institute II and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Straße 47b, D-50674, Germany
| | - Alexander Schulz
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Garvin Meißner
- Pflanzenphysiologie, University Kaiserslautern, Erwin Schrödinger Straße, D-67653 Kaiserslautern, Germany
| | - Nicole Wöstefeld
- Biocenter Cologne, Botanical Institute II and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Straße 47b, D-50674, Germany
| | - Ulf-Ingo Flügge
- Biocenter Cologne, Botanical Institute II and Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Zülpicher Straße 47b, D-50674, Germany
| | - Benjamin Pommerrenig
- Molecular Plant Physiology, University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Petra Wirsching
- Molecular Plant Physiology, University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Norbert Sauer
- Molecular Plant Physiology, University Erlangen-Nuremberg, Staudtstraße 5, D-91058 Erlangen, Germany
| | - Wolfgang Koch
- KWS Saat AG, Grimsehlstr.31, D37555 Einbeck, Germany
| | - Frederik Sommer
- Molecular Biotechnology and Systems Biology, University Kaiserslautern, Paul-Ehrlich-Straße, D-67653 Kaiserslautern Germany
| | - Timo Mühlhaus
- Molecular Biotechnology and Systems Biology, University Kaiserslautern, Paul-Ehrlich-Straße, D-67653 Kaiserslautern Germany
| | - Michael Schroda
- Molecular Biotechnology and Systems Biology, University Kaiserslautern, Paul-Ehrlich-Straße, D-67653 Kaiserslautern Germany
| | - Tracey Ann Cuin
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Dorothea Graus
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Irene Marten
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - Rainer Hedrich
- Biophysics and Molecular Plant Physiology, University Würzburg, Julius von Sachs Platz 2, D-97082 Würzburg, Germany
| | - H Ekkehard Neuhaus
- Pflanzenphysiologie, University Kaiserslautern, Erwin Schrödinger Straße, D-67653 Kaiserslautern, Germany
| |
Collapse
|
114
|
Zhao C, Doucet D, Mittapalli O. Characterization of horizontally transferred β-fructofuranosidase (ScrB) genes in Agrilus planipennis. INSECT MOLECULAR BIOLOGY 2014; 23:821-832. [PMID: 25224649 DOI: 10.1111/imb.12127] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The emerald ash borer (Agrilus planipennis) is an important invasive insect pest of Fraxinus spp. that feeds on host tissues containing high levels of sucrose. However, little is known about how it digests sucrose. Here, using larval midgut transcriptome data and preliminary genome sequence efforts, two β-fructofuranosidase-encoding ScrB genes, AplaScrB-1 and AplaScrB-2, were identified, and proved to reside within the A. planipennis genome. Homology and phylogenetic analysis revealed that they were acquired by A. planipennis via horizontal gene transfer (HGT) from bacteria, possibly an event independent from that reported in bark beetles (eg ScrB genes). Microsynteny between A. planipennis DNA scaffold #2042940, which hosts AplaScrB-1, and a region in the Tribolium castaneum chromosome LG4 suggested that A. planipennis gained this gene after the separation of Buprestidae and Tenebrionidae. Although both of the putative AplaScrB proteins have conserved β-fructofuranosidase motifs, only AplaScrB-2 was predicted to be a secretory protein. Expression of AplaScrB-1 seemed constitutive during development and in all tissues examined, whereas AplaScrB-2 showed a peak expression in adults and in the midgut. We propose that acquisition of these genes by A. planipennis from bacteria is adaptive, and specifically AplaScrB-2 is involved in breaking down dietary sucrose to obtain energy for development.
Collapse
Affiliation(s)
- C Zhao
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, OH, USA
| | | | | |
Collapse
|
115
|
Peng D, Gu X, Xue LJ, Leebens-Mack JH, Tsai CJ. Bayesian phylogeny of sucrose transporters: ancient origins, differential expansion and convergent evolution in monocots and dicots. FRONTIERS IN PLANT SCIENCE 2014; 5:615. [PMID: 25429293 PMCID: PMC4228843 DOI: 10.3389/fpls.2014.00615] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 10/20/2014] [Indexed: 05/19/2023]
Abstract
Sucrose transporters (SUTs) are essential for the export and efficient movement of sucrose from source leaves to sink organs in plants. The angiosperm SUT family was previously classified into three or four distinct groups, Types I, II (subgroup IIB), and III, with dicot-specific Type I and monocot-specific Type IIB functioning in phloem loading. To shed light on the underlying drivers of SUT evolution, Bayesian phylogenetic inference was undertaken using 41 sequenced plant genomes, including seven basal lineages at key evolutionary junctures. Our analysis supports four phylogenetically and structurally distinct SUT subfamilies, originating from two ancient groups (AG1 and AG2) that diverged early during terrestrial colonization. In both AG1 and AG2, multiple intron acquisition events in the progenitor vascular plant established the gene structures of modern SUTs. Tonoplastic Type III and plasmalemmal Type II represent evolutionarily conserved descendants of AG1 and AG2, respectively. Type I and Type IIB were previously thought to evolve after the dicot-monocot split. We show, however, that divergence of Type I from Type III SUT predated basal angiosperms, likely associated with evolution of vascular cambium and phloem transport. Type I SUT was subsequently lost in monocots along with vascular cambium, and independent evolution of Type IIB coincided with modified monocot vasculature. Both Type I and Type IIB underwent lineage-specific expansion. In multiple unrelated taxa, the newly-derived SUTs exhibit biased expression in reproductive tissues, suggesting a functional link between phloem loading and reproductive fitness. Convergent evolution of Type I and Type IIB for SUT function in phloem loading and reproductive organs supports the idea that differential vascular development in dicots and monocots is a strong driver for SUT family evolution in angiosperms.
Collapse
Affiliation(s)
- Duo Peng
- Institute of Bioinformatics, University of GeorgiaAthens, GA, USA
| | - Xi Gu
- Institute of Bioinformatics, University of GeorgiaAthens, GA, USA
| | - Liang-Jiao Xue
- Institute of Bioinformatics, University of GeorgiaAthens, GA, USA
- Warnell School of Forestry and Natural Resources, University of GeorgiaAthens, GA, USA
- Department of Genetics, University of GeorgiaAthens, GA, USA
| | - James H. Leebens-Mack
- Institute of Bioinformatics, University of GeorgiaAthens, GA, USA
- Department of Plant Biology, University of GeorgiaAthens, GA, USA
| | - Chung-Jui Tsai
- Institute of Bioinformatics, University of GeorgiaAthens, GA, USA
- Warnell School of Forestry and Natural Resources, University of GeorgiaAthens, GA, USA
- Department of Genetics, University of GeorgiaAthens, GA, USA
| |
Collapse
|
116
|
Medici A, Laloi M, Atanassova R. Profiling of sugar transporter genes in grapevine coping with water deficit. FEBS Lett 2014; 588:3989-97. [PMID: 25261250 DOI: 10.1016/j.febslet.2014.09.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 09/03/2014] [Indexed: 11/15/2022]
Abstract
The profiling of grapevine (Vitis vinifera L.) genes under water deficit was specifically targeted to sugar transporters. Leaf water status was characterized by physiological parameters and soluble sugars content. The expression analysis provided evidence that VvHT1 hexose transporter gene was strongly down-regulated by the increased sugar content under mild water-deficit. The genes of monosaccharide transporter VvHT5, sucrose carrier VvSUC11, vacuolar invertase VvGIN2 and grape ASR (ABA, stress, ripening) were up-regulated under severe water stress. Their regulation in a drought-ABA signalling network and possible roles in complex interdependence between sugar subcellular partitioning and cell influx/efflux under Grapevine acclimation to dehydration are discussed.
Collapse
Affiliation(s)
- Anna Medici
- Université de Poitiers, UMR CNRS 7267 Écologie & Biologie des Interactions, Équipe Sucres & Echanges Végétaux/Environnement - SEVE, TSA 51106, 86073 Poitiers Cedex 9, France.
| | - Maryse Laloi
- Université de Poitiers, UMR CNRS 7267 Écologie & Biologie des Interactions, Équipe Sucres & Echanges Végétaux/Environnement - SEVE, TSA 51106, 86073 Poitiers Cedex 9, France.
| | - Rossitza Atanassova
- Université de Poitiers, UMR CNRS 7267 Écologie & Biologie des Interactions, Équipe Sucres & Echanges Végétaux/Environnement - SEVE, TSA 51106, 86073 Poitiers Cedex 9, France.
| |
Collapse
|
117
|
Structures of bacterial homologues of SWEET transporters in two distinct conformations. Nature 2014; 515:448-452. [PMID: 25186729 DOI: 10.1038/nature13670] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Accepted: 07/10/2014] [Indexed: 01/15/2023]
Abstract
SWEETs and their prokaryotic homologues are monosaccharide and disaccharide transporters that are present from Archaea to plants and humans. SWEETs play crucial roles in cellular sugar efflux processes: that is, in phloem loading, pollen nutrition and nectar secretion. Their bacterial homologues, which are called SemiSWEETs, are among the smallest known transporters. Here we show that SemiSWEET molecules, which consist of a triple-helix bundle, form symmetrical, parallel dimers, thereby generating the translocation pathway. Two SemiSWEET isoforms were crystallized, one in an apparently open state and one in an occluded state, indicating that SemiSWEETs and SWEETs are transporters that undergo rocking-type movements during the transport cycle. The topology of the triple-helix bundle is similar yet distinct to that of the basic building block of animal and plant major facilitator superfamily (MFS) transporters (for example, GLUTs and SUTs). This finding indicates two possibilities: that SWEETs and MFS transporters evolved from an ancestral triple-helix bundle or that the triple-helix bundle represents convergent evolution. In SemiSWEETs and SWEETs, two triple-helix bundles are arranged in a parallel configuration to produce the 6- and 6 + 1-transmembrane-helix pores, respectively. In the 12-transmembrane-helix MFS transporters, four triple-helix bundles are arranged into an alternating antiparallel configuration, resulting in a much larger 2 × 2 triple-helix bundle forming the pore. Given the similarity of SemiSWEETs and SWEETs to PQ-loop amino acid transporters and to mitochondrial pyruvate carriers (MPCs), the structures characterized here may also be relevant to other transporters in the MtN3 clan. The insight gained from the structures of these transporters and from the analysis of mutations of conserved residues will improve the understanding of the transport mechanism, as well as allow comparative studies of the different superfamilies involved in sugar transport and the evolution of transporters in general.
Collapse
|
118
|
Li F, Wu B, Qin X, Yan L, Hao C, Tan L, Lai J. Molecular cloning and expression analysis of the sucrose transporter gene family from Theobroma cacao L. Gene 2014; 546:336-41. [PMID: 24875417 DOI: 10.1016/j.gene.2014.05.056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 04/30/2014] [Accepted: 05/23/2014] [Indexed: 11/29/2022]
Abstract
In this study, we performed cloning and expression analysis of six putative sucrose transporter genes, designated TcSUT1, TcSUT2, TcSUT3, TcSUT4, TcSUT5 and TcSUT6, from the cacao genotype 'TAS-R8'. The combination of cDNA and genomic DNA sequences revealed that the cacao SUT genes contained exon numbers ranging from 1 to 14. The average molecular mass of all six deduced proteins was approximately 56 kDa (range 52 to 66 kDa). All six proteins were predicted to exhibit typical features of sucrose transporters with 12 trans-membrane spanning domains. Phylogenetic analysis revealed that TcSUT2 and TcSUT4 belonged to Group 2 SUT and Group 4 SUT, respectively, and the other TcSUT proteins were belonging to Group 1 SUT. Real-time PCR was conducted to investigate the expression pattern of each member of the SUT family in cacao. Our experiment showed that TcSUT1 was expressed dominantly in pods and that, TcSUT3 and TcSUT4 were highly expressed in both pods and in bark with phloem. Within pods, TcSUT1 and TcSUT4 were expressed more in the seed coat and seed from the pod enlargement stage to the ripening stage. TcSUT5 expression sharply increased to its highest expression level in the seed coat during the ripening stage. Expression pattern analysis indicated that TcSUT genes may be associated with photoassimilate transport into developing seeds and may, therefore, have an impact on seed production.
Collapse
Affiliation(s)
- Fupeng Li
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, PR China; Key Laboratory of Genetic Resources Utilization of Spice and Beverage Crops, Ministry of Agriculture, Wanning 571533, PR China; Hainan Provincial Key Laboratory of Genetic Improvement and Quality Regulation for Tropical Spice and Beverage Crops, Wanning 571533, PR China
| | - Baoduo Wu
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, PR China; Key Laboratory of Genetic Resources Utilization of Spice and Beverage Crops, Ministry of Agriculture, Wanning 571533, PR China; Hainan Provincial Key Laboratory of Genetic Improvement and Quality Regulation for Tropical Spice and Beverage Crops, Wanning 571533, PR China
| | - Xiaowei Qin
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, PR China; Key Laboratory of Genetic Resources Utilization of Spice and Beverage Crops, Ministry of Agriculture, Wanning 571533, PR China; Hainan Provincial Key Laboratory of Genetic Improvement and Quality Regulation for Tropical Spice and Beverage Crops, Wanning 571533, PR China
| | - Lin Yan
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, PR China; Key Laboratory of Genetic Resources Utilization of Spice and Beverage Crops, Ministry of Agriculture, Wanning 571533, PR China; Hainan Provincial Key Laboratory of Genetic Improvement and Quality Regulation for Tropical Spice and Beverage Crops, Wanning 571533, PR China
| | - Chaoyun Hao
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, PR China; Key Laboratory of Genetic Resources Utilization of Spice and Beverage Crops, Ministry of Agriculture, Wanning 571533, PR China; Hainan Provincial Key Laboratory of Genetic Improvement and Quality Regulation for Tropical Spice and Beverage Crops, Wanning 571533, PR China
| | - Lehe Tan
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, PR China; Key Laboratory of Genetic Resources Utilization of Spice and Beverage Crops, Ministry of Agriculture, Wanning 571533, PR China; Hainan Provincial Key Laboratory of Genetic Improvement and Quality Regulation for Tropical Spice and Beverage Crops, Wanning 571533, PR China
| | - Jianxiong Lai
- Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wanning 571533, PR China; Key Laboratory of Genetic Resources Utilization of Spice and Beverage Crops, Ministry of Agriculture, Wanning 571533, PR China; Hainan Provincial Key Laboratory of Genetic Improvement and Quality Regulation for Tropical Spice and Beverage Crops, Wanning 571533, PR China.
| |
Collapse
|
119
|
Distelfeld A, Avni R, Fischer AM. Senescence, nutrient remobilization, and yield in wheat and barley. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3783-98. [PMID: 24470467 DOI: 10.1093/jxb/ert477] [Citation(s) in RCA: 151] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Cereals including wheat and barley are of primary importance to ensure food security for the 21st century. A combination of lab- and field-based approaches has led to a considerably improved understanding of the importance of organ and particularly of whole-plant (monocarpic) senescence for wheat and barley yield and quality. A delicate balance between senescence timing, grain nutrient content, nutrient-use efficiency, and yield needs to be considered to (further) improve cereal varieties for a given environment and end use. The recent characterization of the Gpc-1 (NAM-1) genes in wheat and barley demonstrates the interdependence of these traits. Lines or varieties with functional Gpc-1 genes demonstrate earlier senescence and enhanced grain protein and micronutrient content but, depending on the environment, somewhat reduced yields. A major effort is needed to dissect regulatory networks centred on additional wheat and barley transcription factors and signalling pathways influencing the senescence process. Similarly, while important molecular details of nutrient (particularly nitrogen) remobilization from senescing organs to developing grains have been identified, important knowledge gaps remain. The genes coding for the major proteases involved in senescence-associated plastidial protein degradation are largely unknown. Membrane transport proteins involved in the different transport steps occurring between senescing organ (such as leaf mesophyll) cells and protein bodies in the endosperm of developing grains remain to be identified or further characterized. Existing data suggest that an improved understanding of all these steps will reveal additional, important targets for continued cereal improvement.
Collapse
Affiliation(s)
- Assaf Distelfeld
- Faculty of Life Sciences, Department of Molecular Biology and Ecology of Plants, Tel Aviv University, 69978, Israel
| | - Raz Avni
- Faculty of Life Sciences, Department of Molecular Biology and Ecology of Plants, Tel Aviv University, 69978, Israel
| | - Andreas M Fischer
- Department of Plant Sciences and Plant Pathology, 119 Plant BioScience Building, Montana State University, Bozeman, MT 59717-3150, USA
| |
Collapse
|
120
|
Braun DM, Wang L, Ruan YL. Understanding and manipulating sucrose phloem loading, unloading, metabolism, and signalling to enhance crop yield and food security. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1713-35. [PMID: 24347463 DOI: 10.1093/jxb/ert416] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Sucrose is produced in, and translocated from, photosynthetically active leaves (sources) to support non-photosynthetic tissues (sinks), such as developing seeds, fruits, and tubers. Different plants can utilize distinct mechanisms to transport sucrose into the phloem sieve tubes in source leaves. While phloem loading mechanisms have been extensively studied in dicot plants, there is less information about phloem loading in monocots. Maize and rice are major dietary staples, which have previously been proposed to use different cellular routes to transport sucrose from photosynthetic cells into the translocation stream. The anatomical, physiological, and genetic evidence supporting these conflicting hypotheses is examined. Upon entering sink cells, sucrose often is degraded into hexoses for a wide range of metabolic and storage processes, including biosynthesis of starch, protein, and cellulose, which are all major constituents for food, fibre, and fuel. Sucrose, glucose, fructose, and their derivate, trehalose-6-phosphate, also serve as signalling molecules to regulate gene expression either directly or through cross-talk with other signalling pathways. As such, sugar transport and metabolism play pivotal roles in plant development and realization of crop yield that needs to be increased substantially to meet the projected population demand in the foreseeable future. This review will discuss the current understanding of the control of carbon partitioning from the cellular to whole-plant levels, focusing on (i) the pathways employed for phloem loading in source leaves, particularly in grasses, and the routes used in sink organs for phloem unloading; (ii) the transporter proteins responsible for sugar efflux and influx across plasma membranes; and (iii) the key enzymes regulating sucrose metabolism, signalling, and utilization. Examples of how sugar transport and metabolism can be manipulated to improve crop productivity and stress tolerance are discussed.
Collapse
Affiliation(s)
- David M Braun
- Division of Biological Sciences, Interdisciplinary Plant Group, and Missouri Maize Center, University of Missouri, Columbia, MO 65211, USA
| | | | | |
Collapse
|
121
|
Ursache R, Heo JO, Helariutta Y. Plant Vascular Biology 2013: vascular trafficking. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1673-1680. [PMID: 24431156 DOI: 10.1093/jxb/ert462] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
About 200 researchers from around the world attended the Third International Conference on Plant Vascular Biology (PVB 2013) held in July 2013 at the Rantapuisto Conference Center, in Helsinki, Finland (http://www.pvb2013.org). The plant vascular system, which connects every organ in the mature plant, continues to attract the interest of researchers representing a wide range of disciplines, including development, physiology, systems biology, and computational biology. At the meeting, participants discussed the latest research advances in vascular development, long- and short-distance vascular transport and long-distance signalling in plant defence, in addition to providing a context for how these studies intersect with each other. The meeting provided an opportunity for researchers working across a broad range of fields to share ideas and to discuss future directions in the expanding field of vascular biology. In this report, the latest advances in understanding the mechanism of vascular trafficking presented at the meeting have been summarized.
Collapse
Affiliation(s)
- Robertas Ursache
- Institute of Biotechnology/Department of Bio and Environmental Sciences, University of Helsinki, FIN-00014, Finland
| | | | | |
Collapse
|
122
|
Chen LQ. SWEET sugar transporters for phloem transport and pathogen nutrition. THE NEW PHYTOLOGIST 2014; 201:1150-5. [PMID: 24649486 DOI: 10.1111/nph.12445] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Many intercellular solute transport processes require an apoplasmic step, that is, efflux from one cell and subsequent uptake by an adjacent cell. Cellular uptake transporters have been identified for many solutes, including sucrose; however, efflux transporters have remained elusive for a long time. Cellular efflux of sugars plays essential roles in many processes, such as sugar efflux as the first step in phloem loading, sugar efflux for nectar secretion, and sugar efflux for supplying symbionts such as mycorrhiza, and maternal efflux for filial tissue development. Furthermore, sugar efflux systems can be hijacked by pathogens for access to nutrition from hosts. Mutations that block recruitment of the efflux mechanism by the pathogen thus cause pathogen resistance. Until recently, little was known regarding the underlying mechanism of sugar efflux. The identification of sugar efflux carriers, SWEETs (Sugars Will Eventually be Exported Transporters), has shed light on cellular sugar efflux. SWEETs appear to function as uniporters, facilitating diffusion of sugars across cell membranes. Indeed, SWEETs probably mediate sucrose efflux from putative phloem parenchyma into the phloem apoplasm, a key step proceeding phloem loading. Engineering of SWEET mutants using transcriptional activator-like effector nuclease (TALEN)-based genomic editing allowed the engineering of pathogen resistance. The widespread expression of the SWEET family promises to provide insights into many other cellular efflux mechanisms.
Collapse
|
123
|
Kuhlmann F, Opitz SEW, Inselsbacher E, Ganeteg U, Näsholm T, Ninkovic V. Exploring the nitrogen ingestion of aphids--a new method using electrical penetration graph and (15)N labelling. PLoS One 2014; 8:e83085. [PMID: 24376642 PMCID: PMC3871520 DOI: 10.1371/journal.pone.0083085] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 10/30/2013] [Indexed: 12/05/2022] Open
Abstract
Studying plant-aphid interactions is challenging as aphid feeding is a complex process hidden in the plant tissue. Here we propose a combination of two well established methods to study nutrient acquisition by aphids focusing on the uptake of isotopically labelled nitrogen (15N). We combined the Electrical Penetration Graph (EPG) technique that allows detailed recording of aphid feeding behaviour and stable isotope ratio mass spectrometry (IRMS) to precisely measure the uptake of nitrogen. Bird cherry-oat aphids Rhopalosiphum padi L. (Hemiptera, Aphididae) fed for 24 h on barley plants (Hordeum vulgare L., cultivar Lina, Poaceae) that were cultivated with a 15N enriched nutrient solution. The time aphids fed in the phloem was strongly positive correlated with their 15N uptake. All other single behavioural phases were not correlated with 15N enrichment in the aphids, which corroborates their classification as non-feeding EPG phases. In addition, phloem-feeding and 15N enrichment of aphids was divided into two groups. One group spent only short time in the phloem phase and was unsuccessful in nitrogen acquisition, while the other group displayed longer phloem-feeding phases and was successful in nitrogen acquisition. This suggests that several factors such as the right feeding site, time span of feeding and individual conditions play a role for the aphids to acquire nutrients successfully. The power of this combination of methods for studying plant-aphid interactions is discussed.
Collapse
Affiliation(s)
- Franziska Kuhlmann
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | | - Erich Inselsbacher
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Ulrika Ganeteg
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Velemir Ninkovic
- Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
| |
Collapse
|
124
|
Zhang H, Zhang S, Qin G, Wang L, Wu T, Qi K, Zhang S. Molecular cloning and expression analysis of a gene for sucrose transporter from pear (Pyrus bretschneideri Rehd.) fruit. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 73:63-69. [PMID: 24056128 DOI: 10.1016/j.plaphy.2013.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 08/21/2013] [Indexed: 05/28/2023]
Abstract
Here we report the cloning of a sucrose transporter cDNA from pear (Pyrus bretschneideri Rehd. cv 'Yali') fruit and an analysis of the expression of the gene. A cDNA clone, designated PbSUT1 was identified as a sucrose transporter cDNA from its sequence homology at the amino acid level to sucrose transporters that have been cloned from other higher plant species. PbSUT1 potentially encoded a protein of 499 amino acid residues with a predicted molecular mass of 53.4 kDa and an isoelectric point (pI) of 9.21. Phylogenetic analysis revealed that the PbSUT1 belonged to type III SUTs and was more closely related to the MdSUT1 from apple fruit. Some major facilitator superfamily (MFS)-specific sequence motifs were found in the predicted PbSUT1 peptides, and an MFS_1 domain was located at the amino acid positions of 29-447 of the sequence. A study of gene expression along fruit development showed that PbSUT1 transcripts are present at all stages but significantly increase before fruit enlargement and during the ripening process with increasing sucrose levels. In contrast, the expression levels don't change much during the period of rapid fruit growth. This work shows that sucrose transporter may play a role in the accumulation of sugars during maturation and in maintaining the internal cellular distribution.
Collapse
Affiliation(s)
- Huping Zhang
- Centre of Pear Engineering & Technology Research, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, PR China; Department of Horticulture, College of Agriculture, Shihezi University, Shihezi 832003, PR China
| | | | | | | | | | | | | |
Collapse
|
125
|
Deol KK, Mukherjee S, Gao F, Brûlé-Babel A, Stasolla C, Ayele BT. Identification and characterization of the three homeologues of a new sucrose transporter in hexaploid wheat (Triticum aestivum L.). BMC PLANT BIOLOGY 2013; 13:181. [PMID: 24237613 PMCID: PMC4225610 DOI: 10.1186/1471-2229-13-181] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 11/11/2013] [Indexed: 05/05/2023]
Abstract
BACKGROUND Sucrose transporters (SUTs) play important roles in regulating the translocation of assimilates from source to sink tissues. Identification and characterization of new SUTs in economically important crops such as wheat provide insights into their role in determining seed yield. To date, however, only one SUT of wheat has been reported and functionally characterized. The present study reports the isolation and characterization of a new SUT, designated as TaSUT2, and its homeologues (TaSUT2A, TaSUT2B and TaSUT2D) in hexaploid wheat (Triticum aestivum L.). RESULTS TaSUT2A and TaSUT2B genes each encode a protein with 506 amino acids, whereas TaSUT2D encodes a protein of 508 amino acids. The molecular mass of these proteins is predicted to be ~ 54 kDA. Topological analysis of the amino acid sequences of the three homeologues revealed that they contain 12 transmembrane spanning helices, which are described as distinct characteristic features of glycoside-pentoside-hexuronide cation symporter family that includes all known plant SUTs, and a histidine residue that appears to be localized at and associated conformationally with the sucrose binding site. Yeast SUSY7/ura3 strain cells transformed with TaSUT2A, TaSUT2B and TaSUT2D were able to uptake sucrose and grow on a medium containing sucrose as a sole source of carbon; however, our subcellular localization study with plant cells revealed that TaSUT2 is localized to the tonoplast. The expression of TaSUT2 was detected in the source, including flag leaf blade, flag leaf sheath, peduncle, glumes, palea and lemma, and sink (seed) tissues. The relative contributions of the three genomes of wheat to the total expression of TaSUT2 appear to differ with tissues and developmental stages. At the cellular level, TaSUT2 is expressed mainly in the vein of developing seeds and subepidermal mesophyll cells of the leaf blade. CONCLUSION This study demonstrated that TaSUT2 is a new wheat SUT protein. Given that TaSUT2 is localized to the tonoplast and sucrose is temporarily stored in the vacuoles of both source and sink tissues, our data imply that TaSUT2 is involved in the intracellular partitioning of sucrose, particularly between the vacuole and cytoplasm.
Collapse
Affiliation(s)
- Kirandeep K Deol
- Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2 N2, Canada
| | - Shalini Mukherjee
- Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2 N2, Canada
| | - Feng Gao
- Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2 N2, Canada
| | - Anita Brûlé-Babel
- Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2 N2, Canada
| | - Claudio Stasolla
- Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2 N2, Canada
| | - Belay T Ayele
- Department of Plant Science, 222 Agriculture Building, University of Manitoba, Winnipeg, Manitoba R3T 2 N2, Canada
| |
Collapse
|
126
|
Klemens PA, Patzke K, Deitmer J, Spinner L, Le Hir R, Bellini C, Bedu M, Chardon F, Krapp A, Neuhaus HE. Overexpression of the vacuolar sugar carrier AtSWEET16 modifies germination, growth, and stress tolerance in Arabidopsis. PLANT PHYSIOLOGY 2013; 163:1338-52. [PMID: 24028846 PMCID: PMC3813654 DOI: 10.1104/pp.113.224972] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 09/11/2013] [Indexed: 05/18/2023]
Abstract
Here, we report that SUGARS WILL EVENTUALLY BE EXPORTED TRANSPORTER (SWEET16) from Arabidopsis (Arabidopsis thaliana) is a vacuole-located carrier, transporting glucose (Glc), fructose (Fru), and sucrose (Suc) after heterologous expression in Xenopus laevis oocytes. The SWEET16 gene, similar to the homologs gene SWEET17, is mainly expressed in vascular parenchyma cells. Application of Glc, Fru, or Suc, as well as cold, osmotic stress, or low nitrogen, provoke the down-regulation of SWEET16 messenger RNA accumulation. SWEET16 overexpressors (35SPro:SWEET16) showed a number of peculiarities related to differences in sugar accumulation, such as less Glc, Fru, and Suc at the end of the night. Under cold stress, 35SPro:SWEET16 plants are unable to accumulate Fru, while under nitrogen starvation, both Glc and Fru, but not Suc, were less abundant. These changes of individual sugars indicate that the consequences of an increased SWEET16 activity are dependent upon the type of external stimulus. Remarkably, 35SPro:SWEET16 lines showed improved germination and increased freezing tolerance. The latter observation, in combination with the modified sugar levels, points to a superior function of Glc and Suc for frost tolerance. 35SPro:SWEET16 plants exhibited increased growth efficiency when cultivated on soil and showed improved nitrogen use efficiency when nitrate was sufficiently available, while under conditions of limiting nitrogen, wild-type biomasses were higher than those of 35SPro:SWEET16 plants. Our results identify SWEET16 as a vacuolar sugar facilitator, demonstrate the substantial impact of SWEET16 overexpression on various critical plant traits, and imply that SWEET16 activity must be tightly regulated to allow optimal Arabidopsis development under nonfavorable conditions.
Collapse
|
127
|
Functional role of oligomerization for bacterial and plant SWEET sugar transporter family. Proc Natl Acad Sci U S A 2013; 110:E3685-94. [PMID: 24027245 DOI: 10.1073/pnas.1311244110] [Citation(s) in RCA: 198] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Eukaryotic sugar transporters of the MFS and SWEET superfamilies consist of 12 and 7 α-helical transmembrane domains (TMs), respectively. Structural analyses indicate that MFS transporters evolved from a series of tandem duplications of an ancestral 3-TM unit. SWEETs are heptahelical proteins carrying a tandem repeat of 3-TM separated by a single TM. Here, we show that prokaryotes have ancestral SWEET homologs with only 3-TM and that the Bradyrhizobium japonicum SemiSWEET1, like Arabidopsis SWEET11, mediates sucrose transport. Eukaryotic SWEETs most likely evolved by internal duplication of the 3-TM, suggesting that SemiSWEETs form oligomers to create a functional pore. However, it remains elusive whether the 7-TM SWEETs are the functional unit or require oligomerization to form a pore sufficiently large to allow for sucrose passage. Split ubiquitin yeast two-hybrid and split GFP assays indicate that Arabidopsis SWEETs homo- and heterooligomerize. We examined mutant SWEET variants for negative dominance to test if oligomerization is necessary for function. Mutation of the conserved Y57 or G58 in SWEET1 led to loss of activity. Coexpression of the defective mutants with functional A. thaliana SWEET1 inhibited glucose transport, indicating that homooligomerization is necessary for function. Collectively, these data imply that the basic unit of SWEETs, similar to MFS sugar transporters, is a 3-TM unit and that a functional transporter contains at least four such domains. We hypothesize that the functional unit of the SWEET family of transporters possesses a structure resembling the 12-TM MFS structure, however, with a parallel orientation of the 3-TM unit.
Collapse
|
128
|
Ahkami AH, Melzer M, Ghaffari MR, Pollmann S, Ghorbani Javid M, Shahinnia F, Hajirezaei MR, Druege U. Distribution of indole-3-acetic acid in Petunia hybrida shoot tip cuttings and relationship between auxin transport, carbohydrate metabolism and adventitious root formation. PLANTA 2013; 238:499-517. [PMID: 23765266 PMCID: PMC3751230 DOI: 10.1007/s00425-013-1907-z] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 05/28/2013] [Indexed: 05/21/2023]
Abstract
To determine the contribution of polar auxin transport (PAT) to auxin accumulation and to adventitious root (AR) formation in the stem base of Petunia hybrida shoot tip cuttings, the level of indole-3-acetic acid (IAA) was monitored in non-treated cuttings and cuttings treated with the auxin transport blocker naphthylphthalamic acid (NPA) and was complemented with precise anatomical studies. The temporal course of carbohydrates, amino acids and activities of controlling enzymes was also investigated. Analysis of initial spatial IAA distribution in the cuttings revealed that approximately 40 and 10 % of the total IAA pool was present in the leaves and the stem base as rooting zone, respectively. A negative correlation existed between leaf size and IAA concentration. After excision of cuttings, IAA showed an early increase in the stem base with two peaks at 2 and 24 h post excision and, thereafter, a decline to low levels. This was mirrored by the expression pattern of the auxin-responsive GH3 gene. NPA treatment completely suppressed the 24-h peak of IAA and severely inhibited root formation. It also reduced activities of cell wall and vacuolar invertases in the early phase of AR formation and inhibited the rise of activities of glucose-6-phosphate dehydrogenase and phosphofructokinase during later stages. We propose a model in which spontaneous AR formation in Petunia cuttings is dependent on PAT and on the resulting 24-h peak of IAA in the rooting zone, where it induces early cellular events and also stimulates sink establishment. Subsequent root development stimulates glycolysis and the pentose phosphate pathway.
Collapse
Affiliation(s)
- Amir H. Ahkami
- Institute of Biological Chemistry (IBC), Washington State University, Pullman, WA 99164-6340 USA
| | - Michael Melzer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, Gatersleben, 06466 Seeland, Germany
| | - Mohammad R. Ghaffari
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, Gatersleben, 06466 Seeland, Germany
| | - Stephan Pollmann
- Parque Científico y Tecnológico de la U.P.M, Centro de Biotecnología y Genómica de Plantas U.P.M.-I.N.I.A, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Majid Ghorbani Javid
- Department of Agronomy and Plant Breeding Sciences, College of Abureihan, University of Tehran, Tehran, Iran
| | - Fahimeh Shahinnia
- Australian Centre for Plant Functional Genomics, University of Adelaide, Waite Campus, Hartley Grove Urrbrae, Adelaide, 5064 Australia
| | - Mohammad R. Hajirezaei
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, Gatersleben, 06466 Seeland, Germany
| | - Uwe Druege
- Leibniz Institute of Vegetable and Ornamental Crops Großbeeren/Erfurt e.V. (IGZ), Kuehnhaeuser Str. 101, 99090 Erfurt, Germany
| |
Collapse
|
129
|
Elashry A, Okumoto S, Siddique S, Koch W, Kreil DP, Bohlmann H. The AAP gene family for amino acid permeases contributes to development of the cyst nematode Heterodera schachtii in roots of Arabidopsis. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 70:379-86. [PMID: 23831821 PMCID: PMC3737465 DOI: 10.1016/j.plaphy.2013.05.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 05/09/2013] [Indexed: 05/02/2023]
Abstract
The beet cyst nematode Heterodera schachtii is able to infect Arabidopsis plants and induce feeding sites in the root. These syncytia are the only source of nutrients for the nematodes throughout their life and are a nutrient sink for the host plant. We have studied here the role of amino acid transporters for nematode development. Arabidopsis contains a large number of different amino acid transporters in several gene families but those of the AAP family were found to be especially expressed in syncytia. Arabidopsis contains 8 AAP genes and they were all strongly expressed in syncytia with the exception of AAP5 and AAP7, which were slightly downregulated. We used promoter::GUS lines and in situ RT-PCR to confirm the expression of several AAP genes and LHT1, a lysine- and histidine-specific amino acid transporter, in syncytia. The strong expression of AAP genes in syncytia indicated that these transporters are important for the transport of amino acids into syncytia and we used T-DNA mutants for several AAP genes to test for their influence on nematode development. We found that mutants of AAP1, AAP2, and AAP8 significantly reduced the number of female nematodes developing on these plants. Our study showed that amino acid transport into syncytia is important for the development of the nematodes.
Collapse
Affiliation(s)
- Abdelnaser Elashry
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna. UFT Tulln, Konrad Lorenz Str. 24, 3430 Tulln, Austria
| | - Sakiko Okumoto
- Department of Plant Pathology, Physiology, and Weed Science, 549 Latham Hall (0390), Virginia Tech, Blacksburg, VA 24061, USA
| | - Shahid Siddique
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna. UFT Tulln, Konrad Lorenz Str. 24, 3430 Tulln, Austria
| | - Wolfgang Koch
- KWS SAAT AG, Grimsehlstrasse 31, 37574 Einbeck, Germany
| | - David P. Kreil
- Chair of Bioinformatics, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
- School of Life Sciences, University of Warwick, UK
| | - Holger Bohlmann
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna. UFT Tulln, Konrad Lorenz Str. 24, 3430 Tulln, Austria
- Corresponding author. Tel.: +43 1 47654 3360; fax: +43 1 47654 3359.
| |
Collapse
|
130
|
Lemoine R, Camera SL, Atanassova R, Dédaldéchamp F, Allario T, Pourtau N, Bonnemain JL, Laloi M, Coutos-Thévenot P, Maurousset L, Faucher M, Girousse C, Lemonnier P, Parrilla J, Durand M. Source-to-sink transport of sugar and regulation by environmental factors. FRONTIERS IN PLANT SCIENCE 2013; 4:272. [PMID: 23898339 PMCID: PMC3721551 DOI: 10.3389/fpls.2013.00272] [Citation(s) in RCA: 530] [Impact Index Per Article: 48.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 07/02/2013] [Indexed: 05/18/2023]
Abstract
Source-to-sink transport of sugar is one of the major determinants of plant growth and relies on the efficient and controlled distribution of sucrose (and some other sugars such as raffinose and polyols) across plant organs through the phloem. However, sugar transport through the phloem can be affected by many environmental factors that alter source/sink relationships. In this paper, we summarize current knowledge about the phloem transport mechanisms and review the effects of several abiotic (water and salt stress, mineral deficiency, CO2, light, temperature, air, and soil pollutants) and biotic (mutualistic and pathogenic microbes, viruses, aphids, and parasitic plants) factors. Concerning abiotic constraints, alteration of the distribution of sugar among sinks is often reported, with some sinks as roots favored in case of mineral deficiency. Many of these constraints impair the transport function of the phloem but the exact mechanisms are far from being completely known. Phloem integrity can be disrupted (e.g., by callose deposition) and under certain conditions, phloem transport is affected, earlier than photosynthesis. Photosynthesis inhibition could result from the increase in sugar concentration due to phloem transport decrease. Biotic interactions (aphids, fungi, viruses…) also affect crop plant productivity. Recent breakthroughs have identified some of the sugar transporters involved in these interactions on the host and pathogen sides. The different data are discussed in relation to the phloem transport pathways. When possible, the link with current knowledge on the pathways at the molecular level will be highlighted.
Collapse
Affiliation(s)
- Remi Lemoine
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Sylvain La Camera
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Rossitza Atanassova
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Fabienne Dédaldéchamp
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Thierry Allario
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Nathalie Pourtau
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Jean-Louis Bonnemain
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Maryse Laloi
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Pierre Coutos-Thévenot
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Laurence Maurousset
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Mireille Faucher
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Christine Girousse
- Diversité et Ecophysiologie des Céréales, Unités Mixtes de RechercheClermont Ferrand, France
| | - Pauline Lemonnier
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Jonathan Parrilla
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| | - Mickael Durand
- Unités Mixtes de Recherche, Ecologie et Biologie des Interactions, Université of Poitiers/Centre National de la Recherche ScientifiquePoitiers, France
| |
Collapse
|
131
|
Wu X, Huang R, Liu Z, Zhang G. Functional characterization of cis-elements conferring vascular vein expression of At4g34880 amidase family protein gene in Arabidopsis. PLoS One 2013; 8:e67562. [PMID: 23844031 PMCID: PMC3699661 DOI: 10.1371/journal.pone.0067562] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 05/20/2013] [Indexed: 12/18/2022] Open
Abstract
The expression of At4g34880 gene encoding amidase in Arabidopsis was characterized in this study. A promoter region of 1.5 kb on the upstream of the start codon of the gene (referred as AmidP) was fused with uidA (GUS) reporter gene, and transformed into Arabidopsis plant for determining its spatial expression. The results indicated that AmidP drived GUS expression in vascular system, predominately in leaves. Truncation analysis of AmidP demonstrated that VASCULAR VEIN ELEMENT (VVE) motif with a region of 176 bp sequence (−1500 to −1324) was necessary and sufficient to direct the vascular vein specific GUS expression in the transgenic plant. Tandem copy of VVE increased vascular system expression, and 5′- and 3′- deletions of VVE motif in combination with a truncated −65 CaMV 35S minimal promoter showed that 11bp cis-acting element, naming DOF2 domain, played an essential role for the vascular vein specific expression. Meanwhile, it was also observed that the other cis-acting elements among the VVE region are also associated with specificity or strength of GUS activities in vascular system.
Collapse
Affiliation(s)
- Xuelong Wu
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
- Institute of Virology and Biotechnology, Key Laboratory of Plant Metabolic Engineering of Zhejiang Province, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Ruizhi Huang
- Institute of Virology and Biotechnology, Key Laboratory of Plant Metabolic Engineering of Zhejiang Province, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Zhihong Liu
- Institute of Virology and Biotechnology, Key Laboratory of Plant Metabolic Engineering of Zhejiang Province, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Guoping Zhang
- Department of Agronomy, Key Laboratory of Crop Germplasm Resource, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, Zhejiang, China
- * E-mail:
| |
Collapse
|
132
|
Milne RJ, Byrt CS, Patrick JW, Grof CPL. Are sucrose transporter expression profiles linked with patterns of biomass partitioning in Sorghum phenotypes? FRONTIERS IN PLANT SCIENCE 2013; 4:223. [PMID: 23805151 PMCID: PMC3693075 DOI: 10.3389/fpls.2013.00223] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 06/08/2013] [Indexed: 05/06/2023]
Abstract
Sorghum bicolor is a genetically diverse C4 monocotyledonous species, encompassing varieties capable of producing high grain yields as well as sweet types which accumulate soluble sugars (predominantly sucrose) within their stems to high concentrations. Sucrose produced in leaves (sources) enters the phloem and is transported to regions of growth and storage (sinks). It is likely that sucrose transporter (SUT) proteins play pivotal roles in phloem loading and the delivery of sucrose to growth and storage sinks in all Sorghum ecotypes. Six SUTs are present in the published Sorghum genome, based on the BTx623 grain cultivar. Homologues of these SUTs were cloned and sequenced from the sweet cultivar Rio, and compared with the publically available genome information. SbSUT5 possessed nine amino acid sequence differences between the two varieties. Two of the remaining five SUTs exhibited single variations in their amino acid sequences (SbSUT1 and SbSUT2) whilst the rest shared identical sequences. Complementation of a mutant Saccharomyces yeast strain (SEY6210), unable to grow upon sucrose as the sole carbon source, demonstrated that the Sorghum SUTs were capable of transporting sucrose. SbSUT1, SbSUT4, and SbSUT6 were highly expressed in mature leaf tissues and hence may contribute to phloem loading. In contrast, SbSUT2 and SbSUT5 were expressed most strongly in sinks consistent with a possible role of facilitating sucrose import into stem storage pools and developing inflorescences.
Collapse
Affiliation(s)
- Ricky J. Milne
- School of Environmental and Life Sciences, University of Newcastle, NewcastleNSW, Australia
| | - Caitlin S. Byrt
- School of Environmental and Life Sciences, University of Newcastle, NewcastleNSW, Australia
- Australian Research Council Centre of Excellence in Plant Cell Walls, Waite Campus, University of AdelaideAdelaide, SA, Australia
| | - John W. Patrick
- School of Environmental and Life Sciences, University of Newcastle, NewcastleNSW, Australia
| | - Christopher P. L. Grof
- School of Environmental and Life Sciences, University of Newcastle, NewcastleNSW, Australia
| |
Collapse
|
133
|
Bihmidine S, Hunter CT, Johns CE, Koch KE, Braun DM. Regulation of assimilate import into sink organs: update on molecular drivers of sink strength. FRONTIERS IN PLANT SCIENCE 2013; 4:177. [PMID: 23761804 PMCID: PMC3671192 DOI: 10.3389/fpls.2013.00177] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 05/17/2013] [Indexed: 05/18/2023]
Abstract
Recent developments have altered our view of molecular mechanisms that determine sink strength, defined here as the capacity of non-photosynthetic structures to compete for import of photoassimilates. We review new findings from diverse systems, including stems, seeds, flowers, and fruits. An important advance has been the identification of new transporters and facilitators with major roles in the accumulation and equilibration of sugars at a cellular level. Exactly where each exerts its effect varies among systems. Sugarcane and sweet sorghum stems, for example, both accumulate high levels of sucrose, but may do so via different paths. The distinction is central to strategies for targeted manipulation of sink strength using transporter genes, and shows the importance of system-specific analyses. Another major advance has been the identification of deep hypoxia as a feature of normal grain development. This means that molecular drivers of sink strength in endosperm operate in very low oxygen levels, and under metabolic conditions quite different than previously assumed. Successful enhancement of sink strength has nonetheless been achieved in grains by up-regulating genes for starch biosynthesis. Additionally, our understanding of sink strength is enhanced by awareness of the dual roles played by invertases (INVs), not only in sucrose metabolism, but also in production of the hexose sugar signals that regulate cell cycle and cell division programs. These contributions of INV to cell expansion and division prove to be vital for establishment of young sinks ranging from flowers to fruit. Since INV genes are themselves sugar-responsive "feast genes," they can mediate a feed-forward enhancement of sink strength when assimilates are abundant. Greater overall productivity and yield have thus been attained in key instances, indicating that even broader enhancements may be achievable as we discover the detailed molecular mechanisms that drive sink strength in diverse systems.
Collapse
Affiliation(s)
- Saadia Bihmidine
- Division of Biological Sciences, University of MissouriColumbia, MO, USA
- Interdisciplinary Plant Group, University of MissouriColumbia, MO, USA
- Missouri Maize Center, University of MissouriColumbia, MO, USA
| | - Charles T. Hunter
- Horticultural Sciences Department, University of FloridaGainesville, FL, USA
- Plant Molecular and Cellular Biology Program, University of FloridaGainesville, FL, USA
| | - Christine E. Johns
- Horticultural Sciences Department, University of FloridaGainesville, FL, USA
- Plant Molecular and Cellular Biology Program, University of FloridaGainesville, FL, USA
| | - Karen E. Koch
- Horticultural Sciences Department, University of FloridaGainesville, FL, USA
- Plant Molecular and Cellular Biology Program, University of FloridaGainesville, FL, USA
| | - David M. Braun
- Division of Biological Sciences, University of MissouriColumbia, MO, USA
- Interdisciplinary Plant Group, University of MissouriColumbia, MO, USA
- Missouri Maize Center, University of MissouriColumbia, MO, USA
| |
Collapse
|
134
|
Baker RF, Slewinski TL, Braun DM. The tie-dyed pathway promotes symplastic trafficking in the phloem. PLANT SIGNALING & BEHAVIOR 2013; 8:e24540. [PMID: 23603956 PMCID: PMC3909061 DOI: 10.4161/psb.24540] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 05/18/2023]
Abstract
The tie-dyed1 (tdy1) and tdy2 mutants of maize exhibit leaf regions with starch hyperaccumulation and display unusual genetic interactions, suggesting they function in the same physiological process. Tdy2 encodes a putative callose synthase and is expressed in developing vascular tissues of immature leaves. Radiolabelling experiments and transmission electron microscopy (TEM) revealed symplastic trafficking within the phloem was perturbed at the companion cell/sieve element interface. Here, we show that as reported for tdy2 mutants, tdy1 yellow leaf regions display an excessive oil-droplet phenotype in the companion cells. Based on the proposed function of Tdy2 as a callose synthase, our previous work characterizing Tdy1 as a novel, transmembrane-localized protein, and the present findings, we speculate how TDY1 and TDY2 might interact to promote symplastic transport of both solutes and developmentally instructive macromolecules during vascular development at the companion cell/sieve element interface.
Collapse
Affiliation(s)
- R. Frank Baker
- Division of Biological Sciences and Interdisciplinary Plant Group; Missouri Maize Center; University of Missouri; Columbia, MO USA
| | | | - David M. Braun
- Division of Biological Sciences and Interdisciplinary Plant Group; Missouri Maize Center; University of Missouri; Columbia, MO USA
- Correspondence to: David M. Braun,
| |
Collapse
|
135
|
Fürstenberg-Hägg J, Zagrobelny M, Bak S. Plant defense against insect herbivores. Int J Mol Sci 2013; 14:10242-97. [PMID: 23681010 PMCID: PMC3676838 DOI: 10.3390/ijms140510242] [Citation(s) in RCA: 357] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 04/27/2013] [Accepted: 05/02/2013] [Indexed: 01/09/2023] Open
Abstract
Plants have been interacting with insects for several hundred million years, leading to complex defense approaches against various insect feeding strategies. Some defenses are constitutive while others are induced, although the insecticidal defense compound or protein classes are often similar. Insect herbivory induce several internal signals from the wounded tissues, including calcium ion fluxes, phosphorylation cascades and systemic- and jasmonate signaling. These are perceived in undamaged tissues, which thereafter reinforce their defense by producing different, mostly low molecular weight, defense compounds. These bioactive specialized plant defense compounds may repel or intoxicate insects, while defense proteins often interfere with their digestion. Volatiles are released upon herbivory to repel herbivores, attract predators or for communication between leaves or plants, and to induce defense responses. Plants also apply morphological features like waxes, trichomes and latices to make the feeding more difficult for the insects. Extrafloral nectar, food bodies and nesting or refuge sites are produced to accommodate and feed the predators of the herbivores. Meanwhile, herbivorous insects have adapted to resist plant defenses, and in some cases even sequester the compounds and reuse them in their own defense. Both plant defense and insect adaptation involve metabolic costs, so most plant-insect interactions reach a stand-off, where both host and herbivore survive although their development is suboptimal.
Collapse
Affiliation(s)
- Joel Fürstenberg-Hägg
- Plant Biochemistry Laboratory and VKR Research Centre ‘Pro-Active Plants’, Department of Plant and Environmental Science, University of Copenhagen, 40 Thorvaldsensvej, Frederiksberg C, Copenhagen DK-1871, Denmark; E-Mails: (J.F.-H.); (M.Z.)
| | - Mika Zagrobelny
- Plant Biochemistry Laboratory and VKR Research Centre ‘Pro-Active Plants’, Department of Plant and Environmental Science, University of Copenhagen, 40 Thorvaldsensvej, Frederiksberg C, Copenhagen DK-1871, Denmark; E-Mails: (J.F.-H.); (M.Z.)
| | - Søren Bak
- Plant Biochemistry Laboratory and VKR Research Centre ‘Pro-Active Plants’, Department of Plant and Environmental Science, University of Copenhagen, 40 Thorvaldsensvej, Frederiksberg C, Copenhagen DK-1871, Denmark; E-Mails: (J.F.-H.); (M.Z.)
| |
Collapse
|
136
|
Vincill ED, Clarin AE, Molenda JN, Spalding EP. Interacting glutamate receptor-like proteins in Phloem regulate lateral root initiation in Arabidopsis. THE PLANT CELL 2013; 25:1304-13. [PMID: 23590882 PMCID: PMC3663269 DOI: 10.1105/tpc.113.110668] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 03/29/2013] [Accepted: 04/04/2013] [Indexed: 05/18/2023]
Abstract
Molecular, genetic, and electrophysiological evidence indicates that at least one of the plant Glu receptor-like molecules, GLR3.4, functions as an amino acid-gated Ca²⁺channel at the plasma membrane. The aspect of plant physiology, growth, or development to which GLR3.4 contributes is an open question. Protein localization studies performed here provide important information. In roots, GLR3.4 and the related GLR3.2 protein were present primarily in the phloem, especially in the vicinity of the sieve plates. GLR3.3 was expressed in most cells of the growing primary root but was not enriched in the phloem, including the sieve plate area. GLR3.2 and GLR3.4 physically interacted with each other better than with themselves as evidenced by a biophotonic assay performed in human embryonic kidney cells and Nicotiana benthamiana leaf cells. GLR3.3 interacted poorly with itself or the other two GLRs. Mutations in GLR3.2, GLR3.4, or GLR3.2 and GLR3.4 caused the same and equally severe phenotype, namely, a large overproduction and aberrant placement of lateral root primordia. Loss of GLR3.3 did not affect lateral root primordia. These results support the hypothesis that apoplastic amino acids acting through heteromeric GLR3.2/GLR3.4 channels affect lateral root development via Ca²⁺ signaling in the phloem.
Collapse
Affiliation(s)
- Eric D Vincill
- Department of Botany, University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | | | |
Collapse
|
137
|
Tazuke A, Asayama M. Expression of CsSEF1 gene encoding putative CCCH zinc finger protein is induced by defoliation and prolonged darkness in cucumber fruit. PLANTA 2013; 237:681-691. [PMID: 23096488 DOI: 10.1007/s00425-012-1787-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 10/12/2012] [Indexed: 06/01/2023]
Abstract
To find a marker gene for photoassimilate limitation in cucumber fruit, genes induced in young fruit by total defoliation were cloned using the subtraction method. Almost every clone matched perfectly to a member of cucumber unigene ver. 3 of the Cucurbit Genomics Database. From the clones obtained, six genes were selected and the effect of defoliation on their expression was analyzed. In particular, expression of a gene that is highly homologous to the cucumber gene CsSEF1 (CAI30889) encoding putative CCCH zinc finger protein, which is reported to be induced at somatic embryogenesis in suspension culture, was enhanced by the treatment by about 50 times. The sequencing of the full-length cDNA and BLAST search in the Cucurbit Genomics Database indicated that our cloned gene is identical to CsSEF1. In control fruit, the expression of CsSEF1 did not change markedly in terms of development. By contrast, the expression of CsSEF1 was enhanced by prolonged darkness at the transcript level. This increase in the expression of CsSEF1 was temporally correlated with the decline in the fruit respiration rate. In mature leaves under prolonged darkness, enhanced expression was observed in the asparagine synthetase gene, but not in CsSEF1. These results suggest that the asparagine synthetase gene can be a good marker for sugar starvation and that CsSEF1 might be involved in the signal transduction pathway from photoassimilate limitation to growth cessation in cucumber fruit.
Collapse
Affiliation(s)
- Akio Tazuke
- College of Agriculture, Ibaraki University, 3-21-1 Chuo, Ami, Ibaraki, 300-0393, Japan.
| | | |
Collapse
|
138
|
Zhang D, Ren L, Yue JH, Wang L, Zhuo LH, Shen XH. A comprehensive analysis of flowering transition in Agapanthus praecox ssp. orientalis (Leighton) Leighton by using transcriptomic and proteomic techniques. J Proteomics 2013; 80:1-25. [DOI: 10.1016/j.jprot.2012.12.028] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Revised: 11/20/2012] [Accepted: 12/15/2012] [Indexed: 10/27/2022]
|
139
|
Systemic Photooxidative Stress Signalling. LONG-DISTANCE SYSTEMIC SIGNALING AND COMMUNICATION IN PLANTS 2013. [DOI: 10.1007/978-3-642-36470-9_13] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
140
|
Slewinski TL, Baker RF, Stubert A, Braun DM. Tie-dyed2 encodes a callose synthase that functions in vein development and affects symplastic trafficking within the phloem of maize leaves. PLANT PHYSIOLOGY 2012; 160:1540-50. [PMID: 22932757 PMCID: PMC3490577 DOI: 10.1104/pp.112.202473] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 08/28/2012] [Indexed: 05/18/2023]
Abstract
The tie-dyed2 (tdy2) mutant of maize (Zea mays) displays variegated green and yellow leaves. Intriguingly, the yellow leaf tissues hyperaccumulate starch and sucrose, the soluble sugar transported long distance through the phloem of veins. To determine the molecular basis for Tdy2 function, we cloned the gene and found that Tdy2 encodes a callose synthase. RNA in situ hybridizations revealed that in developing leaves, Tdy2 was most highly expressed in the vascular tissue. Comparative expression analysis with the vascular marker maize PINFORMED1a-yellow fluorescent protein confirmed that Tdy2 was expressed in developing vein tissues. To ascertain whether the defect in tdy2 leaves affected the movement of sucrose into the phloem or its long-distance transport, we performed radiolabeled and fluorescent dye tracer assays. The results showed that tdy2 yellow leaf regions were defective in phloem export but competent in long-distance transport. Furthermore, transmission electron microscopy of tdy2 yellow leaf regions showed incomplete vascular differentiation and implicated a defect in cell-to-cell solute movement between phloem companion cells and sieve elements. The disruption of sucrose movement in the phloem in tdy2 mutants provides evidence that the Tdy2 callose synthase functions in vascular maturation and that the vascular defects result in impaired symplastic trafficking into the phloem translocation stream.
Collapse
|
141
|
Doidy J, van Tuinen D, Lamotte O, Corneillat M, Alcaraz G, Wipf D. The Medicago truncatula sucrose transporter family: characterization and implication of key members in carbon partitioning towards arbuscular mycorrhizal fungi. MOLECULAR PLANT 2012; 5:1346-58. [PMID: 22930732 DOI: 10.1093/mp/sss079] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We identified de novo sucrose transporter (SUT) genes involved in long-distance transport of sucrose from photosynthetic source leaves towards sink organs in the model leguminous species Medicago truncatula. The identification and functional analysis of sugar transporters provide key information on mechanisms that underlie carbon partitioning in plant-microorganism interactions. In that way, full-length sequences of the M. truncatula SUT (MtSUT) family were retrieved and biochemical characterization of MtSUT members was performed by heterologous expression in yeast. The MtSUT family now comprises six genes which distribute among Dicotyledonous clades. MtSUT1-1 and MtSUT4-1 are key members in regard to their expression profiles in source leaves and sink roots and were characterized as functional H(+)/sucrose transporters. Physiological and molecular responses to phosphorus supply and inoculation by the arbuscular mycorrhizal fungus (AMF) Glomus intraradices was studied by gene expression and sugar quantification analyses. Sucrose represents the main sugar transport form in M. truncatula and the expression profiles of MtSUT1-1, MtSUT2, and MtSUT4-1 highlight a fine-tuning regulation for beneficial sugar fluxes towards the fungal symbiont. Taken together, these results suggest distinct functions for proteins from the SUT1, SUT2, and SUT4 clades in plant and in biotrophic interactions.
Collapse
Affiliation(s)
- Joan Doidy
- UMR INRA 1347, Agrosup, Université de Bourgogne, Agroécologie, Pôle Interactions Plantes Microorganismes ERL CNRS 6300, BP 86510, 21065 Dijon Cedex, France
| | | | | | | | | | | |
Collapse
|
142
|
Urano D, Phan N, Jones JC, Yang J, Huang J, Grigston J, Taylor JP, Jones AM. Endocytosis of the seven-transmembrane RGS1 protein activates G-protein-coupled signalling in Arabidopsis. Nat Cell Biol 2012; 14:1079-88. [PMID: 22940907 PMCID: PMC3463750 DOI: 10.1038/ncb2568] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 07/27/2012] [Indexed: 12/11/2022]
Abstract
Signal transduction typically begins by ligand-dependent activation of a concomitant partner that is otherwise in its resting state. However, in cases where signal activation is constitutive by default, the mechanism of regulation is unknown. The Arabidopsis thaliana heterotrimeric Gα protein self-activates without accessory proteins, and is kept in its resting state by the negative regulator, AtRGS1 (regulator of G-protein signalling 1), which is the prototype of a seven-transmembrane receptor fused with an RGS domain. Endocytosis of AtRGS1 by ligand-dependent endocytosis physically uncouples the GTPase-accelerating activity of AtRGS1 from the Gα protein, permitting sustained activation. Phosphorylation of AtRGS1 by AtWNK8 kinase causes AtRGS1 endocytosis, required for both G-protein-mediated sugar signalling and cell proliferation. In animals, receptor endocytosis results in signal desensitization, whereas in plants, endocytosis results in signal activation. These findings reveal how different organisms rearrange a regulatory system to result in opposite outcomes using similar phosphorylation-dependent endocytosis mechanisms.
Collapse
Affiliation(s)
- Daisuke Urano
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | | | | | | | | | | | | | | |
Collapse
|
143
|
Li Y, Li LL, Fan RC, Peng CC, Sun HL, Zhu SY, Wang XF, Zhang LY, Zhang DP. Arabidopsis sucrose transporter SUT4 interacts with cytochrome b5-2 to regulate seed germination in response to sucrose and glucose. MOLECULAR PLANT 2012; 5:1029-41. [PMID: 22311778 DOI: 10.1093/mp/sss001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
It remains unknown whether a sucrose transporter mediates sugar signaling. Here, we report that the Arabidopsis (Arabidopsis thaliana) sucrose transporter SUT4 interacts with five members of the Arabidopsis cytochrome b5 (Cyb5) family, and sucrose represses the interaction between SUT4 and a Cyb5 member Cyb5-2/A. We observed that down-regulation of SUT4 and three cytochrome b5 members (Cyb5-2, Cyb5-4, and Cyb5-6) confers the sucrose- and glucose-insensitive phenotypes in the sucrose/glucose-induced inhibition of seed germination. The sut4 cyb5-2 double mutant displays slightly stronger sucrose/glucose-insensitive phenotypes than either the sut4 or cyb5-2 single mutant. We showed that the SUT4/Cyb5-2-mediated signaling in the sucrose/glucose-induced inhibition of seed germination does not require ABA or the currently known ABI2/ABI4/ABI5-mediated signaling pathway(s). These data provide evidence that the sucrose transporter SUT4 interacts with Cyb5 to positively mediate sucrose and glucose signaling in the sucrose/glucose-induced inhibition of seed germination.
Collapse
Affiliation(s)
- Yan Li
- College of Biological Sciences, China Agricultural University, Beijing 100094, China
| | | | | | | | | | | | | | | | | |
Collapse
|
144
|
Ferrieri AP, Appel H, Ferrieri RA, Schultz JC. Novel application of 2-[(18)F]fluoro-2-deoxy-D-glucose to study plant defenses. Nucl Med Biol 2012; 39:1152-60. [PMID: 22795788 DOI: 10.1016/j.nucmedbio.2012.06.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 04/30/2012] [Accepted: 06/02/2012] [Indexed: 10/28/2022]
Abstract
INTRODUCTION Since its first use in humans in 1976, 2-[¹⁸F]fluoro-2-deoxy-d-glucose (¹⁸FDG) continues to serve as a tracer to measure tissue glucose metabolism in medical imaging. Here we demonstrate a novel use for this tracer to study glycoside biosynthesis in plants as a measure of plant response to defense induction. METHODS Coupling autoradiography with radio high-performance liquid chromatography analysis of tissue extracts, we examined the combined effects of leaf wounding and treatment using the potent plant defense hormone, methyl jasmonate (MeJA), to measure tracer distribution and tracer use in secondary defense chemistry in Arabidopsis thaliana. We hypothesized that competing sinks like roots and reproductive tissues, as well as vascular architecture, would impact the induction of phenolic defenses of the plant that make use of glucose in glycoside formation by altering distribution and metabolic utilization of ¹⁸FDG. RESULTS Our studies showed that leaf orthostichy defined the major route of ¹⁸FDG transport in both vegetative and reproductive plants when a single petiole was cut as the entry point for tracer introduction. However, when nonorthostichous leaves were damaged and treated with MeJA, ¹⁸FDG was transported in its intact form to these leaves 3 h later, where it was incorporated into phenolic glycosides. CONCLUSIONS Our work demonstrates a new use for ¹⁸FDG in plant science with insights into carbohydrate allocation that contradict conclusions of previous studies showing transport of resources away from damaged sites.
Collapse
Affiliation(s)
- Abigail P Ferrieri
- Division of Plant Sciences, Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA.
| | | | | | | |
Collapse
|
145
|
Doidy J, Grace E, Kühn C, Simon-Plas F, Casieri L, Wipf D. Sugar transporters in plants and in their interactions with fungi. TRENDS IN PLANT SCIENCE 2012; 17:413-22. [PMID: 22513109 DOI: 10.1016/j.tplants.2012.03.009] [Citation(s) in RCA: 174] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 03/06/2012] [Accepted: 03/17/2012] [Indexed: 05/18/2023]
Abstract
Sucrose and monosaccharide transporters mediate long distance transport of sugar from source to sink organs and constitute key components for carbon partitioning at the whole plant level and in interactions with fungi. Even if numerous families of plant sugar transporters are defined; efflux capacities, subcellular localization and association to membrane rafts have only been recently reported. On the fungal side, the investigation of sugar transport mechanisms in mutualistic and pathogenic interactions is now emerging. Here, we review the essential role of sugar transporters for distribution of carbohydrates inside plant cells, as well as for plant-fungal interaction functioning. Altogether these data highlight the need for a better comprehension of the mechanisms underlying sugar exchanges between fungi and their host plants.
Collapse
Affiliation(s)
- Joan Doidy
- UMR INRA 1347, Agrosup, Université de Bourgogne, Agroécologie, Pôle Interactions Plantes Microorganismes ERL CNRS 6300, BP 86510, 21065 Dijon Cedex, France
| | | | | | | | | | | |
Collapse
|
146
|
Wu HX, Yang W, Zhang ZX, Huang T, Yao GK, Xu HH. Uptake and phloem transport of glucose-fipronil conjugate in Ricinus communis involve a carrier-mediated mechanism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:6088-94. [PMID: 22587652 DOI: 10.1021/jf300546t] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Some compounds containing glucose are absorbed via the monosaccharide transporters of the plasma membrane. A glucose-fipronil conjugate, N-[3-cyano-1-[2,6-dichloro-4-(trifluoromethyl)phenyl]-4-[(trifluoromethyl)sulfinyl]-1H-pyrazol-5-yl]-1-(β-d-glucopyranosyl)-1H-1,2,3-triazole-4-methanamine (GTF), has been synthesized in our previous work. GTF exhibits moderate phloem mobility in Ricinus communis. In the current paper, we demonstrate that the uptake of GTF by Ricinus seedling cotyledon discs is partly mediated by an active carrier system (K(m)1 = 0.17 mM; V(max)1 = 2.2 nmol cm(-2) h(-1)). Four compounds [d-glucose, sucrose, phloridzin, and carbonyl cyanide m-chlorophenylhydrazone (CCCP)] were examined for their effect on GTF uptake. Phloridzin as well as CCCP markedly inhibit GTF uptake, and d-glucose weakly competes with it. The phloem transport of GTF in Ricinus seedlings is found to involve an active carrier-mediated mechanism that effectively contributes to the GTF phloem loading. The results prove that adding a glucose core is a reasonable and feasible approach to confer phloem mobility to fipronil by utilizing plant monosaccharide transporters.
Collapse
Affiliation(s)
- Han-Xiang Wu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Ministry of Education, South China Agricultural University, Guangzhou, Guangdong, China
| | | | | | | | | | | |
Collapse
|
147
|
Eom JS, Choi SB, Ward JM, Jeon JS. The mechanism of phloem loading in rice (Oryza sativa). Mol Cells 2012; 33:431-8. [PMID: 22453778 PMCID: PMC3887736 DOI: 10.1007/s10059-012-0071-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 03/09/2012] [Indexed: 01/03/2023] Open
Abstract
Carbohydrates, mainly sucrose, that are synthesized in source organs are transported to sink organs to support growth and development. Phloem loading of sucrose is a crucial step that drives long-distance transport by elevating hydrostatic pressure in the phloem. Three phloem loading strategies have been identified, two active mechanisms, apoplastic loading via sucrose transporters and symplastic polymer trapping, and one passive mechanism. The first two active loading mechanisms require metabolic energy, carbohydrate is loaded into the phloem against a concentration gradient. The passive process, diffusion, involves equilibration of sucrose and other metabolites between cells through plasmodesmata. Many higher plant species including Arabidopsis utilize the active loading mechanisms to increase carbohydrate in the phloem to higher concentrations than that in mesophyll cells. In contrast, recent data revealed that a large number of plants, especially woody species, load sucrose passively by maintaining a high concentration in mesophyll cells. However, it still remains to be determined how the worldwide important cereal crop, rice, loads sucrose into the phloem in source organs. Based on the literature and our results, we propose a potential strategy of phloem loading in rice. Elucidation of the phloem loading mechanism should improve our understanding of rice development and facilitate its manipulation towards the increase of crop productivity.
Collapse
Affiliation(s)
- Joon-Seob Eom
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701,
Korea
| | | | | | - Jong-Seong Jeon
- Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701,
Korea
| |
Collapse
|
148
|
Ruan J, Ma L, Yang Y. Magnesium nutrition on accumulation and transport of amino acids in tea plants. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2012; 92:1375-1383. [PMID: 22083631 DOI: 10.1002/jsfa.4709] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2011] [Revised: 08/31/2011] [Accepted: 09/14/2011] [Indexed: 05/27/2023]
Abstract
BACKGROUND Free amino acids in young tea shoots are important chemical constituents, remarkably influencing the quality of green teas. Nutrient solution, soil pot and field experiments were conducted to investigate the effect of magnesium nutritional status on accumulation and transport of free amino acids in tea plants (Camellia sinensis (L.) O. Kuntze). RESULTS A sufficient supply of Mg in nutrient solution increased biomass production and concentrations of free amino acids, notably theanine in young shoots and roots, without affecting total N in the leaves, absorption rates of inorganic N and glutamine synthetase activity. Amino acids in xylem saps and phloem exudates or total sugars in phloem exudates of tea plants from pot and field experiments showed their highest levels in bud breaking and shoot extension in early spring (March and early April). Application of Mg increased the amounts of amino acids and total sugars in the xylem saps and phloem exudates. CONCLUSION Adequate supply of Mg nutrient promoted the synthesis of theanine in roots and its accumulation in the young shoots of tea plants. Magnesium nutritional status was an important factor influencing the mobility of amino acids and sugars via xylem and phloem especially when N and C reserves remobilized to support spring growth of young shoots.
Collapse
Affiliation(s)
- Jianyun Ruan
- Tea Research Institute of Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang 310008, China.
| | | | | |
Collapse
|
149
|
Eveland AL, Jackson DP. Sugars, signalling, and plant development. JOURNAL OF EXPERIMENTAL BOTANY 2012; 63:3367-77. [PMID: 22140246 DOI: 10.1093/jxb/err379] [Citation(s) in RCA: 268] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Like all organisms, plants require energy for growth. They achieve this by absorbing light and fixing it into a usable, chemical form via photosynthesis. The resulting carbohydrate (sugar) energy is then utilized as substrates for growth, or stored as reserves. It is therefore not surprising that modulation of carbohydrate metabolism can have profound effects on plant growth, particularly cell division and expansion. However, recent studies on mutants such as stimpy or ramosa3 have also suggested that sugars can act as signalling molecules that control distinct aspects of plant development. This review will focus on these more specific roles of sugars in development, and will concentrate on two major areas: (i) cross-talk between sugar and hormonal signalling; and (ii) potential direct developmental effects of sugars. In the latter, developmental mutant phenotypes that are modulated by sugars as well as a putative role for trehalose-6-phosphate in inflorescence development are discussed. Because plant growth and development are plastic, and are greatly affected by environmental and nutritional conditions, the distinction between purely metabolic and specific developmental effects is somewhat blurred, but the focus will be on clear examples where sugar-related processes or molecules have been linked to known developmental mechanisms.
Collapse
Affiliation(s)
- Andrea L Eveland
- Cold Spring Harbor Laboratory, 1 Bungtown Rd, Cold Spring Harbor, NY 11724, USA
| | | |
Collapse
|
150
|
Induced Immunity Against Belowground Insect Herbivores- Activation of Defenses in the Absence of a Jasmonate Burst. J Chem Ecol 2012; 38:629-40. [DOI: 10.1007/s10886-012-0107-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 03/08/2012] [Accepted: 03/20/2012] [Indexed: 12/21/2022]
|