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Thompson MEH, Raizada MN. The Microbiome of Fertilization-Stage Maize Silks (Style) Encodes Genes and Expresses Traits That Potentially Promote Survival in Pollen/Style Niches and Host Reproduction. Microorganisms 2024; 12:1473. [PMID: 39065240 PMCID: PMC11278993 DOI: 10.3390/microorganisms12071473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Within flowers, the style channel receives pollen and transmits male gametes inside elongating pollen tubes to ovules. The styles of maize/corn are called silks. Fertilization-stage silks possess complex microbiomes, which may partially derive from pollen. These microbiomes lack functional analysis. We hypothesize that fertilization-stage silk microbiomes promote host fertilization to ensure their own vertical transmission. We further hypothesize that these microbes encode traits to survive stresses within the silk (water/nitrogen limitation) and pollen (dehydration/aluminum) habitats. Here, bacteria cultured from fertilization-stage silks of 14 North American maize genotypes underwent genome mining and functional testing, which revealed osmoprotection, nitrogen-fixation, and aluminum-tolerance traits. Bacteria contained auxin biosynthesis genes, and testing confirmed indole compound secretion, which is relevant, since pollen delivers auxin to silks to stimulate egg cell maturation. Some isolates encoded biosynthetic/transport compounds known to regulate pollen tube guidance/growth. The isolates encoded ACC deaminase, which degrades the precursor for ethylene that otherwise accelerates silk senescence. The findings suggest that members of the microbiome of fertilization-stage silks encode adaptations to survive the stress conditions of silk/pollen and have the potential to express signaling compounds known to impact reproduction. Overall, whereas these microbial traits have traditionally been assumed to primarily promote vegetative plant growth, this study proposes they may also play selfish roles during host reproduction.
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Affiliation(s)
| | - Manish N. Raizada
- Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada;
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2
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Del Casino C, Conti V, Licata S, Cai G, Cantore A, Ricci C, Cantara S. Mitigation of UV-B Radiation Stress in Tobacco Pollen by Expression of the Tardigrade Damage Suppressor Protein (Dsup). Cells 2024; 13:840. [PMID: 38786062 PMCID: PMC11119994 DOI: 10.3390/cells13100840] [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: 03/24/2024] [Revised: 04/19/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
Pollen, the male gametophyte of seed plants, is extremely sensitive to UV light, which may prevent fertilization. As a result, strategies to improve plant resistance to solar ultraviolet (UV) radiation are required. The tardigrade damage suppressor protein (Dsup) is a putative DNA-binding protein that enables tardigrades to tolerate harsh environmental conditions, including UV radiation, and was therefore considered as a candidate for reducing the effects of UV exposure on pollen. Tobacco pollen was genetically engineered to express Dsup and then exposed to UV-B radiation to determine the effectiveness of the protein in increasing pollen resistance. To establish the preventive role of Dsup against UV-B stress, we carried out extensive investigations into pollen viability, germination rate, pollen tube length, male germ unit position, callose plug development, marker protein content, and antioxidant capacity. The results indicated that UV-B stress has a significant negative impact on both pollen grain and pollen tube growth. However, Dsup expression increased the antioxidant levels and reversed some of the UV-B-induced changes to pollen, restoring the proper distance between the tip and the last callose plug formed, as well as pollen tube length, tubulin, and HSP70 levels. Therefore, the expression of heterologous Dsup in pollen may provide the plant male gametophyte with enhanced responses to UV-B stress and protection against harmful environmental radiation.
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Affiliation(s)
- Cecilia Del Casino
- Dipartimento di Scienze della Vita, University of Siena, via Mattioli 4, 53100 Siena, Italy; (C.D.C.); (S.L.)
| | - Veronica Conti
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Bologna, via Irnerio 42, 40126 Bologna, Italy;
| | - Silvia Licata
- Dipartimento di Scienze della Vita, University of Siena, via Mattioli 4, 53100 Siena, Italy; (C.D.C.); (S.L.)
| | - Giampiero Cai
- Dipartimento di Scienze della Vita, University of Siena, via Mattioli 4, 53100 Siena, Italy; (C.D.C.); (S.L.)
| | - Anna Cantore
- Department of Medical, Surgical and Neurological Sciences, University of Siena, Viale Bracci, 53100 Siena, Italy; (A.C.); (C.R.); (S.C.)
| | - Claudia Ricci
- Department of Medical, Surgical and Neurological Sciences, University of Siena, Viale Bracci, 53100 Siena, Italy; (A.C.); (C.R.); (S.C.)
| | - Silvia Cantara
- Department of Medical, Surgical and Neurological Sciences, University of Siena, Viale Bracci, 53100 Siena, Italy; (A.C.); (C.R.); (S.C.)
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3
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Çetinbaş-Genç A, Toksöz O, Piccini C, Kilin Ö, Sesal NC, Cai G. Effects of UV-B Radiation on the Performance, Antioxidant Response and Protective Compounds of Hazelnut Pollen. PLANTS (BASEL, SWITZERLAND) 2022; 11:2574. [PMID: 36235440 PMCID: PMC9573160 DOI: 10.3390/plants11192574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 09/25/2022] [Accepted: 09/27/2022] [Indexed: 06/16/2023]
Abstract
Increasing ultraviolet (UV) radiation is expected to become a problem in hazelnut cultivation. The aim of this study is to examine the effects of UV-B on hazelnut pollen. To this end, the pollens were exposed to UV-B for 1, 2, and 3 h at distances of 10, 20, 30, and 40 cm. Groups treated for 2 h at 20 cm and 3 h at 10 and 20 cm were identified as the most affected based on the results of viability, germination, and tube elongation. Further studies on these groups showed that UV-B does not change the DPPH radical scavenging activity for all groups. However, total phenolic compounds decreased after 3 h of treatment at 10 and 20 cm, while total flavonoid compounds decreased after all treatment groups. The UV-B absorbance of cytoplasmic and cell-wall-bound fractions decreased for all groups. The UV-B absorbance of the sporopollenin-derived fraction increased after 2 h of treatment at 20 cm but decreases after treatment for 3 h at 10 and 20 cm. In summary, exposure to UV-B for different times and distances adversely affected pollen grains in terms of pollen viability, germination rate, tube length, and the level of antioxidant molecules and UV-absorbing compounds.
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Affiliation(s)
- Aslıhan Çetinbaş-Genç
- Department of Biology, Faculty of Science, Marmara University, Kadıköy, Istanbul 34722, Turkey
| | - Orçun Toksöz
- Institute of Pure and Applied Sciences, Marmara University, Istanbul 34722, Turkey
| | - Chiara Piccini
- Department of Life Sciences, University of Siena, Via Mattioli 4, 53100 Siena, Italy
| | - Özkan Kilin
- Department of Biology, Faculty of Science, Marmara University, Kadıköy, Istanbul 34722, Turkey
| | - Nüzhet Cenk Sesal
- Department of Biology, Faculty of Science, Marmara University, Kadıköy, Istanbul 34722, Turkey
| | - Giampiero Cai
- Department of Life Sciences, University of Siena, Via Mattioli 4, 53100 Siena, Italy
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4
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Aloisi I, Piccini C, Cai G, Del Duca S. Male Fertility under Environmental Stress: Do Polyamines Act as Pollen Tube Growth Protectants? Int J Mol Sci 2022; 23:1874. [PMID: 35163795 PMCID: PMC8836739 DOI: 10.3390/ijms23031874] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 02/02/2022] [Accepted: 02/04/2022] [Indexed: 02/06/2023] Open
Abstract
Although pollen structure and morphology evolved toward the optimization of stability and fertilization efficiency, its performance is affected by harsh environmental conditions, e.g., heat, cold, drought, pollutants, and other stressors. These phenomena are expected to increase in the coming years in relation to predicted environmental scenarios, contributing to a rapid increase in the interest of the scientific community in understanding the molecular and physiological responses implemented by male gametophyte to accomplish reproduction. Here, after a brief introduction summarizing the main events underlying pollen physiology with a focus on polyamine involvement in its development and germination, we review the main effects that environmental stresses can cause on pollen. We report the most relevant evidence in the literature underlying morphological, cytoskeletal, metabolic and signaling alterations involved in stress perception and response, focusing on the final stage of pollen life, i.e., from when it hydrates, to pollen tube growth and sperm cell transport, with these being the most sensitive to environmental changes. Finally, we hypothesize the molecular mechanisms through which polyamines, well-known molecules involved in plant development, stress response and adaptation, can exert a protective action against environmental stresses in pollen by decoding the essential steps and the intersection between polyamines and pollen tube growth mechanisms.
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Affiliation(s)
- Iris Aloisi
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università Degli Studi di Bologna, Via Irnerio, 40126 Bologna, Italy; (I.A.); (S.D.D.)
| | - Chiara Piccini
- Dipartimento di Scienze della Vita, University of Siena, Via Mattioli 4, 53100 Siena, Italy;
| | - Giampiero Cai
- Dipartimento di Scienze della Vita, University of Siena, Via Mattioli 4, 53100 Siena, Italy;
| | - Stefano Del Duca
- Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università Degli Studi di Bologna, Via Irnerio, 40126 Bologna, Italy; (I.A.); (S.D.D.)
- Interdepartmental Center for Agri-Food Industrial Research, University of Bologna, 40126 Bologna, Italy
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5
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Cervantes-Pérez D, Ortega-García A, Medina-Andrés R, Batista-García RA, Lira-Ruan V. Exogenous Nitric Oxide Delays Plant Regeneration from Protoplast and Protonema Development in Physcomitrella patens. PLANTS 2020; 9:plants9101380. [PMID: 33081222 PMCID: PMC7602845 DOI: 10.3390/plants9101380] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/04/2020] [Accepted: 10/13/2020] [Indexed: 12/21/2022]
Abstract
Nitric oxide (NO) has been recognized as a major player in the regulation of plant physiology and development. NO regulates cell cycle progression and cell elongation in flowering plants and green algae, although the information about NO function in non-vascular plants is scarce. Here, we analyze the effect of exogenous NO on Physcomitrella patens protonema growth. We find that increasing concentrations of the NO donor sodium nitroprusside (SNP) inhibit protonema relative growth rate and cell length. To further comprehend the effect of NO on moss development, we analyze the effect of SNP 5 and 10 µM on protoplast regeneration and, furthermore, protonema formation compared with untreated plants (control). Isolated protoplasts were left to regenerate for 24 h before starting the SNP treatments that lasted five days. The results show that SNP restrains the protoplast regeneration process and the formation of new protonema cells. When SNP treatments started five days after protoplast isolation, a decrease in cell number per protonema filament was observed, indicating an inhibition of cell cycle progression. Our results show that in non-vascular plants, NO negatively regulates plant regeneration, cell cycle and cell elongation.
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6
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Wong A, Donaldson L, Portes MT, Eppinger J, Feijó JA, Gehring C. Arabidopsis DIACYLGLYCEROL KINASE4 is involved in nitric oxide-dependent pollen tube guidance and fertilization. Development 2020; 147:dev.183715. [PMID: 32220864 DOI: 10.1242/dev.183715] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 02/26/2020] [Indexed: 12/16/2022]
Abstract
Nitric oxide (NO) is a key signaling molecule that regulates diverse biological processes in both animals and plants, including important roles in male gamete physiology. In plants, NO is generated in pollen tubes (PTs) and affects intracellular responses through the modulation of Ca2+ signaling, actin organization, vesicle trafficking and cell wall deposition, bearing consequences in pollen-stigma interactions and PT guidance. In contrast, the NO-responsive proteins that mediate these responses remain elusive. Here, we show that PTs of Arabidopsis thaliana mutants impaired in the pollen-specific DIACYLGLYCEROL KINASE4 (DGK4) grow slower and become partially insensitive to NO-dependent growth inhibition and re-orientation responses. Recombinant DGK4 protein yields NO-responsive spectral and catalytic changes in vitro that are compatible with a role in NO perception and signaling in PTs. In addition to the expected phosphatidic acid-producing kinase activity, DGK4 recombinant protein also revealed guanylyl cyclase activity, as inferred by sequence analysis. Our results are compatible with a role for the fast-diffusible NO gas in signaling and cell-cell communication via the modulation of DGK4 activity during the progamic phase of angiosperm reproduction.
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Affiliation(s)
- Aloysius Wong
- Department of Biology, College of Science and Technology, Wenzhou-Kean University, 88 Daxue Road, Ouhai, Wenzhou, Zhejiang Province 325060, China.,Division of Biological and Environmental Sciences and Engineering, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Lara Donaldson
- Division of Biological and Environmental Sciences and Engineering, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia.,Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, South Africa
| | - Maria Teresa Portes
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA
| | - Jörg Eppinger
- Division of Physical Sciences and Engineering, Biological and Organometallic Catalysis Laboratory, KAUST Catalysis Center, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - José A Feijó
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742-5815, USA
| | - Christoph Gehring
- Division of Biological and Environmental Sciences and Engineering, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
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León J, Costa-Broseta Á. Present knowledge and controversies, deficiencies, and misconceptions on nitric oxide synthesis, sensing, and signaling in plants. PLANT, CELL & ENVIRONMENT 2020; 43. [PMID: 31323702 DOI: 10.1111/pce.13617] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 07/15/2019] [Indexed: 05/17/2023]
Abstract
After 30 years of intensive work, nitric oxide (NO) has just started to be characterized as a relevant regulatory molecule on plant development and responses to stress. Its reactivity as a free radical determines its mode of action as an inducer of posttranslational modifications of key target proteins through cysteine S-nitrosylation and tyrosine nitration. Many of the NO-triggered regulatory actions are exerted in tight coordination with phytohormone signaling. This review not only summarizes and updates the information accumulated on how NO is synthesized, sensed, and transduced in plants but also makes emphasis on controversies, deficiencies, and misconceptions that are hampering our present knowledge on the biology of NO in plants. The development of noninvasive accurate tools for the endogenous NO quantitation as well as the implementation of genetic approaches that overcome misleading pharmacological experiments will be critical for getting significant advances in better knowledge of NO homeostasis and regulatory actions in plants.
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Affiliation(s)
- José León
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Valencia, 46022, Valencia, Spain
| | - Álvaro Costa-Broseta
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Valencia, 46022, Valencia, Spain
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8
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Edlund AF, Olsen K, Mendoza C, Wang J, Buckley T, Nguyen M, Callahan B, Owen HA. Pollen wall degradation in the Brassicaceae permits cell emergence after pollination. AMERICAN JOURNAL OF BOTANY 2017; 104:1266-1273. [PMID: 29756225 DOI: 10.3732/ajb.1700201] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 07/26/2017] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY Despite attempts to degrade the sporopollenin in pollen walls, this material has withstood a hundred years of experimental treatments and thousands of years of environmental attack in insects and soil. We present evidence that sporopollenin, nonetheless, locally degrades only minutes after pollination in Arabidopsis thaliana flowers, and describe here a two-part pollen germination mechanism in A. thaliana involving both chemical weakening of the exine wall and swelling of the underlying intine. METHODS We explored naturally occurring components from pollen and stigma surfaces and found a tripartite mix of hydrogen peroxide, peroxidase and catalase enzymes (all at high levels at the pollination interface) to be experimentally sufficient to degrade the sporopollenin of some Brassicaceae family members. KEY RESULTS At pollination, factors carried on the pollen surface may mix with factors on the stigma surface in a reaction that locally oxidizes the exine pollen wall. Hydrogen peroxide, catalases, and peroxidases are biologically present at the right time and place and, when mixed experimentally, are sufficient to degrade the walls of susceptible pollen. CONCLUSIONS Our work on native biochemistry for breaching sporopollenin suggests new research directions in pollen aperture evolution and could aid efforts to analyze sporopollenin's composition, needed for application of this corrosion-resistant, but long-intractable material.
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Affiliation(s)
- Anna F Edlund
- Biology Department, Lafayette College, Easton, Pennsylvania 18042 USA
| | - Katrina Olsen
- Department of Biological Sciences, University of Wisconsin-Milwaukee, 3209 North Maryland Avenue, Milwaukee, Wisconsin 53211 USA
| | - Christian Mendoza
- Biology Department, Lafayette College, Easton, Pennsylvania 18042 USA
| | - Jing Wang
- Department of Biological Sciences, University of Wisconsin-Milwaukee, 3209 North Maryland Avenue, Milwaukee, Wisconsin 53211 USA
| | - Trudyann Buckley
- Biology Department, Lafayette College, Easton, Pennsylvania 18042 USA
| | - Mai Nguyen
- Biology Department, Lafayette College, Easton, Pennsylvania 18042 USA
| | - Brooke Callahan
- Biology Department, Lafayette College, Easton, Pennsylvania 18042 USA
| | - Heather A Owen
- Department of Biological Sciences, University of Wisconsin-Milwaukee, 3209 North Maryland Avenue, Milwaukee, Wisconsin 53211 USA
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Corpas FJ, Alché JD, Barroso JB. Current overview of S-nitrosoglutathione (GSNO) in higher plants. FRONTIERS IN PLANT SCIENCE 2013; 4:126. [PMID: 23658557 PMCID: PMC3647110 DOI: 10.3389/fpls.2013.00126] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 04/17/2013] [Indexed: 05/19/2023]
Affiliation(s)
- Francisco J. Corpas
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasGranada, Spain
- *Correspondence:
| | - Juan D. Alché
- Departamento de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, Consejo Superior de Investigaciones CientíficasGranada, Spain
| | - Juan B. Barroso
- Grupo de Señalización Molecular y Sistemas Antioxidantes en Plantas, Unidad Asociada al Consejo Superior de Investigaciones Científicas (EEZ), Área de Bioquímica y Biología Molecular, Universidad de JaénJaén, Spain
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10
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Nitric oxide participates in cold-inhibited Camellia sinensis pollen germination and tube growth partly via cGMP in vitro. PLoS One 2012; 7:e52436. [PMID: 23272244 PMCID: PMC3525538 DOI: 10.1371/journal.pone.0052436] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Accepted: 11/13/2012] [Indexed: 11/26/2022] Open
Abstract
Nitric oxide (NO) plays essential roles in many biotic and abiotic stresses in plant development procedures, including pollen tube growth. Here, effects of NO on cold stress inhibited pollen germination and tube growth in Camellia sinensis were investigated in vitro. The NO production, NO synthase (NOS)-like activity, cGMP content and proline (Pro) accumulation upon treatment with NO scavenger cPTIO, NOS inhibitor L-NNA, NO donor DEA NONOate, guanylate cyclase (GC) inhibitor ODQ or phosphodiesterase (PDE) inhibitor Viagra at 25°C (control) or 4°C were analyzed. Exposure to 4°C for 2 h reduced pollen germination and tube growth along with increase of NOS-like activity, NO production and cGMP content in pollen tubes. DEA NONOate treatment inhibited pollen germination and tube growth in a dose-dependent manner under control and reinforced the inhibition under cold stress, during which NO production and cGMP content promoted in pollen tubes. L-NNA and cPTIO markedly reduced the generation of NO induced by cold or NO donor along with partly reverse of cold- or NO donor-inhibited pollen germination and tube growth. Furthermore, ODQ reduced the cGMP content under cold stress and NO donor treatment in pollen tubes. Meanwhile, ODQ disrupted the reinforcement of NO donor on the inhibition of pollen germination and tube growth under cold condition. Additionally, Pro accumulation of pollen tubes was reduced by ODQ compared with that receiving NO donor under cold or control condition. Effects of cPTIO and L-NNA in improving cold-treated pollen germination and pollen tube growth could be lowered by Viagra. Moreover, the inhibitory effects of cPTIO and L-NNA on Pro accumulation were partly reversed by Viagra. These data suggest that NO production from NOS-like enzyme reaction decreased the cold-responsive pollen germination, inhibited tube growth and reduced Pro accumulation, partly via cGMP signaling pathway in C. sinensis.
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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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