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Paul S, Mitra A. Histochemical, metabolic and ultrastructural changes in leaf patelliform nectaries explain extrafloral nectar synthesis and secretion in Clerodendrum chinense. ANNALS OF BOTANY 2024; 133:621-642. [PMID: 38366151 PMCID: PMC11037555 DOI: 10.1093/aob/mcae019] [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: 10/07/2023] [Accepted: 02/10/2024] [Indexed: 02/18/2024]
Abstract
BACKGROUND AND AIMS Extrafloral nectaries are nectar-secreting structures present on vegetative parts of plants which provide indirect defences against herbivore attack. Extrafloral nectaries in Clerodendrum chinense are patelliform-shaped specialized trichomatous structures. However, a complete understanding of patelliform extrafloral nectaries in general, and of C. chinense in particular, has not yet been established to provide fundamental insight into the cellular physiological machinery involved in nectar biosynthesis and secretory processes. METHODS We studied temporal changes in the morphological, anatomical and ultrastructural features in the architectures of extrafloral nectaries. We also compared metabolite profiles of extrafloral nectar, nectary tissue, non-nectary tissue and phloem sap. Further, both in situ histolocalization and normal in vitro activities of enzymes related to sugar metabolism were examined. KEY RESULTS Four distinct tissue regions in the nectar gland were revealed from histochemical characterization, among which the middle nectariferous tissue was found to be the metabolically active region, while the intermediate layer was found to be lipid-rich. Ultrastructural study showed the presence of a large number of mitochondria along with starch-bearing chloroplasts in the nectariferous region. However, starch depletion was noted with progressive maturation of nectaries. Metabolite analysis revealed compositional differences among nectar, phloem sap, nectary and non-nectary tissue. Invertase activity was higher in secretory stages and localized in nectariferous tissue and adjacent region. CONCLUSIONS Our study suggests extrafloral nectar secretion in C. chinense to be both eccrine and merocrine in nature. A distinct intermediate lipid-rich layer that separates the epidermis from nectary parenchyma was revealed, which possibly acts as a barrier to water flow in nectar. This study also revealed a distinction between nectar and phloem sap, and starch could act as a nectar precursor, as evidenced from enzymatic and ultrastructural studies. Thus, our findings on changing architecture of extrafloral nectaries with temporal secretion revealed a cell physiological process involved in nectar biosynthesis and secretion.
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Affiliation(s)
- Shobhon Paul
- Natural Product Biotechnology Group, Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur – 721 302, India
| | - Adinpunya Mitra
- Natural Product Biotechnology Group, Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur – 721 302, India
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Maximo D, Ferreira MJP, Demarco D. Inaugural Description of Extrafloral Nectaries in Sapindaceae: Structure, Diversity and Nectar Composition. PLANTS (BASEL, SWITZERLAND) 2023; 12:3411. [PMID: 37836152 PMCID: PMC10574849 DOI: 10.3390/plants12193411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023]
Abstract
Sapindales is a large order with a great diversity of nectaries; however, to date, there is no information about extrafloral nectaries (EFN) in Sapindaceae, except recent topological and morphological data, which indicate an unexpected structural novelty for the family. Therefore, the goal of this study was to describe the EFN in Sapindaceae for the first time and to investigate its structure and nectar composition. Shoots and young leaves of Urvillea ulmacea were fixed for structural analyses of the nectaries using light and scanning electron microscopy. For nectar composition investigation, GC-MS and HPLC were used, in addition to histochemical tests. Nectaries of Urvillea are circular and sunken, corresponding to ocelli. They are composed of a multiple-secretory epidermis located on a layer of transfer cells, vascularized by phloem and xylem. Nectar is composed of sucrose, fructose, xylitol and glucose, in addition to amino acids, lipids and phenolic compounds. Many ants were observed gathering nectar from young leaves. These EFNs have an unprecedented structure in the family and also differ from the floral nectaries of Sapindaceae, which are composed of secretory parenchyma and release nectar through stomata. The ants observed seem to protect the plant against herbivores, and in this way, the nectar increases the defence of vegetative organs synergistically with latex.
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Affiliation(s)
| | | | - Diego Demarco
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo 05508-090, SP, Brazil; (D.M.); (M.J.P.F.)
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Ribeiro JC, Tölke ED, Demarco D. Secretory Patterns in Colleters of Apocynaceae. PLANTS 2021; 10:plants10122770. [PMID: 34961240 PMCID: PMC8703501 DOI: 10.3390/plants10122770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 11/16/2022]
Abstract
Colleters of Apocynaceae are glands related to different types of protection of vegetative and floral meristems through the production of mucilage or a mixture of many different compounds. Although several anatomical papers have shown histological and histochemical aspects of colleters of the family, almost nothing is known about their secretory process. In this study, we analyzed two types of colleters in Apocynaceae: one produces mucilage and lipophilic compounds, while the other produces an exclusively mucilaginous secretion. The secretory epidermis of the colleters of Allamanda schottii and Blepharodon bicuspidatum has a dense cytoplasm with organelles responsible for the production of mucilage and lipids. This heterogeneous secretion is released through granulocrine and eccrine mechanisms and is temporarily stored in a subcuticular space before crossing the cuticle. Conversely, colleters of Mandevilla splendens and Peplonia axillaris produce only mucilage and have a very different secretory apparatus. The mechanism of secretion is granulocrine, and the exudate is firstly accumulated in a large periplasmic space and later in an intramural space before crossing the cuticle. Notably, the structure of the cuticle varies according to the secretion composition. Although the colleters of the family are histologically similar, this study demonstrates a metabolic and subcellular variability previously unknown for Apocynaceae.
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Affiliation(s)
- Josiana Cristina Ribeiro
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Sao Paulo 05508-090, Brazil
| | - Elisabeth Dantas Tölke
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Sao Paulo 05508-090, Brazil
| | - Diego Demarco
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Sao Paulo 05508-090, Brazil
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Wang Q, Huang Y, Ren Z, Zhang X, Ren J, Su J, Zhang C, Tian J, Yu Y, Gao GF, Li L, Kong Z. Transfer cells mediate nitrate uptake to control root nodule symbiosis. NATURE PLANTS 2020; 6:800-808. [PMID: 32514144 DOI: 10.1038/s41477-020-0683-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 04/29/2020] [Indexed: 05/25/2023]
Abstract
Root nodule symbiosis enables nitrogen fixation in legumes and, therefore, improves crop production for sustainable agriculture1,2. Environmental nitrate levels affect nodulation and nitrogen fixation, but the mechanisms by which legume plants modulate nitrate uptake to regulate nodule symbiosis remain unclear1. Here, we identify a member of the Medicago truncatula nitrate peptide family (NPF), NPF7.6, which is expressed specifically in the nodule vasculature. NPF7.6 localizes to the plasma membrane of nodule transfer cells (NTCs), where it functions as a high-affinity nitrate transporter. Transfer cells show characteristic wall ingrowths that enhance the capacity for membrane transport at the apoplasmic-symplasmic interface between the vasculature and surrounding tissues3. Importantly, knockout of NPF7.6 using CRISPR-Cas9 resulted in developmental defects of the nodule vasculature, with excessive expansion of NTC plasma membranes. npf7.6 nodules showed severely compromised nitrate responsiveness caused by an attenuated ability to transport nitrate. Moreover, npf7.6 nodules exhibited disturbed nitric oxide homeostasis and a notable decrease in nitrogenase activity. Our findings indicate that NPF7.6 has been co-opted into a regulatory role in nodulation, functioning in nitrate uptake through NTCs to fine-tune nodule symbiosis in response to fluctuating environmental nitrate status. These observations will inform efforts to optimize nitrogen fixation in legume crops.
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Affiliation(s)
- Qi Wang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Yige Huang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhijie Ren
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Xiaxia Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jing Ren
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Jiaqi Su
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Chen Zhang
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Juan Tian
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - Yanjun Yu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - George F Gao
- Chinese Academy of Sciences Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Legong Li
- College of Life Sciences, Capital Normal University, Beijing, China
| | - Zhaosheng Kong
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China.
- College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China.
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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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da Silva Pereira P, de Almeida Gonçalves L, da Silva MJ, Rezende MH. Extrafloral nectaries of four varieties of Chamaecrista ramosa (Vogel) H.S.Irwin & Barneby (Fabaceae): anatomy, chemical nature, mechanisms of nectar secretion, and elimination. PROTOPLASMA 2018; 255:1635-1647. [PMID: 29704049 DOI: 10.1007/s00709-018-1253-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: 11/12/2017] [Accepted: 04/09/2018] [Indexed: 06/08/2023]
Abstract
Considering the importance of extrafloral nectaries (EFNs) in Fabaceae, the objectives of this research were to analyze (1) the anatomical and histochemical characteristics of the EFNs of Chamaecrista ramosa var. ramosa, C. ramosa var. curvifoliola, C. ramosa var. parvifoliola, and C. ramosa var. lucida and (2) the ultrastructure of the EFNs of C. ramosa var. ramosa. Standard techniques in plant anatomy and transmission electron microscopy were used. The anatomical analyses confirmed the characteristics described for extrafloral nectaries, evidencing three well-defined regions: epidermis, nectariferous, and subnectariferous parenchymas. Carbohydrates, proteins, pectins/mucilages, and lipids were detected by histochemical analyzes in all varieties. The ultrastructure of the EFNs of C. ramosa var. ramosa allowed the observation of microchannels at the external periclinal cell walls of the epidermis covering the secretory region. The nectariferous and subnectariferous parenchyma cells have periplasmic spaces, large plastids containing starch grains and plastoglobules, mitochondria, developed endoplasmic reticulum, large vacuoles with electron-dense contents, and membrane residues may be associated with the vacuole, suggesting the occurrence of autophagic processes. The anatomical, histochemical, and ultrastructural patterns revealed characteristics that confirm the glands of C. ramosa as extrafloral nectaries and suggest the eccrine mechanism of secretion.
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Affiliation(s)
- Priscila da Silva Pereira
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 2nd floor, room 206, Goiânia, 74690-900, Brazil.
| | - Letícia de Almeida Gonçalves
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 2nd floor, room 206, Goiânia, 74690-900, Brazil
| | - Marcos José da Silva
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 1st floor, room 114A, Goiânia, 74690-900, Brazil
| | - Maria Helena Rezende
- Pós-graduação em Biodiversidade Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, Universidade Federal de Goiás, Avenida Esperança, S/N, Campus Samambaia, ICB - 1, 2nd floor, room 206, Goiânia, 74690-900, Brazil
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Płachno BJ, Stpiczyńska M, Adamec L, Miranda VFO, Świątek P. Nectar trichome structure of aquatic bladderworts from the section Utricularia (Lentibulariaceae) with observation of flower visitors and pollinators. PROTOPLASMA 2018; 255:1053-1064. [PMID: 29404696 PMCID: PMC5994208 DOI: 10.1007/s00709-018-1216-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 01/26/2018] [Indexed: 05/09/2023]
Abstract
In Utricularia, the flower spur is a nectary and in this organ, nectar is produced and stored. This study aimed to examine the structure of the nectary trichomes in four Utricularia species (Utricularia vulgaris L., U. australis R.Br., U. bremii Heer and U. foliosa L.) from the generic section Utricularia. We have investigated whether species with different spur morphology had similar spur anatomy and nectary trichome structure. In Utricularia flowers, nectar is produced by spur capitate trichomes (sessile or stalked). Our results showed that regardless of the various spur morphology, trichomes have similar architecture and ultrastructure. Head cells of these trichomes are transfer cells with an eccrine nectar secretion. Examined species differed in the micromorphology of papillae in spurs. The fly Eristalis tenax was found to be a pollinator of U. vulgaris. Small Halictidae bees seem to be pollinators of U. foliosa.
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Affiliation(s)
- Bartosz J Płachno
- Department of Plant Cytology and Embryology, Jagiellonian University in Kraków, 9 Gronostajowa St, 30-387, Cracow, Poland.
| | - Małgorzata Stpiczyńska
- Botanic Garden, Faculty of Biology, University of Warsaw, Al. Ujazdowskie 4, 00-478, Warsaw, Poland
| | - Lubomír Adamec
- Section of Plant Ecology, Institute of Botany of the Czech Academy of Sciences, Dukelská 135, -37982, Třeboň, CZ, Czech Republic
| | - Vitor Fernandes Oliveira Miranda
- Faculdade de Ciências Agrárias e Veterinárias, Jaboticabal, Departamento de Biologia Aplicada à Agropecuária, Universidade Estadual Paulista (Unesp), São Paulo, Brazil
| | - Piotr Świątek
- Department of Animal Histology and Embryology, University of Silesia in Katowice, 9 Bankowa St, 40-007, Katowice, Poland
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