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Olavarria K, Becker MV, Sousa DZ, van Loosdrecht MC, Wahl SA. Design and thermodynamic analysis of a pathway enabling anaerobic production of poly-3-hydroxybutyrate in Escherichia coli. Synth Syst Biotechnol 2023; 8:629-639. [PMID: 37823039 PMCID: PMC10562921 DOI: 10.1016/j.synbio.2023.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 09/14/2023] [Accepted: 09/19/2023] [Indexed: 10/13/2023] Open
Abstract
Utilizing anaerobic metabolisms for the production of biotechnologically relevant products presents potential advantages, such as increased yields and reduced energy dissipation. However, lower energy dissipation may indicate that certain reactions are operating closer to their thermodynamic equilibrium. While stoichiometric analyses and genetic modifications are frequently employed in metabolic engineering, the use of thermodynamic tools to evaluate the feasibility of planned interventions is less documented. In this study, we propose a novel metabolic engineering strategy to achieve an efficient anaerobic production of poly-(R)-3-hydroxybutyrate (PHB) in the model organism Escherichia coli. Our approach involves re-routing of two-thirds of the glycolytic flux through non-oxidative glycolysis and coupling PHB synthesis with NADH re-oxidation. We complemented our stoichiometric analysis with various thermodynamic approaches to assess the feasibility and the bottlenecks in the proposed engineered pathway. According to our calculations, the main thermodynamic bottleneck are the reactions catalyzed by the acetoacetyl-CoA β-ketothiolase (EC 2.3.1.9) and the acetoacetyl-CoA reductase (EC 1.1.1.36). Furthermore, we calculated thermodynamically consistent sets of kinetic parameters to determine the enzyme amounts required for sustaining the conversion fluxes. In the case of the engineered conversion route, the protein pool necessary to sustain the desired fluxes could account for 20% of the whole cell dry weight.
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Affiliation(s)
- Karel Olavarria
- Laboratory of Microbiology, Wageningen University and Research, Stippenenweg 4, 6708 WE, Wageningen, The Netherlands
- Centre for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Marco V. Becker
- Department of Biotechnology, Applied Sciences Faculty, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Diana Z. Sousa
- Laboratory of Microbiology, Wageningen University and Research, Stippenenweg 4, 6708 WE, Wageningen, The Netherlands
- Centre for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Princetonlaan 6, 3584 CB, Utrecht, The Netherlands
| | - Mark C.M. van Loosdrecht
- Department of Biotechnology, Applied Sciences Faculty, Delft University of Technology, van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - S. Aljoscha Wahl
- Lehrstuhl für Bioverfahrenstechnik, Friedrich-Alexander-Universität, Paul-Gordan-Strasse 3, 91052, Erlangen, Germany
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2
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Morin A, Porcheron B, Kodjovi GC, Moumen B, Vriet C, Maurousset L, Lemoine R, Pourtau N, Doidy J. Genome-wide transcriptional responses to water deficit during seed development in Pisum sativum, focusing on sugar transport and metabolism. PHYSIOLOGIA PLANTARUM 2023; 175:e14062. [PMID: 38148238 DOI: 10.1111/ppl.14062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 10/06/2023] [Accepted: 10/12/2023] [Indexed: 12/28/2023]
Abstract
Agriculture is particularly impacted by global changes, drought being a main limiting factor of crop production. Here, we focus on pea (Pisum sativum), a model legume cultivated for its seed nutritional value. A water deficit (WD) was applied during its early reproductive phase, harvesting plant organs at two key developmental stages, either at the embryonic or the seed-filling stages. We combined phenotypic, physiological and transcriptome analyses to better understand the adaptive response to drought. First, we showed that apical growth arrest is a major phenotypic indicator of water stress. Sugar content was also greatly impacted, especially leaf fructose and starch contents. Our RNA-seq analysis identified 2001 genes regulated by WD in leaf, 3684 genes in root and 2273 genes in embryonic seed, while only 80 genes were regulated during seed-filling. Hence, a large transcriptional reprogramming occurred in response to WD in seeds during early embryonic stage, but no longer during the later stage of nutritional filling. Biological processes involved in transcriptional regulation, carbon transport and metabolism were greatly regulated by WD in both source and sink organs, as illustrated by the expression of genes encoding transcription factors, sugar transporters and enzymes of the starch synthesis pathway. We then looked at the transcriptomic changes during seed development, highlighting a transition from monosaccharide utilization at the embryonic stage to sucrose transport feeding the starch synthesis pathway at the seed-filling stage. Altogether, our study presents an integrative picture of sugar transport and metabolism in response to drought and during seed development at a genome-wide level.
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Affiliation(s)
- Amélie Morin
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
- Team "Environment, Bioenergies, Microalgae and Plants", BiAM DRF, CEA Cadarache, France
| | - Benoit Porcheron
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Gatepe Cedoine Kodjovi
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Bouziane Moumen
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Cécile Vriet
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Laurence Maurousset
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Rémi Lemoine
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Nathalie Pourtau
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Joan Doidy
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
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Zhou B, Fang Y, Xiao X, Yang J, Qi J, Qi Q, Fan Y, Tang C. Trehalose 6-Phosphate/SnRK1 Signaling Participates in Harvesting-Stimulated Rubber Production in the Hevea Tree. PLANTS (BASEL, SWITZERLAND) 2022; 11:2879. [PMID: 36365332 PMCID: PMC9655858 DOI: 10.3390/plants11212879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Revised: 10/14/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Trehalose 6-phosphate (T6P), the intermediate of trehalose biosynthesis and a signaling molecule, affects crop yield via targeting sucrose allocation and utilization. As there have been no reports of T6P signaling affecting secondary metabolism in a crop plant, the rubber tree Hevea brasiliensis serves as an ideal model in this regard. Sucrose metabolism critically influences the productivity of natural rubber, a secondary metabolite of industrial importance. Here, we report on the characterization of the T6P synthase (TPS) gene family and the T6P/SNF1-related protein kinase1 (T6P/SnRK1) signaling components in Hevea laticifers under tapping (rubber harvesting), an agronomic manipulation that itself stimulates rubber production. A total of fourteen TPS genes were identified, among which a class II TPS gene, HbTPS5, seemed to have evolved with a function specialized in laticifers. T6P and trehalose increased when the trees were tapped, this being consistent with the observed enhanced activities of TPS and T6P phosphatase (TPP) and expression of an active TPS-encoding gene, HbTPS1. On the other hand, SnRK1 activities decreased, suggesting the inhibition of elevated T6P on SnRK1. Expression profiles of the SnRK1 marker genes coincided with elevated T6P and depressed SnRK1. Interestingly, HbTPS5 expression decreased significantly with the onset of tapping, suggesting a regulatory function in the T6P pathway associated with latex production in laticifers. In brief, transcriptional, enzymatic, and metabolic evidence supports the participation of T6P/SnRK1 signaling in rubber formation, thus providing a possible avenue to increasing the yield of a valuable secondary metabolite by targeting T6P in specific cells.
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Affiliation(s)
- Binhui Zhou
- College of Tropical Crops, Hainan University, Haikou 570228, China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Yongjun Fang
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Xiaohu Xiao
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Jianghua Yang
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Jiyan Qi
- College of Tropical Crops, Hainan University, Haikou 570228, China
- Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, Haikou 570228, China
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
| | - Qi Qi
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Yujie Fan
- College of Tropical Crops, Hainan University, Haikou 570228, China
- Rubber Research Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Chaorong Tang
- College of Tropical Crops, Hainan University, Haikou 570228, China
- Natural Rubber Cooperative Innovation Center of Hainan Province and Ministry of Education of PRC, Haikou 570228, China
- Sanya Nanfan Research Institute of Hainan University, Hainan Yazhou Bay Seed Laboratory, Sanya 572025, China
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Zhu Y, Li Z, Shen J, Wu K, Zhao P, Wu Z, Liu Z, Yang J, Liu H, Rensing C, Feng R. Toxicity of different forms of antimony to rice plants: Photosynthetic electron transfer, gas exchange, photosynthetic efficiency, and carbon assimilation combined with metabolome analysis. JOURNAL OF HAZARDOUS MATERIALS 2022; 437:129433. [PMID: 35897190 DOI: 10.1016/j.jhazmat.2022.129433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 06/08/2022] [Accepted: 06/18/2022] [Indexed: 06/15/2023]
Abstract
Antimony (Sb) is a toxic metalloid, and excess Sb causes damage to the plant photosynthetic system. However, the underlying mechanisms of Sb toxicity in the plant photosynthetic system are not clear. Hydroponic culture experiments were conducted to illustrate the toxicity differences of antimonite [Sb(III)] and antimonate [Sb(V)] to the photosynthetic system in a rice plant (Yangdao No. 6). The results showed that Sb(III) showed a higher toxicity than Sb(V), judging from (1) lower shoot and root biomass, leaf water moisture content, water use efficiency, stomatal conductance, net photosynthetic rate, and transpiration rate; (2) higher water vapor deficit, soluble sugar content, starch content, and oligosaccharide content (sucrose, stachyose, and 1-kestose). To further analyze the direction of the photosynthetic products, we conducted a metabonomic analysis. More glycosyls were allocated to the synthesis pathways of oligosaccharides (sucrose, stachyose, and 1-kestose), anthocyanins, salicylic acid, flavones, flavonols, and lignin under Sb stress to quench excess oxygen free radicals (ROS), strengthen the cell wall structure, rebalance the cell membrane, and/or regulate cell permeability. This study provides a complete mechanism to elucidate the toxicity differences of Sb(III) and Sb(V) by exploring their effects on photosynthesis, saccharide synthesis, and the subsequent flow directions of glycosyls.
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Affiliation(s)
- YanMing Zhu
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - ZengFei Li
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - Jun Shen
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - KongYuan Wu
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - PingPing Zhao
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - ZiHan Wu
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - ZiQing Liu
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - JiGang Yang
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - Hong Liu
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China.
| | - Christopher Rensing
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China
| | - RenWei Feng
- Institute of Environmental Microbiology, College of Resources and Environment, Fujian Agriculture & Forestry University, Fuzhou 350002, China.
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5
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Morin A, Maurousset L, Vriet C, Lemoine R, Doidy J, Pourtau N. Carbon fluxes and environmental interactions during legume development, with a specific focus on Pisum sativum. PHYSIOLOGIA PLANTARUM 2022; 174:e13729. [PMID: 35662039 PMCID: PMC9328368 DOI: 10.1111/ppl.13729] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 05/25/2022] [Accepted: 06/01/2022] [Indexed: 06/15/2023]
Abstract
Grain legumes are major food crops cultivated worldwide for their seeds with high nutritional content. To answer the growing concern about food safety and protein autonomy, legume cultivation must increase in the coming years. In parallel, current agricultural practices are facing environmental challenges, including global temperature increase and more frequent and severe episodes of drought stress. Crop yield directly relies on carbon allocation and is particularly affected by these global changes. We review the current knowledge on source-sink relationships and carbon resource allocation at all developmental stages, from germination to vegetative growth and seed production in grain legumes, focusing on pea (Pisum sativum). We also discuss how these source-sink relationships and carbon fluxes are influenced by biotic and abiotic factors. Major agronomic traits, including seed yield and quality, are particularly impacted by drought, temperatures, salinity, waterlogging, or pathogens and can be improved through the promotion of beneficial soil microorganisms or through optimized plant carbon resource allocation. Altogether, our review highlights the need for a better understanding of the cellular and molecular mechanisms regulating carbon fluxes from source leaves to sink organs, roots, and seeds. These advancements will further improve our understanding of yield stability and stress tolerance and contribute to the selection of climate-resilient crops.
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Affiliation(s)
- Amélie Morin
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions"PoitiersFrance
| | - Laurence Maurousset
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions"PoitiersFrance
| | - Cécile Vriet
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions"PoitiersFrance
| | - Rémi Lemoine
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions"PoitiersFrance
| | - Joan Doidy
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions"PoitiersFrance
| | - Nathalie Pourtau
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions"PoitiersFrance
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6
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Salvi P, Agarrwal R, Gandass N, Manna M, Kaur H, Deshmukh R. Sugar transporters and their molecular tradeoffs during abiotic stress responses in plants. PHYSIOLOGIA PLANTARUM 2022; 174:e13652. [PMID: 35174495 DOI: 10.1111/ppl.13652] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/25/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Sugars as photosynthates are well known as energy providers and as building blocks of various structural components of plant cells, tissues and organs. Additionally, as a part of various sugar signaling pathways, they interact with other cellular machinery and influence many important cellular decisions in plants. Sugar signaling is further reliant on the differential distribution of sugars throughout the plant system. The distribution of sugars from source to sink tissues or within organelles of plant cells is a highly regulated process facilitated by various sugar transporters located in plasma membranes and organelle membranes, respectively. Sugar distribution, as well as signaling, is impacted during unfavorable environments such as extreme temperatures, salt, nutrient scarcity, or drought. Here, we have discussed the mechanism of sugar transport via various types of sugar transporters as well as their differential response during environmental stress exposure. The functional involvement of sugar transporters in plant's abiotic stress tolerance is also discussed. Besides, we have also highlighted the challenges in engineering sugar transporter proteins as well as the undeciphered modules associated with sugar transporters in plants. Thus, this review provides a comprehensive discussion on the role and regulation of sugar transporters during abiotic stresses and enables us to target the candidate sugar transporter(s) for crop improvement to develop climate-resilient crops.
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Affiliation(s)
- Prafull Salvi
- Department of Agriculture Biotechnology, National Agri-Food Biotechnology Institute, Mohali, Punjab, India
| | | | - Nishu Gandass
- Department of Agriculture Biotechnology, National Agri-Food Biotechnology Institute, Mohali, Punjab, India
| | - Mrinalini Manna
- National Institute of Plant Genome Research, New Delhi, India
| | - Harmeet Kaur
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
| | - Rupesh Deshmukh
- Department of Agriculture Biotechnology, National Agri-Food Biotechnology Institute, Mohali, Punjab, India
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7
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Ko HY, Ho LH, Neuhaus HE, Guo WJ. Transporter SlSWEET15 unloads sucrose from phloem and seed coat for fruit and seed development in tomato. PLANT PHYSIOLOGY 2021; 187:2230-2245. [PMID: 34618023 PMCID: PMC8644451 DOI: 10.1093/plphys/kiab290] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 06/02/2021] [Indexed: 05/06/2023]
Abstract
Tomato (Solanum lycopersium), an important fruit crop worldwide, requires efficient sugar allocation for fruit development. However, molecular mechanisms for sugar import to fruits remain poorly understood. Expression of sugars will eventually be exported transporters (SWEETs) proteins is closely linked to high fructose/glucose ratios in tomato fruits and may be involved in sugar allocation. Here, we discovered that SlSWEET15 is highly expressed in developing fruits compared to vegetative organs. In situ hybridization and β-glucuronidase fusion analyses revealed SlSWEET15 proteins accumulate in vascular tissues and seed coats, major sites of sucrose unloading in fruits. Localizing SlSWEET15-green fluorescent protein to the plasma membrane supported its putative role in apoplasmic sucrose unloading. The sucrose transport activity of SlSWEET15 was confirmed by complementary growth assays in a yeast (Saccharomyces cerevisiae) mutant. Elimination of SlSWEET15 function by clustered regularly interspaced short palindromic repeats (CRISPRs)/CRISPR-associated protein gene editing significantly decreased average sizes and weights of fruits, with severe defects in seed filling and embryo development. Altogether, our studies suggest a role of SlSWEET15 in mediating sucrose efflux from the releasing phloem cells to the fruit apoplasm and subsequent import into storage parenchyma cells during fruit development. Furthermore, SlSWEET15-mediated sucrose efflux is likely required for sucrose unloading from the seed coat to the developing embryo.
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Affiliation(s)
- Han-Yu Ko
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan 7013, Taiwan
| | - Li-Hsuan Ho
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan 7013, Taiwan
- Department of Plant Physiology, University of Kaiserslautern, Kaiserslautern, Germany
| | - H Ekkehard Neuhaus
- Department of Plant Physiology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Woei-Jiun Guo
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan 7013, Taiwan
- Author for communication:
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Guo Y, Song H, Zhao Y, Qin X, Cao Y, Zhang L. Switch from symplasmic to aspoplasmic phloem unloading in Xanthoceras sorbifolia fruit and sucrose influx XsSWEET10 as a key candidate for Sugar transport. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2021; 313:111089. [PMID: 34763874 DOI: 10.1016/j.plantsci.2021.111089] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/30/2021] [Accepted: 10/10/2021] [Indexed: 06/13/2023]
Abstract
The process of phloem unloading and post-unloading transport of photoassimilate is critical to crop output. Xanthoceras sorbifolia is a woody oil species with great biomass energy prospects in China; however, underproduction of seeds seriously restricts its development. Here, our cytological studies by ultrastructural observation revealed that the sieve element-companion cell complex in carpellary bundle was symplasmically interconnected with surrounding parenchyma cells at the early and late fruit developmental stages, whereas it was symplasmically isolated at middle stage. Consistently, real-time imaging showed that fluorescent tracer 6(5)carboxyfluorescein was confined to phloem strands at middle stage but released into surrounding parenchymal cells at early and late stages. Enzymatic assay showed that sucrose synthase act as the key enzyme catalyzing the progress of Suc degradation post-unloading pathway whether in pericarp or in seed, while vacuolar acid invertase and neutral invertase play compensation roles in sucrose decomposition. Sugar transporter XsSWEET10 had a high expression profile in fruit, especially at middle stage. XsSWEET10 is a plasma membrane-localized protein and heterologous expression in SUC2-deficient yeast strain SUSY7/ura3 confirmed its ability to uptake sucrose. These findings approved the transition from symplasmic to apoplasmic phloem unloading in Xanthoceras sorbifolia fruit and XsSWEET10 as a key candidate in sugar transport.
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Affiliation(s)
- Yuxiao Guo
- Research & Development Center of Blueberry, Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, China
| | - Huifang Song
- Research & Development Center of Blueberry, Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, China
| | - Yangyang Zhao
- Research & Development Center of Blueberry, Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, China
| | - Xuejing Qin
- Research & Development Center of Blueberry, Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, China
| | - Yibo Cao
- Research & Development Center of Blueberry, Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, China
| | - Lingyun Zhang
- Research & Development Center of Blueberry, Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, The College of Forestry, Beijing Forestry University, Beijing, China.
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Li Y, Liu H, Yao X, Wang J, Feng S, Sun L, Ma S, Xu K, Chen LQ, Sui X. Hexose transporter CsSWEET7a in cucumber mediates phloem unloading in companion cells for fruit development. PLANT PHYSIOLOGY 2021; 186:640-654. [PMID: 33604597 PMCID: PMC8154047 DOI: 10.1093/plphys/kiab046] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 01/14/2021] [Indexed: 05/20/2023]
Abstract
In the fleshy fruit of cucumbers (Cucumis sativus L.), the phloem flow is unloaded via an apoplasmic pathway, which requires protein carriers to export sugars derived from stachyose and raffinose into the apoplasm. However, transporter(s) involved in this process remain unidentified. Here, we report that a hexose transporter, CsSWEET7a (Sugar Will Eventually be Exported Transporter 7a), was highly expressed in cucumber sink tissues and localized to the plasma membrane in companion cells of the phloem. Its expression level increased gradually during fruit development. Down-regulation of CsSWEET7a by RNA interference (RNAi) resulted in smaller fruit size along with reduced soluble sugar levels and reduced allocation of 14C-labelled carbon to sink tissues. CsSWEET7a overexpression lines showed an opposite phenotype. Interestingly, genes encoding alkaline α-galactosidase (AGA) and sucrose synthase (SUS) were also differentially regulated in CsSWEET7a transgenic lines. Immunohistochemical analysis demonstrated that CsAGA2 co-localized with CsSWEET7a in companion cells, indicating cooperation between AGA and CsSWEET7a in fruit phloem unloading. Our findings indicated that CsSWEET7a is involved in sugar phloem unloading in cucumber fruit by removing hexoses from companion cells to the apoplasmic space to stimulate the raffinose family of oligosaccharides (RFOs) metabolism so that additional sugars can be unloaded to promote fruit growth. This study also provides a possible avenue towards improving fruit production in cucumber.
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Affiliation(s)
- Yaxin Li
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
- Department of Plant Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Huan Liu
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Xuehui Yao
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Jiang Wang
- Department of Plant Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Sheng Feng
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Lulu Sun
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Si Ma
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Kang Xu
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
| | - Li-Qing Chen
- Department of Plant Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Xiaolei Sui
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China
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Hageman A, Van Volkenburgh E. Sink Strength Maintenance Underlies Drought Tolerance in Common Bean. PLANTS 2021; 10:plants10030489. [PMID: 33807580 PMCID: PMC8001466 DOI: 10.3390/plants10030489] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/02/2021] [Accepted: 03/02/2021] [Indexed: 11/20/2022]
Abstract
Drought is a major limiter of yield in common bean, decreasing food security for those who rely on it as an important source of protein. While drought can have large impacts on yield by reducing photosynthesis and therefore resources availability, source strength is not a reliable indicator of yield. One reason resource availability does not always translate to yield in common bean is because of a trait inherited from wild ancestors. Wild common bean halts growth and seed filling under drought and awaits better conditions to resume its developmental program. This trait has been carried into domesticated lines, where it can result in strong losses of yield in plants already producing pods and seeds, especially since many domesticated lines were bred to have a determinate growth habit. This limits the plants ability to produce another flush of flowers, even if the first set is aborted. However, some bred lines are able to maintain higher yields under drought through maintaining growth and seed filling rates even under water limitations, unlike their wild predecessors. We believe that maintenance of sink strength underlies this ability, since plants which fill seeds under drought maintain growth of sinks generally, and growth of sinks correlates strongly with yield. Sink strength is determined by a tissue’s ability to acquire resources, which in turn relies on resource uptake and metabolism in that tissue. Lines which achieve higher yields maintain higher resource uptake rates into seeds and overall higher partitioning efficiencies of total biomass to yield. Drought limits metabolism and resource uptake through the signaling molecule abscisic acid (ABA) and its downstream affects. Perhaps lines which maintain higher sink strength and therefore higher yields do so through decreased sensitivity to or production of ABA.
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Wang X, Fang J, Liu P, Liu J, Fang W, Fang Z, Xiao Y. Mucoromycotina Fungi Possess the Ability to Utilize Plant Sucrose as a Carbon Source: Evidence From Gongronella sp. w5. Front Microbiol 2021; 11:591697. [PMID: 33584561 PMCID: PMC7874188 DOI: 10.3389/fmicb.2020.591697] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 12/02/2020] [Indexed: 12/02/2022] Open
Abstract
Mucoromycotina is one of the earliest fungi to establish a mutualistic relationship with plants in the ancient land. However, the detailed information on their carbon supply from the host plants is largely unknown. In this research, a free-living Mucoromycotina called Gongronella sp. w5 (w5) was employed to explore its effect on Medicago truncatula growth and carbon source utilization from its host plant during the interaction process. W5 promoted M. truncatula growth and caused the sucrose accumulation in M. truncatula root tissue at 16 days post-inoculation (dpi). The transportation of photosynthetic product sucrose to the rhizosphere by M. truncatula root cells seemed accelerated by upregulating the SWEET gene. A predicted cytoplasmic invertase (GspInv) gene and a sucrose transporter (GspSUT1) homology gene in the w5 genome upregulated significantly at the transcriptional level during w5–M. truncatula interaction at 16 dpi, indicating the possibility of utilizing plant sucrose directly by w5 as the carbon source. Further investigation showed that the purified GspInv displayed an optimal pH of 5.0 and a specific activity of 3380 ± 26 U/mg toward sucrose. The heterologous expression of GspInv and GspSUT1 in Saccharomyces cerevisiae confirmed the function of GspInv as invertase and GspSUT1 as sugar transporter with high affinity to sucrose in vivo. Phylogenetic tree analysis showed that the ability of Mucoromycotina to utilize sucrose from its host plant underwent a process of “loss and gain.” These results demonstrated the capacity of Mucoromycotina to interact with extant land higher plants and may employ a novel strategy of directly up-taking and assimilating sucrose from the host plant during the interaction.
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Affiliation(s)
- Xiaojie Wang
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei, China.,Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, China
| | - Junnan Fang
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei, China.,Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, China
| | - Pu Liu
- College of Horticulture, Anhui Agricultural University, Hefei, China
| | - Juanjuan Liu
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei, China.,Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, China
| | - Wei Fang
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei, China.,Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, China
| | - Zemin Fang
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei, China.,Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, China
| | - Yazhong Xiao
- School of Life Sciences, Anhui University, Hefei, China.,Anhui Key Laboratory of Modern Biomanufacturing, Hefei, China.,Anhui Provincial Engineering Technology Research Center of Microorganisms and Biocatalysis, Hefei, China
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12
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Parreira JR, Cappuccio M, Balestrazzi A, Fevereiro P, Araújo SDS. MicroRNAs expression dynamics reveal post-transcriptional mechanisms regulating seed development in Phaseolus vulgaris L. HORTICULTURE RESEARCH 2021; 8:18. [PMID: 33436559 PMCID: PMC7804330 DOI: 10.1038/s41438-020-00448-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/24/2020] [Accepted: 11/27/2020] [Indexed: 05/04/2023]
Abstract
The knowledge on post-transcriptional regulation mechanisms implicated in seed development (SD) is still limited, particularly in one of the most consumed grain legumes, Phaseolus vulgaris L. We explore for the first time the miRNA expression dynamics in P. vulgaris developing seeds. Seventy-two known and 39 new miRNAs were found expressed in P. vulgaris developing seeds. Most of the miRNAs identified were more abundant at 10 and 40 days after anthesis, suggesting that late embryogenesis/early filling and desiccation were SD stages in which miRNA action is more pronounced. Degradome analysis and target prediction identified targets for 77 expressed miRNAs. While several known miRNAs were predicted to target HD-ZIP, ARF, SPL, and NF-Y transcription factors families, most of the predicted targets for new miRNAs encode for functional proteins. MiRNAs-targets expression profiles evidenced that these miRNAs could tune distinct seed developmental stages. MiRNAs more accumulated at early SD stages were implicated in regulating the end of embryogenesis, postponing the seed maturation program, storage compound synthesis and allocation. MiRNAs more accumulated at late SD stages could be implicated in seed quiescence, desiccation tolerance, and longevity with still uncovered roles in germination. The miRNAs herein described represent novel P. vulgaris resources with potential application in future biotechnological approaches to modulate the expression of genes implicated in legume seed traits with impact in horticultural production systems.
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Affiliation(s)
- José Ricardo Parreira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal
| | - Michela Cappuccio
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Ferrata 9, 27100, Pavia, Italy
| | - Alma Balestrazzi
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, via Ferrata 9, 27100, Pavia, Italy
| | - Pedro Fevereiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal
- InnovPlantProtect Collaborative Laboratory, Estrada de Gil Vaz, 7351-901, Elvas, Portugal
| | - Susana de Sousa Araújo
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, 2780-157, Oeiras, Portugal.
- Association BLC3-Technology and Innovation Campus, Centre Bio R&D Unit, Rua Nossa Senhora da Conceição 2, Lagares da Beira, 3405-155, Oliveira do Hospital, Portugal.
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13
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Energy coupling of membrane transport and efficiency of sucrose dissimilation in yeast. Metab Eng 2020; 65:243-254. [PMID: 33279674 DOI: 10.1016/j.ymben.2020.11.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 11/04/2020] [Accepted: 11/30/2020] [Indexed: 11/22/2022]
Abstract
Proton coupled transport of α-glucosides via Mal11 into Saccharomyces cerevisiae costs one ATP per imported molecule. Targeted mutation of all three acidic residues in the active site resulted in sugar uniport, but expression of these mutant transporters in yeast did not enable growth on sucrose. We then isolated six unique transporter variants of these mutants by directed evolution of yeast for growth on sucrose. In three variants, new acidic residues emerged near the active site that restored proton-coupled sucrose transport, whereas the other evolved transporters still catalysed sucrose uniport. The localization of mutations and transport properties of the mutants enabled us to propose a mechanistic model of proton-coupled sugar transport by Mal11. Cultivation of yeast strains expressing one of the sucrose uniporters in anaerobic, sucrose-limited chemostat cultures indicated an increase in the efficiency of sucrose dissimilation by 21% when additional changes in strain physiology were taken into account. We thus show that a combination of directed and evolutionary engineering results in more energy efficient sucrose transport, as a starting point to engineer yeast strains with increased yields for industrially relevant products.
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14
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Wang S, Liu S, Wang J, Yokosho K, Zhou B, Yu YC, Liu Z, Frommer WB, Ma JF, Chen LQ, Guan Y, Shou H, Tian Z. Simultaneous changes in seed size, oil content and protein content driven by selection of SWEET homologues during soybean domestication. Natl Sci Rev 2020; 7:1776-1786. [PMID: 34691511 PMCID: PMC8290959 DOI: 10.1093/nsr/nwaa110] [Citation(s) in RCA: 113] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 05/18/2020] [Accepted: 05/20/2020] [Indexed: 02/02/2023] Open
Abstract
Soybean accounts for more than half of the global production of oilseed and more than a quarter of the protein used globally for human food and animal feed. Soybean domestication involved parallel increases in seed size and oil content, and a concomitant decrease in protein content. However, science has not yet discovered whether these effects were due to selective pressure on a single gene or multiple genes. Here, re-sequencing data from >800 genotypes revealed a strong selection during soybean domestication on GmSWEET10a. The selection of GmSWEET10a conferred simultaneous increases in soybean-seed size and oil content as well as a reduction in the protein content. The result was validated using both near-isogenic lines carrying substitution of haplotype chromosomal segments and transgenic soybeans. Moreover, GmSWEET10b was found to be functionally redundant with its homologue GmSWEET10a and to be undergoing selection in current breeding, leading the the elite allele GmSWEET10b, a potential target for present-day soybean breeding. Both GmSWEET10a and GmSWEET10b were shown to transport sucrose and hexose, contributing to sugar allocation from seed coat to embryo, which consequently determines oil and protein contents and seed size in soybean. We conclude that past selection of optimal GmSWEET10a alleles drove the initial domestication of multiple soybean-seed traits and that targeted selection of the elite allele GmSWEET10b may further improve the yield and seed quality of modern soybean cultivars.
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Affiliation(s)
- Shoudong Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life sciences, Zhejiang University, Hangzhou 310058, China
| | - Shulin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Wang
- College of Resources and Environment, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Kengo Yokosho
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Bin Zhou
- Institute of Crop Science, Anhui Academy of Agricultural Sciences, Hefei 230031, China
| | - Ya-Chi Yu
- Department of Plant Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Zhi Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wolf B Frommer
- Institute for Molecular Physiology and Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Jian Feng Ma
- Institute of Plant Science and Resources, Okayama University, Kurashiki 710-0046, Japan
| | - Li-Qing Chen
- Department of Plant Biology, School of Integrative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yuefeng Guan
- FAFU-UCR Joint Center for Horticultural Plant Biology and Metabolomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Huixia Shou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life sciences, Zhejiang University, Hangzhou 310058, China
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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15
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Santiago JP, Ward JM, Sharkey TD. Phaseolus vulgaris SUT1.1 is a high affinity sucrose-proton co-transporter. PLANT DIRECT 2020; 4:e00260. [PMID: 32885136 PMCID: PMC7453976 DOI: 10.1002/pld3.260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/31/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Plant sucrose transporters are required for phloem loading, and therefore are essential for plant growth and development. In common beans (Phaseolus vulgaris) there are only two sucrose transporters functionally characterized. Through a previous RNA-seq study, we identified a putative sucrose transporter in common bean, which we hypothesize to function in import of sucrose into plant cells. In silico analysis revealed that PvSUT1.1 is a putative sucrose-proton co-transporter distinct from other characterized sucrose transporters in common bean indicating that this is a previously undescribed transporter protein in beans. Further analysis revealed that PvSUT1.1 shares high protein sequence homology to the phloem loader Arabidopsis SUC2; both have 12 transmembrane domains, a typical characteristic of plant sucrose transporters. Heterologous expression in yeast further showed PvSUT1.1 to be functional and it imported sucrose into yeast cells with a Km of 0.7 mM sucrose. Import of sucrose through PvSUT1.1 is also pH-dependent with highest uptake at pH 4.0, and activity is lost in the presence of the uncoupler carbonyl cyanide 3-chlorophenylhydrazone. Consistent with identification of PvSUT1.1 as a Type I transporter, PvSUT1.1 also transports esculin. Finally, PvSUT1.1 showed expression in multiple tissues and the protein was localized to the plasma membrane. The results show that PvSUT1.1 is a sucrose transporter that is probably involved in the uptake of sucrose into source and sink cells. The potential role of PvSUT1.1 in leaf phloem loading of sucrose in common beans and its importance in heat tolerance of reproductive tissues are further discussed.
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Affiliation(s)
- James P. Santiago
- Plant Resilience InstituteMichigan State UniversityEast LansingMIUSA
- Michigan State University‐Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMIUSA
| | - John M. Ward
- Department of Plant and Microbial BiologyUniversity of MinnesotaSaint PaulMNUSA
| | - Thomas D. Sharkey
- Plant Resilience InstituteMichigan State UniversityEast LansingMIUSA
- Michigan State University‐Department of Energy Plant Research LaboratoryMichigan State UniversityEast LansingMIUSA
- Department of Biochemistry and Molecular BiologyMichigan State UniversityEast LansingMIUSA
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16
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Doidy J, Vidal U, Lemoine R. Sugar transporters in Fabaceae, featuring SUT MST and SWEET families of the model plant Medicago truncatula and the agricultural crop Pisum sativum. PLoS One 2019; 14:e0223173. [PMID: 31568488 PMCID: PMC6768477 DOI: 10.1371/journal.pone.0223173] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 09/16/2019] [Indexed: 01/22/2023] Open
Abstract
Sugar transporters play a crucial role for plant productivity, as they coordinate sugar fluxes from source leaf towards sink organs (seed, fruit, root) and regulate the supply of carbon resources towards the microorganisms of the rhizosphere (bacteria and fungi). Thus, sugar fluxes mediated by SUT (sucrose transporters), MST (monosaccharide transporters) and SWEET (sugar will eventually be exported transporters) families are key determinants of crop yield and shape the microbial communities living in the soil. In this work, we performed a systematic search for sugar transporters in Fabaceae genomes, focusing on model and agronomical plants. Here, we update the inventory of sugar transporter families mining the latest version of the Medicago truncatula genome and identify for the first time SUT MST and SWEET families of the agricultural crop Pisum sativum. The sugar transporter families of these Fabaceae species comprise respectively 7 MtSUT 7 PsSUT, 72 MtMST 59 PsMST and 26 MtSWEET 22 PsSWEET. Our comprehensive phylogenetic analysis sets a milestone for the scientific community, as we propose a new and simple nomenclature to correctly name SUT MST and SWEET families. Then, we searched for transcriptomic data available for our gene repertoire. We show that several clusters of homologous genes are co-expressed in different organs, suggesting that orthologous sugar transporters may have a conserved function. We focused our analysis on gene candidates that may be involved in remobilizing resources during flowering, grain filling and in allocating carbon towards roots colonized by arbuscular mycorrhizal fungi and Rhizobia. Our findings open new perspectives for agroecological applications in legume crops, as for instance improving the yield and quality of seed productions and promoting the use of symbiotic microorganisms.
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Affiliation(s)
- Joan Doidy
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Ugo Vidal
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
| | - Rémi Lemoine
- Université de Poitiers, UMR CNRS 7267, EBI "Ecologie et Biologie des Interactions", Poitiers, France
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17
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Marques WL, van der Woude LN, Luttik MAH, van den Broek M, Nijenhuis JM, Pronk JT, van Maris AJA, Mans R, Gombert AK. Laboratory evolution and physiological analysis of Saccharomyces cerevisiae strains dependent on sucrose uptake via the Phaseolus vulgaris Suf1 transporter. Yeast 2018; 35:639-652. [PMID: 30221387 DOI: 10.1002/yea.3357] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/17/2018] [Accepted: 09/10/2018] [Indexed: 01/03/2023] Open
Abstract
Knowledge on the genetic factors important for the efficient expression of plant transporters in yeast is still very limited. Phaseolus vulgaris sucrose facilitator 1 (PvSuf1), a presumable uniporter, was an essential component in a previously published strategy aimed at increasing ATP yield in Saccharomyces cerevisiae. However, attempts to construct yeast strains in which sucrose metabolism was dependent on PvSUF1 led to slow sucrose uptake. Here, PvSUF1-dependent S. cerevisiae strains were evolved for faster growth. Of five independently evolved strains, two showed an approximately twofold higher anaerobic growth rate on sucrose than the parental strain (μ = 0.19 h-1 and μ = 0.08 h-1 , respectively). All five mutants displayed sucrose-induced proton uptake (13-50 μmol H+ (g biomass)-1 min-1 ). Their ATP yield from sucrose dissimilation, as estimated from biomass yields in anaerobic chemostat cultures, was the same as that of a congenic strain expressing the native sucrose symporter Mal11p. Four out of six observed amino acid substitutions encoded by evolved PvSUF1 alleles removed or introduced a cysteine residue and may be involved in transporter folding and/or oligomerization. Expression of one of the evolved PvSUF1 alleles (PvSUF1I209F C265F G326C ) in an unevolved strain enabled it to grow on sucrose at the same rate (0.19 h-1 ) as the corresponding evolved strain. This study shows how laboratory evolution may improve sucrose uptake in yeast via heterologous plant transporters, highlights the importance of cysteine residues for their efficient expression, and warrants reinvestigation of PvSuf1's transport mechanism.
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Affiliation(s)
- Wesley Leoricy Marques
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.,School of Food Engineering, University of Campinas, Campinas, Brazil
| | | | - Marijke A H Luttik
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Marcel van den Broek
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | | | - Robert Mans
- Department of Biotechnology, Delft University of Technology, Delft, The Netherlands
| | - Andreas K Gombert
- School of Food Engineering, University of Campinas, Campinas, Brazil
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18
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Kashiide T, Kikuta S, Yamaguchi M, Irie T, Kouguchi H, Yagi K, Matsumoto J. Molecular and functional characterization of glucose transporter genes of the fox tapeworm Echinococcus multilocularis. Mol Biochem Parasitol 2018; 225:7-14. [PMID: 30130566 DOI: 10.1016/j.molbiopara.2018.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/15/2018] [Accepted: 08/15/2018] [Indexed: 11/16/2022]
Abstract
Alveolar echinococcosis (AE) is a zoonotic parasitosis caused by larvae of the fox tapeworm, Echinococcus multilocularis. E. multilocularis is distributed widely in the Northern hemisphere, causing serious health problems in various animals and humans. E. multilocularis, like other cestodes, lacks a digestive tract and absorbs essential nutrients, including glucose, across the syncytial tegument on its external surface. Therefore, it is hypothesized that E. multilocularis uses glucose transporters on its surface similar to a closely-related species, Taenia solium. Based on this hypothesis, we cloned and characterized glucose transporter homologues from E. multilocularis. As a result, we obtained full-length sequences of 2 putative glucose transporter genes (EmGLUT1 and EmGLUT2) from E. multilocularis. In silico analysis predicted that these were classified in the solute carrier family 2 group. Functional expression analysis using Xenopus oocytes demonstrated clear uptake of 2-deoxy-D-glucose (2-DG) by EmGLUT1, but not by EmGLUT2 in this experimental system. EmGLUT1 was shown to have relatively high glucose transport activity. Further analyses using the Xenopus oocyte system revealed that 2-DG uptake of EmGLUT1 did not depend on the presence or concentration of Na+ nor H+, respectively. Immunoblot analyses using cultured metacestode, ex vivo protoscolex, and adult worm samples demonstrated that both EmGLUTs were stably expressed during each developmental stage of the parasite. Based on the above-mentioned findings, we conclude that EmGLUT1 is a simple facilitated glucose transporter and possibly plays an important role in glucose uptake by E. multilocularis throughout its life cycle.
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Affiliation(s)
- Takuya Kashiide
- Laboratory of Medical Zoology, Nihon University College of Bioresource Sciences, Fujisawa, Kanagawa 252-0880, Japan
| | - Shingo Kikuta
- Graduate School of Bio-Applications & Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan; College of Agriculture, Ibaraki University, Ami, Ibaraki 300-0393, Japan
| | - Misaki Yamaguchi
- Laboratory of Medical Zoology, Nihon University College of Bioresource Sciences, Fujisawa, Kanagawa 252-0880, Japan
| | - Takao Irie
- Department of Infectious Disease, Hokkaido Institute of Public Health, Sapporo 060-0819, Japan
| | - Hirokazu Kouguchi
- Department of Infectious Disease, Hokkaido Institute of Public Health, Sapporo 060-0819, Japan
| | - Kinpei Yagi
- Department of Infectious Disease, Hokkaido Institute of Public Health, Sapporo 060-0819, Japan
| | - Jun Matsumoto
- Laboratory of Medical Zoology, Nihon University College of Bioresource Sciences, Fujisawa, Kanagawa 252-0880, Japan.
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19
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Plant Desiccation Tolerance and its Regulation in the Foliage of Resurrection “Flowering-Plant” Species. AGRONOMY-BASEL 2018. [DOI: 10.3390/agronomy8080146] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The majority of flowering-plant species can survive complete air-dryness in their seed and/or pollen. Relatively few species (‘resurrection plants’) express this desiccation tolerance in their foliage. Knowledge of the regulation of desiccation tolerance in resurrection plant foliage is reviewed. Elucidation of the regulatory mechanism in resurrection grasses may lead to identification of genes that can improve stress tolerance and yield of major crop species. Well-hydrated leaves of resurrection plants are desiccation-sensitive and the leaves become desiccation tolerant as they are drying. Such drought-induction of desiccation tolerance involves changes in gene-expression causing extensive changes in the complement of proteins and the transition to a highly-stable quiescent state lasting months to years. These changes in gene-expression are regulated by several interacting phytohormones, of which drought-induced abscisic acid (ABA) is particularly important in some species. Treatment with only ABA induces desiccation tolerance in vegetative tissue of Borya constricta Churchill. and Craterostigma plantagineum Hochstetter. but not in the resurrection grass Sporobolus stapfianus Gandoger. Suppression of drought-induced senescence is also important for survival of drying. Further research is needed on the triggering of the induction of desiccation tolerance, on the transition between phases of protein synthesis and on the role of the phytohormone, strigolactone and other potential xylem-messengers during drying and rehydration.
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20
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Milne RJ, Grof CP, Patrick JW. Mechanisms of phloem unloading: shaped by cellular pathways, their conductances and sink function. CURRENT OPINION IN PLANT BIOLOGY 2018; 43:8-15. [PMID: 29248828 DOI: 10.1016/j.pbi.2017.11.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/24/2017] [Accepted: 11/30/2017] [Indexed: 05/03/2023]
Abstract
Phloem unloading represents a series of cell-to-cell transport steps transferring phloem-mobile constituents from phloem to sink tissues/organs to fuel their development or resource storage. Our analysis focuses on unloading of two major phloem-mobile constituents, sugars and water. Their unloading can occur across phloem plasma membranes (apoplasmic unloading), through plasmodesmata interconnecting phloem and sink cells (symplasmic unloading) or predominately symplasmically with an intervening post-phloem apoplasmic step. In planta studies of phloem unloading encounter substantial technical challenges in accessing phloem within a meshwork of vascular/ground tissues. Thus, current understanding of phloem-unloading mechanisms largely has been deduced from indirect experimental measures or modelling. Here we highlight recent advances in understanding phloem unloading mechanisms and identify where important knowledge gaps remain.
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Affiliation(s)
- Ricky J Milne
- CSIRO Agriculture and Food, Canberra, Australian Capital Territory 2601, Australia
| | - Christopher Pl Grof
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia
| | - John W Patrick
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, New South Wales 2308, Australia.
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Yang J, Luo D, Yang B, Frommer WB, Eom JS. SWEET11 and 15 as key players in seed filling in rice. THE NEW PHYTOLOGIST 2018; 218:604-615. [PMID: 29393510 DOI: 10.1111/nph.15004] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 12/15/2017] [Indexed: 05/04/2023]
Abstract
Despite the relevance of seed-filling mechanisms for crop yield, we still have only a rudimentary understanding of the transport processes that supply the caryopsis with sugars. We hypothesized that SWEET sucrose transporters may play important roles in nutrient import pathways in the rice caryopsis. We used a combination of mRNA quantification, histochemical analyses, translational promoter-reporter fusions and analysis of knockout mutants created by genomic editing to evaluate the contribution of SWEET transporters to seed filling. In rice caryopses, SWEET11 and 15 had the highest mRNA levels and proteins localized to four key sites: all regions of the nucellus at early stages; the nucellar projection close to the dorsal vein; the nucellar epidermis that surrounds the endosperm; and the aleurone. ossweet11;15 double knockout lines accumulated starch in the pericarp, whereas caryopses did not contain a functional endosperm. Jointly, SWEET11 and 15 show all the hallmarks of being necessary for seed filling with sucrose efflux functions at the nucellar projection and a role in transfer across the nucellar epidermis/aleurone interface, delineating two major steps for apoplasmic seed filling, observations that are discussed in relation to observations made in rice and barley regarding the relative prevalence of these two potential import routes.
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Affiliation(s)
- Jungil Yang
- Institute for Molecular Physiology, Heinrich-Heine University Duesseldorf, 40225, Duesseldorf, Germany
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Dangping Luo
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Bing Yang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Wolf B Frommer
- Institute for Molecular Physiology, Heinrich-Heine University Duesseldorf, 40225, Duesseldorf, Germany
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
- Institute of Transformative Bio-Molecules (ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602, Japan
| | - Joon-Seob Eom
- Institute for Molecular Physiology, Heinrich-Heine University Duesseldorf, 40225, Duesseldorf, Germany
- Max Planck Institute for Plant Breeding Research, 50829, Cologne, Germany
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
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22
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Kumar R, Mukherjee S, Ayele BT. Molecular aspects of sucrose transport and its metabolism to starch during seed development in wheat: A comprehensive review. Biotechnol Adv 2018; 36:954-967. [PMID: 29499342 DOI: 10.1016/j.biotechadv.2018.02.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/27/2018] [Accepted: 02/24/2018] [Indexed: 10/17/2022]
Abstract
Wheat is one of the most important crops globally, and its grain is mainly used for human food, accounting for 20% of the total dietary calories. It is also used as animal feed and as a raw material for a variety of non-food and non-feed industrial products such as a feedstock for the production of bioethanol. Starch is the major constituent of a wheat grain, as a result, it is considered as a critical determinant of wheat yield and quality. The amount and composition of starch deposited in wheat grains is controlled primarily by sucrose transport from source tissues to the grain and its conversion to starch. Therefore, elucidation of the molecular mechanisms regulating these physiological processes provides important opportunities to improve wheat starch yield and quality through biotechnological approaches. This review comprehensively discusses the current understanding of the molecular aspects of sucrose transport and sucrose-to-starch metabolism in wheat grains. It also highlights the advances and prospects of starch biotechnology in wheat.
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Affiliation(s)
- Rohit Kumar
- Department of Plant Science, University of Manitoba, 222 Agriculture Building, Winnipeg, Manitoba R3T 2N2, Canada
| | - Shalini Mukherjee
- Department of Plant Science, University of Manitoba, 222 Agriculture Building, Winnipeg, Manitoba R3T 2N2, Canada
| | - Belay T Ayele
- Department of Plant Science, University of Manitoba, 222 Agriculture Building, Winnipeg, Manitoba R3T 2N2, Canada.
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23
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Lu L, Dong C, Liu R, Zhou B, Wang C, Shou H. Roles of Soybean Plasma Membrane Intrinsic Protein GmPIP2;9 in Drought Tolerance and Seed Development. FRONTIERS IN PLANT SCIENCE 2018; 9:530. [PMID: 29755491 PMCID: PMC5932197 DOI: 10.3389/fpls.2018.00530] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/05/2018] [Indexed: 05/21/2023]
Abstract
Aquaporins play an essential role in water uptake and transport in vascular plants. The soybean genome contains a total of 22 plasma membrane intrinsic protein (PIP) genes. To identify candidate PIPs important for soybean yield and stress tolerance, we studied the transcript levels of all 22 soybean PIPs. We found that a GmPIP2 subfamily member, GmPIP2;9, was predominately expressed in roots and developing seeds. Here, we show that GmPIP2;9 localized to the plasma membrane and had high water channel activity when expressed in Xenopus oocytes. Using transgenic soybean plants expressing a native GmPIP2;9 promoter driving a GUS-reporter gene, it was found high GUS expression in the roots, in particular, in the endoderm, pericycle, and vascular tissues of the roots of transgenic plants. In addition, GmPIP2;9 was also highly expressed in developing pods. GmPIP2;9 expression significantly increased in short term of polyethylene glycol (PEG)-mediated drought stress treatment. GmPIP2;9 overexpression increased tolerance to drought stress in both solution cultures and soil plots. Drought stress in combination with GmPIP2;9 overexpression increased net CO2 assimilation of photosynthesis, stomata conductance, and transpiration rate, suggesting that GmPIP2;9-overexpressing transgenic plants were less stressed than wild-type (WT) plants. Furthermore, field experiments showed that GmPIP2;9-overexpressing plants had significantly more pod numbers and larger seed sizes than WT plants. In summary, the study demonstrated that GmPIP2;9 has water transport activity. Its relative high expression levels in roots and developing pods are in agreement with the phenotypes of GmPIP2;9-overexpressing plants in drought stress tolerance and seed development.
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Affiliation(s)
- Linghong Lu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
- Institute of Horticulture, Zhejiang Academy of Agricultural Sciences, Hangzhou, China
| | - Changhe Dong
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Ruifang Liu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Bin Zhou
- Institute of Crop Science, Anhui Academy of Agricultural Sciences, Hefei, China
| | - Chuang Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
- College of Resources and Environment, Huazhong Agricultural University, Wuhan, China
| | - Huixia Shou
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, China
- *Correspondence: Huixia Shou,
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24
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Yamada K, Osakabe Y. Sugar compartmentation as an environmental stress adaptation strategy in plants. Semin Cell Dev Biol 2017; 83:106-114. [PMID: 29287835 DOI: 10.1016/j.semcdb.2017.12.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/15/2017] [Accepted: 12/21/2017] [Indexed: 10/18/2022]
Abstract
The sessile nature of plants has driven their evolution to cope flexibly with ever-changing surrounding environments. The development of stress tolerance traits is complex, and a broad range of cellular processes are involved. Recent studies have revealed that sugar transporters contribute to environmental stress tolerance in plants, suggesting that sugar flow is dynamically fluctuated towards optimization of cellular conditions in adverse environments. Here, we highlight sugar compartmentation mediated by sugar transporters as an adaptation strategy against biotic and abiotic stresses. Competition for sugars between host plants and pathogens shapes their evolutionary arms race. Pathogens, which rely on host-derived carbon, manipulate plant sugar transporters to access sugars easily, while plants sequester sugars from pathogens by enhancing sugar uptake activity. Furthermore, we discuss pathogen tactics to circumvent sugar competition with host plants. Sugar transporters also play a role in abiotic stress tolerance. Exposure to abiotic stresses such as cold or drought stress induces sugar accumulation in various plants. We also discuss how plants allocate sugars under such conditions. Collectively, these findings are relevant to basic plant biology as well as potential applications in agriculture, and provide opportunities to improve crop yield for a growing population.
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Affiliation(s)
- Kohji Yamada
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima, Japan; PRESTO, Japan Science and Technology Agency, Japan.
| | - Yuriko Osakabe
- Graduate School of Technology, Industrial and Social Sciences, Tokushima University, Tokushima, Japan.
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25
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Abstract
The phloem plays a central role in transporting resources and signalling molecules from fully expanded leaves to provide precursors for, and to direct development of, heterotrophic organs located throughout the plant body. We review recent advances in understanding mechanisms regulating loading and unloading of resources into, and from, the phloem network; highlight unresolved questions regarding the physiological significance of the vast array of proteins and RNAs found in phloem saps; and evaluate proposed structure/function relationships considered to account for bulk flow of sap, sustained at high rates and over long distances, through the transport phloem.
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Affiliation(s)
- Johannes Liesche
- Biomass Energy Center for Arid and Semi-arid lands, Northwest A&F University, Yangling, China
- College of Life Science, Northwest A&F University, Yangling , China
| | - John Patrick
- Department of Biological Sciences, School of Environmental and Life Sciences, The University of Newcastle, Callaghan, Australia
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26
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Combined engineering of disaccharide transport and phosphorolysis for enhanced ATP yield from sucrose fermentation in Saccharomyces cerevisiae. Metab Eng 2017; 45:121-133. [PMID: 29196124 DOI: 10.1016/j.ymben.2017.11.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/27/2017] [Accepted: 11/24/2017] [Indexed: 11/24/2022]
Abstract
Anaerobic industrial fermentation processes do not require aeration and intensive mixing and the accompanying cost savings are beneficial for production of chemicals and fuels. However, the free-energy conservation of fermentative pathways is often insufficient for the production and export of the desired compounds and/or for cellular growth and maintenance. To increase free-energy conservation during fermentation of the industrially relevant disaccharide sucrose by Saccharomyces cerevisiae, we first replaced the native yeast α-glucosidases by an intracellular sucrose phosphorylase from Leuconostoc mesenteroides (LmSPase). Subsequently, we replaced the native proton-coupled sucrose uptake system by a putative sucrose facilitator from Phaseolus vulgaris (PvSUF1). The resulting strains grew anaerobically on sucrose at specific growth rates of 0.09 ± 0.02h-1 (LmSPase) and 0.06 ± 0.01h-1 (PvSUF1, LmSPase). Overexpression of the yeast PGM2 gene, which encodes phosphoglucomutase, increased anaerobic growth rates on sucrose of these strains to 0.23 ± 0.01h-1 and 0.08 ± 0.00h-1, respectively. Determination of the biomass yield in anaerobic sucrose-limited chemostat cultures was used to assess the free-energy conservation of the engineered strains. Replacement of intracellular hydrolase with a phosphorylase increased the biomass yield on sucrose by 31%. Additional replacement of the native proton-coupled sucrose uptake system by PvSUF1 increased the anaerobic biomass yield by a further 8%, resulting in an overall increase of 41%. By experimentally demonstrating an energetic benefit of the combined engineering of disaccharide uptake and cleavage, this study represents a first step towards anaerobic production of compounds whose metabolic pathways currently do not conserve sufficient free-energy.
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27
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Jameson PE, Dhandapani P, Novak O, Song J. Cytokinins and Expression of SWEET, SUT, CWINV and AAP Genes Increase as Pea Seeds Germinate. Int J Mol Sci 2016; 17:E2013. [PMID: 27916945 PMCID: PMC5187813 DOI: 10.3390/ijms17122013] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 11/24/2016] [Accepted: 11/25/2016] [Indexed: 02/06/2023] Open
Abstract
Transporter genes and cytokinins are key targets for crop improvement. These genes are active during the development of the seed and its establishment as a strong sink. However, during germination, the seed transitions to being a source for the developing root and shoot. To determine if the sucrose transporter (SUT), amino acid permease (AAP), Sugar Will Eventually be Exported Transporter (SWEET), cell wall invertase (CWINV), cytokinin biosynthesis (IPT), activation (LOG) and degradation (CKX) gene family members are involved in both the sink and source activities of seeds, we used RT-qPCR to determine the expression of multiple gene family members, and LC-MS/MS to ascertain endogenous cytokinin levels in germinating Pisum sativum L. We show that genes that are actively expressed when the seed is a strong sink during its development, are also expressed when the seed is in the reverse role of being an active source during germination and early seedling growth. Cytokinins were detected in the imbibing seeds and were actively biosynthesised during germination. We conclude that, when the above gene family members are targeted for seed yield improvement, a downstream effect on subsequent seed germination or seedling vigour must be taken into consideration.
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Affiliation(s)
- Paula E Jameson
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
| | - Pragatheswari Dhandapani
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
| | - Ondrej Novak
- Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany CAS & Faculty of Science of Palacký University, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
| | - Jiancheng Song
- School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
- School of Life Sciences, Yantai University, Yantai 264005, China.
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28
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Griffiths CA, Paul MJ, Foyer CH. Metabolite transport and associated sugar signalling systems underpinning source/sink interactions. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1857:1715-25. [PMID: 27487250 PMCID: PMC5001786 DOI: 10.1016/j.bbabio.2016.07.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 06/06/2016] [Accepted: 07/23/2016] [Indexed: 11/19/2022]
Abstract
Metabolite transport between organelles, cells and source and sink tissues not only enables pathway co-ordination but it also facilitates whole plant communication, particularly in the transmission of information concerning resource availability. Carbon assimilation is co-ordinated with nitrogen assimilation to ensure that the building blocks of biomass production, amino acids and carbon skeletons, are available at the required amounts and stoichiometry, with associated transport processes making certain that these essential resources are transported from their sites of synthesis to those of utilisation. Of the many possible posttranslational mechanisms that might participate in efficient co-ordination of metabolism and transport only reversible thiol-disulphide exchange mechanisms have been described in detail. Sucrose and trehalose metabolism are intertwined in the signalling hub that ensures appropriate resource allocation to drive growth and development under optimal and stress conditions, with trehalose-6-phosphate acting as an important signal for sucrose availability. The formidable suite of plant metabolite transporters provides enormous flexibility and adaptability in inter-pathway coordination and source-sink interactions. Focussing on the carbon metabolism network, we highlight the functions of different transporter families, and the important of thioredoxins in the metabolic dialogue between source and sink tissues. In addition, we address how these systems can be tailored for crop improvement.
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Affiliation(s)
- Cara A Griffiths
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Matthew J Paul
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK
| | - Christine H Foyer
- Centre for Plant Sciences, School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
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29
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Morkunas I, Woźniak A, Formela M, Mai VC, Marczak Ł, Narożna D, Borowiak-Sobkowiak B, Kühn C, Grimm B. Pea aphid infestation induces changes in flavonoids, antioxidative defence, soluble sugars and sugar transporter expression in leaves of pea seedlings. PROTOPLASMA 2016; 253:1063-79. [PMID: 26239447 DOI: 10.1007/s00709-015-0865-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 07/23/2015] [Indexed: 05/25/2023]
Abstract
The perception of aphid infestation induces highly coordinated and sequential defensive reactions in plants at the cellular and molecular levels. The aim of the study was to explore kinetics of induced antioxidative defence responses in leaf cells of Pisum sativum L.cv. Cysterski upon infestation of the pea aphid Acyrthosiphon pisum at varying population sizes, including accumulation of flavonoids, changes of carbon metabolism, and expression of nuclear genes involved in sugar transport. Within the first 96 h, after A. pisum infestation, flavonoid accumulation and increased peroxidase activity were observed in leaves. The level of pisatin increased after 48 h of infestation and reached a maximum at 96 h. At this time point, a higher concentration of flavonols was observed in the infested tissue than in the control. Additionally, strong post-infestation accumulation of chalcone synthase (CHS) and isoflavone synthase (IFS) transcription products was also found. The levels of sucrose and fructose in 24-h leaves infested by 10, 20, and 30 aphids were significantly lower than in the control. Moreover, in leaves infested by 30 aphids, the reduced sucrose level observed up to 48 h was accompanied by a considerable increase in the expression level of the PsSUT1 gene encoding the sucrose transporter. In conclusion, A. pisum infestation on pea leads to stimulation of metabolic pathways associated with defence.
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Affiliation(s)
- Iwona Morkunas
- Department of Plant Physiology, Poznań University of Life Sciences, Wołyńska 35, 60-637, Poznań, Poland.
| | - Agnieszka Woźniak
- Department of Plant Physiology, Poznań University of Life Sciences, Wołyńska 35, 60-637, Poznań, Poland
| | - Magda Formela
- Department of Plant Physiology, Poznań University of Life Sciences, Wołyńska 35, 60-637, Poznań, Poland
| | - Van Chung Mai
- Department of Plant Physiology, Poznań University of Life Sciences, Wołyńska 35, 60-637, Poznań, Poland
- Department of Plant Physiology, Vinh University, Le Duan 182, Vinh city, Vietnam
| | - Łukasz Marczak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Z. Noskowskiego 12/14, 61-704, Poznań, Poland
| | - Dorota Narożna
- Department of Biochemistry and Biotechnology, Poznań University of Life Sciences, Dojazd 11, 60-632, Poznań, Poland
| | - Beata Borowiak-Sobkowiak
- Department of Entomology and Environment Protection, Poznań University of Life Sciences, Dąbrowskiego 159, 60-594, Poznań, Poland
| | - Christina Kühn
- Department of Plant Physiology, Institute of Biology, Humboldt University of Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - Bernhard Grimm
- Department of Plant Physiology, Institute of Biology, Humboldt University of Berlin, Philippstrasse 13, 10115, Berlin, Germany
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30
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Öner-Sieben S, Rappl C, Sauer N, Stadler R, Lohaus G. Characterization, localization, and seasonal changes of the sucrose transporter FeSUT1 in the phloem of Fraxinus excelsior. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:4807-19. [PMID: 26022258 PMCID: PMC4507781 DOI: 10.1093/jxb/erv255] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Trees are generally assumed to be symplastic phloem loaders. A typical feature for most wooden species is an open minor vein structure with symplastic connections between mesophyll cells and phloem cells, which allow sucrose to move cell-to-cell through the plasmodesmata into the phloem. Fraxinus excelsior (Oleaceae) also translocates raffinose family oligosaccharides in addition to sucrose. Sucrose concentration was recently shown to be higher in the phloem sap than in the mesophyll cells. This suggests the involvement of apoplastic steps and the activity of sucrose transporters in addition to symplastic phloem-loading processes. In this study, the sucrose transporter FeSUT1 from F. excelsior was analysed. Heterologous expression in baker's yeast showed that FeSUT1 mediates the uptake of sucrose. Immunohistochemical analyses revealed that FeSUT1 was exclusively located in phloem cells of minor veins and in the transport phloem of F. excelsior. Further characterization identified these cells as sieve elements and possibly ordinary companion cells but not as intermediary cells. The localization and expression pattern point towards functions of FeSUT1 in phloem loading of sucrose as well as in sucrose retrieval. FeSUT1 is most likely responsible for the observed sucrose gradient between mesophyll and phloem. The elevated expression level of FeSUT1 indicated an increased apoplastic carbon export activity from the leaves during spring and late autumn. It is hypothesized that the importance of apoplastic loading is high under low-sucrose conditions and that the availability of two different phloem-loading mechanisms confers advantages for temperate woody species like F. excelsior.
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Affiliation(s)
- Soner Öner-Sieben
- Molekulare Pflanzenforschung/Pflanzenbiochemie (Botanik), Bergische Universität Wuppertal, Gaußstraße 20, D-42119 Wuppertal, Germany
| | - Christine Rappl
- Lehrstuhl Molekulare Pflanzenphysiologie Department Biologie, Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany
| | - Norbert Sauer
- Lehrstuhl Molekulare Pflanzenphysiologie Department Biologie, Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany
| | - Ruth Stadler
- Lehrstuhl Molekulare Pflanzenphysiologie Department Biologie, Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany
| | - Gertrud Lohaus
- Molekulare Pflanzenforschung/Pflanzenbiochemie (Botanik), Bergische Universität Wuppertal, Gaußstraße 20, D-42119 Wuppertal, Germany
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31
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Patil G, Valliyodan B, Deshmukh R, Prince S, Nicander B, Zhao M, Sonah H, Song L, Lin L, Chaudhary J, Liu Y, Joshi T, Xu D, Nguyen HT. Soybean (Glycine max) SWEET gene family: insights through comparative genomics, transcriptome profiling and whole genome re-sequence analysis. BMC Genomics 2015; 16:520. [PMID: 26162601 PMCID: PMC4499210 DOI: 10.1186/s12864-015-1730-y] [Citation(s) in RCA: 127] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 06/26/2015] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND SWEET (MtN3_saliva) domain proteins, a recently identified group of efflux transporters, play an indispensable role in sugar efflux, phloem loading, plant-pathogen interaction and reproductive tissue development. The SWEET gene family is predominantly studied in Arabidopsis and members of the family are being investigated in rice. To date, no transcriptome or genomics analysis of soybean SWEET genes has been reported. RESULTS In the present investigation, we explored the evolutionary aspect of the SWEET gene family in diverse plant species including primitive single cell algae to angiosperms with a major emphasis on Glycine max. Evolutionary features showed expansion and duplication of the SWEET gene family in land plants. Homology searches with BLAST tools and Hidden Markov Model-directed sequence alignments identified 52 SWEET genes that were mapped to 15 chromosomes in the soybean genome as tandem duplication events. Soybean SWEET (GmSWEET) genes showed a wide range of expression profiles in different tissues and developmental stages. Analysis of public transcriptome data and expression profiling using quantitative real time PCR (qRT-PCR) showed that a majority of the GmSWEET genes were confined to reproductive tissue development. Several natural genetic variants (non-synonymous SNPs, premature stop codons and haplotype) were identified in the GmSWEET genes using whole genome re-sequencing data analysis of 106 soybean genotypes. A significant association was observed between SNP-haplogroup and seed sucrose content in three gene clusters on chromosome 6. CONCLUSION Present investigation utilized comparative genomics, transcriptome profiling and whole genome re-sequencing approaches and provided a systematic description of soybean SWEET genes and identified putative candidates with probable roles in the reproductive tissue development. Gene expression profiling at different developmental stages and genomic variation data will aid as an important resource for the soybean research community and can be extremely valuable for understanding sink unloading and enhancing carbohydrate delivery to developing seeds for improving yield.
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Affiliation(s)
- Gunvant Patil
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Babu Valliyodan
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Rupesh Deshmukh
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Silvas Prince
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Bjorn Nicander
- Department of Plant Biology and Forest Genetics and Linnean Center for Plant Biology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
| | - Mingzhe Zhao
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
- Current address: Agronomy College of Shenyang Agricultural University, Shenyang, China.
| | - Humira Sonah
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Li Song
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Li Lin
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Juhi Chaudhary
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
| | - Yang Liu
- Department of Computer Science, Informatics Institute, and Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA.
| | - Trupti Joshi
- Department of Computer Science, Informatics Institute, and Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA.
| | - Dong Xu
- Department of Computer Science, Informatics Institute, and Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA.
| | - Henry T Nguyen
- National Center for Soybean Biotechnology and Division of Plant Sciences, University of Missouri, Columbia, MO, 65211, USA.
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32
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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.
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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
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Keller M, Shrestha PM. Solute accumulation differs in the vacuoles and apoplast of ripening grape berries. PLANTA 2014; 239:633-42. [PMID: 24310282 DOI: 10.1007/s00425-013-2004-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 11/25/2013] [Indexed: 05/20/2023]
Abstract
Phloem unloading is thought to switch from a symplastic route to an apoplastic route at the beginning of ripening in grape berries and some other fleshy fruits. However, it is unclear whether different solutes accumulate in both the mesocarp vacuoles and the apoplast. We modified a method developed for tomato fruit to extract apoplastic sap from grape berries and measured the changes in apoplastic and vacuolar pH, soluble sugars, organic acids, and potassium in ripening berries of Vitis vinifera 'Merlot' and V. labruscana 'Concord'. Solute accumulation varied by genotype, compartment, and chemical species. The apoplast pH was substantially higher than the vacuolar pH, especially in Merlot (approximately two units). However, the vacuole-apoplast proton gradient declined during ripening and in Merlot, but not in Concord, collapsed entirely at maturity. Hexoses accumulated in both the vacuoles and apoplast but at different rates. Organic acids, especially malate, declined much more in the vacuoles than in the apoplast. Potassium accumulated in the vacuoles and apoplast of Merlot. In Concord, by contrast, potassium increased in the vacuoles but decreased in the apoplast. These results suggest that solutes in the fruit apoplast are tightly regulated and under developmental control.
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Affiliation(s)
- Markus Keller
- Irrigated Agriculture Research and Extension Center, Washington State University, 24106 N. Bunn Rd., Prosser, WA, 99350, USA,
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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.
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Hafke JB, Höll SR, Kühn C, van Bel AJE. Electrophysiological approach to determine kinetic parameters of sucrose uptake by single sieve elements or phloem parenchyma cells in intact Vicia faba plants. FRONTIERS IN PLANT SCIENCE 2013; 4:274. [PMID: 23914194 PMCID: PMC3728481 DOI: 10.3389/fpls.2013.00274] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 07/04/2013] [Indexed: 05/05/2023]
Abstract
Apart from cut aphid stylets in combination with electrophysiology, no attempts have been made thus far to measure in vivo sucrose-uptake properties of sieve elements. We investigated the kinetics of sucrose uptake by single sieve elements and phloem parenchyma cells in Vicia faba plants. To this end, microelectrodes were inserted into free-lying phloem cells in the main vein of the youngest fully-expanded leaf, half-way along the stem, in the transition zone between the autotrophic and heterotrophic part of the stem, and in the root axis. A top-to-bottom membrane potential gradient of sieve elements was observed along the stem (-130 mV to -110 mV), while the membrane potential of the phloem parenchyma cells was stable (approx. -100 mV). In roots, the membrane potential of sieve elements dropped abruptly to -55 mV. Bathing solutions having various sucrose concentrations were administered and sucrose/H(+)-induced depolarizations were recorded. Data analysis by non-linear least-square data fittings as well as by linear Eadie-Hofstee (EH) -transformations pointed at biphasic Michaelis-Menten kinetics (2 MM, EH: K m1 1.2-1.8 mM, K m2 6.6-9.0 mM) of sucrose uptake by sieve elements. However, Akaike's Information Criterion (AIC) favored single MM kinetics. Using single MM as the best-fitting model, K m values for sucrose uptake by sieve elements decreased along the plant axis from 1 to 7 mM. For phloem parenchyma cells, higher K m values (EH: K m1 10 mM, K m2 70 mM) as compared to sieve elements were found. In preliminary patch-clamp experiments with sieve-element protoplasts, small sucrose-coupled proton currents (-0.1 to -0.3 pA/pF) were detected in the whole-cell mode. In conclusion (a) K m values for sucrose uptake measured by electrophysiology are similar to those obtained with heterologous systems, (b) electrophysiology provides a useful tool for in situ determination of K m values, (c) As yet, it remains unclear if one or two uptake systems are involved in sucrose uptake by sieve elements, (d) Affinity for sucrose uptake by sieve elements exceeds by far that by phloem parenchyma cells, (e) Patch-clamp studies provide a feasible basis for quantification of sucrose uptake by single cells. The consequences of the findings for whole-plant carbohydrate partitioning are discussed.
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Affiliation(s)
- Jens B. Hafke
- Institute of Plant Physiology, Justus-Liebig-UniversityGiessen, Germany
- Institute of General Botany, Plant Cell Biology Research Group, Justus-Liebig-UniversityGiessen, Germany
| | - Sabina-Roxana Höll
- Institute of General Botany, Plant Cell Biology Research Group, Justus-Liebig-UniversityGiessen, Germany
| | - Christina Kühn
- Department of Plant Physiology, Institute of Biology, Humboldt UniversityBerlin, Germany
| | - Aart J. E. van Bel
- Institute of General Botany, Plant Cell Biology Research Group, Justus-Liebig-UniversityGiessen, Germany
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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.
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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
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Patrick JW, Botha FC, Birch RG. Metabolic engineering of sugars and simple sugar derivatives in plants. PLANT BIOTECHNOLOGY JOURNAL 2013; 11:142-56. [PMID: 23043616 DOI: 10.1111/pbi.12002] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2012] [Revised: 08/22/2012] [Accepted: 08/31/2012] [Indexed: 05/21/2023]
Abstract
Carbon captured through photosynthesis is transported, and sometimes stored in plants, as sugar. All organic compounds in plants trace to carbon from sugars, so sugar metabolism is highly regulated and integrated with development. Sugars stored by plants are important to humans as foods and as renewable feedstocks for industrial conversion to biofuels and biomaterials. For some purposes, sugars have advantages over polymers including starches, cellulose or storage lipids. This review considers progress and prospects in plant metabolic engineering for increased yield of endogenous sugars and for direct production of higher-value sugars and simple sugar derivatives. Opportunities are examined for enhancing export of sugars from leaves. Focus then turns to manipulation of sugar metabolism in sugar-storing sink organs such as fruits, sugarcane culms and sugarbeet tubers. Results from manipulation of suspected 'limiting' enzymes indicate a need for clearer understanding of flux control mechanisms, to achieve enhanced levels of endogenous sugars in crops that are highly selected for this trait. Outcomes from in planta conversion to novel sugars and derivatives range from severe interference with plant development to field demonstration of crops accumulating higher-value sugars at high yields. The differences depend on underlying biological factors including the effects of the novel products on endogenous metabolism, and on biotechnological fine-tuning including developmental expression and compartmentation patterns. Ultimately, osmotic activity may limit the accumulation of sugars to yields below those achievable using polymers; but results indicate the potential for increases above current commercial sugar yields, through metabolic engineering underpinned by improved understanding of plant sugar metabolism.
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Affiliation(s)
- John W Patrick
- The University of Newcastle, School of Environmental and Life Sciences, Callaghan, NSW, Australia
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Chincinska I, Gier K, Krügel U, Liesche J, He H, Grimm B, Harren FJM, Cristescu SM, Kühn C. Photoperiodic regulation of the sucrose transporter StSUT4 affects the expression of circadian-regulated genes and ethylene production. FRONTIERS IN PLANT SCIENCE 2013; 4:26. [PMID: 23429841 PMCID: PMC3576705 DOI: 10.3389/fpls.2013.00026] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Accepted: 02/04/2013] [Indexed: 05/19/2023]
Abstract
Several recent publications reported different subcellular localization of the sucrose transporters belonging to the SUT4 subfamily. The physiological function of the SUT4 sucrose transporters requires clarification, because down-regulation of the members of the SUT4 clade had different effects in rice, poplar, and potato. Here, we provide new data for the localization and function of the Solanaceous StSUT4 protein, further elucidating involvement in the onset of flowering, tuberization and in the shade avoidance syndrome of potato plants. Induction of an early flowering and a tuberization in the SUT4-inhibited potato plants correlates with increased sucrose export from leaves and increased sucrose and starch accumulation in terminal sink organs, such as developing tubers. SUT4 affects expression of the enzymes involved in gibberellin and ethylene biosynthesis, as well as the rate of ethylene biosynthesis in potato. In the SUT4-inhibited plants, the ethylene production no longer follows a diurnal rhythm. Thus it was concluded that StSUT4 controls circadian gene expression, potentially by regulating sucrose export from leaves. Furthermore, SUT4 expression affects clock-regulated genes such as StFT, StSOC1, and StCO, which might be also involved in a photoperiod-dependent tuberization. A model is proposed in which StSUT4 controls a phloem-mobile signaling molecule generated in leaves, which together with enhanced sucrose export affects developmental switches in apical meristems. SUT4 seems to link photoreceptor-perceived information about the light quality and day length with phytohormone biosynthesis and the expression of circadian-regulated genes.
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Affiliation(s)
- Izabela Chincinska
- Department of Plant Physiology, Institute of Biology, Humboldt University of BerlinBerlin, Germany
| | - Konstanze Gier
- Department of Plant Physiology, Institute of Biology, Humboldt University of BerlinBerlin, Germany
| | - Undine Krügel
- Department of Plant Physiology, Institute of Biology, Humboldt University of BerlinBerlin, Germany
| | - Johannes Liesche
- Department of Plant Physiology, Institute of Biology, Humboldt University of BerlinBerlin, Germany
| | - Hongxia He
- Department of Plant Physiology, Institute of Biology, Humboldt University of BerlinBerlin, Germany
| | - Bernhard Grimm
- Department of Plant Physiology, Institute of Biology, Humboldt University of BerlinBerlin, Germany
| | - Frans J. M. Harren
- Department of Molecular and Laser Physics, Radboud University NijmegenNijmegen, Netherlands
| | - Simona M. Cristescu
- Department of Molecular and Laser Physics, Radboud University NijmegenNijmegen, Netherlands
| | - Christina Kühn
- Department of Plant Physiology, Institute of Biology, Humboldt University of BerlinBerlin, Germany
- *Correspondence: Christina Kühn, Department of Plant Physiology, Institute of Biology, Humboldt University of Berlin, Philippstr. 13, Building 12, 10115 Berlin, Germany. e-mail:
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Ludewig F, Flügge UI. Role of metabolite transporters in source-sink carbon allocation. FRONTIERS IN PLANT SCIENCE 2013; 4:231. [PMID: 23847636 PMCID: PMC3698459 DOI: 10.3389/fpls.2013.00231] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 06/13/2013] [Indexed: 05/18/2023]
Abstract
Plants assimilate carbon dioxide during photosynthesis in chloroplasts. Assimilated carbon is subsequently allocated throughout the plant. Generally, two types of organs can be distinguished, mature green source leaves as net photoassimilate exporters, and net importers, the sinks, e.g., roots, flowers, small leaves, and storage organs like tubers. Within these organs, different tissue types developed according to their respective function, and cells of either tissue type are highly compartmentalized. Photoassimilates are allocated to distinct compartments of these tissues in all organs, requiring a set of metabolite transporters mediating this intercompartmental transfer. The general route of photoassimilates can be briefly described as follows. Upon fixation of carbon dioxide in chloroplasts of mesophyll cells, triose phosphates either enter the cytosol for mainly sucrose formation or remain in the stroma to form transiently stored starch which is degraded during the night and enters the cytosol as maltose or glucose to be further metabolized to sucrose. In both cases, sucrose enters the phloem for long distance transport or is transiently stored in the vacuole, or can be degraded to hexoses which also can be stored in the vacuole. In the majority of plant species, sucrose is actively loaded into the phloem via the apoplast. Following long distance transport, it is released into sink organs, where it enters cells as source of carbon and energy. In storage organs, sucrose can be stored, or carbon derived from sucrose can be stored as starch in plastids, or as oil in oil bodies, or - in combination with nitrogen - as protein in protein storage vacuoles and protein bodies. Here, we focus on transport proteins known for either of these steps, and discuss the implications for yield increase in plants upon genetic engineering of respective transporters.
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Affiliation(s)
- Frank Ludewig
- *Correspondence: Frank Ludewig, Botanical Institute II, Cologne Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany e-mail:
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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.
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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
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Kikuta S, Hagiwara-Komoda Y, Noda H, Kikawada T. A novel member of the trehalose transporter family functions as an h(+)-dependent trehalose transporter in the reabsorption of trehalose in malpighian tubules. Front Physiol 2012; 3:290. [PMID: 22934042 PMCID: PMC3429062 DOI: 10.3389/fphys.2012.00290] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 07/03/2012] [Indexed: 11/28/2022] Open
Abstract
In insects, Malpighian tubules are functionally analogous to mammalian kidneys in that they not only are essential to excrete waste molecules into the lumen but also are responsible for the reabsorption of indispensable molecules, such as sugars, from the lumen to the principal cells. Among sugars, the disaccharide trehalose is highly important to insects because it is the main hemolymph sugar to serve as a source of energy and carbon. The trehalose transporter TRET1 participates in the transfer of newly synthesized trehalose from the fat body across the cellular membrane into the hemolymph. Although transport proteins must play a pivotal role in the reabsorption of trehalose in Malpighian tubules, the molecular context underlying this process remains obscure. Previously, we identified a Tret1 homolog (Nlst8) that is expressed principally in the Malpighian tubules of the brown planthopper (BPH). Here, we used the Xenopus oocyte expression system to show that NlST8 exerts trehalose transport activity that is elevated under low pH conditions. These functional assays indicate that Nlst8 encodes a proton-dependent trehalose transporter (H-TRET1). To examine the involvement of Nlst8 in trehalose reabsorption, we analyzed the sugar composition of honeydew by using BPH with RNAi gene silencing. Trehalose was detected in the honeydew as waste excreted from Nlst8-dsRNA-injected BPH under hyperglycemic conditions. However, trehalose was not expelled from GFP-dsRNA-injected BPH even under hyperglycemic conditions. We conclude that NlST8 could participate in trehalose reabsorption driven by a H(+) gradient from the lumen to the principal cells of the Malpighian tubules.
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Affiliation(s)
- Shingo Kikuta
- National Institute of Agrobiological SciencesTsukuba, Ibaraki, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of TokyoKashiwa, Chiba, Japan
| | | | - Hiroaki Noda
- National Institute of Agrobiological SciencesTsukuba, Ibaraki, Japan
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of TokyoKashiwa, Chiba, Japan
| | - Takahiro Kikawada
- National Institute of Agrobiological SciencesTsukuba, Ibaraki, Japan
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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.
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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
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Reinders A, Sivitz AB, Ward JM. Evolution of plant sucrose uptake transporters. FRONTIERS IN PLANT SCIENCE 2012; 3:22. [PMID: 22639641 PMCID: PMC3355574 DOI: 10.3389/fpls.2012.00022] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 01/20/2012] [Indexed: 05/18/2023]
Abstract
In angiosperms, sucrose uptake transporters (SUTs) have important functions especially in vascular tissue. Here we explore the evolutionary origins of SUTs by analysis of angiosperm SUTs and homologous transporters in a vascular early land plant, Selaginella moellendorffii, and a non-vascular plant, the bryophyte Physcomitrella patens, the charophyte algae Chlorokybus atmosphyticus, several red algae and fission yeast, Schizosaccharomyces pombe. Plant SUTs cluster into three types by phylogenetic analysis. Previous studies using angiosperms had shown that types I and II are localized to the plasma membrane while type III SUTs are associated with vacuolar membrane. SUT homologs were not found in the chlorophyte algae Chlamydomonas reinhardtii and Volvox carterii. However, the characean algae Chlorokybus atmosphyticus contains a SUT homolog (CaSUT1) and phylogenetic analysis indicated that it is basal to all other streptophyte SUTs analyzed. SUTs are present in both red algae and S. pombe but they are less related to plant SUTs than CaSUT1. Both Selaginella and Physcomitrella encode type II and III SUTs suggesting that both plasma membrane and vacuolar sucrose transporter activities were present in early land plants. It is likely that SUT transporters are important for scavenging sucrose from the environment and intracellular compartments in charophyte and non-vascular plants. Type I SUTs were only found in eudicots and we conclude that they evolved from type III SUTs, possibly through loss of a vacuolar targeting sequence. Eudicots utilize type I SUTs for phloem (vascular tissue) loading while monocots use type II SUTs for phloem loading. We show that HvSUT1 from barley, a type II SUT, reverted the growth defect of the Arabidopsis atsuc2 (type I) mutant. This indicates that type I and II SUTs evolved similar (and interchangeable) phloem loading transporter capabilities independently.
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Affiliation(s)
- Anke Reinders
- Department of Plant Biology, University of MinnesotaSt. Paul, MN, USA
| | - Alicia B. Sivitz
- Department of Biological Sciences, Dartmouth CollegeHanover, NH, USA
| | - John M. Ward
- Department of Plant Biology, University of MinnesotaSt. Paul, MN, USA
- *Correspondence: John M. Ward, Department of Plant Biology, University of Minnesota, 250 Biological Sciences Center, 1445 Gortner Avenue, St. Paul, MN 55108, USA. e-mail:
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Henry C, Rabot A, Laloi M, Mortreau E, Sigogne M, Leduc N, Lemoine R, Sakr S, Vian A, Pelleschi-Travier S. Regulation of RhSUC2, a sucrose transporter, is correlated with the light control of bud burst in Rosa sp. PLANT, CELL & ENVIRONMENT 2011; 34:1776-89. [PMID: 21635271 DOI: 10.1111/j.1365-3040.2011.02374.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In roses, light is a central environmental factor controlling bud break and involves a stimulation of sugar metabolism. Very little is known about the role of sucrose transporters in the bud break process and its regulation by light. In this study, we show that sugar promotes rose bud break and that bud break is accompanied by an import of sucrose. Radio-labelled sucrose accumulation is higher in buds exposed to light than to darkness and involves an active component. Several sucrose transporter (RhSUC1, 2, 3 and 4) transcripts are expressed in rose tissues, but RhSUC2 transcript level is the only one induced in buds exposed to light after removing the apical dominance. RhSUC2 is preferentially expressed in bursting buds and stems. Functional analyses in baker's yeast demonstrate that RhSUC2 encodes a sucrose/proton co-transporter with a K(m) value of 2.99 mm at pH 4.5 and shows typical features of sucrose symporters. We therefore propose that bud break photocontrol partly depends upon the modulation of sucrose import into buds by RhSUC2.
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Affiliation(s)
- Clemence Henry
- Universite D'Angers, UFR Sciences, UMR-462 SAGAH, 2 Bd Lavoisier, F-49045 Angers Cedex, France
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Ayre BG. Membrane-transport systems for sucrose in relation to whole-plant carbon partitioning. MOLECULAR PLANT 2011; 4:377-94. [PMID: 21502663 DOI: 10.1093/mp/ssr014] [Citation(s) in RCA: 183] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Sucrose is the principal product of photosynthesis used for the distribution of assimilated carbon in plants. Transport mechanisms and efficiency influence photosynthetic productivity by relieving product inhibition and contribute to plant vigor by controlling source/sink relationships and biomass partitioning. Sucrose is synthesized in the cytoplasm and may move cell to cell through plasmodesmata or may cross membranes to be compartmentalized or exported to the apoplasm for uptake into adjacent cells. As a relatively large polar compound, sucrose requires proteins to facilitate efficient membrane transport. Transport across the tonoplast by facilitated diffusion, antiport with protons, and symport with protons have been proposed; for transport across plasma membranes, symport with protons and a mechanism resembling facilitated diffusion are evident. Despite decades of research, only symport with protons is well established at the molecular level. This review aims to integrate recent and older studies on sucrose flux across membranes with principles of whole-plant carbon partitioning.
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Affiliation(s)
- Brian G Ayre
- University of North Texas, Department of Biological Sciences, Denton, Texas, USA.
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Payyavula RS, Tay KHC, Tsai CJ, Harding SA. The sucrose transporter family in Populus: the importance of a tonoplast PtaSUT4 to biomass and carbon partitioning. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 65:757-70. [PMID: 21261761 DOI: 10.1111/j.1365-313x.2010.04463.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Plasma membrane, proton-coupled Group II sucrose symporters (SUT) mediate apoplastic phloem loading and sucrose efflux from source leaves in Arabidopsis and agricultural crop species that have been studied to date. We now report that the most abundantly expressed SUT isoform in Populus tremula×alba, PtaSUT4, is a tonoplast (Group IV) symporter. PtaSUT4 transcripts were readily detected in conducting as well as mesophyll cells in stems and source leaves. In comparison, Group II orthologs PtaSUT1 and PtaSUT3 were very weakly expressed in leaves. Both Group II and Group IV SUT genes were expressed in secondary stem xylem of Populus. Transgenic poplars with RNAi-suppressed PtaSUT4 exhibited increased leaf-to-stem biomass ratios, elevated sucrose content in source leaves and stems, and altered phenylpropanoid metabolism. Transcript abundance of several carbohydrate-active enzymes and phenylalanine ammonia-lyases was also altered in transgenic source leaves. Nitrogen-limitation led to a down-regulation of vacuolar invertases in all plants, which resulted in an augmentation of sucrose pooling and hexose depletion in source leaves and secondary xylem of the transgenic plants. These results are consistent with a major role for PtaSUT4 in orchestrating the intracellular partitioning, and consequently, the efflux of sucrose from source leaves and the utilization of sucrose by lateral and terminal sinks. Our findings also support the idea that PtaSUT4 modulates sucrose efflux and utilization in concert with plant N-status.
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Affiliation(s)
- Raja S Payyavula
- School of Forest Resources and Environmental Sciences, Michigan Technological University, Houghton, MI 49931, USA
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Lahuta LB, Dzik T. D-chiro-inositol affects accumulation of raffinose family oligosaccharides in developing embryos of Pisum sativum. JOURNAL OF PLANT PHYSIOLOGY 2011; 168:352-8. [PMID: 20947202 DOI: 10.1016/j.jplph.2010.07.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 07/28/2010] [Accepted: 07/28/2010] [Indexed: 05/30/2023]
Abstract
Developing garden pea embryos are able to take up exogenously applied cyclitols: myo-inositol, which naturally occurs in pea, and two cyclitols absent in pea plants: d-chiro-inositol and d-pinitol. The competition in the uptake of cyclitols by pea embryo, insensitivity to glucose and sucrose, and susceptibility to inhibitor(s) of H(+)-symporters (e.g. CCCP and antimycin A) suggest that a common cyclitol transporter is involved. Both d-chiro-inositol and d-pinitol can be translocated through the pea plant to developing embryos. During seed maturation drying, they are used for synthesis of mainly mono-galactosides, such as fagopyritol B1 and galactosyl pinitol A. Accumulation of d-chiro-inositol (and formation of fagopyritols), but not d-pinitol, strongly reduces accumulation of verbascose, the main raffinose oligosaccharide in pea seeds. The reasons for the observed changes are discussed.
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Affiliation(s)
- Lesław B Lahuta
- Department of Plant Physiology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Oczapowskiego, Poland.
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Vargas WA, Crutcher FK, Kenerley CM. Functional characterization of a plant-like sucrose transporter from the beneficial fungus Trichoderma virens. Regulation of the symbiotic association with plants by sucrose metabolism inside the fungal cells. THE NEW PHYTOLOGIST 2011; 189:777-789. [PMID: 21070245 DOI: 10.1111/j.1469-8137.2010.03517.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
• Sucrose exuded by plants into the rhizosphere is a crucial component for the symbiotic association between the beneficial fungus Trichoderma and plant roots. In this article we sought to identify and characterize the molecular basis of sucrose uptake into the fungal cells. • Several bioinformatics tools enabled us to identify a plant-like sucrose transporter in the genome of Trichoderma virens Gv29-8 (TvSut). Gene expression profiles in the fungal cells were analyzed by Northern blotting and quantitative real-time PCR (qRT-PCR). Biochemical and physiological studies were conducted on Gv29-8 and fungal strains impaired in the expression of TvSut. • TvSut exhibits biochemical properties similar to those described for sucrose symporters from plants. The null expression of tvsut caused a detrimental effect on fungal growth when sucrose was the sole source of carbon in the medium, and also affected the expression of genes involved in the symbiotic association. • Similar to plants, T. virens contains a highly specific sucrose/H(+) symporter that is induced in the early stages of root colonization. Our results suggest an active sucrose transference from the plant to the fungal cells during the beneficial associations. In addition, our expression experiments suggest the existence of a sucrose-dependent network in the fungal cells that regulates the symbiotic association.
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Affiliation(s)
- Walter A Vargas
- Department of Plant Pathology and Microbiology Texas A&M University, College Station, TX 77843, USA
- Present address: Centro Hispanoluso de Investigaciones Agrárias (CIALE), Departamento de Microbiologia y Genética, Universidad de Salamanca, 37185 Salamanca, Spain
| | - Frankie K Crutcher
- Department of Plant Pathology and Microbiology Texas A&M University, College Station, TX 77843, USA
| | - Charles M Kenerley
- Department of Plant Pathology and Microbiology Texas A&M University, College Station, TX 77843, USA
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