1
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Grierson ERP, Thrimawithana AH, van Klink JW, Lewis DH, Carvajal I, Shiller J, Miller P, Deroles SC, Clearwater MJ, Davies KM, Chagné D, Schwinn KE. A phosphatase gene is linked to nectar dihydroxyacetone accumulation in mānuka (Leptospermum scoparium). THE NEW PHYTOLOGIST 2024. [PMID: 38532557 DOI: 10.1111/nph.19714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 03/06/2024] [Indexed: 03/28/2024]
Abstract
Floral nectar composition beyond common sugars shows great diversity but contributing genetic factors are generally unknown. Mānuka (Leptospermum scoparium) is renowned for the antimicrobial compound methylglyoxal in its derived honey, which originates from the precursor, dihydroxyacetone (DHA), accumulating in the nectar. Although this nectar trait is highly variable, genetic contribution to the trait is unclear. Therefore, we investigated key gene(s) and genomic regions underpinning this trait. We used RNAseq analysis to identify nectary-associated genes differentially expressed between high and low nectar DHA genotypes. We also used a mānuka high-density linkage map and quantitative trait loci (QTL) mapping population, supported by an improved genome assembly, to reveal genetic regions associated with nectar DHA content. Expression and QTL analyses both pointed to the involvement of a phosphatase gene, LsSgpp2. The expression pattern of LsSgpp2 correlated with nectar DHA accumulation, and it co-located with a QTL on chromosome 4. The identification of three QTLs, some of the first reported for a plant nectar trait, indicates polygenic control of DHA content. We have established plant genetics as a key influence on DHA accumulation. The data suggest the hypothesis of LsSGPP2 releasing DHA from DHA-phosphate and variability in LsSgpp2 gene expression contributing to the trait variability.
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Affiliation(s)
- Ella R P Grierson
- The New Zealand Institute for Plant and Food Research Limited (PFR), Palmerston North, 4472, New Zealand
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | | | - John W van Klink
- PFR, Chemistry Department, University of Otago, Dunedin, 9016, New Zealand
| | - David H Lewis
- The New Zealand Institute for Plant and Food Research Limited (PFR), Palmerston North, 4472, New Zealand
| | | | - Jason Shiller
- PFR, Te Puke Research Centre, Te Puke, 3182, New Zealand
| | - Poppy Miller
- PFR, Te Puke Research Centre, Te Puke, 3182, New Zealand
| | | | - Michael J Clearwater
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | - Kevin M Davies
- The New Zealand Institute for Plant and Food Research Limited (PFR), Palmerston North, 4472, New Zealand
| | - David Chagné
- The New Zealand Institute for Plant and Food Research Limited (PFR), Palmerston North, 4472, New Zealand
| | - Kathy E Schwinn
- The New Zealand Institute for Plant and Food Research Limited (PFR), Palmerston North, 4472, New Zealand
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2
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Wen X, Chen Z, Yang Z, Wang M, Jin S, Wang G, Zhang L, Wang L, Li J, Saeed S, He S, Wang Z, Wang K, Kong Z, Li F, Zhang X, Chen X, Zhu Y. A comprehensive overview of cotton genomics, biotechnology and molecular biological studies. SCIENCE CHINA. LIFE SCIENCES 2023; 66:2214-2256. [PMID: 36899210 DOI: 10.1007/s11427-022-2278-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/09/2023] [Indexed: 03/12/2023]
Abstract
Cotton is an irreplaceable economic crop currently domesticated in the human world for its extremely elongated fiber cells specialized in seed epidermis, which makes it of high research and application value. To date, numerous research on cotton has navigated various aspects, from multi-genome assembly, genome editing, mechanism of fiber development, metabolite biosynthesis, and analysis to genetic breeding. Genomic and 3D genomic studies reveal the origin of cotton species and the spatiotemporal asymmetric chromatin structure in fibers. Mature multiple genome editing systems, such as CRISPR/Cas9, Cas12 (Cpf1) and cytidine base editing (CBE), have been widely used in the study of candidate genes affecting fiber development. Based on this, the cotton fiber cell development network has been preliminarily drawn. Among them, the MYB-bHLH-WDR (MBW) transcription factor complex and IAA and BR signaling pathway regulate the initiation; various plant hormones, including ethylene, mediated regulatory network and membrane protein overlap fine-regulate elongation. Multistage transcription factors targeting CesA 4, 7, and 8 specifically dominate the whole process of secondary cell wall thickening. And fluorescently labeled cytoskeletal proteins can observe real-time dynamic changes in fiber development. Furthermore, research on the synthesis of cotton secondary metabolite gossypol, resistance to diseases and insect pests, plant architecture regulation, and seed oil utilization are all conducive to finding more high-quality breeding-related genes and subsequently facilitating the cultivation of better cotton varieties. This review summarizes the paramount research achievements in cotton molecular biology over the last few decades from the above aspects, thereby enabling us to conduct a status review on the current studies of cotton and provide strong theoretical support for the future direction.
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Affiliation(s)
- Xingpeng Wen
- Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Zhiwen Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, University of CAS, Chinese Academy of Sciences, Shanghai, 200032, China
- Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China
| | - Zuoren Yang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Maojun Wang
- Hubei Hongshan Laboratory, National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shuangxia Jin
- Hubei Hongshan Laboratory, National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Guangda Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Li Zhang
- Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China
| | - Lingjian Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, University of CAS, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Jianying Li
- Hubei Hongshan Laboratory, National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sumbul Saeed
- Hubei Hongshan Laboratory, National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shoupu He
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Zhi Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China
| | - Kun Wang
- College of Life Sciences, Wuhan University, Wuhan, 430072, China
| | - Zhaosheng Kong
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China.
- Shanxi Agricultural University, Jinzhong, 030801, China.
| | - Fuguang Li
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, 455000, China.
| | - Xianlong Zhang
- Hubei Hongshan Laboratory, National Key Laboratory of Crop Genetic Improvement, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Xiaoya Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, University of CAS, Chinese Academy of Sciences, Shanghai, 200032, China.
- Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China.
| | - Yuxian Zhu
- Institute for Advanced Studies, Wuhan University, Wuhan, 430072, China.
- College of Life Sciences, Wuhan University, Wuhan, 430072, China.
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3
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Magner ET, Roy R, Freund Saxhaug K, Zambre A, Bruns K, Snell-Rood EC, Hampton M, Hegeman AD, Carter CJ. Post-secretory synthesis of a natural analog of iron-gall ink in the black nectar of Melianthus spp. THE NEW PHYTOLOGIST 2023. [PMID: 36880409 DOI: 10.1111/nph.18859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/20/2023] [Indexed: 06/18/2023]
Abstract
The black nectar produced by Melianthus flowers is thought to serve as a visual attractant to bird pollinators, but the chemical identity and synthesis of the black pigment are unknown. A combination of analytical biochemistry, transcriptomics, proteomics, and enzyme assays was used to identify the pigment that gives Melianthus nectar its black color and how it is synthesized. Visual modeling of pollinators was also used to infer a potential function of the black coloration. High concentrations of ellagic acid and iron give the nectar its dark black color, which can be recapitulated through synthetic solutions containing only ellagic acid and iron(iii). The nectar also contains a peroxidase that oxidizes gallic acid to form ellagic acid. In vitro reactions containing the nectar peroxidase, gallic acid, hydrogen peroxide, and iron(iii) fully recreate the black color of the nectar. Visual modeling indicates that the black color is highly conspicuous to avian pollinators within the context of the flower. Melianthus nectar contains a natural analog of iron-gall ink, which humans have used since at least medieval times. This pigment is derived from an ellagic acid-Fe complex synthesized in the nectar and is likely involved in the attraction of passerine pollinators endemic to southern Africa.
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Affiliation(s)
- Evin T Magner
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Avenue, 140 Gortner Lab, St Paul, MN, 55108, USA
| | - Rahul Roy
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Avenue, 140 Gortner Lab, St Paul, MN, 55108, USA
- Department of Biology, St. Catherine University, St Paul, MN, 55105, USA
| | - Katrina Freund Saxhaug
- Department of Horticultural Science, University of Minnesota, Room 290 Alderman Hall, 1970 Folwell Avenue, St Paul, MN, 55108, USA
| | - Amod Zambre
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Kaitlyn Bruns
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Avenue, 140 Gortner Lab, St Paul, MN, 55108, USA
| | - Emilie C Snell-Rood
- Department of Ecology, Evolution, and Behavior, University of Minnesota, St Paul, MN, 55108, USA
| | - Marshall Hampton
- Department of Mathematics & Statistics, University of Minnesota Duluth, Duluth, MN, 55812, USA
| | - Adrian D Hegeman
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Avenue, 140 Gortner Lab, St Paul, MN, 55108, USA
- Department of Horticultural Science, University of Minnesota, Room 290 Alderman Hall, 1970 Folwell Avenue, St Paul, MN, 55108, USA
| | - Clay J Carter
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Avenue, 140 Gortner Lab, St Paul, MN, 55108, USA
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4
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Chahtane H, Lai X, Tichtinsky G, Rieu P, Arnoux-Courseaux M, Cancé C, Marondedze C, Parcy F. Flower Development in Arabidopsis. Methods Mol Biol 2023; 2686:3-38. [PMID: 37540352 DOI: 10.1007/978-1-0716-3299-4_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
Like in other angiosperms, the development of flowers in Arabidopsis starts right after the floral transition, when the shoot apical meristem (SAM) stops producing leaves and makes flowers instead. On the flanks of the SAM emerge the flower meristems (FM) that will soon differentiate into the four main floral organs, sepals, petals, stamens, and pistil, stereotypically arranged in concentric whorls. Each phase of flower development-floral transition, floral bud initiation, and floral organ development-is under the control of specific gene networks. In this chapter, we describe these different phases and the gene regulatory networks involved, from the floral transition to the floral termination.
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Affiliation(s)
- Hicham Chahtane
- CNRS, Université Grenoble Alpes, CEA, INRAE, IRIG, BIG-LPCV, Grenoble, France
- Institut de Recherche Pierre Fabre, Green Mission Pierre Fabre, Conservatoire Botanique Pierre Fabre, Soual, France
| | - Xuelei Lai
- CNRS, Université Grenoble Alpes, CEA, INRAE, IRIG, BIG-LPCV, Grenoble, France
- Huazhong Agricultural University, National Key Laboratory of Crop Genetic Improvement, Hubei Hongshan Laboratory, Wuhan, China
| | | | - Philippe Rieu
- CNRS, Université Grenoble Alpes, CEA, INRAE, IRIG, BIG-LPCV, Grenoble, France
- Structural Plant Biology Laboratory, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | | | - Coralie Cancé
- CNRS, Université Grenoble Alpes, CEA, INRAE, IRIG, BIG-LPCV, Grenoble, France
| | - Claudius Marondedze
- CNRS, Université Grenoble Alpes, CEA, INRAE, IRIG, BIG-LPCV, Grenoble, France
- Department of Biochemistry, Faculty of Medicine, Midlands State University, Senga, Gweru, Zimbabwe
| | - François Parcy
- CNRS, Université Grenoble Alpes, CEA, INRAE, IRIG, BIG-LPCV, Grenoble, France.
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5
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Egan PA, Stevenson PC, Stout JC. Pollinator selection against toxic nectar as a key facilitator of a plant invasion. Philos Trans R Soc Lond B Biol Sci 2022; 377:20210168. [PMID: 35491597 DOI: 10.1098/rstb.2021.0168] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plant compounds associated with herbivore defence occur widely in floral nectar and can impact pollinator health. We showed previously that Rhododendron ponticum nectar contains grayanotoxin I (GTX I) at concentrations that are lethal or sublethal to honeybees and a solitary bee in the plant's non-native range in Ireland. Here we further examined this conflict and tested the hypotheses that nectar GTX I is subject to negative pollinator-mediated selection in the non-native range, but that phenotypic linkage between GTX I levels in nectar and leaves acts as a constraint on independent evolution. We found that nectar GTX I experienced negative directional selection in the non-native range, in contrast to the native Iberian range, and that the magnitude and frequency of pollinator limitation indicated that selection was pollinator-mediated. Surprisingly, nectar GTX I levels were decoupled from those of leaves in the non-native range, which may have assisted post-invasion evolution of nectar without compromising the anti-herbivore function of GTX I (here demonstrated in bioassays with an ecologically relevant herbivore). Our study emphasizes the centrality of pollinator health as a concept linked to the invasion process, and how post-invasion evolution can be targeted toward minimizing lethal or sub-lethal effects on pollinators. This article is part of the theme issue 'Natural processes influencing pollinator health: from chemistry to landscapes'.
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Affiliation(s)
- Paul A Egan
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, PO Box 102, Alnarp 23053, Sweden
| | - Philip C Stevenson
- Royal Botanic Gardens, Kew, Kew Green, Richmond, Surrey TW9 3AE, UK.,Natural Resources Institute, University of Greenwich, Chatham, Kent ME4 4TB, UK
| | - Jane C Stout
- Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
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6
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Clearwater MJ, Noe ST, Manley-Harris M, Truman GL, Gardyne S, Murray J, Obeng-Darko SA, Richardson SJ. Nectary photosynthesis contributes to the production of mānuka (Leptospermum scoparium) floral nectar. THE NEW PHYTOLOGIST 2021; 232:1703-1717. [PMID: 34287899 DOI: 10.1111/nph.17632] [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: 04/06/2021] [Accepted: 07/04/2021] [Indexed: 06/13/2023]
Abstract
Current models of floral nectar production do not include a contribution from photosynthesis by green nectary tissue, even though many species have green nectaries. Mānuka (Leptospermum scoparium) floral nectaries are green, and in addition to sugars, their nectar contains dihydroxyacetone (DHA), the precursor of the antimicrobial agent in the honey. We investigated causes of variation in mānuka floral nectar production, particularly the effect of light incident on the nectary. Flower gas exchange, chlorophyll fluorescence, and the effects on nectar of age, temperature, light, sucrose, 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), pyridoxal phosphate, and 13 CO2 , were measured for attached and excised flowers. Flower age affected all nectar traits, whilst temperature affected total nectar sugar only. Increased light reduced floral CO2 efflux, increased nectar sugar production, and affected the ratio of DHA to other nectar sugars. DCMU, an inhibitor of photosystem II, reduced nectar sugar production. Pyridoxal phosphate, an inhibitor of the chloroplast envelope triose phosphate transporter, reduced nectar DHA content. Incubation of excised flowers with 13 CO2 in the light resulted in enrichment of nectar sugars, including DHA. Photosynthesis within green nectaries contributes to nectar sugars and influences nectar composition. Mānuka nectar DHA arises from pools of triose phosphate that are modulated by nectary photosynthesis.
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Affiliation(s)
- Michael J Clearwater
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | - Stevie T Noe
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | - Merilyn Manley-Harris
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | - Georgia-Leigh Truman
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | - Stephen Gardyne
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | - Jessica Murray
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
| | - Sylvester A Obeng-Darko
- Te Aka Mātuatua - School of Science, University of Waikato, Hamilton, 3216, New Zealand
- School of Biological Science, University of Western Australia, Perth, WA, 6009, Australia
| | - Sarah J Richardson
- Manaaki Whenua - Landcare Research, PO Box 69040, Lincoln, 7640, New Zealand
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7
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Minami A, Kang X, Carter CJ. A cell wall invertase controls nectar volume and sugar composition. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 107:1016-1028. [PMID: 34048120 DOI: 10.1111/tpj.15357] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 06/12/2023]
Abstract
Nectar volume and sugar composition are key determinants of the strength of plant-pollinator mutualisms. The main nectar sugars are sucrose, glucose and fructose, which can vary widely in ratio and concentration across species. Brassica spp. produce a hexose-dominant nectar (high in the monosaccharides glucose and fructose) with very low levels of the disaccharide sucrose. Cell wall invertases (CWINVs) catalyze the irreversible hydrolysis of sucrose into glucose and fructose in the apoplast. We found that BrCWINV4A is highly expressed in the nectaries of Brassica rapa. Moreover, a brcwinv4a null mutant: (i) has greatly reduced CWINV activity in the nectaries; (ii) produces a sucrose-rich nectar; but (iii) with significantly less volume. These results definitively demonstrate that CWINV activity is not only essential for the production of a hexose-rich nectar, but also support a hypothetical model of nectar secretion in which its hydrolase activity is required for maintaining a high intracellular-to-extracellular sucrose ratio that facilitates the continuous export of sucrose into the nectary apoplast. The extracellular hydrolysis of each sucrose into two hexoses by BrCWINV4A also likely creates the osmotic potential required for nectar droplet formation. These results cumulatively indicate that modulation of CWINV activity can at least partially account for naturally occurring differences in nectar volume and sugar composition. Finally, honeybees prefer nectars with some sucrose, but wild-type B. rapa flowers were much more heavily visited than flowers of brcwinv4a, suggesting that the potentially attractive sucrose-rich nectar of brcwinv4a could not compensate for its low volume.
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Affiliation(s)
- Anzu Minami
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Ave, St. Paul, MN, 55108, USA
| | - Xiaojun Kang
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Ave, St. Paul, MN, 55108, USA
| | - Clay J Carter
- Department of Plant & Microbial Biology, University of Minnesota, 1479 Gortner Ave, St. Paul, MN, 55108, USA
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8
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Chatt EC, Mahalim SN, Mohd-Fadzil NA, Roy R, Klinkenberg PM, Horner HT, Hampton M, Carter CJ, Nikolau BJ. Nectar biosynthesis is conserved among floral and extrafloral nectaries. PLANT PHYSIOLOGY 2021; 185:1595-1616. [PMID: 33585860 PMCID: PMC8133665 DOI: 10.1093/plphys/kiab018] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/28/2020] [Indexed: 06/12/2023]
Abstract
Nectar is a primary reward mediating plant-animal mutualisms to improve plant fitness and reproductive success. Four distinct trichomatic nectaries develop in cotton (Gossypium hirsutum), one floral and three extrafloral, and the nectars they secrete serve different purposes. Floral nectar attracts bees for promoting pollination, while extrafloral nectar attracts predatory insects as a means of indirect protection from herbivores. Cotton therefore provides an ideal system for contrasting mechanisms of nectar production and nectar composition between different nectary types. Here, we report the transcriptome and ultrastructure of the four cotton nectary types throughout development and compare these with the metabolomes of secreted nectars. Integration of these datasets supports specialization among nectary types to fulfill their ecological niche, while conserving parallel coordination of the merocrine-based and eccrine-based models of nectar biosynthesis. Nectary ultrastructures indicate an abundance of rough endoplasmic reticulum positioned parallel to the cell walls and a profusion of vesicles fusing to the plasma membranes, supporting the merocrine model of nectar biosynthesis. The eccrine-based model of nectar biosynthesis is supported by global transcriptomics data, which indicate a progression from starch biosynthesis to starch degradation and sucrose biosynthesis and secretion. Moreover, our nectary global transcriptomics data provide evidence for novel metabolic processes supporting de novo biosynthesis of amino acids secreted in trace quantities in nectars. Collectively, these data demonstrate the conservation of nectar-producing models among trichomatic and extrafloral nectaries.
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Affiliation(s)
- Elizabeth C Chatt
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, 50010, Iowa
| | - Siti-Nabilla Mahalim
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, 50010, Iowa
| | - Nur-Aziatull Mohd-Fadzil
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, 50010, Iowa
| | - Rahul Roy
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, St. Paul, 55108, Minnesota
- Department of Biology, St. Catherine University, St. Paul, 55105, Minnesota
| | - Peter M Klinkenberg
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, St. Paul, 55108, Minnesota
| | - Harry T Horner
- Department of Genetics, Development and Cell Biology, Iowa State University, Ames, 50010, Iowa
- Roy J. Carver High Resolution Microscopy Facility, Iowa State University, Ames, 50010, Iowa
| | - Marshall Hampton
- Department of Mathematics and Statistics, University of Minnesota Duluth, Duluth, 55812, Minnesota
| | - Clay J Carter
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, St. Paul, 55108, Minnesota
| | - Basil J Nikolau
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, 50010, Iowa
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9
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Slavković F, Dogimont C, Morin H, Boualem A, Bendahmane A. The Genetic Control of Nectary Development. TRENDS IN PLANT SCIENCE 2021; 26:260-271. [PMID: 33246889 DOI: 10.1016/j.tplants.2020.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 10/28/2020] [Accepted: 11/02/2020] [Indexed: 06/12/2023]
Abstract
Nectar is the most important reward offered by flowering plants to pollinators for pollination services. Since pollinator decline has emerged as a major threat for agriculture, and the food demand is growing globally, studying the nectar gland is of utmost importance. Although the genetic mechanisms that control the development of angiosperm flowers have been quite well understood for many years, the development and maturation of the nectar gland and the secretion of nectar in synchrony with the maturation of the sexual organs appears to be one of the flower's best-kept secrets. Here we review key findings controlling these processes. We also raise key questions that need to be addressed to develop crop ecological functions that take into consideration pollinators' needs.
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Affiliation(s)
- Filip Slavković
- Université Paris-Saclay, INRAE, CNRS, Univ. Evry, Institute of Plant Sciences Paris-Saclay, 91405 Orsay, France
| | - Catherine Dogimont
- INRAE, UR 1052, Unité de Génétique et d'Amélioration des Fruits et Légumes, BP 94, F-84143 Montfavet, France
| | - Halima Morin
- Université Paris-Saclay, INRAE, CNRS, Univ. Evry, Institute of Plant Sciences Paris-Saclay, 91405 Orsay, France
| | - Adnane Boualem
- Université Paris-Saclay, INRAE, CNRS, Univ. Evry, Institute of Plant Sciences Paris-Saclay, 91405 Orsay, France
| | - Abdelhafid Bendahmane
- Université Paris-Saclay, INRAE, CNRS, Univ. Evry, Institute of Plant Sciences Paris-Saclay, 91405 Orsay, France.
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10
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Solhaug EM, Roy R, Venterea RT, Carter CJ. The role of alanine synthesis and nitrate-induced nitric oxide production during hypoxia stress in Cucurbita pepo nectaries. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2021; 105:580-599. [PMID: 33119149 DOI: 10.1111/tpj.15055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 10/09/2020] [Accepted: 10/21/2020] [Indexed: 05/19/2023]
Abstract
Floral nectar is a sugary solution produced by nectaries to attract and reward pollinators. Nectar metabolites, such as sugars, are synthesized within the nectary during secretion from both pre-stored and direct phloem-derived precursors. In addition to sugars, nectars contain nitrogenous compounds such as amino acids; however, little is known about the role(s) of nitrogen (N) compounds in nectary function. In this study, we investigated N metabolism in Cucurbita pepo (squash) floral nectaries in order to understand how various N-containing compounds are produced and determine the role of N metabolism in nectar secretion. The expression and activity of key enzymes involved in primary N assimilation, including nitrate reductase (NR) and alanine aminotransferase (AlaAT), were induced during secretion in C. pepo nectaries. Alanine (Ala) accumulated to about 35% of total amino acids in nectaries and nectar during peak secretion; however, alteration of vascular nitrate supply had no impact on Ala accumulation during secretion, suggesting that nectar(y) amino acids are produced by precursors other than nitrate. In addition, nitric oxide (NO) is produced from nitrate and nitrite, at least partially by NR, in nectaries and nectar. Hypoxia-related processes are induced in nectaries during secretion, including lactic acid and ethanolic fermentation. Finally, treatments that alter nitrate supply affect levels of hypoxic metabolites, nectar volume and nectar sugar composition. The induction of N metabolism in C. pepo nectaries thus plays an important role in the synthesis and secretion of nectar sugar.
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Affiliation(s)
- Erik M Solhaug
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
| | - Rahul Roy
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
| | - Rodney T Venterea
- Soil and Water Management Research Unit, Agricultural Research Service, USDA, St Paul, MN, 55108, USA
| | - Clay J Carter
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, MN, 55108, USA
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11
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Diversity of Floral Glands and Their Secretions in Pollinator Attraction. REFERENCE SERIES IN PHYTOCHEMISTRY 2020. [DOI: 10.1007/978-3-319-96397-6_48] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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12
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Liu H, Ma J, Li H. Transcriptomic and microstructural analyses in Liriodendron tulipifera Linn. reveal candidate genes involved in nectary development and nectar secretion. BMC PLANT BIOLOGY 2019; 19:531. [PMID: 31791230 PMCID: PMC6889543 DOI: 10.1186/s12870-019-2140-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 11/14/2019] [Indexed: 05/22/2023]
Abstract
BACKGROUND Nectar is a major floral attractant and reward for insects that ensures pollination. Liriodendron, a genus of the Magnoliaceae family, includes only two relict species, L. chinense and L. tulipifera, which are considered "basal angiosperms" according to plant evolutionary history. The flowers of Liriodendron plants are insect pollinated and secrete nectar to attract pollinators. To date, the morphology and anatomy of nectaries, the mechanism of nectar secretion and the molecular mechanism of nectary development in Liriodendron remain poorly understood. METHODS In this study, we examined the nectary surface cells and change in starch in L. tulipifera by using scanning electron microscopy and periodic acid-Schiff techniques to select appropriate samples for subsequent research. Transcriptome sequencing was of the top and middle parts of immature nectaries and the middle part of mature and postsecretory nectaries in L. tulipifera was performed. We evaluated the expression profiles of 21 DEGs that are closely related to nectary development and nectar secretion for real-time quantitative PCR analysis. RESULTS L. tulipifera nectaries are starch-storing nectaries and are located in the top and middle parts of L. tulipifera petals. After analyzing the RNA-seq data, we obtained 115.26 Gb of clean data in 12 libraries and mapped the results to the L. chinense reference genome with 71.02-79.77% efficiency. In total, 26,955 DEGs were identified by performing six pairwise comparisons. The flavonoid biosynthesis, phenylpropanoid biosynthesis, anthocyanin biosynthesis and starch and sucrose metabolism pathways were enriched and related to nectar secretion and pigment change. We identified 56 transcription factor families, and members of the TCP, Trihelix, C2H2, ERF, and MADS families changed dynamically during nectary development. Moreover, to further verify the accuracy of the RNA-seq results, we validated the expression profiles of 21 candidate genes. CONCLUSIONS We evaluated the nectary development and secretion processes comprehensively and identified many related candidate genes in L. tulipifera. These findings suggest that nectaries play important roles in flavonoid synthesis and petal color presentation.
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Affiliation(s)
- Huanhuan Liu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, Jiangsu, China
| | - Jikai Ma
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, Jiangsu, China
| | - Huogen Li
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, 159 Longpan Road, Nanjing, 210037, Jiangsu, China.
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13
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Ma XL, Milne RI, Zhou HX, Song YQ, Fang JY, Zha HG. Proteomics and post-secretory content adjustment of Nicotiana tabacum nectar. PLANTA 2019; 250:1703-1715. [PMID: 31414205 DOI: 10.1007/s00425-019-03258-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Accepted: 08/08/2019] [Indexed: 06/10/2023]
Abstract
MAIN CONCLUSION The tobacco nectar proteome mainly consists of pathogenesis-related proteins with two glycoproteins. Expression of nectarins was non-synchronous, and not nectary specific. After secretion, tobacco nectar changed from sucrose rich to hexose rich. Floral nectar proteins (nectarins) play important roles in inhibiting microbial growth in nectar, and probably also tailoring nectar chemistry before or after secretion; however, very few plant species have had their nectar proteomes thoroughly investigated. Nectarins from Nicotiana tabacum (NT) were separated using two-dimensional gel electrophoresis and then analysed using mass spectrometry. Seven nectarins were identified: acidic endochitinase, β-xylosidase, α-galactosidase, α-amylase, G-type lectin S-receptor-like serine/threonine-protein kinase, pathogenesis-related protein 5, and early nodulin-like protein 2. An eighth nectarin, a glycoprotein with unknown function, was identified following isolation from NT nectar using a Qproteome total glycoprotein kit, separation by SDS-PAGE, and identification by mass spectrometry. Expression of all identified nectarins, plus four invertase genes, was analysed by qRT PCR; none of these genes had nectary-specific expression, and none had synchronous expression. The total content of sucrose, hexoses, proteins, phenolics, and hydrogen peroxide were determined at different time intervals in secreted nectar, both within the nectar tube (in vivo) and following extraction from it during incubation at 30 °C for up to 40 h in plastic tubes (in vitro). After secretion, the ratio of hexose to sucrose substantially increased for in vivo nectar, but no sugar composition changes were detected in vitro. This implies that sucrose hydrolysis in vivo might be done by fixed apoplastic invertase. Both protein and hydrogen peroxide levels declined in vitro but not in vivo, implying that some factors other than nectarins act to maintain their levels in the flower, after secretion.
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Affiliation(s)
- Xue-Long Ma
- College of Life and Environment Sciences, Huangshan University, Huangshan, China
| | - Richard I Milne
- Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh, UK
| | - Hong-Xia Zhou
- College of Life and Environment Sciences, Huangshan University, Huangshan, China
| | - Yue-Qin Song
- College of Life and Environment Sciences, Huangshan University, Huangshan, China
| | - Jiang-Yu Fang
- College of Life and Environment Sciences, Huangshan University, Huangshan, China
| | - Hong-Guang Zha
- College of Life and Environment Sciences, Huangshan University, Huangshan, China.
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14
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Solhaug EM, Roy R, Chatt EC, Klinkenberg PM, Mohd‐Fadzil N, Hampton M, Nikolau BJ, Carter CJ. An integrated transcriptomics and metabolomics analysis of the Cucurbita pepo nectary implicates key modules of primary metabolism involved in nectar synthesis and secretion. PLANT DIRECT 2019; 3:e00120. [PMID: 31245763 PMCID: PMC6508809 DOI: 10.1002/pld3.120] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 01/27/2019] [Accepted: 02/11/2019] [Indexed: 05/24/2023]
Abstract
Nectar is the main reward that flowers offer to pollinators to entice repeated visitation. Cucurbita pepo (squash) is an excellent model for studying nectar biology, as it has large nectaries that produce large volumes of nectar relative to most other species. Squash is also monoecious, having both female and male flowers on the same plant, which allows comparative analyses of nectary function in one individual. Here, we report the nectary transcriptomes from both female and male nectaries at four stages of floral maturation. Analysis of these transcriptomes and subsequent confirmatory experiments revealed a metabolic progression in nectaries leading from starch synthesis to starch degradation and to sucrose biosynthesis. These results are consistent with previously published models of nectar secretion and also suggest how a sucrose-rich nectar can be synthesized and secreted in the absence of active transport across the plasma membrane. Nontargeted metabolomic analyses of nectars also confidently identified 40 metabolites in both female and male nectars, with some displaying preferential accumulation in nectar of either male or female flowers. Cumulatively, this study identified gene targets for reverse genetics approaches to study nectary function, as well as previously unreported nectar metabolites that may function in plant-biotic interactions.
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Affiliation(s)
- Erik M. Solhaug
- Department of Plant & Microbial BiologyUniversity of MinnesotaSt. PaulMinnesota
| | - Rahul Roy
- Department of Plant & Microbial BiologyUniversity of MinnesotaSt. PaulMinnesota
| | - Elizabeth C. Chatt
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular BiologyCenter for Metabolic BiologyIowa State UniversityAmesIowa
| | | | - Nur‐Aziatull Mohd‐Fadzil
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular BiologyCenter for Metabolic BiologyIowa State UniversityAmesIowa
| | - Marshall Hampton
- Department of Mathematics & StatisticsUniversity of Minnesota DuluthDuluthMinnesota
| | - Basil J. Nikolau
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular BiologyCenter for Metabolic BiologyIowa State UniversityAmesIowa
| | - Clay J. Carter
- Department of Plant & Microbial BiologyUniversity of MinnesotaSt. PaulMinnesota
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15
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Li Z, Jiang Y, Liu D, Ma J, Li J, Li M, Sui S. Floral Scent Emission from Nectaries in the Adaxial Side of the Innermost and Middle Petals in Chimonanthus praecox. Int J Mol Sci 2018; 19:ijms19103278. [PMID: 30360370 PMCID: PMC6214010 DOI: 10.3390/ijms19103278] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/15/2018] [Accepted: 10/18/2018] [Indexed: 11/16/2022] Open
Abstract
Wintersweet (Chimonanthus praecox) is a well-known traditional fragrant plant and a winter-flowering deciduous shrub that originated in China. The five different developmental stages of wintersweet, namely, flower-bud period (FB), displayed petal stage (DP), open flower stage (OF), later blooming period (LB), and wilting period (WP) were studied using a scanning electron microscope (SEM) to determine the distribution characteristics of aroma-emitting nectaries. Results showed that the floral scent was probably emitted from nectaries distributed on the adaxial side of the innermost and middle petals, but almost none on the abaxial side. The nectaries in different developmental periods on the petals differ in numbers, sizes, and characteristics. Although the distribution of nectaries on different rounds of petals showed a diverse pattern at the same developmental periods, that of the nectaries on the same round of petals showed some of regularity. The nectary is concentrated on the adaxial side of the petals, especially in the region near the axis of the lower part of the petals. Based on transcriptional sequence and phylogenetic analysis, we report one nectary development related gene CpCRC (CRABS CLAW), and the other four YABBY family genes, CpFIL (FILAMENTOUS FLOWER), CpYABBY2, CpYABBY5-1, and CpYABBY5-2 in C. praecox (accession no. MH718960-MH718964). Quantitative RT-PCR (qRT-PCR) results showed that the expression characteristics of these YABBY family genes were similar to those of 11 floral scent genes, namely, CpSAMT, CpDMAPP, CpIPP, CpGPPS1, CpGPPS2, CpGPP, CpLIS, CpMYR1, CpFPPS, CpTER3, and CpTER5. The expression levels of these genes were generally higher in the lower part of the petals than in the upper halves in different rounds of petals, the highest being in the innermost petals, but the lowest in the outer petals. Relative expression level of CpFIL, CpCRC, CpYABBY5-1, and CpLIS in the innermost and middle petals in OF stages is significant higher than that of in outer petals, respectively. SEM and qRT-PCR results in C. praecox showed that floral scent emission is related to the distribution of nectaries.
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Affiliation(s)
- Zhineng Li
- College of Horticulture and Landscape Achitecture, Southwest University, Chongqing 400715, China.
- Key Laboratory of Horticulture Science for Southern Mountains Regions, Ministry of Education, Chongqing 400715, China.
- Chongqing Engineering Research Center for Floriculture, Chongqing 400715, China.
| | - Yingjie Jiang
- College of Horticulture and Landscape Achitecture, Southwest University, Chongqing 400715, China.
- Key Laboratory of Horticulture Science for Southern Mountains Regions, Ministry of Education, Chongqing 400715, China.
- Chongqing Engineering Research Center for Floriculture, Chongqing 400715, China.
| | - Daofeng Liu
- College of Horticulture and Landscape Achitecture, Southwest University, Chongqing 400715, China.
- Key Laboratory of Horticulture Science for Southern Mountains Regions, Ministry of Education, Chongqing 400715, China.
- Chongqing Engineering Research Center for Floriculture, Chongqing 400715, China.
| | - Jing Ma
- College of Horticulture and Landscape Achitecture, Southwest University, Chongqing 400715, China.
- Key Laboratory of Horticulture Science for Southern Mountains Regions, Ministry of Education, Chongqing 400715, China.
- Chongqing Engineering Research Center for Floriculture, Chongqing 400715, China.
| | - Jing Li
- College of Horticulture and Landscape Achitecture, Southwest University, Chongqing 400715, China.
- Key Laboratory of Horticulture Science for Southern Mountains Regions, Ministry of Education, Chongqing 400715, China.
- Chongqing Engineering Research Center for Floriculture, Chongqing 400715, China.
| | - Mingyang Li
- College of Horticulture and Landscape Achitecture, Southwest University, Chongqing 400715, China.
- Key Laboratory of Horticulture Science for Southern Mountains Regions, Ministry of Education, Chongqing 400715, China.
- Chongqing Engineering Research Center for Floriculture, Chongqing 400715, China.
| | - Shunzhao Sui
- College of Horticulture and Landscape Achitecture, Southwest University, Chongqing 400715, China.
- Key Laboratory of Horticulture Science for Southern Mountains Regions, Ministry of Education, Chongqing 400715, China.
- Chongqing Engineering Research Center for Floriculture, Chongqing 400715, China.
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16
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Chatt EC, von Aderkas P, Carter CJ, Smith D, Elliott M, Nikolau BJ. Sex-Dependent Variation of Pumpkin ( Cucurbita maxima cv. Big Max) Nectar and Nectaries as Determined by Proteomics and Metabolomics. FRONTIERS IN PLANT SCIENCE 2018; 9:860. [PMID: 30008725 PMCID: PMC6034135 DOI: 10.3389/fpls.2018.00860] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 06/04/2018] [Indexed: 05/06/2023]
Abstract
Nectar is a floral reward that sustains mutualisms with pollinators, which in turn, improves fruit set. While it is known that nectar is a chemically complex solution, extensive identification and quantification of this complexity has been lacking. Cucurbita maxima cv. Big Max, like many cucurbits, is monoecious with separate male and female flowers. Attraction of bees to the flowers through the reward of nectar is essential for reproductive success in this economically valuable crop. In this study, the sex-dependent variation in composition of male and female nectar and the nectaries were defined using a combination of GC-MS based metabolomics and LC-MS/MS based proteomics. Metabolomics analysis of nectar detected 88 metabolites, of which 40 were positively identified, and includes sugars, sugar alcohols, aromatics, diols, organic acids, and amino acids. There are differences in 29 metabolites between male and female nectar. The nectar proteome consists of 45 proteins, of which 70% overlap between nectar types. Only two proteins are unique to female nectar, and 10 are specific to male nectar. The nectary proteome data, accessible at ProteomeXchange with identifier PXD009810, contained 339 identifiable proteins, 71% of which were descriptively annotatable by homology to Plantae. The abundance of 45 proteins differs significantly between male and female nectaries, as determined by iTRAQ labeling. This rich dataset significantly expands the known complexity of nectar composition, supports the hypothesis of H+-driven nectar solute export, and provides genetic and chemical targets to understand plant-pollinator interactions.
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Affiliation(s)
- Elizabeth C. Chatt
- Department of Biochemistry Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | | | - Clay J. Carter
- Department of Plant and Microbial Biology, University of Minnesota Twin Cities, St. Paul, MN, United States
| | - Derek Smith
- UVic Genome BC Protein Centre, Victoria, BC, Canada
| | | | - Basil J. Nikolau
- Department of Biochemistry Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
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17
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Borghi M, Xie DY. Cloning and characterization of a monoterpene synthase gene from flowers of Camelina sativa. PLANTA 2018; 247:443-457. [PMID: 29075872 DOI: 10.1007/s00425-017-2801-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 10/20/2017] [Indexed: 05/15/2023]
Abstract
CsTPS1 encodes for a monoterpene synthase that contributes to the emission of a blend of volatile compounds emitted from flowers of Camelina sativa. The work describes the in vitro characterization of a monoterpene synthase and its regulatory region that we cloned from Camelina sativa (Camelina). Here, we named this gene as C. sativa terpene synthase 1 (CsTPS1). In vitro experiments performed with the CsTPS1 protein after expression and purification from Escherichia coli (E. coli) showed production of a blend of monoterpene volatile organic compounds, of which the emission was also detected in the floral bouquet of wild-type Camelina plants. Quantitative-PCR measurements revealed a high abundance of CsTPS1 transcripts in flowers and experiments performed with the GUS reporter showed high CsTPS1 expression in the pistil, in the cells of the wall of the ovary and in the stigma. Subcellular localization of the CsTPS1 protein was investigated with a GFP reporter construct that showed expression in plastids. The CsTPS1 gene identified in this study belongs to a mid-size family of 60 genes putatively codifying for TPS enzymes. This enlarged family of TPS genes suggests that Camelina has the structural framework for the production of terpenes and other secondary metabolites of relevance for the consumers.
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Affiliation(s)
- Monica Borghi
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA
- Max-Planck-Institute of Molecular Plant Physiology, Am Mühlenberg, 1, 14476, Potsdam-Golm, Germany
| | - De-Yu Xie
- Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA.
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18
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Thomas JB, Hampton ME, Dorn KM, David Marks M, Carter CJ. The pennycress (Thlaspi arvense L.) nectary: structural and transcriptomic characterization. BMC PLANT BIOLOGY 2017; 17:201. [PMID: 29137608 PMCID: PMC5686818 DOI: 10.1186/s12870-017-1146-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 10/31/2017] [Indexed: 05/08/2023]
Abstract
BACKGROUND Pennycress [Thlaspi arvense L (Brassicaceae)] is being domesticated as a renewable biodiesel feedstock that also provides crucial ecosystems services, including as a nutritional resource for pollinators. However, its flowers produce significantly less nectar than other crop relatives in the Brassicaceae. This study was undertaken to understand the basic biology of the pennycress nectary as an initial step toward the possibility of enhancing nectar output from its flowers. RESULTS Pennycress flowers contain four equivalent nectaries located extrastaminally at the base of the insertion sites of short and long stamens. Like other Brassicaceae, the nectaries have open stomates on their surface, which likely serve as the sites of nectar secretion. The nectaries produce four distinct nectar droplets that accumulate in concave structures at the base of each of the four petals. To understand the molecular biology of the pennycress nectary, RNA was isolated from 'immature' (pre-secretory) and 'mature' (secretory) nectaries and subjected to RNA-seq. Approximately 184 M paired-end reads (368 M total reads) were de novo assembled into a total of 16,074 independent contigs, which mapped to 12,335 unique genes in the pennycress genome. Nearly 3700 genes were found to be differentially expressed between immature and mature nectaries and subjected to gene ontology and metabolic pathway analyses. Lastly, in silico analyses identified 158 pennycress orthologs to Arabidopsis genes with known enriched expression in nectaries. These nectary-enriched expression patterns were verified for select pennycress loci by semi-quantitative RT-PCR. CONCLUSIONS Pennycress nectaries are unique relative to those of other agriculturally important Brassicaceae, as they contain four equivalent nectaries that present their nectar in specialized cup-shaped structures at the base of the petals. In spite of these morphological differences, the genes underlying the regulation and production of nectar appear to be largely conserved between pennycress and Arabidopsis thaliana. These results provide a starting point for using forward and reverse genetics approaches to enhance nectar synthesis and secretion in pennycress.
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Affiliation(s)
- Jason B. Thomas
- Department of Plant & Microbial Biology, University of Minnesota Twin Cities, Saint Paul, MN 55108 USA
| | - Marshall E. Hampton
- Department of Mathematics & Statistics, University of Minnesota Duluth, Duluth, MN 55812 USA
| | - Kevin M. Dorn
- Department of Plant & Microbial Biology, University of Minnesota Twin Cities, Saint Paul, MN 55108 USA
- Department of Plant Pathology, Kansas State University, Manhattan, Kansas, 66506 USA
| | - M. David Marks
- Department of Plant & Microbial Biology, University of Minnesota Twin Cities, Saint Paul, MN 55108 USA
| | - Clay J. Carter
- Department of Plant & Microbial Biology, University of Minnesota Twin Cities, Saint Paul, MN 55108 USA
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19
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Roy R, Schmitt AJ, Thomas JB, Carter CJ. Review: Nectar biology: From molecules to ecosystems. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2017; 262:148-164. [PMID: 28716410 DOI: 10.1016/j.plantsci.2017.04.012] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 04/17/2017] [Accepted: 04/19/2017] [Indexed: 05/06/2023]
Abstract
Plants attract mutualistic animals by offering a reward of nectar. Specifically, floral nectar (FN) is produced to attract pollinators, whereas extrafloral nectar (EFN) mediates indirect defenses through the attraction of mutualist predatory insects to limit herbivory. Nearly 90% of all plant species, including 75% of domesticated crops, benefit from animal-mediated pollination, which is largely facilitated by FN. Moreover, EFN represents one of the few defense mechanisms for which stable effects on plant health and fitness have been demonstrated in multiple systems, and thus plays a crucial role in the resistance phenotype of plants producing it. In spite of its central role in plant-animal interactions, the molecular events involved in the development of both floral and extrafloral nectaries (the glands that produce nectar), as well as the synthesis and secretion of the nectar itself, have been poorly understood until recently. This review will cover major recent developments in the understanding of (1) nectar chemistry and its role in plant-mutualist interactions, (2) the structure and development of nectaries, (3) nectar production, and (4) its regulation by phytohormones.
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Affiliation(s)
- Rahul Roy
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Anthony J Schmitt
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Jason B Thomas
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA
| | - Clay J Carter
- Department of Plant and Microbial Biology, University of Minnesota, Saint Paul, MN 55108, USA.
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20
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Borghi M, Fernie AR, Schiestl FP, Bouwmeester HJ. The Sexual Advantage of Looking, Smelling, and Tasting Good: The Metabolic Network that Produces Signals for Pollinators. TRENDS IN PLANT SCIENCE 2017; 22:338-350. [PMID: 28111171 DOI: 10.1016/j.tplants.2016.12.009] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 12/10/2016] [Accepted: 12/21/2016] [Indexed: 05/08/2023]
Abstract
A striking feature of the angiosperms that use animals as pollen carriers to sexually reproduce is the great diversity of their flowers with regard to morphology and traits such as color, odor, and nectar. These traits are underpinned by the synthesis of secondary metabolites such as pigments and volatiles, as well as carbohydrates and amino acids, which are used by plants to lure and reward animal pollinators. We review here the knowledge of the metabolic network that supports the biosynthesis of these compounds and the behavioral responses that these molecules elicit in the animal pollinators. Such knowledge provides us with a deeper insight into the ecology and evolution of plant-pollinator interactions, and should help us to better manage these ecologically essential interactions in agricultural ecosystems.
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Affiliation(s)
- Monica Borghi
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Am Muehlenberg 1, 14476, Potsdam-Golm, Germany
| | - Florian P Schiestl
- Department of Systematic and Evolutionary Botany, University of Zürich, Zollikerstrasse 107, 8008 Zürich
| | - Harro J Bouwmeester
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands; Present address: Plant Hormone Biology group, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
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21
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Ahmad P, Rasool S, Gul A, Sheikh SA, Akram NA, Ashraf M, Kazi AM, Gucel S. Jasmonates: Multifunctional Roles in Stress Tolerance. FRONTIERS IN PLANT SCIENCE 2016; 7:813. [PMID: 27379115 PMCID: PMC4908892 DOI: 10.3389/fpls.2016.00813] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 05/25/2016] [Indexed: 05/18/2023]
Abstract
Jasmonates (JAs) [Jasmonic acid (JA) and methyl jasmonates (MeJAs)] are known to take part in various physiological processes. Exogenous application of JAs so far tested on different plants under abiotic stresses particularly salinity, drought, and temperature (low/high) conditions have proved effective in improving plant stress tolerance. However, its extent of effectiveness entirely depends on the type of plant species tested or its concentration. The effects of introgression or silencing of different JA- and Me-JA-related genes have been summarized in this review, which have shown a substantial role in improving crop yield and quality in different plants under stress or non-stress conditions. Regulation of JAs synthesis is impaired in stressed as well as unstressed plant cells/tissues, which is believed to be associated with a variety of metabolic events including signal transduction. Although, mitogen activated protein kinases (MAPKs) are important components of JA signaling and biosynthesis pathways, nitric oxide, ROS, calcium, ABA, ethylene, and salicylic acid are also important mediators of plant growth and development during JA signal transduction and synthesis. The exploration of other signaling molecules can be beneficial to examine the details of underlying molecular mechanisms of JA signal transduction. Much work is to be done in near future to find the proper answers of the questions like action of JA related metabolites, and identification of universal JA receptors etc. Complete signaling pathways involving MAPKs, CDPK, TGA, SIPK, WIPK, and WRKY transcription factors are yet to be investigated to understand the complete mechanism of action of JAs.
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Affiliation(s)
- Parvaiz Ahmad
- Department of Botany, S.P. CollegeSrinagar, India
- Department of Botany and Microbiology, College of Sciences, King Saud UniversityRiyadh, Saudi Arabia
| | - Saiema Rasool
- Forest Biotech Lab, Department of Forest Management, Faculty of Forestry, Universiti Putra MalaysiaSelangor, Malaysia
| | - Alvina Gul
- Atta-ur-Rahman School of Applied Biosciences, National University of Science and TechnologyIslamabad, Pakistan
| | - Subzar A. Sheikh
- Department of Botany, Govt. Degree College (Boys), AnantnagAnantnag, India
| | - Nudrat A. Akram
- Department of Botany, GC University FaisalabadFaisalabad, Pakistan
| | - Muhammad Ashraf
- Department of Botany and Microbiology, College of Sciences, King Saud UniversityRiyadh, Saudi Arabia
- Pakistan Science FoundationIslamabad, Pakistan
| | - A. M. Kazi
- Department of Botany, University of SargodhaSargodha, Pakistan
| | - Salih Gucel
- Centre for Environmental Research, Near East UniversityNicosia, Cyprus
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Liu YN, Li Y, Yang FS, Wang XQ. Floral nectary, nectar production dynamics, and floral reproductive isolation among closely related species of Pedicularis. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:178-87. [PMID: 26172034 DOI: 10.1111/jipb.12374] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 07/06/2015] [Indexed: 05/22/2023]
Abstract
Floral nectar is thought to be one of the most important rewards that attract pollinators in Pedicularis; however, few studies have examined variation of nectary structure and/or nectar secretion in the genus, particularly among closely related species. Here we investigated nectary morphology, nectar quality, and nectar production dynamics in flowers of Pedicularis section Cyathophora. We found a conical floral nectary at the base of the ovary in species of the rex-thamnophila clade. Stomata were found on the surface of the nectary, and copious starch grains were detected in the nectary tissues. In contrast, a semi-annular nectary was found in flowers of the species of the superba clade. Only a few starch grains were observed in tissues of the semi-annular nectary, and the nectar sugar concentration in these flowers was much lower than that in the flowers of the rex-thamnophila clade. Our results indicate that the floral nectary has experienced considerable morphological, structural, and functional differentiation among closely related species of Pedicularis. This could have affected nectar production, leading to a shift of the pollination mode. Our results also imply that variation of the nectary morphology and nectar production may have played an important role in the speciation of sect. Cyathophora.
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Affiliation(s)
- Ya-Nan Liu
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Yan Li
- Institute of Alpine Economic Plant, Yunnan Academy of Agricultural Sciences, Lijiang, 674100, China
| | - Fu-Sheng Yang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xiao-Quan Wang
- State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
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Zhou Y, Li M, Zhao F, Zha H, Yang L, Lu Y, Wang G, Shi J, Chen J. Floral Nectary Morphology and Proteomic Analysis of Nectar of Liriodendron tulipifera Linn. FRONTIERS IN PLANT SCIENCE 2016; 7:826. [PMID: 27379122 PMCID: PMC4905952 DOI: 10.3389/fpls.2016.00826] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 05/26/2016] [Indexed: 05/08/2023]
Abstract
Nectar is a primary nutrient reward for a variety of pollinators. Recent studies have demonstrated that nectar also has defensive functions against microbial invasion. In this study, the Liriodendron tulipifera nectary was first examined by scanning electron microscopy, and then the nectar was analyzed by two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry, which led to identification of 42 nectar proteins involved in various biological functions. Bioinformatic analysis was then performed on an identified novel rubber elongation factor (REF) protein in L. tulipifera nectar. The protein was particularly abundant, representing ∼60% of the major bands of 31 to 43 kDa, and showed high, stage-specific expression in nectary tissue. The REF family proteins are the major allergens in latex. We propose that REF in L. tulipifera nectar has defensive characteristics against microorganisms.
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Affiliation(s)
- Yanwei Zhou
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry UniversityNanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry UniversityNanjing, China
| | - Meiping Li
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry UniversityNanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry UniversityNanjing, China
| | - Fangfang Zhao
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry UniversityNanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry UniversityNanjing, China
| | - Hongguang Zha
- College of Life and Environment Science, Huangshan UniversityHuangshan, China
| | - Liming Yang
- School of Life science, Huaiyin Normal UniversityHuai’an, China
| | - Ye Lu
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry UniversityNanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry UniversityNanjing, China
| | - Guangping Wang
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry UniversityNanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry UniversityNanjing, China
| | - Jisen Shi
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry UniversityNanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry UniversityNanjing, China
- *Correspondence: Jinhui Chen, ; Jisen Shi,
| | - Jinhui Chen
- Key Laboratory of Forest Genetics and Biotechnology, Ministry of Education, Nanjing Forestry UniversityNanjing, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry UniversityNanjing, China
- *Correspondence: Jinhui Chen, ; Jisen Shi,
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Segami S, Makino S, Miyake A, Asaoka M, Maeshima M. Dynamics of vacuoles and H+-pyrophosphatase visualized by monomeric green fluorescent protein in Arabidopsis: artifactual bulbs and native intravacuolar spherical structures. THE PLANT CELL 2014; 26:3416-34. [PMID: 25118245 PMCID: PMC4371836 DOI: 10.1105/tpc.114.127571] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
We prepared Arabidopsis thaliana lines expressing a functional green fluorescent protein (GFP)-linked vacuolar H(+)-pyrophosphatase (H(+)-PPase) under the control of its own promoter to investigate morphological dynamics of vacuoles and tissue-specific expression of H(+)-PPase. The lines obtained had spherical structures in vacuoles with strong fluorescence, which are referred to as bulbs. Quantitative analyses revealed that the occurrence of the bulbs correlated with the amount of GFP. Next, we prepared a construct of H(+)-PPase linked with a nondimerizing GFP (mGFP); we detected no bulbs. These results indicate that the membranes adhere face-to-face by antiparallel dimerization of GFP, resulting in the formation of bulbs. In plants expressing H(+)-PPase-mGFP, intravacuolar spherical structures with double membranes, which differed from bulbs in fluorescence intensity and intermembrane spacing, were still observed in peripheral endosperm, pistil epidermis and hypocotyls. Four-dimensional imaging revealed the dynamics of formation, transformation, and disappearance of intravacuolar spherical structures and transvacuolar strands in living cells. Visualization of H(+)-PPase-mGFP revealed intensive accumulation of the enzyme, not only in dividing and elongating cells but also in mesophyll, phloem, and nectary cells, which may have high sugar content. Dynamic morphological changes including transformation of vacuolar structures between transvacuolar strands, intravacuolar sheet-like structures, and intravacuolar spherical structures were also revealed.
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Affiliation(s)
- Shoji Segami
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Sachi Makino
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Ai Miyake
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Mariko Asaoka
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
| | - Masayoshi Maeshima
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan
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25
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Lin IW, Sosso D, Chen LQ, Gase K, Kim SG, Kessler D, Klinkenberg PM, Gorder MK, Hou BH, Qu XQ, Carter CJ, Baldwin IT, Frommer WB. Nectar secretion requires sucrose phosphate synthases and the sugar transporter SWEET9. Nature 2014; 508:546-9. [PMID: 24670640 DOI: 10.1038/nature13082] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Accepted: 01/27/2014] [Indexed: 01/09/2023]
Abstract
Angiosperms developed floral nectaries that reward pollinating insects. Although nectar function and composition have been characterized, the mechanism of nectar secretion has remained unclear. Here we identify SWEET9 as a nectary-specific sugar transporter in three eudicot species: Arabidopsis thaliana, Brassica rapa (extrastaminal nectaries) and Nicotiana attenuata (gynoecial nectaries). We show that SWEET9 is essential for nectar production and can function as an efflux transporter. We also show that sucrose phosphate synthase genes, encoding key enzymes for sucrose biosynthesis, are highly expressed in nectaries and that their expression is also essential for nectar secretion. Together these data are consistent with a model in which sucrose is synthesized in the nectary parenchyma and subsequently secreted into the extracellular space via SWEET9, where sucrose is hydrolysed by an apoplasmic invertase to produce a mixture of sucrose, glucose and fructose. The recruitment of SWEET9 for sucrose export may have been a key innovation, and could have coincided with the evolution of core eudicots and contributed to the evolution of nectar secretion to reward pollinators.
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Affiliation(s)
- I Winnie Lin
- 1] Department of Biology, Stanford University, Stanford, California 94305, USA [2] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Davide Sosso
- 1] Department of Biology, Stanford University, Stanford, California 94305, USA [2] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Li-Qing Chen
- Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Klaus Gase
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Sang-Gyu Kim
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Danny Kessler
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Peter M Klinkenberg
- 1] Department of Biology, University of Minnesota Duluth, Duluth, Minnesota 55812, USA [2] Department of Plant Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Molly K Gorder
- 1] Department of Biology, University of Minnesota Duluth, Duluth, Minnesota 55812, USA [2] Department of Plant Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Bi-Huei Hou
- Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
| | - Xiao-Qing Qu
- 1] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA [2] Key Laboratory of Plant and Soil Interactions, College of Resources and Environmental Sciences, China Agricultural University, 100193 Beijing, China
| | - Clay J Carter
- 1] Department of Biology, University of Minnesota Duluth, Duluth, Minnesota 55812, USA [2] Department of Plant Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Ian T Baldwin
- Max Planck Institute for Chemical Ecology, Jena D-07745, Germany
| | - Wolf B Frommer
- 1] Department of Biology, Stanford University, Stanford, California 94305, USA [2] Carnegie Institution for Science, 260 Panama Street, Stanford, California 94305, USA
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Lohaus G, Schwerdtfeger M. Comparison of sugars, iridoid glycosides and amino acids in nectar and phloem sap of Maurandya barclayana, Lophospermum erubescens, and Brassica napus. PLoS One 2014; 9:e87689. [PMID: 24489951 PMCID: PMC3906183 DOI: 10.1371/journal.pone.0087689] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Accepted: 01/02/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Floral nectar contains sugars and amino acids to attract pollinators. In addition, nectar also contains different secondary compounds, but little is understood about their origin or function. Does nectar composition reflect phloem composition, or is nectar synthesized and/or modified in nectaries? Studies where both, the nectar as well as the phloem sap taken from the same plant species were analyzed in parallel are rare. Therefore, phloem sap and nectar from different plant species (Maurandya barclayana, Lophospermum erubescens, and Brassica napus) were compared. METHODOLOGY AND PRINCIPAL FINDINGS Nectar was collected with microcapillary tubes and phloem sap with the laser-aphid-stylet technique. The nectar of all three plant species contained high amounts of sugars with different percentages of glucose, fructose, and sucrose, whereas phloem sap sugars consisted almost exclusively of sucrose. One possible reason for this could be the activity of invertases in the nectaries. The total concentration of amino acids was much lower in nectars than in phloem sap, indicating selective retention of nitrogenous solutes during nectar formation. Nectar amino acid concentrations were negatively correlated with the nectar volumes per flower of the different plant species. Both members of the tribe Antirrhineae (Plantaginaceae) M. barclayana and L. erubescens synthesized the iridoid glycoside antirrhinoside. High amounts of antirrhinoside were found in the phloem sap and lower amounts in the nectar of both plant species. CONCLUSIONS/SIGNIFICANCE The parallel analyses of nectar and phloem sap have shown that all metabolites which were found in nectar were also detectable in phloem sap with the exception of hexoses. Otherwise, the composition of both aqueous solutions was not the same. The concentration of several metabolites was lower in nectar than in phloem sap indicating selective retention of some metabolites. Furthermore, the existence of antirrhinoside in nectar could be based on passive secretion from the phloem.
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Affiliation(s)
- Gertrud Lohaus
- Molecular Plant Science and Plant Biochemistry, Bergische University of Wuppertal, Wuppertal, Germany
| | - Michael Schwerdtfeger
- Albrecht-von-Haller-Institute, Systematic Botany, Georg-August-University of Göttingen, Göttingen, Germany
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Veiga Blanco T, Galetto L, Machado IC. Nectar regulation in Euphorbia tithymaloides L., a hummingbird-pollinated Euphorbiaceae. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15:910-918. [PMID: 23173933 DOI: 10.1111/j.1438-8677.2012.00695.x] [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] [Received: 06/04/2012] [Accepted: 09/25/2012] [Indexed: 06/01/2023]
Abstract
Floral sexual phases can differ in nectar production and might be under selective pressure by pollinators. We studied Euphorbia tithymaloides, which has inflorescences that are initially female and then hermaphroditic. Volume and concentration of nectar were measured in both stages. Nectar production and the effect of extractions were determined using sets of bagged inflorescences; inflorescences in the hermaphroditic phase had higher values of nectar concentration, volume and sugar mass than inflorescences in the female phase. Nectar resorption was detected in senescent inflorescences. To test for homeostatic nectar regulation, artificial nectar was added and the response assessed after 24 h. The experiments showed that concentration and sugar mass are regulated within a narrow range, and the homeostatic points differ between the two sexual phases. These differences in nectar can be detected by hummingbirds, which prefer the female stage. Resorption and secretion seem to be part of a homeostatic mechanism by which nectar attributes are maintained to optimise sugar recovery.
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Affiliation(s)
- T Veiga Blanco
- Departamento de Botánica, Facultad de Farmacia, Universidad de Santiago de Compostela, Santiago de Compostela, Galicia, Spain.
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28
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Seo PJ, Wielsch N, Kessler D, Svatos A, Park CM, Baldwin IT, Kim SG. Natural variation in floral nectar proteins of two Nicotiana attenuata accessions. BMC PLANT BIOLOGY 2013; 13:101. [PMID: 23848992 PMCID: PMC3728157 DOI: 10.1186/1471-2229-13-101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 07/10/2013] [Indexed: 05/22/2023]
Abstract
BACKGROUND Floral nectar (FN) contains not only energy-rich compounds to attract pollinators, but also defense chemicals and several proteins. However, proteomic analysis of FN has been hampered by the lack of publically available sequence information from nectar-producing plants. Here we used next-generation sequencing and advanced proteomics to profile FN proteins in the opportunistic outcrossing wild tobacco, Nicotiana attenuata. RESULTS We constructed a transcriptome database of N. attenuata and characterized its nectar proteome using LC-MS/MS. The FN proteins of N. attenuata included nectarins, sugar-cleaving enzymes (glucosidase, galactosidase, and xylosidase), RNases, pathogen-related proteins, and lipid transfer proteins. Natural variation in FN proteins of eleven N. attenuata accessions revealed a negative relationship between the accumulation of two abundant proteins, nectarin1b and nectarin5. In addition, microarray analysis of nectary tissues revealed that protein accumulation in FN is not simply correlated with the accumulation of transcripts encoding FN proteins and identified a group of genes that were specifically expressed in the nectary. CONCLUSIONS Natural variation of identified FN proteins in the ecological model plant N. attenuata suggests that nectar chemistry may have a complex function in plant-pollinator-microbe interactions.
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Affiliation(s)
- Pil Joon Seo
- Department of Chemistry, Chonbuk National University, Jeonju, 561-756, Korea
| | - Natalie Wielsch
- Mass Spectrometry/Proteomics Research Group, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, D-07745, Germany
| | - Danny Kessler
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, D-07745, Germany
| | - Ales Svatos
- Mass Spectrometry/Proteomics Research Group, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, D-07745, Germany
| | - Chung-Mo Park
- Molecular Signaling Laboratory, Department of Chemistry, Seoul National University, Seoul, 151-742, Korea
| | - Ian T Baldwin
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, D-07745, Germany
| | - Sang-Gyu Kim
- Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, Jena, D-07745, Germany
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Bender RL, Fekete ML, Klinkenberg PM, Hampton M, Bauer B, Malecha M, Lindgren K, A Maki J, Perera MADN, Nikolau BJ, Carter CJ. PIN6 is required for nectary auxin response and short stamen development. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 74:893-904. [PMID: 23551385 DOI: 10.1111/tpj.12184] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 03/15/2013] [Accepted: 03/20/2013] [Indexed: 05/04/2023]
Abstract
The PIN family of proteins is best known for its involvement in polar auxin transport and tropic responses. PIN6 (At1g77110) is one of the remaining PIN family members in Arabidopsis thaliana to which a biological function has not yet been ascribed. Here we report that PIN6 is a nectary-enriched gene whose expression level is positively correlated with total nectar production in Arabidopsis, and whose function is required for the proper development of short stamens. PIN6 accumulates in internal membranes consistent with the ER, and multiple lines of evidence demonstrate that PIN6 is required for auxin-dependent responses in nectaries. Wild-type plants expressing auxin-responsive DR5:GFP or DR5:GUS reporters displayed intense signal in lateral nectaries, but pin6 lateral nectaries showed little or no signal for these reporters. Further, exogenous auxin treatment increased nectar production more than tenfold in wild-type plants, but nectar production was not increased in pin6 mutants when treated with auxin. Conversely, the auxin transport inhibitor N-1-naphthylphthalamic acid (NPA) reduced nectar production in wild-type plants by more than twofold, but had no significant effect on pin6 lines. Interestingly, a MYB57 transcription factor mutant, myb57-2, closely phenocopied the loss-of-function mutant pin6-2. However, PIN6 expression was not dependent on MYB57, and RNA-seq analyses of pin6-2 and myb57-2 mutant nectaries showed little overlap in terms of differentially expressed genes. Cumulatively, these results demonstrate that PIN6 is required for proper auxin response and nectary function in Arabidopsis. These results also identify auxin as an important factor in the regulation of nectar production, and implicate short stamens in the maturation of lateral nectaries.
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Affiliation(s)
- Ricci L Bender
- Department of Biology, University of Minnesota Duluth, Duluth, MN 55812, USA
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30
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Damerval C, Citerne H, Le Guilloux M, Domenichini S, Dutheil J, Ronse de Craene L, Nadot S. Asymmetric morphogenetic cues along the transverse plane: shift from disymmetry to zygomorphy in the flower of Fumarioideae. AMERICAN JOURNAL OF BOTANY 2013; 100:391-402. [PMID: 23378492 DOI: 10.3732/ajb.1200376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
PREMISE OF THE STUDY Zygomorphy has evolved multiple times in angiosperms. Near-actinomorphy is the ancestral state in the early diverging eudicot family Papaveraceae. Zygomorphy evolved once in the subfamily Fumarioideae from a disymmetric state. Unusual within angiosperms, zygomorphy takes place along the transverse plane of the flower. METHODS We investigated floral development to understand the developmental bases of the evolution of floral symmetry in Papaveraceae. We then assessed the expression of candidate genes for the key developmental events responsible for the shift from disymmetry to transverse zygomorphy, namely CrabsClaw for nectary formation (PapCRC), ShootMeristemless (PapSTL) for spur formation, and Cycloidea (PapCYL) for growth control. KEY RESULTS We found that an early disymmetric groundplan is common to all species studied, and that actinomorphy was acquired after sepal initiation in Papaveroideae. The shift from disymmetry to zygomorphy in Fumarioideae was associated with early asymmetric growth of stamen filaments, followed by asymmetric development of nectary outgrowth and spur along the transverse plane. Patterns of PapSTL expression could not be clearly related to spur formation. PapCRC and PapCYL genes were expressed in the nectary outgrowths, with a pattern of expression correlated with asymmetric nectary development in the zygomorphic species. Additionally, PapCYL genes were found asymmetrically expressed along the transverse plane in the basal region of outer petals in the zygomorphic species. CONCLUSION Genes of PapCRC and PapCYL families could be direct or indirect targets of the initial transversally asymmetric cue responsible for the shift from disymmetry to zygomorphy in Fumarioideae.
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Affiliation(s)
- Catherine Damerval
- UMR de Génétique Végétale, CNRS/Université Paris-Sud/INRA, Ferme du Moulon 91190 Gif-sur-Yvette, France.
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31
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Escalante-Pérez M, Jaborsky M, Lautner S, Fromm J, Müller T, Dittrich M, Kunert M, Boland W, Hedrich R, Ache P. Poplar extrafloral nectaries: two types, two strategies of indirect defenses against herbivores. PLANT PHYSIOLOGY 2012; 159:1176-91. [PMID: 22573802 PMCID: PMC3387703 DOI: 10.1104/pp.112.196014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 05/08/2012] [Indexed: 05/20/2023]
Abstract
Many plant species grow extrafloral nectaries and produce nectar to attract carnivore arthropods as defenders against herbivores. Two nectary types that evolved with Populus trichocarpa (Ptr) and Populus tremula × Populus tremuloides (Ptt) were studied from their ecology down to the genes and molecules. Both nectary types strongly differ in morphology, nectar composition and mode of secretion, and defense strategy. In Ptt, nectaries represent constitutive organs with continuous merocrine nectar flow, nectary appearance, nectar production, and flow. In contrast, Ptr nectaries were found to be holocrine and inducible. Neither mechanical wounding nor the application of jasmonic acid, but infestation by sucking insects, induced Ptr nectar secretion. Thus, nectaries of Ptr and Ptt seem to answer the same threat by the use of different mechanisms.
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Affiliation(s)
| | | | - Silke Lautner
- University Würzburg, Biozentrum, Julius-von-Sachs-Institut für Biowissenschaften, D–97082 Wuerzburg, Germany (M.E.-P., M.J., R.H., P.A.)
- University Hamburg, Zentrum Holzwirtschaft, D–21031 Hamburg, Germany (S.L., J.F.)
- University Würzburg, Bioinformatics Department, Am Hubland/Biozentrum, D–97074 Wuerzburg, Germany (T.M., M.D.)
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (M.K., W.B.); and
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia (R.H.)
| | - Jörg Fromm
- University Würzburg, Biozentrum, Julius-von-Sachs-Institut für Biowissenschaften, D–97082 Wuerzburg, Germany (M.E.-P., M.J., R.H., P.A.)
- University Hamburg, Zentrum Holzwirtschaft, D–21031 Hamburg, Germany (S.L., J.F.)
- University Würzburg, Bioinformatics Department, Am Hubland/Biozentrum, D–97074 Wuerzburg, Germany (T.M., M.D.)
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (M.K., W.B.); and
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia (R.H.)
| | - Tobias Müller
- University Würzburg, Biozentrum, Julius-von-Sachs-Institut für Biowissenschaften, D–97082 Wuerzburg, Germany (M.E.-P., M.J., R.H., P.A.)
- University Hamburg, Zentrum Holzwirtschaft, D–21031 Hamburg, Germany (S.L., J.F.)
- University Würzburg, Bioinformatics Department, Am Hubland/Biozentrum, D–97074 Wuerzburg, Germany (T.M., M.D.)
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (M.K., W.B.); and
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia (R.H.)
| | - Marcus Dittrich
- University Würzburg, Biozentrum, Julius-von-Sachs-Institut für Biowissenschaften, D–97082 Wuerzburg, Germany (M.E.-P., M.J., R.H., P.A.)
- University Hamburg, Zentrum Holzwirtschaft, D–21031 Hamburg, Germany (S.L., J.F.)
- University Würzburg, Bioinformatics Department, Am Hubland/Biozentrum, D–97074 Wuerzburg, Germany (T.M., M.D.)
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (M.K., W.B.); and
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia (R.H.)
| | - Maritta Kunert
- University Würzburg, Biozentrum, Julius-von-Sachs-Institut für Biowissenschaften, D–97082 Wuerzburg, Germany (M.E.-P., M.J., R.H., P.A.)
- University Hamburg, Zentrum Holzwirtschaft, D–21031 Hamburg, Germany (S.L., J.F.)
- University Würzburg, Bioinformatics Department, Am Hubland/Biozentrum, D–97074 Wuerzburg, Germany (T.M., M.D.)
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (M.K., W.B.); and
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia (R.H.)
| | - Wilhelm Boland
- University Würzburg, Biozentrum, Julius-von-Sachs-Institut für Biowissenschaften, D–97082 Wuerzburg, Germany (M.E.-P., M.J., R.H., P.A.)
- University Hamburg, Zentrum Holzwirtschaft, D–21031 Hamburg, Germany (S.L., J.F.)
- University Würzburg, Bioinformatics Department, Am Hubland/Biozentrum, D–97074 Wuerzburg, Germany (T.M., M.D.)
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (M.K., W.B.); and
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia (R.H.)
| | - Rainer Hedrich
- University Würzburg, Biozentrum, Julius-von-Sachs-Institut für Biowissenschaften, D–97082 Wuerzburg, Germany (M.E.-P., M.J., R.H., P.A.)
- University Hamburg, Zentrum Holzwirtschaft, D–21031 Hamburg, Germany (S.L., J.F.)
- University Würzburg, Bioinformatics Department, Am Hubland/Biozentrum, D–97074 Wuerzburg, Germany (T.M., M.D.)
- Max Planck Institute for Chemical Ecology, 07745 Jena, Germany (M.K., W.B.); and
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia (R.H.)
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Bender R, Klinkenberg P, Jiang Z, Bauer B, Karypis G, Nguyen N, Perera MAD, Nikolau BJ, Carter CJ. Functional genomics of nectar production in the Brassicaceae. FLORA - MORPHOLOGY, DISTRIBUTION, FUNCTIONAL ECOLOGY OF PLANTS 2012. [PMID: 0 DOI: 10.1016/j.flora.2012.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
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Nectar Secretion: Its Ecological Context and Physiological Regulation. SIGNALING AND COMMUNICATION IN PLANTS 2012. [DOI: 10.1007/978-3-642-23047-9_9] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Ji X, Dong B, Shiran B, Talbot MJ, Edlington JE, Hughes T, White RG, Gubler F, Dolferus R. Control of abscisic acid catabolism and abscisic acid homeostasis is important for reproductive stage stress tolerance in cereals. PLANT PHYSIOLOGY 2011; 156:647-62. [PMID: 21502188 PMCID: PMC3177265 DOI: 10.1104/pp.111.176164] [Citation(s) in RCA: 147] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 04/17/2011] [Indexed: 05/18/2023]
Abstract
Drought stress at the reproductive stage causes pollen sterility and grain loss in wheat (Triticum aestivum). Drought stress induces abscisic acid (ABA) biosynthesis genes in anthers and ABA accumulation in spikes of drought-sensitive wheat varieties. In contrast, drought-tolerant wheat accumulates lower ABA levels, which correlates with lower ABA biosynthesis and higher ABA catabolic gene expression (ABA 8'-hydroxylase). Wheat TaABA8'OH1 deletion lines accumulate higher spike ABA levels and are more drought sensitive. ABA treatment of the spike mimics the effect of drought, causing high levels of sterility. ABA treatment represses the anther cell wall invertase gene TaIVR1, and drought-tolerant lines appeared to be more sensitive to the effect of ABA. Drought-induced sterility shows similarity to cold-induced sterility in rice (Oryza sativa). In cold-stressed rice, the rate of ABA accumulation was similar in cold-sensitive and cold-tolerant lines during the first 8 h of cold treatment, but in the tolerant line, ABA catabolism reduced ABA levels between 8 and 16 h of cold treatment. The ABA biosynthesis gene encoding 9-cis-epoxycarotenoid dioxygenase in anthers is mainly expressed in parenchyma cells surrounding the vascular bundle of the anther. Transgenic rice lines expressing the wheat TaABA8'OH1 gene under the control of the OsG6B tapetum-specific promoter resulted in reduced anther ABA levels under cold conditions. The transgenic lines showed that anther sink strength (OsINV4) was maintained under cold conditions and that this correlated with improved cold stress tolerance. Our data indicate that ABA and ABA 8'-hydroxylase play an important role in controlling anther ABA homeostasis and reproductive stage abiotic stress tolerance in cereals.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Rudy Dolferus
- Commonwealth Scientific and Industrial Research Organization Plant Industry, Canberra, Australian Capital Territory 2601, Australia
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Heil M. Nectar: generation, regulation and ecological functions. TRENDS IN PLANT SCIENCE 2011; 16:191-200. [PMID: 21345715 DOI: 10.1016/j.tplants.2011.01.003] [Citation(s) in RCA: 260] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 01/05/2011] [Accepted: 01/14/2011] [Indexed: 05/23/2023]
Abstract
Nectar contains water, sugars and amino acids to attract pollinators and defenders and is protected from nectar robbers and microorganisms by secondary compounds and antimicrobial proteins. Floral and extrafloral nectar secretion can be induced by jasmonic acid, it is often adjusted to consumer identity and consumption rate and depends on invertase activity. Invertases are likely to play at least three roles: the uploading of sucrose from the phloem, carbohydrate mobilization during active secretion and the postsecretory adjustment of the sucrose:hexose ratio of nectar. However, it remains to be studied how plants produce and secrete non-carbohydrate components. More research is needed to understand how plants produce nectar, the most important mediator of their interactions with mutualistic animals.
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Affiliation(s)
- Martin Heil
- Departamento de Ingeniería Genética, CINVESTAV - Irapuato, Km. 9.6 Libramiento Norte, CP 36821, Irapuato, Guanajuato, México.
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Hampton M, Xu WW, Kram BW, Chambers EM, Ehrnriter JS, Gralewski JH, Joyal T, Carter CJ. Identification of differential gene expression in Brassica rapa nectaries through expressed sequence tag analysis. PLoS One 2010; 5:e8782. [PMID: 20098697 PMCID: PMC2808342 DOI: 10.1371/journal.pone.0008782] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 12/19/2009] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Nectaries are the floral organs responsible for the synthesis and secretion of nectar. Despite their central roles in pollination biology, very little is understood about the molecular mechanisms underlying nectar production. This project was undertaken to identify genes potentially involved in mediating nectary form and function in Brassica rapa. METHODOLOGY AND PRINCIPAL FINDINGS Four cDNA libraries were created using RNA isolated from the median and lateral nectaries of B. rapa flowers, with one normalized and one non-normalized library being generated from each tissue. Approximately 3,000 clones from each library were randomly sequenced from the 5' end to generate a total of 11,101 high quality expressed sequence tags (ESTs). Sequence assembly of all ESTs together allowed the identification of 1,453 contigs and 4,403 singleton sequences, with the Basic Localized Alignment Search Tool (BLAST) being used to identify 4,138 presumptive orthologs to Arabidopsis thaliana genes. Several genes differentially expressed between median and lateral nectaries were initially identified based upon the number of BLAST hits represented by independent ESTs, and later confirmed via reverse transcription polymerase chain reaction (RT PCR). RT PCR was also used to verify the expression patterns of eight putative orthologs to known Arabidopsis nectary-enriched genes. CONCLUSIONS/SIGNIFICANCE This work provided a snapshot of gene expression in actively secreting B. rapa nectaries, and also allowed the identification of differential gene expression between median and lateral nectaries. Moreover, 207 orthologs to known nectary-enriched genes from Arabidopsis were identified through this analysis. The results suggest that genes involved in nectar production are conserved amongst the Brassicaceae, and also supply clones and sequence information that can be used to probe nectary function in B. rapa.
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Affiliation(s)
- Marshall Hampton
- Department of Mathematics and Statistics, University of Minnesota Duluth, Duluth, Minnesota, United States of America
| | - Wayne W. Xu
- Minnesota Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Brian W. Kram
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, United States of America
| | - Emily M. Chambers
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, United States of America
| | - Jerad S. Ehrnriter
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, United States of America
| | - Jonathan H. Gralewski
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, United States of America
| | - Teresa Joyal
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, United States of America
| | - Clay J. Carter
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota, United States of America
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