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Rafińska K, Niedojadło K, Świdziński M, Bednarska-Kozakiewicz E. Distribution of exchangeable Ca 2+ during the process of Larix decidua Mill. pollination and germination. Sci Rep 2024; 14:5639. [PMID: 38454044 PMCID: PMC10920793 DOI: 10.1038/s41598-024-54903-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 02/18/2024] [Indexed: 03/09/2024] Open
Abstract
The involvement of Ca2+ ions in angiosperms sexual processes is well established, while in gymnosperms, such knowledge remains limited and is still a topic of discussion. In this study, we focused on Larix decidua, using Alizarin-red S staining and the pyroantimonate method to examine the tissue and subcellular distribution of free and loosely bound Ca2+ ions at different stages of the male gametophyte's development and its interaction with the ovule. Our findings show that in larch, both the germination of pollen grains and the growth of pollen tubes occur in an environment rich in Ca2+. These ions play a crucial role in the adhesion of the pollen grain to the stigmatic tip and its subsequent movement to the micropylar canal. There is a significant presence of free and loosely bound Ca2+ ions in both the fluid of the micropylar canal and the extracellular matrix of the nucellus. As the pollen tube extends through the nucellus, we observed a notable accumulation of Ca2+ ions just above the entry to the mature archegonium, a region likely crucial for the male gametophyte's directional growth. Meanwhile, the localized presence of free and loosely bound Ca2+ ions within the egg cell cytoplasm may inhibit the pollen tubes growth and rupture, playing an important role in fertilization.
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Affiliation(s)
- Katarzyna Rafińska
- Department of Environmental Chemistry and Bioanalysis, Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100, Toruń, Poland
| | - Katarzyna Niedojadło
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland.
| | - Michał Świdziński
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland
| | - Elżbieta Bednarska-Kozakiewicz
- Department of Cellular and Molecular Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87-100, Toruń, Poland
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2
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Del Pino AM, Regni L, D’Amato R, Di Michele A, Proietti P, Palmerini CA. Persistence of the Effects of Se-Fertilization in Olive Trees over Time, Monitored with the Cytosolic Ca 2+ and with the Germination of Pollen. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10112290. [PMID: 34834652 PMCID: PMC8624298 DOI: 10.3390/plants10112290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 10/19/2021] [Accepted: 10/20/2021] [Indexed: 05/13/2023]
Abstract
Selenium (Se) is an important micronutrient for living organisms, since it is involved in several physiological and metabolic processes. Biofortification with Se increases the nutritional and qualitative values of foods in Se-deficient regions and increases tolerance to oxidative stress in olive trees. Many studies have shown that Se, in addition to improving the qualitative and nutritional properties of EVO oil, also improves the plant's response to abiotic stress. This study addressed this issue by monitoring the effects of Se on cytosolic Ca2+ and on the germination of olive pollen grains in oxidative stress. The olive trees subjected to treatment with Na-selenate in the field produced pollen with a Se content 6-8 times higher than the controls, even after 20 months from the treatment. Moreover, part of the micronutrient was organic in selenium methionine. The higher selenium content did not produce toxic effects in the pollen, rather it antagonized the undesirable effects of oxidative stress in the parameters under study. The persistence of the beneficial effects of selenium observed over time in pollens, in addition to bringing out an undisputed adaptability of olive trees to the micronutrient, suggested the opportunity to reduce the number of treatments in the field.
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Affiliation(s)
- Alberto Marco Del Pino
- Department of Agricultural, Food and Environmental Sciences (DSA3), University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy; (A.M.D.P.); (R.D.); (C.A.P.)
| | - Luca Regni
- Department of Agricultural, Food and Environmental Sciences (DSA3), University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy; (A.M.D.P.); (R.D.); (C.A.P.)
- Correspondence: (L.R.); (P.P.)
| | - Roberto D’Amato
- Department of Agricultural, Food and Environmental Sciences (DSA3), University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy; (A.M.D.P.); (R.D.); (C.A.P.)
| | - Alessandro Di Michele
- Department of Physics and Geology, University of Perugia, Via Pascoli, 06123 Perugia, Italy;
| | - Primo Proietti
- Department of Agricultural, Food and Environmental Sciences (DSA3), University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy; (A.M.D.P.); (R.D.); (C.A.P.)
- Correspondence: (L.R.); (P.P.)
| | - Carlo Alberto Palmerini
- Department of Agricultural, Food and Environmental Sciences (DSA3), University of Perugia, Borgo XX Giugno 74, 06121 Perugia, Italy; (A.M.D.P.); (R.D.); (C.A.P.)
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3
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Breygina M, Klimenko E, Schekaleva O. Pollen Germination and Pollen Tube Growth in Gymnosperms. PLANTS (BASEL, SWITZERLAND) 2021; 10:1301. [PMID: 34206892 PMCID: PMC8309077 DOI: 10.3390/plants10071301] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 01/08/2023]
Abstract
Pollen germination and pollen tube growth are common to all seed plants, but these processes first developed in gymnosperms and still serve for their successful sexual reproduction. The main body of data on the reproductive physiology, however, was obtained on flowering plants, and one should be careful to extrapolate the discovered patterns to gymnosperms. In recent years, physiological studies of coniferous pollen have been increasing, and both the features of this group and the similarities with flowering plants have already been identified. The main part of the review is devoted to physiological studies carried out on conifer pollen. The main properties and diversity of pollen grains and pollination strategies in gymnosperms are described.
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Affiliation(s)
- Maria Breygina
- Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, 119991 Moscow, Russia; (E.K.); (O.S.)
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4
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Breygina M, Klimenko E, Podolyan A, Voronkov A. Dynamics of Pollen Activation and the Role of H +-ATPase in Pollen Germination in Blue Spruce ( Picea pungens). PLANTS (BASEL, SWITZERLAND) 2020; 9:E1760. [PMID: 33322609 PMCID: PMC7763870 DOI: 10.3390/plants9121760] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/05/2022]
Abstract
Pollen is a highly specialized structure for sexual plant reproduction. Early stages of pollen germination require the transition from dormant state to active metabolism. In particular, an important role during this early phase of angiosperm pollen germination is played by H+-ATPase. Very little is known about pollen activation in gymnosperm species, and information on the involvement of H+-ATPase is lacking. We tracked four indicators characterizing the physiological state of pollen: membrane potential, intracellular pH, anion efflux and oxygen uptake, in order to monitor the dynamics of activation in Picea pungens. Based on pH dynamics during activation, we assumed the important role of H+-ATPase in spruce pollen germination. Indeed, germination was severely suppressed by P-type ATPase inhibitor orthovanadate. In spruce pollen tubes, a pronounced pH gradient with a maximum in the apical zone was found, which was different from the pollen tubes of flowering plants. Using orthovanadate and fusicoccin, we found that the proton pump is largely responsible for maintaining the gradient. Immunolocalization of the enzyme in pollen tubes showed that the distribution of H+-ATPase generally coincides with the shape of the pH gradient: its maximum accumulation is observed in the apical zone.
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Affiliation(s)
- Maria Breygina
- Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, Leninskiye Gory 1-12, 119991 Moscow, Russia; (E.K.); (A.P.)
| | - Ekaterina Klimenko
- Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, Leninskiye Gory 1-12, 119991 Moscow, Russia; (E.K.); (A.P.)
| | - Alexandra Podolyan
- Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, Leninskiye Gory 1-12, 119991 Moscow, Russia; (E.K.); (A.P.)
| | - Alexander Voronkov
- Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya St. 35, 127276 Moscow, Russia;
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5
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Selenium maintains cytosolic Ca 2+ homeostasis and preserves germination rates of maize pollen under H 2O 2-induced oxidative stress. Sci Rep 2019; 9:13502. [PMID: 31534157 PMCID: PMC6751180 DOI: 10.1038/s41598-019-49760-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/19/2019] [Indexed: 12/17/2022] Open
Abstract
Selenium (Se) displays antioxidant properties that can be exploited, in plants, to counteract abiotic stresses caused by overly-produced reactive oxygen species (ROS). Here, we show that fertigation of maize crops with sodium selenate effectively protects pollen against oxidative stress. Pollen isolated from Se-treated plants (Se1) and untreated controls (Se0) was incubated in vitro with H2O2 to produce oxidative challenge. Given the impact of ROS on Ca2+ homeostasis and Ca2+-dependent signaling, cytosolic Ca2+ was measured to monitor cellular perturbations. We found that H2O2 disrupted Ca2+ homeostasis in Se0 pollen only, while Se1 samples were preserved. The same trend was observed when Se0 samples were treated with sodium selenate or Se-methionine, which recapitulated in vitro the protective capacity of Se-fertigation. Furthermore, we found that germination rates were much better retained in Se1 as compared to Se0 (46% vs 8%, respectively) after exposure to 20 mM H2O2. The same was observed with Se0 pollen treated with Se-methionine, which is the organic form of Se into which most fertigated sodium selenate converts in the plant. These results, together, show a close correlation between ROS, Ca2+ homeostasis and pollen fertility, and provide strong evidence that Se-fertigation is an excellent approach to preserve or enhance agricultural productivity.
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6
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Del Pino AM, Regni L, D’Amato R, Tedeschini E, Businelli D, Proietti P, Palmerini CA. Selenium-Enriched Pollen Grains of Olea europaea L.: Ca 2+ Signaling and Germination Under Oxidative Stress. FRONTIERS IN PLANT SCIENCE 2019; 10:1611. [PMID: 31921256 PMCID: PMC6917658 DOI: 10.3389/fpls.2019.01611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 11/15/2019] [Indexed: 05/07/2023]
Abstract
Selenium (Se) shows antioxidant properties that can be exploited in plants to combat abiotic stresses caused by reactive oxygen species produced in excess (ROS). Here, we show that the Se-fertilization of olive trees with sodium selenate effectively protects the pollen from oxidative stress. Pollen isolated from plants treated with Se or from untreated controls was incubated in vitro with H2O2 to produce an oxidative challenge. Given the impact of ROS on Ca2+ homeostasis and Ca2+-dependent signaling, cytosolic Ca2+ was measured to monitor cellular perturbations. We found that H2O2 interrupted Ca2+ homeostasis only in untreated pollen, while in samples treated in vitro with sodium selenate or selenium methionine, Ca2+ homeostasis was preserved. Furthermore, germination rates were considerably better maintained in Se-fertilized pollen compared to non-fertilized pollen (30% vs. 15%, respectively) after exposure to 1 mM H2O2. The same was observed with pollen treated in vitro with Se-methionine, which is the organic form of Se, in which part of the fertigated sodium selenate is converted in the plant. Combined, our results show a close correlation between ROS, Ca2+ homeostasis, and pollen fertility and provide clear evidence that Se-fertilization is a potential approach to preserve or improve agricultural productivity.
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Affiliation(s)
| | - Luca Regni
- *Correspondence: Luca Regni, ; Primo Proietti,
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7
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Maksimov N, Evmenyeva A, Breygina M, Yermakov I. The role of reactive oxygen species in pollen germination in Picea pungens (blue spruce). PLANT REPRODUCTION 2018; 31:357-365. [PMID: 29619606 DOI: 10.1007/s00497-018-0335-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Accepted: 03/29/2018] [Indexed: 05/06/2023]
Abstract
Endogenous ROS, including those produced by NADPH oxidase, are required for spruce pollen germination and regulate membrane potential in pollen tubes; [Formula: see text] and H 2 O 2 are unevenly distributed along the tube. Recently, the key role of reactive oxygen species (ROS) in plant reproduction has been decisively demonstrated for angiosperms. This paper is dedicated to the involvement of ROS in pollen germination of gymnosperms, which remained largely unknown. We found that ROS are secreted from pollen grains of blue spruce during the early stage of activation. The localization of different ROS in pollen tube initials and pollen tubes demonstrated the accumulation of H2O2 in pollen tube apex. Colocalization with mitochondria-derived [Formula: see text] showed that H2O2 is produced in mitochondria and amyloplasts in addition to its apical gradient in the cytosol. The necessity of intracellular ROS and, particularly, [Formula: see text] for pollen germination was demonstrated using different antioxidants. ·OH and extracellular ROS, on the contrary, were found to be not necessary for germination. Exogenous hydrogen peroxide did not affect the germination efficiency but accelerated pollen tube growth in a concentration-dependent manner. The optical measurements of membrane potential showed that in spruce pollen tubes there is a gradient which is controlled by H+-ATPase, potassium- and calcium-permeable channels, anion channels and ROS, as demonstrated by inhibitory analysis. An important role of NADPH oxidase in the regulation of ROS balance in particular, and in germination in general, has been demonstrated by inhibiting the enzyme, which leads to the reduction in ROS release, depolarization of pollen tube plasma membrane, and blocking of pollen germination.
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Affiliation(s)
- Nikita Maksimov
- Lomonosov Moscow State University, Leninskiye Gory 1-12, Moscow, Russia, 119991
| | - Anastasia Evmenyeva
- Lomonosov Moscow State University, Leninskiye Gory 1-12, Moscow, Russia, 119991
| | - Maria Breygina
- Lomonosov Moscow State University, Leninskiye Gory 1-12, Moscow, Russia, 119991.
- Pirogov Russian National Research Medical University, Ostrovitjanova Street 1, Moscow, Russia, 117997.
| | - Igor Yermakov
- Lomonosov Moscow State University, Leninskiye Gory 1-12, Moscow, Russia, 119991
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8
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Diao M, Qu X, Huang S. Calcium imaging in Arabidopsis pollen cells using G-CaMP5. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2018; 60:897-906. [PMID: 29424471 DOI: 10.1111/jipb.12642] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 02/07/2018] [Indexed: 05/18/2023]
Abstract
Calcium (Ca2+ ) signaling has been implicated in pollen germination and pollen tube growth. To date, however, we still know very little about how exactly Ca2+ signaling links to various physiological subcellular processes during pollen germination and pollen tube growth. Given that Ca2+ signaling is tightly related to the cytosolic concentration and dynamics of Ca2+ , it is vital to trace the dynamic changes in Ca2+ levels in order to decode Ca2+ signaling. Here, we demonstrate that G-CaMP5 serves well as an indicator for monitoring cytosolic Ca2+ dynamics in pollen cells. Using this probe, we show that cytosolic Ca2+ changes dramatically during pollen germination, and, as reported previously, Ca2+ forms a tip-focused gradient in the pollen tube and undergoes oscillation in the tip region during pollen tube growth. In particular, using G-CaMP5 allowed us to capture the dynamic changes in the cytosolic Ca2+ concentration ([Ca2+ ]cyt ) in pollen tubes in response to various exogenous treatments. Our data suggest that G-CaMP5 is a suitable probe for monitoring the dynamics of [Ca2+ ]cyt in pollen cells.
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Affiliation(s)
- Min Diao
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaolu Qu
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shanjin Huang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
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9
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Abstract
The eukaryotic actin cytoskeleton is a highly dynamic framework that is involved in many biological processes, such as cell growth, division, morphology, and motility. G-actin polymerizes into microfilaments that associate into bundles, patches, and networks, which, in turn, organize into higher order structures that are fundamental for the course of important physiological events. Actin rings are an example for such higher order actin entities, but this term represents an actually diverse set of subcellular structures that are involved in various processes. This review especially sheds light on a crucial type of non-constricting ring-like actin networks, and categorizes them under the term 'actin fringe'. These 'actin fringes' are visualized as highly dynamic and yet steady structures in the tip of various polarized growing cells. The present comprehensive overview compares the actin fringe characteristics of rapidly elongating pollen tubes with several related actin arrays in other cell types of diverse species. The current state of knowledge about various actin fringe functions is summarized, and the key role of this structure in the polar growth process is discussed.
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Affiliation(s)
- Octavian O H Stephan
- Department of Biology, Friedrich-Alexander University of Erlangen-Nuremberg, Erlangen, Bavaria 91058, Germany
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10
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Liu S, Liu H, Feng S, Lin M, Xu F, Lu TJ. Fountain streaming contributes to fast tip-growth through regulating the gradients of turgor pressure and concentration in pollen tubes. SOFT MATTER 2017; 13:2919-2927. [PMID: 28352884 DOI: 10.1039/c6sm01915c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Fountain streaming is a typical microfluidic pattern in plant cells, especially for cells with a high aspect ratio such as pollen tubes. Although it has been found that fountain streaming plays crucial roles in the transport of nutrients and metabolites, the positioning of organelles and the mixing of cytoplasms, its implications for the fast tip growth of pollen tubes remain a mystery. To address this, based on the observations of asiatic lily Lilium Casablanca, we developed physical models for reverse fountain streaming in pollen tubes and solved the hydrodynamics and advection-diffusion dynamics of viscous Stokes flow in the shank and apical region of pollen tubes. Theoretical and numerical results demonstrated that the gradients of turgor pressure and concentration of wall materials along the length of pollen tubes provide undamped driving force and high-efficiency materials supply, which are supposed to contribute to the fast tip-growth of pollen tubes. The sample experimental results show that the tip-growth will be abnormal when the gradients of turgor pressure change under osmotic stress induced by different concentrations of PEG-6000 (a dehydrant).
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Affiliation(s)
- ShaoBao Liu
- State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China. and Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, P. R. China.
| | - Han Liu
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, P. R. China. and MOE Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - ShangSheng Feng
- State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China. and Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, P. R. China.
| | - Min Lin
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, P. R. China. and MOE Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Feng Xu
- Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, P. R. China. and MOE Key Laboratory of Biomedical Information Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Tian Jian Lu
- State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China. and Bioinspired Engineering and Biomechanics Center (BEBC), Xi'an Jiaotong University, Xi'an 710049, P. R. China.
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11
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An Y, Li J, Duan C, Liu L, Sun Y, Cao R, Wang L. 5-Aminolevulinic Acid Thins Pear Fruits by Inhibiting Pollen Tube Growth via Ca(2+)-ATPase-Mediated Ca(2+) Efflux. FRONTIERS IN PLANT SCIENCE 2016; 7:121. [PMID: 26904082 PMCID: PMC4746310 DOI: 10.3389/fpls.2016.00121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 01/22/2016] [Indexed: 05/08/2023]
Abstract
Chemical fruit thinning has become a popular practice in modern fruit orchards for achieving high quality fruits, reducing costs of hand thinning and promoting return bloom. However, most of the suggested chemical thinners are often concerned for their detrimental effects and environmental problems. 5-Aminolevulic acid (ALA) is a natural, nontoxic, biodegradable, and environment-friendly plant growth regulator. One of its outstanding roles is improving plant photosynthesis and fruit quality. Here, results showed that applying 100-200 mg/L ALA at full bloom stage significantly reduced pear fruit set. Both in vivo and in vitro studies showed that ALA significantly inhibited pollen germination and tube growth. ALA decreased not only cytosolic Ca(2+) concentration ([Ca(2+)]cyt) but also "tip-focused" [Ca(2+)]cyt gradient, indicating that ALA inhibited pollen tube growth by down-regulating calcium signaling. ALA drastically enhanced pollen Ca(2+)-ATPase activity, suggesting that ALA-induced decrease of calcium signaling probably resulted from activating calcium pump. The significant negative correlations between Ca(2+)-ATPase activity and pollen germination or pollen tube length further demonstrated the critical role of calcium pump in ALA's negative effect on pollen germination. Taken together, our results suggest that ALA at low concentrations is a potential biochemical thinner, and it inhibits pollen germination and tube growth via Ca(2+) efflux by activating Ca(2+)-ATPase, thereby thinning fruits by preventing fertilization.
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Affiliation(s)
- Yuyan An
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Jie Li
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Chunhui Duan
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Longbo Liu
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
| | - Yongping Sun
- Nanjing Institute of Agricultural SciencesNanjing, China
| | - Rongxiang Cao
- Nanjing Institute of Agricultural SciencesNanjing, China
| | - Liangju Wang
- College of Horticulture, Nanjing Agricultural UniversityNanjing, China
- *Correspondence: Liangju Wang
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12
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Lipchinsky A. Osmophoresis—a possible mechanism for vesicle trafficking in tip-growing cells. Phys Biol 2015; 12:066012. [DOI: 10.1088/1478-3975/12/6/066012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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13
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Yang X, Wang SS, Wang M, Qiao Z, Bao CC, Zhang W. Arabidopsis thaliana calmodulin-like protein CML24 regulates pollen tube growth by modulating the actin cytoskeleton and controlling the cytosolic Ca(2+) concentration. PLANT MOLECULAR BIOLOGY 2014; 86:225-36. [PMID: 25139229 DOI: 10.1007/s11103-014-0220-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 06/23/2014] [Indexed: 05/10/2023]
Abstract
Cytosolic free calcium ([Ca(2+)]cyt), which is essential during pollen germination and pollen tube growth, can be sensed by calmodulin-like proteins (CMLs). The Arabidopsis thaliana genome encodes over 50 CMLs, the physiological role(s) of most of which are unknown. Here we show that the gene AtCML24 acts as a regulator of pollen germination and pollen tube extension, since the pollen produced by loss-of-function mutants germinated less rapidly than that of wild-type (WT) plants, the rate of pollen tube extension was slower, and the final length of the pollen tube was shorter. The [Ca(2+)]cyt within germinated pollen and extending pollen tubes produced by the cml24 mutant were higher than their equivalents in WT plants, and pollen tube extension was less sensitive to changes in external [K(+)] and [Ca(2+)]. The pollen and pollen tubes produced by cml24 mutants were characterized by a disorganized actin cytoskeleton and lowered sensitivity to the action of latrunculin B. The observations support an interaction between CML24 and [Ca(2+)]cyt and an involvement of CML24 in actin organization, thereby affecting pollen germination and pollen tube elongation.
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Affiliation(s)
- Xue Yang
- Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, School of Life Science, Shandong University, Jinan, 250100, China
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14
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Rafińska K, Świdziński M, Bednarska-Kozakiewicz E. Homogalacturonan deesterification during pollen-ovule interaction in Larix decidua Mill.: an immunocytochemical study. PLANTA 2014; 240:195-208. [PMID: 24793355 PMCID: PMC4065381 DOI: 10.1007/s00425-014-2074-6] [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: 10/17/2013] [Accepted: 04/01/2014] [Indexed: 05/07/2023]
Abstract
Studies on angiosperm plants have shown that homogalacturonan present in the extracellular matrix of pistils plays an important role in the interaction with the male gametophyte. However, in gymnosperms, knowledge on the participation of HG in the pollen-ovule interaction is limited, and only a few studies on male gametophytes have been reported. Thus, the aim of this study was to determine the distribution of HG in male gametophytes and ovules during their interaction in Larix decidua Mill. The distribution of HG in pollen grains and unpollinated and pollinated ovules was investigated by immunofluorescence techniques using monoclonal antibodies that recognise high methyl-esterified HG (JIM7), low methyl-esterified HG (JIM5) and calcium cross-linked HG (2F4). All studied categories of HG were detected in the ovule. Highly methyl-esterified HG was present in the cell walls of all cells throughout the interaction; however, the distribution of low methyl-esterified and calcium cross-linked HG changed during the course of interaction. Both of these categories of HG appeared only in the apoplast and the extracellular matrix of the ovule tissues, which interact with the male gametophyte. This finding suggests that in L. decidua, low methyl-esterified and calcium cross-linked HG play an important role in pollen-ovule interaction. The last category of HG is most likely involved in adhesion between the pollen and the ovule and might provide an optimal calcium environment for pollen grain germination and pollen tube growth.
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Affiliation(s)
- Katarzyna Rafińska
- Department of Cell Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland
| | - Michał Świdziński
- Department of Cell Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland
| | - Elżbieta Bednarska-Kozakiewicz
- Department of Cell Biology, Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Lwowska 1, 87-100 Toruń, Poland
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15
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Ling Y, Chen T, Jing Y, Fan L, Wan Y, Lin J. γ-Aminobutyric acid (GABA) homeostasis regulates pollen germination and polarized growth in Picea wilsonii. PLANTA 2013; 238:831-43. [PMID: 23900837 DOI: 10.1007/s00425-013-1938-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 07/19/2013] [Indexed: 05/10/2023]
Abstract
γ-Aminobutyric acid (GABA) is a four-carbon non-protein amino acid found in a wide range of organisms. Recently, GABA accumulation has been shown to play a role in the stress response and cell growth in angiosperms. However, the effect of GABA deficiency on pollen tube development remains unclear. Here, we demonstrated that specific concentrations of exogenous GABA stimulated pollen tube growth in Picea wilsonii, while an overdose suppressed pollen tube elongation. The germination percentage of pollen grains and morphological variations in pollen tubes responded in a dose-dependent manner to treatment with 3-mercaptopropionic acid (3-MP), a glutamate decarboxylase inhibitor, while the inhibitory effects could be recovered in calcium-containing medium supplemented with GABA. Using immunofluorescence labeling, we found that the actin cables were disorganized in 3-MP treated cells, followed by the transition of endo/exocytosis activating sites from the apex to the whole tube shank. In addition, variations in the deposition of cell wall components were detected upon labeling with JIM5, JIM7, and aniline blue. Our results demonstrated that calcium-dependent GABA signaling regulates pollen germination and polarized tube growth in P. wilsonii by affecting actin filament patterns, vesicle trafficking, and the configuration and distribution of cell wall components.
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Affiliation(s)
- Yu Ling
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing, 100083, China
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16
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Lazzaro MD, Marom EY, Reddy ASN. Polarized cell growth, organelle motility, and cytoskeletal organization in conifer pollen tube tips are regulated by KCBP, the calmodulin-binding kinesin. PLANTA 2013; 238:587-97. [PMID: 23784715 DOI: 10.1007/s00425-013-1919-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 06/11/2013] [Indexed: 05/07/2023]
Abstract
Kinesin-like calmodulin-binding protein (KCBP), a member of the Kinesin 14 family, is a minus end directed C-terminal motor unique to plants and green algae. Its motor activity is negatively regulated by calcium/calmodulin binding, and its tail region contains a secondary microtubule-binding site. It has been identified but not functionally characterized in the conifer Picea abies. Conifer pollen tubes exhibit polarized growth as organelles move into the tip in an unusual fountain pattern directed by microfilaments but uniquely organized by microtubules. We demonstrate here that PaKCBP and calmodulin regulate elongation and motility. PaKCBP is a 140 kDa protein immunolocalized to the elongating tip, coincident with microtubules. This localization is lost when microtubules are disrupted with oryzalin, which also reorganizes microfilaments into bundles. Colocalization of PaKCBP along microtubules is enhanced when microfilaments are disrupted with latrunculin B, which also disrupts the fine network of microtubules throughout the tip while preserving thicker microtubule bundles. Calmodulin inhibition by W-12 perfusion reversibly slows pollen tube elongation, alters organelle motility, promotes microfilament bundling, and microtubule bundling coincident with increased PaKCBP localization. The constitutive activation of PaKCBP by microinjection of an antibody that displaces calcium/calmodulin and activates microtubule bundling repositions vacuoles in the tip before rapidly stopping organelle streaming and pollen tube elongation. We propose that PaKCBP is one of the target proteins in conifer pollen modulated by calmodulin inhibition leading to microtubule bundling, which alters microtubule and microfilament organization, repositions vacuoles and slows organelle motility and pollen tube elongation.
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Affiliation(s)
- Mark D Lazzaro
- Department of Biology, College of Charleston, Charleston, SC, USA.
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17
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Abstract
Cellular organelles move within the cellular volume and the effect of the resulting drag forces on the liquid causes bulk movement in the cytosol. The movement of both organelles and cytosol leads to an overall motion pattern called cytoplasmic streaming or cyclosis. This streaming enables the active and passive transport of molecules and organelles between cellular compartments. Furthermore, the fusion and budding of vesicles with and from the plasma membrane (exo/endocytosis) allow for transport of material between the inside and the outside of the cell. In the pollen tube, cytoplasmic streaming and exo/endocytosis are very active and fulfill several different functions. In this review, we focus on the logistics of intracellular motion and transport processes as well as their biophysical underpinnings. We discuss various modeling attempts that have been performed to understand both long-distance shuttling and short-distance targeting of organelles. We show how the combination of mechanical and mathematical modeling with cell biological approaches has contributed to our understanding of intracellular transport logistics.
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Affiliation(s)
- Youssef Chebli
- Département de Sciences Biologiques, Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Québec, Canada
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18
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Wang L, Lv X, Li H, Zhang M, Wang H, Jin B, Chen T. Inhibition of apoplastic calmodulin impairs calcium homeostasis and cell wall modeling during Cedrus deodara pollen tube growth. PLoS One 2013; 8:e55411. [PMID: 23405148 PMCID: PMC3566176 DOI: 10.1371/journal.pone.0055411] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 12/21/2012] [Indexed: 12/14/2022] Open
Abstract
Calmodulin (CaM) is one of the most well-studied Ca(2+) transducers in eukaryotic cells. It is known to regulate the activity of numerous proteins with diverse cellular functions; however, the functions of apoplastic CaM in plant cells are still poorly understood. By combining pharmacological analysis and microscopic techniques, we investigated the involvement of apoplastic CaM in pollen tube growth of Cedrus deodara (Roxb.) Loud. It was found that the tip-focused calcium gradient was rapidly disturbed as one of the early events after application of pharmacological agents, while the cytoplasmic organization was not significantly affected. The deposition and distribution of acidic pectins and esterified pectins were also dramatically changed, further perturbing the normal modeling of the cell wall. Several protein candidates from different functional categories may be involved in the responses to inhibition of apoplastic CaM. These results revealed that apoplastic CaM functions to maintain the tip-focused calcium gradient and to modulate the distribution/transformation of pectins during pollen tube growth.
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Affiliation(s)
- Li Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, China
| | - Xueqin Lv
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Biological Science and Technology, Yangzhou University, Yangzhou, China
| | - Hong Li
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Biological Science and Technology, Yangzhou University, Yangzhou, China
| | - Min Zhang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, China
| | - Hong Wang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Biao Jin
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu, China
| | - Tong Chen
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China
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19
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Chen Y, Liu P, Hoehenwarter W, Lin J. Proteomic and Phosphoproteomic Analysis of Picea wilsonii Pollen Development under Nutrient Limitation. J Proteome Res 2012; 11:4180-90. [DOI: 10.1021/pr300295m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yanmei Chen
- State Key Laboratory of Plant Physiology and Biochemistry, College
of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Peng Liu
- Key Laboratory of Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Wolfgang Hoehenwarter
- Department Molecular Systems Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse
14, A-1090, Vienna
| | - Jinxing Lin
- Key Laboratory of Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
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20
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Yu Y, Li Y, Huang G, Meng Z, Zhang D, Wei J, Yan K, Zheng C, Zhang L. PwHAP5, a CCAAT-binding transcription factor, interacts with PwFKBP12 and plays a role in pollen tube growth orientation in Picea wilsonii. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:4805-17. [PMID: 21784992 PMCID: PMC3192995 DOI: 10.1093/jxb/err120] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2011] [Revised: 03/16/2011] [Accepted: 03/24/2011] [Indexed: 05/21/2023]
Abstract
The HAP complex occurs in many eukaryotic organisms and is involved in multiple physiological processes. Here it was found that in Picea wilsonii, HAP5 (PwHAP5), a putative CCAAT-binding transcription factor gene, is involved in pollen tube development and control of tube orientation. Quantitative real-time reverse transcription-PCR showed that PwHAP5 transcripts were expressed strongly in germinating pollen and could be induced by Ca(2+). Overexpression of PwHAP5 in pollen altered pollen tube orientation, whereas the tube with PwHAP5RNAi showed normal growth without diminishing pollen tube growth. Furthermore, PwFKBP12, which encodes an FK506-binding protein (FKBP) was screened and a bimolecular fluorescence complementation assay performed to confirm the interaction of PwHAP5 and PwFKBP12 in vivo. Transient expression of PwFKBP12 in pollen showed normal pollen tube growth, whereas the tube with PwFKBP12RNAi bent. The phenotype of overexpression of HAP5 on pollen tube was restored by FKBP12. Altogether, our study supported the role of HAP5 in pollen tube development and orientation regulation and identified FKBP12 as a novel partner to interact with HAP5 involved in the process.
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Affiliation(s)
- Yanli Yu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, P.R. China
- Maize Institute, Shandong Academy of Agricultural Sciences/National Maize Improvement Sub-Center, Jinan 250100, P.R.China
| | - Yanze Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, P.R. China
| | - Guixue Huang
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, PR China
| | - Zhaodong Meng
- Maize Institute, Shandong Academy of Agricultural Sciences/National Maize Improvement Sub-Center, Jinan 250100, P.R.China
| | - Dun Zhang
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, PR China
| | - Jing Wei
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, PR China
| | - Kang Yan
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, P.R. China
| | - Chengchao Zheng
- Maize Institute, Shandong Academy of Agricultural Sciences/National Maize Improvement Sub-Center, Jinan 250100, P.R.China
| | - Lingyun Zhang
- Key Laboratory of Forest Silviculture and Conservation of the Ministry of Education, Beijing Forestry University, Beijing 100083, PR China
- To whom correspondence should be addressed. E-mail:
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21
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Verchot-Lubicz J, Goldstein RE. Cytoplasmic streaming enables the distribution of molecules and vesicles in large plant cells. PROTOPLASMA 2010; 240:99-107. [PMID: 19937356 DOI: 10.1007/s00709-009-0088-x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Accepted: 11/02/2009] [Indexed: 05/19/2023]
Abstract
Recent studies of aquatic and land plants show that similar phenomena determine intracellular transport of organelles and vesicles. This suggests that aspects of cell signaling involved in development and response to external stimuli are conserved across species. The movement of molecular motors along cytoskeletal filaments directly or indirectly entrains the fluid cytosol, driving cyclosis (i.e., cytoplasmic streaming) and affecting gradients of molecular species within the cell, with potentially important metabolic implications as a driving force for cell expansion. Research has shown that myosin XI functions in organelle movement driving cytoplasmic streaming in aquatic and land plants. Despite the conserved cytoskeletal machinery propelling organelle movement among aquatic and land plants, the velocities of cyclosis in plant cells varies according to cell types, developmental stage of the cell, and plant species. Here, we synthesize recent insights into cytoplasmic streaming, molecular gradients, cytoskeletal and membrane dynamics, and expand current cellular models to identify important gaps in current research.
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Affiliation(s)
- Jeanmarie Verchot-Lubicz
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
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22
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Deng F, Zhu S, Wu L, Cheng B. Effects of low-energy argon ion implantation on the dynamic organization of the actin cytoskeleton during maize pollen germination. GENETICS AND MOLECULAR RESEARCH 2010; 9:785-96. [DOI: 10.4238/vol9-2gmr768] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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23
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Wang Y, Chen T, Zhang C, Hao H, Liu P, Zheng M, Baluška F, Šamaj J, Lin J. Nitric oxide modulates the influx of extracellular Ca2+ and actin filament organization during cell wall construction in Pinus bungeana pollen tubes. THE NEW PHYTOLOGIST 2009; 182:851-862. [PMID: 19646068 DOI: 10.1111/j.1469-8137.2009.02820.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nitric oxide (NO) plays a key role in many physiological processes in plants, including pollen tube growth. Here, effects of NO on extracellular Ca(2+) flux and microfilaments during cell wall construction in Pinus bungeana pollen tubes were investigated. Extracellular Ca(2+) influx, the intracellular Ca(2+) gradient, patterns of actin organization, vesicle trafficking and cell wall deposition upon treatment with the NO donor S-nitroso-N-acetylpenicillamine (SNAP), the NO synthase (NOS) inhibitor N(omega)-nitro-L-arginine (L-NNA) or the NO scavenger 2-(4-carboxyphenyl)-4, 4, 5, 5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) were analyzed. SNAP enhanced pollen tube growth in a dose-dependent manner, while L-NNA and cPTIO inhibited NO production and arrested pollen tube growth. Noninvasive detection and microinjection of a Ca(2+) indicator revealed that SNAP promoted extracellular Ca(2+) influx and increased the steepness of the tip-focused Ca(2+) gradient, while cPTIO and L-NNA had the opposite effect. Fluorescence labeling indicated that SNAP, cPTIO and L-NNA altered actin organization, which subsequently affected vesicle trafficking. Finally, the configuration and/or distribution of cell wall components such as pectins and callose were significantly altered in response to L-NNA. Fourier transform infrared (FTIR) microspectroscopy confirmed the changes in the chemical composition of walls. Our results indicate that NO affects the configuration and distribution of cell wall components in pollen tubes by altering extracellular Ca(2+) influx and F-actin organization.
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Affiliation(s)
- Yuhua Wang
- Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
- The College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Tong Chen
- Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Chunyang Zhang
- Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
| | - Huaiqing Hao
- Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Peng Liu
- Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
| | - Maozhong Zheng
- Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Graduate School of Chinese Academy of Sciences, Beijing 100049, China
| | - František Baluška
- Institute of Cellular and Molecular Botany, Rheinische Friedrich-Wilhelms-University Bonn, Department of Plant Cell Biology, Kirschallee 1, D-53115 Bonn, Germany
| | - Jozef Šamaj
- Institute of Cellular and Molecular Botany, Rheinische Friedrich-Wilhelms-University Bonn, Department of Plant Cell Biology, Kirschallee 1, D-53115 Bonn, Germany
- Institute of Plant Genetics and Biotechnology, Slovak Academy of Sciences, Akademicka 2, SK-95007, Nitra, Slovak Republic
- Palacky University Olomouc, Faculty of Natural Science, Olomouc 771 46, Czech Republic
| | - Jinxing Lin
- Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
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24
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Williams JH. Amborella trichopoda (Amborellaceae) and the evolutionary developmental origins of the angiosperm progamic phase. AMERICAN JOURNAL OF BOTANY 2009; 96:144-65. [PMID: 21628181 DOI: 10.3732/ajb.0800070] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A remarkable number of the defining features of flowering plants are expressed during the life history stage between pollination and fertilization. Hand pollinations of Amborella trichopoda (Amborellaceae) in New Caledonia show that when the stigma is first receptive, the female gametophyte is near maturity. Pollen germinates within 2 h, and pollen tubes with callose walls and plugs grow entirely within secretions from stigma to stylar canal and ovarian cavity. Pollen tubes enter the micropyle within 14 h, and double fertilization occurs within 24 h. Hundreds of pollen tubes grow to the base of the stigma, but few enter the open stylar canal. New data from Amborella, combined with a review of fertilization biology of other early-divergent angiosperms, show that an evolutionary transition from slow reproduction to rapid reproduction occurred early in angiosperm history. I identify increased pollen tube growth rates within novel secretory carpel tissues as the primary mechanism for such a shift. The opportunity for prezygotic selection through interactions with the stigma is also an important innovation. Pollen tube wall construction and substantial modifications of the ovule and its associated structures greatly facilitated a new kind of reproductive biology.
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Affiliation(s)
- Joseph H Williams
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee 37996 USA
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25
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Chen KM, Wu GL, Wang YH, Tian CT, Samaj J, Baluska F, Lin JX. The block of intracellular calcium release affects the pollen tube development of Picea wilsonii by changing the deposition of cell wall components. PROTOPLASMA 2008; 233:39-49. [PMID: 18726547 DOI: 10.1007/s00709-008-0310-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Accepted: 02/23/2008] [Indexed: 05/07/2023]
Abstract
Two potent drugs, neomycin and TMB-8, which can block intracellular calcium release, were used to investigate their influence on pollen tube growth and cell wall deposition in Picea wilsonii. Apart from inhibiting pollen germination and pollen tube growth, the two drugs largely influenced tube morphology. The drugs not only obviously disturbed the generation and maintenance of the tip-localized Ca(2+) gradient but also led to a heavy accumulation of callose at the tip region of P. wilsonii pollen tubes. Fourier transform infrared (FTIR) spectroscopy analysis showed that the deposition of cell wall components, such as carboxylic acid, pectins, and other polysaccharides, in pollen tubes was changed by the two drugs. The results obtained from immunolabeling with different pectin and arabinogalactan protein antibodies agreed well with the FTIR results and further demonstrated that the generation and maintenance of the gradient of cross-linked pectins, as well as the proportional distribution of arabinogalactan proteins in tube cell walls, are essential for pollen tube growth. These results strongly suggest that intracellular calcium release mediates the processes of pollen germination and pollen tube growth in P. wilsonii and its inhibition can lead to abnormal growth by disturbing the deposition of cell wall components in pollen tube tips.
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Affiliation(s)
- Kun-Ming Chen
- Institute of Crop Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou
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26
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Chen T, Teng N, Wu X, Wang Y, Tang W, Samaj J, Baluska F, Lin J. Disruption of actin filaments by latrunculin B affects cell wall construction in Picea meyeri pollen tube by disturbing vesicle trafficking. PLANT & CELL PHYSIOLOGY 2007; 48:19-30. [PMID: 17118947 DOI: 10.1093/pcp/pcl036] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The involvement of actin filaments (AFs) in vesicle trafficking, cell wall construction and tip growth was investigated during pollen tube development of Picea meyeri. Pollen germination and tube elongation were inhibited in a dose-dependent manner by the latrunculin B (LatB) treatment. The fine AFs were broken down into disorganized fragments showing a tendency to aggregate. FM4-64 labeling revealed that the dynamic balance of vesicle trafficking was perturbed due to F-actin disruption and the fountain-like cytoplasmic pattern changed into disorganized Brownian movement. The configuration and/or distribution of cell wall components, such as pectins, callose and cellulose, as well as arabinogalactan proteins changed in obvious ways after the LatB application. Fourier transform infrared (FTIR) analysis further established significant changes in the chemical composition of the wall material. Our results indicate that depolymerization of AFs affects the distribution and configuration of cell wall components in Picea meyeri pollen tube by disturbing vesicle trafficking.
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Affiliation(s)
- Tong Chen
- Key Laboratory of Photosynthesis and Environmental Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
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27
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Wu Y, Xu X, Li S, Liu T, Ma L, Shang Z. Heterotrimeric G-protein participation in Arabidopsis pollen germination through modulation of a plasmamembrane hyperpolarization-activated Ca2+-permeable channel. THE NEW PHYTOLOGIST 2007; 176:550-559. [PMID: 17953540 DOI: 10.1111/j.1469-8137.2007.02214.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The role of heterotrimeric G proteins in pollen germination and tube growth was investigated using Arabidopsis thaliana plants in which the gene (GPA) encoding the G-protein a subunit (Galpha) was null or overexpressed. Pollen germination, free cytosolic calcium concentration ([Ca(2+)](cyt)) and Ca(2+) channel activity in the plasma membrane (PM) of pollen cells were investigated. Results showed that, compared with pollen grains of the wild type (ecotype Wassilewskija, ws), in vitro germinated pollen of Galpha null mutants (gpa1-1 and gpa1-2) had lower germination percentages and shorter pollen tubes, while pollen from Galpha overexpression lines (wGalpha and cGalpha) had higher germination percentages and longer pollen tubes. Compared with ws pollen cells, [Ca(2+)](cyt) was lower in gpa1-1 and gpa1-2 and higher in wGalpha and cGalpha. In whole-cell patch clamp recordings, a hyperpolarization-activated Ca(2+)-permeable conductance was identified in the PM of pollen protoplasts. The conductance was suppressed by trivalent cations but insensitive to organic blockers; its permeability to divalent cations was Ba(2+) > Ca(2+) > Mg(2+) > Sr(2+) > Mn(2+). The activity of the Ca(2+)-permeable channel conductance was down-regulated in pollen protoplasts of gpa1-1 and gpa1-2, and up-regulated in wGalpha and cGalpha. The results suggest that Galpha may participate in pollen germination through modulation of the hyperpolarization-activated Ca(2+) channel in the PM of pollen cells.
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Affiliation(s)
- Yansheng Wu
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Xiaodong Xu
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Sujuan Li
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Ting Liu
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Ligeng Ma
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
| | - Zhonglin Shang
- College of Life Science, Hebei Normal University, Shijiazhuang 050016, China
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28
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Dauphin A, Gérard J, Lapeyrie F, Legué V. Fungal hypaphorine reduces growth and induces cytosolic calcium increase in root hairs of Eucalyptus globulus. PROTOPLASMA 2007; 231:83-8. [PMID: 17370110 DOI: 10.1007/s00709-006-0240-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2005] [Accepted: 06/06/2006] [Indexed: 05/14/2023]
Abstract
Root hairs are tubular cells resulting from a tip-localized growth in which calcium ions play a key role. Hypaphorine, an indole alkaloid secreted by the fungus Pisolithus microcarpus during the formation of ectomycorrhizae with the host plant Eucalyptus globulus, inhibits root hair tip growth. Hypaphorine-induced inhibition is linked to a transient depolarization of the plasma membrane and a reorganization of the actin and microtubule cytoskeletons. Here we investigated the activity of hypaphorine on calcium distribution in E. globulus root hairs with the ratiometric fluorochrome calcium indicator Indo-1. In 85% of actively growing root hairs, a significant but modest calcium gradient between the apex and the base was observed due to an elevated cytoplasmic calcium concentration at the apical tip. Following exposure to 1 mM hypaphorine, the apical and basal cytoplasmic Ca(2+) concentration increased in 70 and 77% of the hairs, respectively, 10 min after treatment. This led to a reduced calcium gradient in 81% of the cells. The hypothetical links between calcium concentration elevation, regulation of actin cytoskeleton dynamics, and root hair growth inhibition in response to hypaphorine treatment are discussed.
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Affiliation(s)
- A Dauphin
- Unité Mixte de Recherche 1136 Interactions Arbres-Microorganismes, Institut National de la Recherche Agronomique, Faculté des Sciences, Université Henri Poincaré, Vandoeuvre, France
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29
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Samaj J, Müller J, Beck M, Böhm N, Menzel D. Vesicular trafficking, cytoskeleton and signalling in root hairs and pollen tubes. TRENDS IN PLANT SCIENCE 2006; 11:594-600. [PMID: 17092761 DOI: 10.1016/j.tplants.2006.10.002] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 09/11/2006] [Accepted: 10/23/2006] [Indexed: 05/12/2023]
Abstract
Root hairs and pollen tubes show strictly polar cell expansion called tip growth. Recent studies of tip growth in root hairs and pollen tubes have revealed that small GTPases of the Rab, Arf and Rho/Rac families, along with their regulatory proteins, are essential for spatio-temporal regulation of vesicular trafficking, cytoskeleton organization and signalling. ROP/RAC GTPases are involved in a multiplicity of functions including the regulation of cytoskeleton organization, calcium signalling and endocytosis in pollen tubes and root hairs. One of the most exciting recent discoveries is the preferential localization of vesicles of the trans-Golgi network (TGN), defined by specific RAB GTPases, in the apical "clear zone" and the definition of TGN as a bona fide organelle involved in both polarized secretion and endocytosis. The TGN is thought to serve the function of an early endosome in plants because it is involved in early endocytosis and rapid vesicular recycling of the plasma membrane in root epidermal cells.
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Affiliation(s)
- Jozef Samaj
- Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, D-53115 Bonn, Germany.
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