1
|
van Nunen SA, Burk MB, Burton PK, Ford G, Harvey RJ, Lozynsky A, Pickford E, Rimmer JS, Smart J, Sutherland MF, Thien F, Weber HC, Zehnwirth H, Newbigin E, Katelaris CH. 5-grass-pollen SLIT effectiveness in seasonal allergic rhinitis: Impact of sensitization to subtropical grass pollen. World Allergy Organ J 2022; 15:100632. [PMID: 35280502 PMCID: PMC8873945 DOI: 10.1016/j.waojou.2022.100632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/24/2022] [Accepted: 01/27/2022] [Indexed: 01/08/2023] Open
Abstract
Background Temperate grass (eg, ryegrass) pollen is a major driver of seasonal allergic rhinitis (SAR) and asthma risks, including thunderstorm asthma. Data for the effectiveness of temperate grass pollen allergen immunotherapy (AIT) in SAR patients from the southern hemisphere, who are frequently polysensitized to subtropical grass pollens, are limited. The 300 IR 5-grass pollen sublingual immunotherapy tablet (300 IR 5-grass SLIT) is known to be effective in polysensitized SAR patients with primary allergy to temperate grasses, however, the influence of polysensitization to subtropical grass pollen on treatment responses has yet to be specifically addressed. Key aims of this study were to measure patient treatment satisfaction during 300 IR 5-grass SLIT treatment and evaluate how polysensitization to subtropical grass pollens affects treatment responses. Methods A prospective observational study was conducted in 63 patients (aged ≥5 years) in several temperate regions of Australia prescribed 300 IR 5-grass SLIT for SAR over 3 consecutive grass pollen seasons. Ambient levels of pollen were measured at representative sites. Patient treatment satisfaction was assessed using a QUARTIS questionnaire. Rhinoconjunctivitis Total Symptom Score (RTSS) and a Hodges-Lehmann Estimator analysis was performed to evaluate if polysensitization to subtropical grass pollen affected SAR symptom intensity changes during SLIT. Results A diagnosis of ryegrass pollen allergy was nearly universal. There were 74.6% (47/63) polysensitized to subtropical and temperate grass pollens. There were 23.8% (15/63) monosensitized to temperate grass pollens. From the first pollen season, statistically significant improvements occurred in SAR symptoms compared with baseline in both monosensitized and polysensitized patients, particularly in those polysensitized (P = 0.0297). Improvements in SAR symptoms were sustained and similar in both groups in the second and third pollen seasons, reaching 70–85% improvement (P < 0.01). Polysensitized patients from both northerly and southerly temperate regions in Australia showed similar improvements. Grass pollen counts in both regions were consistently highest during springtime. Conclusions 300 IR 5-grass SLIT is effective in a real-life setting in SAR patients in the southern hemisphere with primary allergy to temperate grass pollen and predominantly springtime grass pollen exposures. Importantly, SLIT treatment effectiveness was irrespective of the patient's polysensitization status to subtropical grass pollens.
Collapse
|
2
|
Sabrina Idrose N, Tham R, Lodge C, Lowe A, Bui D, Perret J, Vicendese D, Newbigin E, Tang M, Aldakheel F, Douglass J, Abramson M, Walters H, Erbas B, Dharmage S. 550Short-term exposure to grass pollen is associated with lower lung function and increased airway inflammation. Int J Epidemiol 2021. [DOI: 10.1093/ije/dyab168.307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
The association between grass pollen exposure and lung function changes and airway inflammation is limited. We investigated these associations in a community-based sample, and whether any such associations were modified by current asthma, current hay fever, pollen sensitization and age.
Methods
Cross-sectional analyses of data from the Melbourne Atopy Cohort Study (MACS) participants (n = 936). Lung function was assessed using spirometry. Airway inflammation was assessed by fractional exhaled nitric oxide (FeNO), and exhaled breath condensate pH and nitrogen oxides (NOx). Daily pollen counts were collected using a volumetric spore trap. The associations were examined by linear regression.
Results
Higher ambient levels of grass pollen 2 days before (lag 2) were associated with lower mid-forced expiratory flow (FEF25-75%) and FEV1/FVC ratio (Coef. [95% CI] = -119 [-226, -11] mL/s and -1.0 [-3.0, -0.03] %, respectively) and also 3 days before (lag 3). Increased levels of grass pollen a day before (lag 1) was associated with increased FeNO (4.35 [-0.1, 8.7] ppb) and also at lag 2. Adverse associations between pollen and multiple outcomes were greater in adults with current asthma, hay fever and pollen sensitization.
Conclusions
Grass pollen exposure was associated with eosinophilic airway inflammation 1-2 days after exposure and airway obstruction 2-3 days after exposure.
Key messages
There is a more delayed effect on lung function compared to airway inflammation. Adults with current asthma, hay fever and grass pollen sensitisation are especially vulnerable.
Collapse
Affiliation(s)
| | - Rachel Tham
- Australian Catholic University, Melbourne, Australia
| | | | - Adrian Lowe
- University Of Melbourne, Melbourne, Australia
| | - Dinh Bui
- University Of Melbourne, Melbourne, Australia
| | | | - Don Vicendese
- University Of Melbourne, Melbourne, Australia
- La Trobe University, Melbourne, Australia
| | - Ed Newbigin
- University Of Melbourne, Melbourne, Australia
| | - Mimi Tang
- University Of Melbourne, Melbourne, Australia
- Murdoch Children's Research Institute, Melbourne, Australia
| | | | - Jo Douglass
- University Of Melbourne, Melbourne, Australia
- Royal Melbourne Hospital, Melbourne, Australia
| | | | - Haydn Walters
- University Of Melbourne, Melbourne, Australia
- University of Tasmania, Hobart, Australia
| | | | | |
Collapse
|
3
|
Rojo J, Oteros J, Pérez-Badia R, Cervigón P, Ferencova Z, Gutiérrez-Bustillo AM, Bergmann KC, Oliver G, Thibaudon M, Albertini R, Rodríguez-De la Cruz D, Sánchez-Reyes E, Sánchez-Sánchez J, Pessi AM, Reiniharju J, Saarto A, Calderón MC, Guerrero C, Berra D, Bonini M, Chiodini E, Fernández-González D, García J, Trigo MM, Myszkowska D, Fernández-Rodríguez S, Tormo-Molina R, Damialis A, Kolek F, Traidl-Hoffmann C, Severova E, Caeiro E, Ribeiro H, Magyar D, Makra L, Udvardy O, Alcázar P, Galán C, Borycka K, Kasprzyk I, Newbigin E, Adams-Groom B, Apangu GP, Frisk CA, Skjøth CA, Radišić P, Šikoparija B, Celenk S, Schmidt-Weber CB, Buters J. Near-ground effect of height on pollen exposure. Environ Res 2019; 174:160-169. [PMID: 31077991 DOI: 10.1016/j.envres.2019.04.027] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 06/09/2023]
Abstract
The effect of height on pollen concentration is not well documented and little is known about the near-ground vertical profile of airborne pollen. This is important as most measuring stations are on roofs, but patient exposure is at ground level. Our study used a big data approach to estimate the near-ground vertical profile of pollen concentrations based on a global study of paired stations located at different heights. We analyzed paired sampling stations located at different heights between 1.5 and 50 m above ground level (AGL). This provided pollen data from 59 Hirst-type volumetric traps from 25 different areas, mainly in Europe, but also covering North America and Australia, resulting in about 2,000,000 daily pollen concentrations analyzed. The daily ratio of the amounts of pollen from different heights per location was used, and the values of the lower station were divided by the higher station. The lower station of paired traps recorded more pollen than the higher trap. However, while the effect of height on pollen concentration was clear, it was also limited (average ratio 1.3, range 0.7-2.2). The standard deviation of the pollen ratio was highly variable when the lower station was located close to the ground level (below 10 m AGL). We show that pollen concentrations measured at >10 m are representative for background near-ground levels.
Collapse
Affiliation(s)
- Jesús Rojo
- Center of Allergy & Environment (ZAUM), Member of the German Center for Lung Research (DZL), Technical University and Helmholtz Center Munich, Germany; University of Castilla-La Mancha Institute of Environmental Sciences (Botany), Toledo, Spain.
| | - Jose Oteros
- Center of Allergy & Environment (ZAUM), Member of the German Center for Lung Research (DZL), Technical University and Helmholtz Center Munich, Germany
| | - Rosa Pérez-Badia
- University of Castilla-La Mancha Institute of Environmental Sciences (Botany), Toledo, Spain
| | | | | | | | | | - Gilles Oliver
- Réseau National de Surveillance Aérobiologique, Brussieu, France
| | - Michel Thibaudon
- Réseau National de Surveillance Aérobiologique, Brussieu, France
| | | | | | | | | | - Anna-Mari Pessi
- University of Turku, Turun yliopisto, Aerobiology Unit, Finland
| | | | - Annika Saarto
- University of Turku, Turun yliopisto, Aerobiology Unit, Finland
| | | | | | | | - Maira Bonini
- Local Health Authority ATS della Città Metropolitana di Milano, Italy
| | | | | | | | | | | | | | | | - Athanasios Damialis
- Chair and Institute of Environmental Medicine, UNIKA-T, Technical University of Munich and Helmholtz Zentrum München, Research Center for Environmental Health, Augsburg, Germany
| | - Franziska Kolek
- Chair and Institute of Environmental Medicine, UNIKA-T, Technical University of Munich and Helmholtz Zentrum München, Research Center for Environmental Health, Augsburg, Germany
| | - Claudia Traidl-Hoffmann
- Chair and Institute of Environmental Medicine, UNIKA-T, Technical University of Munich and Helmholtz Zentrum München, Research Center for Environmental Health, Augsburg, Germany; CK CARE Crhistine Kühne Center for Allergy Research and Education, Switzerland
| | | | - Elsa Caeiro
- Sociedade Portuguesa de Alergologia e Imunologia Clínica, Lisboa, Portugal
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Carsten B Schmidt-Weber
- Center of Allergy & Environment (ZAUM), Member of the German Center for Lung Research (DZL), Technical University and Helmholtz Center Munich, Germany
| | - Jeroen Buters
- Center of Allergy & Environment (ZAUM), Member of the German Center for Lung Research (DZL), Technical University and Helmholtz Center Munich, Germany
| |
Collapse
|
4
|
Lindstrom SJ, Silver JD, Sutherland MF, Treloar AB, Newbigin E, McDonald CF, Douglass JA. Thunderstorm asthma outbreak of November 2016: a natural disaster requiring planning. Med J Aust 2018; 207:235-237. [PMID: 28899321 DOI: 10.5694/mja17.00285] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/26/2017] [Indexed: 11/17/2022]
|
5
|
Devadas R, Huete AR, Vicendese D, Erbas B, Beggs PJ, Medek D, Haberle SG, Newnham RM, Johnston FH, Jaggard AK, Campbell B, Burton PK, Katelaris CH, Newbigin E, Thibaudon M, Davies JM. Dynamic ecological observations from satellites inform aerobiology of allergenic grass pollen. Sci Total Environ 2018; 633:441-451. [PMID: 29579655 DOI: 10.1016/j.scitotenv.2018.03.191] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 03/16/2018] [Accepted: 03/17/2018] [Indexed: 06/08/2023]
Abstract
Allergic diseases, including respiratory conditions of allergic rhinitis (hay fever) and asthma, affect up to 500 million people worldwide. Grass pollen are one major source of aeroallergens globally. Pollen forecast methods are generally site-based and rely on empirical meteorological relationships and/or the use of labour-intensive pollen collection traps that are restricted to sparse sampling locations. The spatial and temporal dynamics of the grass pollen sources themselves, however, have received less attention. Here we utilised a consistent set of MODIS satellite measures of grass cover and seasonal greenness (EVI) over five contrasting urban environments, located in Northern (France) and Southern Hemispheres (Australia), to evaluate their utility for predicting airborne grass pollen concentrations. Strongly seasonal and pronounced pollinating periods, synchronous with satellite measures of grass cover greenness, were found at the higher latitude temperate sites in France (46-50° N. Lat.), with peak pollen activity lagging peak greenness, on average by 2-3weeks. In contrast, the Australian sites (34-38° S. Lat.) displayed pollinating periods that were less synchronous with satellite greenness measures as peak pollen concentrations lagged peak greenness by as much as 4 to 7weeks. The Australian sites exhibited much higher spatial and inter-annual variations compared to the French sites and at the Sydney site, broader and multiple peaks in both pollen concentrations and greenness data coincided with flowering of more diverse grasses including subtropical species. Utilising generalised additive models (GAMs) we found the satellite greenness data of grass cover areas explained 80-90% of airborne grass pollen concentrations across the three French sites (p<0.001) and accounted for 34 to 76% of grass pollen variations over the two sites in Australia (p<0.05). Our results demonstrate the potential of satellite sensing to augment forecast models of grass pollen aerobiology as a tool to reduce the health and socioeconomic burden of pollen-sensitive allergic diseases.
Collapse
Affiliation(s)
- Rakhesh Devadas
- Climate Change Cluster, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia.
| | - Alfredo R Huete
- Climate Change Cluster, University of Technology Sydney, 15 Broadway, Ultimo, NSW 2007, Australia.
| | - Don Vicendese
- School of Psychology and Public Health, La Trobe University, VIC 3086, Australia.
| | - Bircan Erbas
- School of Psychology and Public Health, La Trobe University, VIC 3086, Australia.
| | - Paul J Beggs
- Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, NSW 2109, Australia.
| | | | - Simon G Haberle
- Department of Archaeology and Natural History, College of Asia and the Pacific, The Australian National University, Acton, ACT 2601, Australia.
| | - Rewi M Newnham
- School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand.
| | - Fay H Johnston
- The Menzies Institute for Medical Research at the University of Tasmania, Hobart, Tasmania, Australia.
| | - Alison K Jaggard
- Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, NSW 2109, Australia.
| | - Bradley Campbell
- School of Agriculture and Food Science, University of Queensland, QLD, Australia.
| | - Pamela K Burton
- Department of Medicine, Campbelltown, Hospital, NSW, Australia.
| | - Constance H Katelaris
- Campbelltown Hospital and the School of Medicine, Western Sydney University, Macarthur, NSW, Australia.
| | - Ed Newbigin
- School of Botany, The University of Melbourne, VIC 3010, Australia.
| | - Michel Thibaudon
- European Aerobiology Society, Réseau National de Surveillance Aérobiologique, 11 chemin de la Creuzille, 69690 Brussieu, France.
| | - Janet M Davies
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Centre for Children's Health Research, Queensland University of Technology, South Brisbane, QLD 4101, Australia.
| |
Collapse
|
6
|
Erbas B, Jazayeri M, Lambert KA, Katelaris CH, Prendergast LA, Tham R, Parrodi MJ, Davies J, Newbigin E, Abramson MJ, Dharmage S. Outdoor pollen is a trigger of child and adolescent asthma emergency department presentations: A systematic review and meta-analysis. Allergy 2018; 73:1632-1641. [PMID: 29331087 DOI: 10.1111/all.13407] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/22/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND In the context of increased asthma exacerbations associated with climatic changes such as thunderstorm asthma, interest in establishing the link between pollen exposure and asthma hospital admissions has intensified. Here, we systematically reviewed and performed a meta-analysis of studies on pollen and emergency department (ED) attendance. METHODS A search for studies with appropriate search strategy in MEDLINE, EMBASE, Web of Science and CINAHL was conducted. Each study was assessed for quality and risk of bias. The available evidence was summarized both qualitatively and meta-analysed using random-effects models when moderate heterogeneity was observed. RESULTS Fourteen studies were included. The pollen taxa investigated differed between studies, allowing meta-analysis only of the effect of grass pollen. A statistically significant increase in the percentage change in the mean number of asthma ED presentations (MPC) (pooled results from 3 studies) was observed for an increase in 10 grass pollen grains per cubic metre of exposure 1.88% (95% CI = 0.94%, 2.82%). Time series studies showed positive correlations between pollen concentrations and ED presentations. Age-stratified studies found strongest associations in children aged 5-17 years old. CONCLUSION Exposure to ambient grass pollen is an important trigger for childhood asthma exacerbations requiring ED attendance. As pollen exposure is increasingly a problem especially in relation to thunderstorm asthma, studies with uniform measures of pollen and similar analytical methods are necessary to fully understand its impact on human health.
Collapse
Affiliation(s)
- B. Erbas
- School of Psychology and Public Health; La Trobe University; Bundoora Vic. Australia
| | - M. Jazayeri
- Department of Mathematics and Statistics; La Trobe University; Bundoora Vic. Australia
| | - K. A. Lambert
- School of Psychology and Public Health; La Trobe University; Bundoora Vic. Australia
| | - C. H. Katelaris
- Department of Medicine, Immunology and Allergy; Campbelltown Hospital; Western Sydney University; Campbelltown NSW Australia
| | - L. A. Prendergast
- Department of Mathematics and Statistics; La Trobe University; Bundoora Vic. Australia
| | - R. Tham
- Allergy and Lung Health Unit; Melbourne School of Population and Global Health; University of Melbourne; Melbourne Vic. Australia
| | - M. J. Parrodi
- School of Psychology and Public Health; La Trobe University; Bundoora Vic. Australia
| | - J. Davies
- Institute of Health and Biomedical Innovation; Queensland University of Technology; South Brisbane Qld Australia
| | - E. Newbigin
- School of Biosciences; University of Melbourne; Melbourne Vic. Australia
| | - M. J. Abramson
- Department of Epidemiology and Preventive Medicine; School of Public Health and Preventive Medicine; Monash University; Melbourne Vic. Australia
| | - S. C. Dharmage
- Allergy and Lung Health Unit; Melbourne School of Population and Global Health; University of Melbourne; Melbourne Vic. Australia
| |
Collapse
|
7
|
Andrew E, Nehme Z, Bernard S, Abramson MJ, Newbigin E, Piper B, Dunlop J, Holman P, Smith K. Stormy weather: a retrospective analysis of demand for emergency medical services during epidemic thunderstorm asthma. BMJ 2017; 359:j5636. [PMID: 29237604 PMCID: PMC5727436 DOI: 10.1136/bmj.j5636] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To describe the demand for emergency medical assistance during the largest outbreak of thunderstorm asthma reported globally, which occurred on 21 November 2016. DESIGN A time series analysis was conducted of emergency medical service caseload between 1 January 2015 and 31 December 2016. Demand during the thunderstorm asthma event was compared to historical trends for the overall population and across specific subgroups. SETTING Victoria, Australia. MAIN OUTCOME MEASURES Number of overall cases attended by emergency medical services, and within patient subgroups. RESULTS On 21 November 2016, the emergency medical service received calls for 2954 cases, which was 1014 more cases than the average over the historical period. Between 6 pm and midnight, calls for 1326 cases were received, which was 2.5 times higher than expected. A total of 332 patients were assessed by paramedics as having acute respiratory distress on 21 November, compared with a daily average of 52 during the historical period. After adjustment for temporal trends, thunderstorm asthma was associated with a 42% (95% confidence interval 40% to 44%) increase in overall caseload for the emergency medical service and a 432% increase in emergency medical attendances for acute respiratory distress symptoms. Emergency transports to hospital increased by 17% (16% to 19%) and time critical referrals from general practitioners increased by 47% (21% to 80%). Large increases in demand were seen among patients with a history of asthma and bronchodilator use. The incidence of out-of-hospital cardiac arrest increased by 82% (67% to 99%) and pre-hospital deaths by 41% (29% to 55%). CONCLUSIONS An unprecedented outbreak of thunderstorm asthma was associated with substantial increase in demand for emergency medical services and pre-hospital cardiac arrest. The health impact of future events may be minimised through use of preventive measures by patients and predictive early warning systems.
Collapse
Affiliation(s)
- Emily Andrew
- Centre for Research and Evaluation, Ambulance Victoria, Doncaster, VIC 3108, Australia 3108
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Ziad Nehme
- Centre for Research and Evaluation, Ambulance Victoria, Doncaster, VIC 3108, Australia 3108
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
- Department of Community Emergency Health and Paramedic Practice, Frankston, VIC 3199, Australia
| | - Stephen Bernard
- Centre for Research and Evaluation, Ambulance Victoria, Doncaster, VIC 3108, Australia 3108
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
- Intensive Care Unit, The Alfred Hospital, Melbourne, VIC 3004, Australia
| | - Michael J Abramson
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Ed Newbigin
- School of BioSciences, University of Melbourne, Melbourne, VIC 3052, Australia
| | - Ben Piper
- Emergency Services Telecommunications Authority, Burwood East, VIC 3151, Australia 3151
| | - Justin Dunlop
- Emergency Management Unit, Ambulance Victoria, Melbourne, VIC 3000, Australia
| | - Paul Holman
- Emergency Management Unit, Ambulance Victoria, Melbourne, VIC 3000, Australia
| | - Karen Smith
- Centre for Research and Evaluation, Ambulance Victoria, Doncaster, VIC 3108, Australia 3108
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
- Department of Community Emergency Health and Paramedic Practice, Frankston, VIC 3199, Australia
| |
Collapse
|
8
|
Davies JM, Erbas B, Katelaris CH, Newbigin E, Heute A, Ebert E, van Klinken RD, Haberle S, Medek D, Beggs PJ. ASCIA-P30: THE AUSPOLLEN PARTNERSHIP: IMPLEMENTING A STANDARDISED NATIONAL POLLEN ALERT SYSTEM FOR BETTER MANAGEMENT OF ALLERGIC RESPIRATORY HEALTH. Intern Med J 2016. [DOI: 10.1111/imj.30_13197] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - Ed Newbigin
- The University of Melbourne; Melbourne Australia
| | | | | | - Rieks D van Klinken
- Commonwealth Scientific and Industrial Research Organisation; Brisbane Australia
| | - Simon Haberle
- The Australian National University; Canberra Australia
| | | | | |
Collapse
|
9
|
Tham R, Vicendese D, Dharmage SC, Hyndman RJ, Newbigin E, Lewis E, O'Sullivan M, Lowe AJ, Taylor P, Bardin P, Tang MLK, Abramson MJ, Erbas B. Associations between outdoor fungal spores and childhood and adolescent asthma hospitalizations. J Allergy Clin Immunol 2016; 139:1140-1147.e4. [PMID: 27523960 DOI: 10.1016/j.jaci.2016.06.046] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 05/30/2016] [Accepted: 06/03/2016] [Indexed: 11/25/2022]
Abstract
BACKGROUND Childhood asthma is a significant public health problem and severe exacerbations can result in diminished quality of life and hospitalization. OBJECTIVE We sought to examine the contribution of outdoor fungi to childhood and adolescent asthma hospitalizations. METHODS The Melbourne Air Pollen Children and Adolescent study is a case-crossover study of 644 children and adolescents (aged 2-17 years) hospitalized for asthma. The Melbourne Air Pollen Children and Adolescent study collected individual data on human rhinovirus infection and sensitization to Alternaria and Cladosporium and daily counts of ambient concentrations of fungal spores, pollen, and air pollutants. Conditional logistic regression models were used to assess associations with increases in spore counts while controlling for potential confounding and testing interactions. RESULTS Exposure to Alternaria (adjusted odds ratio [aOR], 1.07; 95% CI, 1.03-1.11), Leptosphaeria (aOR, 1.05; 95% CI, 1.02-1.07), Coprinus (aOR, 1.04; 95% CI, 1.01-1.07), Drechslera (aOR, 1.03; 95% CI, 1.00-1.05), and total spores (aOR, 1.05; 95% CI, 1.01-1.09) was significantly associated with child asthma hospitalizations independent of human rhinovirus infection. There were significant lagged effects up to 3 days with Alternaria, Leptosphaeria, Cladosporium, Sporormiella, Coprinus, and Drechslera. Some of these associations were significantly greater in participants with Cladosporium sensitization. CONCLUSIONS Exposures to several outdoor fungal spore taxa, including some not reported in previous research, are associated with the risk of child and adolescent asthma hospitalization, particularly in individuals sensitized to Cladosporium. We need further studies to examine cross-reactivity causing asthma exacerbations. Identifying sensitization to multiple fungal allergens in children with asthma could support the design and implementation of more effective strategies to prevent asthma exacerbations.
Collapse
Affiliation(s)
- Rachel Tham
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, the University of Melbourne, Melbourne, Australia
| | - Don Vicendese
- School of Public Health, College of Science, Health and Engineering, La Trobe University, Bundoora, Victoria, Australia
| | - Shyamali C Dharmage
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, the University of Melbourne, Melbourne, Australia
| | - Rob J Hyndman
- Department of Econometrics & Business Statistics, Monash University, Clayton, Australia
| | - Ed Newbigin
- School of Biosciences, the University of Melbourne, Melbourne, Australia
| | - Emma Lewis
- School of Biosciences, the University of Melbourne, Melbourne, Australia
| | - Molly O'Sullivan
- Allergy & Immune Disorders, Murdoch Children's Research Institute, the Royal Children's Hospital, Melbourne, Australia
| | - Adrian J Lowe
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, the University of Melbourne, Melbourne, Australia; Allergy & Immune Disorders, Murdoch Children's Research Institute, the Royal Children's Hospital, Melbourne, Australia
| | - Philip Taylor
- School of Life and Environmental Sciences, Deakin University, Geelong, Australia
| | - Philip Bardin
- Monash Lung & Sleep, Monash Medical Centre and University and Hudson Institute, Melbourne, Australia
| | - Mimi L K Tang
- Allergy and Lung Health Unit, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, the University of Melbourne, Melbourne, Australia; Allergy & Immune Disorders, Murdoch Children's Research Institute, the Royal Children's Hospital, Melbourne, Australia; Department of Paediatrics, the University of Melbourne, Melbourne, Australia
| | - Michael J Abramson
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia
| | - Bircan Erbas
- School of Public Health, College of Science, Health and Engineering, La Trobe University, Bundoora, Victoria, Australia.
| |
Collapse
|
10
|
Beggs PJ, Katelaris CH, Medek D, Johnston FH, Burton PK, Campbell B, Jaggard AK, Vicendese D, Bowman DMJS, Godwin I, Huete AR, Erbas B, Green BJ, Newnham RM, Newbigin E, Haberle SG, Davies JM. Differences in grass pollen allergen exposure across Australia. Aust N Z J Public Health 2016; 39:51-5. [PMID: 25648730 PMCID: PMC4704082 DOI: 10.1111/1753-6405.12325] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Revised: 08/01/2014] [Accepted: 10/01/2014] [Indexed: 11/28/2022] Open
Abstract
Objective: Allergic rhinitis and allergic asthma are important chronic diseases posing serious public health issues in Australia with associated medical, economic, and societal burdens. Pollen are significant sources of clinically relevant outdoor aeroallergens, recognised as both a major trigger for, and cause of, allergic respiratory diseases. This study aimed to provide a national, and indeed international, perspective on the state of Australian pollen data using a large representative sample. Methods: Atmospheric grass pollen concentration is examined over a number of years within the period 1995 to 2013 for Brisbane, Canberra, Darwin, Hobart, Melbourne, and Sydney, including determination of the ‘clinical’ grass pollen season and grass pollen peak. Results: The results of this study describe, for the first time, a striking spatial and temporal variability in grass pollen seasons in Australia, with important implications for clinicians and public health professionals, and the Australian grass pollen‐allergic community. Conclusions: These results demonstrate that static pollen calendars are of limited utility and in some cases misleading. This study also highlights significant deficiencies and limitations in the existing Australian pollen monitoring and data. Implications: Establishment of an Australian national pollen monitoring network would help facilitate advances in the clinical and public health management of the millions of Australians with asthma and allergic rhinitis.
Collapse
Affiliation(s)
- Paul J Beggs
- Department of Environment and Geography, Macquarie University, New South Wales
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Medek DE, Beggs PJ, Erbas B, Jaggard AK, Campbell BC, Vicendese D, Johnston FH, Godwin I, Huete AR, Green BJ, Burton PK, Bowman DMJS, Newnham RM, Katelaris CH, Haberle SG, Newbigin E, Davies JM. Regional and seasonal variation in airborne grass pollen levels between cities of Australia and New Zealand. Aerobiologia (Bologna) 2016; 32:289-302. [PMID: 27069303 PMCID: PMC4826055 DOI: 10.1007/s10453-015-9399-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Although grass pollen is widely regarded as the major outdoor aeroallergen source in Australia and New Zealand (NZ), no assemblage of airborne pollen data for the region has been previously compiled. Grass pollen count data collected at 14 urban sites in Australia and NZ over periods ranging from 1 to 17 years were acquired, assembled and compared, revealing considerable spatiotemporal variability. Although direct comparison between these data is problematic due to methodological differences between monitoring sites, the following patterns are apparent. Grass pollen seasons tended to have more than one peak from tropics to latitudes of 37°S and single peaks at sites south of this latitude. A longer grass pollen season was therefore found at sites below 37°S, driven by later seasonal end dates for grass growth and flowering. Daily pollen counts increased with latitude; subtropical regions had seasons of both high intensity and long duration. At higher latitude sites, the single springtime grass pollen peak is potentially due to a cooler growing season and a predominance of pollen from C3 grasses. The multiple peaks at lower latitude sites may be due to a warmer season and the predominance of pollen from C4 grasses. Prevalence and duration of seasonal allergies may reflect the differing pollen seasons across Australia and NZ. It must be emphasized that these findings are tentative due to limitations in the available data, reinforcing the need to implement standardized pollen-monitoring methods across Australasia. Furthermore, spatiotemporal differences in grass pollen counts indicate that local, current, standardized pollen monitoring would assist with the management of pollen allergen exposure for patients at risk of allergic rhinitis and asthma.
Collapse
Affiliation(s)
| | - Paul J Beggs
- Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, Australia
| | - Bircan Erbas
- School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| | - Alison K Jaggard
- Department of Environmental Sciences, Faculty of Science and Engineering, Macquarie University, Sydney, Australia
| | - Bradley C Campbell
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Australia
| | - Don Vicendese
- School of Psychology and Public Health, La Trobe University, Melbourne, Australia
| | - Fay H Johnston
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Australia
| | - Ian Godwin
- School of Agriculture and Food Science, The University of Queensland, Brisbane, Australia
| | - Alfredo R Huete
- Plant Functional Biology and Climate Change, University of Technology, Sydney, Sydney, Australia
| | - Brett J Green
- National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Pamela K Burton
- Campbelltown Hospital and the School of Medicine, University of Western Sydney, Macarthur, NSW, Australia
| | - David M J S Bowman
- School of Biological Sciences, University of Tasmania, Hobart, Australia
| | - Rewi M Newnham
- School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Constance H Katelaris
- Campbelltown Hospital and the School of Medicine, University of Western Sydney, Macarthur, NSW, Australia
| | - Simon G Haberle
- Department of Archaeology and Natural History, College of Asia and the Pacific, The Australian National University, Canberra, Australia
| | - Ed Newbigin
- School of BioSciences, The University of Melbourne, Melbourne, Australia
| | - Janet M Davies
- School of Medicine, Translational Research Institute, The University of Queensland, Brisbane, Australia
| |
Collapse
|
12
|
Lampugnani ER, Ho YY, Moller IE, Koh PL, Golz JF, Bacic A, Newbigin E. A Glycosyltransferase from Nicotiana alata Pollen Mediates Synthesis of a Linear (1,5)-α-L-Arabinan When Expressed in Arabidopsis. Plant Physiol 2016; 170:1962-74. [PMID: 26850276 PMCID: PMC4825119 DOI: 10.1104/pp.15.02005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/04/2016] [Indexed: 05/09/2023]
Abstract
The walls of Nicotiana alata pollen tubes contain a linear arabinan composed of (1,5)-α-linked arabinofuranose residues. Although generally found as a side chain on the backbone of the pectic polysaccharide rhamnogalacturonan I, the arabinan in N. alata pollen tubes is considered free, as there is no detectable rhamnogalacturonan I in these walls. Carbohydrate-specific antibodies detected arabinan epitopes at the tip and along the shank of N. alata pollen tubes that are predominantly part of the primary layer of the bilayered wall. A sequence related to ARABINAN DEFICIENT1 (AtARAD1), a presumed arabinan arabinosyltransferase from Arabidopsis (Arabidopsis thaliana), was identified by searching an N alata pollen transcriptome. Transcripts for this ARAD1-like sequence, which we have named N. alata ARABINAN DEFICIENT-LIKE1 (NaARADL1), accumulate in various tissues, most abundantly in the pollen grain and tube, and encode a protein that is a type II membrane protein with its catalytic carboxyl terminus located in the Golgi lumen. The NaARADL1 protein can form homodimers when transiently expressed in Nicotiana benthamiana leaves and heterodimers when coexpressed with AtARAD1 The expression of NaARADL1 in Arabidopsis led to plants with more arabinan in their walls and that also exuded a guttation fluid rich in arabinan. Chemical and enzymatic characterization of the guttation fluid showed that a soluble, linear α-(1,5)-arabinan was the most abundant polymer present. These results are consistent with NaARADL1 having an arabinan (1,5)-α-arabinosyltransferase activity.
Collapse
Affiliation(s)
- Edwin R Lampugnani
- Plant Cell Biology Research Centre, School of BioSciences (E.R.L., Y.Y.H., I.E.M., P.-L.K., A.B., E.N.), and School of BioSciences (J.F.G.), University of Melbourne, Melbourne, Victoria, 3010 Australia; andAustralian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (E.R.L., Y.Y.H., I.E.M., A.B.)
| | - Yin Ying Ho
- Plant Cell Biology Research Centre, School of BioSciences (E.R.L., Y.Y.H., I.E.M., P.-L.K., A.B., E.N.), and School of BioSciences (J.F.G.), University of Melbourne, Melbourne, Victoria, 3010 Australia; andAustralian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (E.R.L., Y.Y.H., I.E.M., A.B.)
| | - Isabel E Moller
- Plant Cell Biology Research Centre, School of BioSciences (E.R.L., Y.Y.H., I.E.M., P.-L.K., A.B., E.N.), and School of BioSciences (J.F.G.), University of Melbourne, Melbourne, Victoria, 3010 Australia; andAustralian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (E.R.L., Y.Y.H., I.E.M., A.B.)
| | - Poh-Ling Koh
- Plant Cell Biology Research Centre, School of BioSciences (E.R.L., Y.Y.H., I.E.M., P.-L.K., A.B., E.N.), and School of BioSciences (J.F.G.), University of Melbourne, Melbourne, Victoria, 3010 Australia; andAustralian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (E.R.L., Y.Y.H., I.E.M., A.B.)
| | - John F Golz
- Plant Cell Biology Research Centre, School of BioSciences (E.R.L., Y.Y.H., I.E.M., P.-L.K., A.B., E.N.), and School of BioSciences (J.F.G.), University of Melbourne, Melbourne, Victoria, 3010 Australia; andAustralian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (E.R.L., Y.Y.H., I.E.M., A.B.)
| | - Antony Bacic
- Plant Cell Biology Research Centre, School of BioSciences (E.R.L., Y.Y.H., I.E.M., P.-L.K., A.B., E.N.), and School of BioSciences (J.F.G.), University of Melbourne, Melbourne, Victoria, 3010 Australia; andAustralian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (E.R.L., Y.Y.H., I.E.M., A.B.)
| | - Ed Newbigin
- Plant Cell Biology Research Centre, School of BioSciences (E.R.L., Y.Y.H., I.E.M., P.-L.K., A.B., E.N.), and School of BioSciences (J.F.G.), University of Melbourne, Melbourne, Victoria, 3010 Australia; andAustralian Research Council Centre of Excellence in Plant Cell Walls, School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia (E.R.L., Y.Y.H., I.E.M., A.B.)
| |
Collapse
|
13
|
Haberle SG, Bowman DMJS, Newnham RM, Johnston FH, Beggs PJ, Buters J, Campbell B, Erbas B, Godwin I, Green BJ, Huete A, Jaggard AK, Medek D, Murray F, Newbigin E, Thibaudon M, Vicendese D, Williamson GJ, Davies JM. The macroecology of airborne pollen in Australian and New Zealand urban areas. PLoS One 2014; 9:e97925. [PMID: 24874807 PMCID: PMC4038531 DOI: 10.1371/journal.pone.0097925] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 04/26/2014] [Indexed: 11/19/2022] Open
Abstract
The composition and relative abundance of airborne pollen in urban areas of Australia and New Zealand are strongly influenced by geographical location, climate and land use. There is mounting evidence that the diversity and quality of airborne pollen is substantially modified by climate change and land-use yet there are insufficient data to project the future nature of these changes. Our study highlights the need for long-term aerobiological monitoring in Australian and New Zealand urban areas in a systematic, standardised, and sustained way, and provides a framework for targeting the most clinically significant taxa in terms of abundance, allergenic effects and public health burden.
Collapse
Affiliation(s)
- Simon G. Haberle
- Department of Archaeology and Natural History, College of Asia and the Pacific, Australian National University, Canberra, Australian Capital Territory, Australia
- * E-mail:
| | | | - Rewi M. Newnham
- School of Geography, Environment and Earth Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Fay H. Johnston
- Menzies Research Institute Tasmania, University of Tasmania, Hobart, Tasmania, Australia
| | - Paul J. Beggs
- Department of Environment and Geography, Faculty of Science, Macquarie University, Sydney, New South Wales, Australia
| | - Jeroen Buters
- Center for Allergy and Environment, Technical University of Munich, Munich, Germany
| | - Bradley Campbell
- School of Agriculture and Food Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Bircan Erbas
- School of Public Health and Human Biosciences, La Trobe University, Bundoora, Victoria, Australia
| | - Ian Godwin
- School of Agriculture and Food Science, The University of Queensland, St Lucia, Queensland, Australia
| | - Brett J. Green
- Allergy and Clinical Immunology Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centre for Disease Control and Prevention, Morgantown, West Virginia, United States of America
| | - Alfredo Huete
- Plant Functional Biology and Climate Change, University of Technology, Sydney, New South Wales, Australia
| | - Alison K. Jaggard
- Department of Environment and Geography, Faculty of Science, Macquarie University, Sydney, New South Wales, Australia
| | - Danielle Medek
- School of Medicine, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Frank Murray
- School of Environmental Science, Murdoch University, Murdoch, Western Australia, Australia
| | - Ed Newbigin
- School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| | - Michel Thibaudon
- European Aerobiology Society, Réseau National de Surveillance Aérobiologique, Lyon, Rhône-Alpes, France
| | - Don Vicendese
- School of Public Health and Human Biosciences, La Trobe University, Bundoora, Victoria, Australia
| | - Grant J. Williamson
- School of Plant Science, University of Tasmania, Hobart, Tasmania, Australia
| | - Janet M. Davies
- Lung and Allergy Research Centre, School of Medicine, and Translational Research Institute, The University of Queensland, Woolloongabba, Queensland, Australia
| |
Collapse
|
14
|
Lampugnani ER, Moller IE, Cassin A, Jones DF, Koh PL, Ratnayake S, Beahan CT, Wilson SM, Bacic A, Newbigin E. In vitro grown pollen tubes of Nicotiana alata actively synthesise a fucosylated xyloglucan. PLoS One 2013; 8:e77140. [PMID: 24116212 PMCID: PMC3792914 DOI: 10.1371/journal.pone.0077140] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 08/29/2013] [Indexed: 12/15/2022] Open
Abstract
Nicotiana alata pollen tubes are a widely used model for studies of polarized tip growth and cell wall synthesis in plants. To better understand these processes, RNA-Seq and de novo assembly methods were used to produce a transcriptome of N. alata pollen grains. Notable in the reconstructed transcriptome were sequences encoding proteins that are involved in the synthesis and remodelling of xyloglucan, a cell wall polysaccharide previously not thought to be deposited in Nicotiana pollen tube walls. Expression of several xyloglucan-related genes in actively growing pollen tubes was confirmed and xyloglucan epitopes were detected in the wall with carbohydrate-specific antibodies: the major xyloglucan oligosaccharides found in N. alata pollen grains and tubes were fucosylated, an unusual structure for the Solanaceae, the family to which Nicotiana belongs. Finally, carbohydrate linkages consistent with xyloglucan were identified chemically in the walls of N. alata pollen grains and pollen tubes grown in culture. The presence of a fucosylated xyloglucan in Nicotiana pollen tube walls was thus confirmed. The consequences of this discovery to models of pollen tube growth dynamics and more generally to polarised tip-growing cells in plants are discussed.
Collapse
Affiliation(s)
| | - Isabel E. Moller
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| | - Andrew Cassin
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| | - Daniel F. Jones
- Department of Botany, La Trobe University, Bundoora, Victoria, Australia
| | - Poh Ling Koh
- School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| | - Sunil Ratnayake
- School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| | - Cherie T. Beahan
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| | - Sarah M. Wilson
- Australian Research Council Centre of Excellence in Plant Cell Walls, School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| | - Antony Bacic
- Bio21 Institute for Molecular Science & Biotechnology, University of Melbourne, Victoria, Australia
| | - Ed Newbigin
- School of Botany, University of Melbourne, Melbourne, Victoria, Australia
| |
Collapse
|
15
|
Erbas B, Akram M, Dharmage SC, Tham R, Dennekamp M, Newbigin E, Taylor P, Tang MLK, Abramson MJ. The role of seasonal grass pollen on childhood asthma emergency department presentations. Clin Exp Allergy 2012; 42:799-805. [PMID: 22515396 DOI: 10.1111/j.1365-2222.2012.03995.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Few studies have focused on the role of grass pollen on asthma emergency department (ED) presentations among children. None have examined whether a dose-response effect exists between grass pollen levels and these asthma exacerbations. OBJECTIVES To examine the association between increasing ambient levels of grass pollen and asthma ED presentations in children. To determine whether these associations are seen only after a thunderstorm, or whether grass pollen levels have a consistent influence on childhood asthma ED visits during the season. METHODS A short time series ecological study was conducted for asthma presentations to ED among children in Melbourne, Victoria, and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi-parametric Poisson regression model was used to examine dose-response associations between daily grass pollen levels and mean daily ED attendance for asthma. RESULTS A smoothed plot suggested a dose-response association. As ambient grass pollen increased to about 19 grains/m(3) , the same day risk of childhood ED presentations also increased linearly (P < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, P < 0.001). CONCLUSION This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and levels of ambient grass pollen below 20 grains/m(3) , independent of any impact of thunderstorm-associated asthma. These findings have important implications for patient care, such as asthma management programs that notify the general public regarding periods of high grass pollen exposure, as well as defining the timing of initiation of pollen immunotherapy.
Collapse
Affiliation(s)
- B Erbas
- School of Public Health, La Trobe University, Melbourne, VIC, Australia.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Erbas B, Akram M, Dharmage S, Tham R, Dennekamp M, Newbigin E, Taylor P, Tang M, Abramson M. The Role of Seasonal Grass Pollen on Childhood Asthma Emergency Department Presentations. J Allergy Clin Immunol 2012. [DOI: 10.1016/j.jaci.2011.12.382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
17
|
Dwivany FM, Yulia D, Burton RA, Shirley NJ, Wilson SM, Fincher GB, Bacic A, Newbigin E, Doblin MS. The CELLULOSE-SYNTHASE LIKE C (CSLC) family of barley includes members that are integral membrane proteins targeted to the plasma membrane. Mol Plant 2009; 2:1025-1039. [PMID: 19825677 DOI: 10.1093/mp/ssp064] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The CELLULOSE SYNTHASE-LIKE C (CSLC) family is an ancient lineage within the CELLULOSE SYNTHASE/CELLULOSE SYNTHASE-LIKE (CESA/CSL) polysaccharide synthase superfamily that is thought to have arisen before the divergence of mosses and vascular plants. As studies in the flowering plant Arabidopsis have suggested synthesis of the (1,4)-beta-glucan backbone of xyloglucan (XyG), a wall polysaccharide that tethers adjacent cellulose microfibrils to each other, as a probable function for the CSLCs, CSLC function was investigated in barley (Hordeum vulgare L.), a species with low amounts of XyG in its walls. Four barley CSLC genes were identified (designated HvCSLC1-4). Phylogenetic analysis reveals three well supported clades of CSLCs in flowering plants, with barley having representatives in two of these clades. The four barley CSLCs were expressed in various tissues, with in situ PCR detecting transcripts in all cell types of the coleoptile and root, including cells with primary and secondary cell walls. Co-expression analysis showed that HvCSLC3 was coordinately expressed with putative XyG xylosyltransferase genes. Both immuno-EM and membrane fractionation showed that HvCSLC2 was located in the plasma membrane of barley suspension-cultured cells and was not in internal membranes such as endoplasmic reticulum or Golgi apparatus. Based on our current knowledge of the sub-cellular locations of polysaccharide synthesis, we conclude that the CSLC family probably contains more than one type of polysaccharide synthase.
Collapse
Affiliation(s)
- Fenny M Dwivany
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Widodo, Patterson JH, Newbigin E, Tester M, Bacic A, Roessner U. Metabolic responses to salt stress of barley (Hordeum vulgare L.) cultivars, Sahara and Clipper, which differ in salinity tolerance. J Exp Bot 2009; 60:4089-103. [PMID: 19666960 PMCID: PMC2755029 DOI: 10.1093/jxb/erp243] [Citation(s) in RCA: 204] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 07/09/2009] [Accepted: 07/13/2009] [Indexed: 05/30/2023]
Abstract
Plants show varied cellular responses to salinity that are partly associated with maintaining low cytosolic Na(+) levels and a high K(+)/Na(+) ratio. Plant metabolites change with elevated Na(+), some changes are likely to help restore osmotic balance while others protect Na(+)-sensitive proteins. Metabolic responses to salt stress are described for two barley (Hordeum vulgare L.) cultivars, Sahara and Clipper, which differed in salinity tolerance under the experimental conditions used. After 3 weeks of salt treatment, Clipper ceased growing whereas Sahara resumed growth similar to the control plants. Compared with Clipper, Sahara had significantly higher leaf Na(+) levels and less leaf necrosis, suggesting they are more tolerant to accumulated Na(+). Metabolite changes in response to the salt treatment also differed between the two cultivars. Clipper plants had elevated levels of amino acids, including proline and GABA, and the polyamine putrescine, consistent with earlier suggestions that such accumulation may be correlated with slower growth and/or leaf necrosis rather than being an adaptive response to salinity. It is suggested that these metabolites may be an indicator of general cellular damage in plants. By contrast, in the more tolerant Sahara plants, the levels of the hexose phosphates, TCA cycle intermediates, and metabolites involved in cellular protection increased in response to salt. These solutes remain unchanged in the more sensitive Clipper plants. It is proposed that these responses in the more tolerant Sahara are involved in cellular protection in the leaves and are involved in the tolerance of Sahara leaves to high Na(+).
Collapse
Affiliation(s)
- Widodo
- Australian Centre for Plant Functional Genomics, School of Botany, University of Melbourne, 3010 VIC, Australia
| | - John H. Patterson
- Australian Centre for Plant Functional Genomics, School of Botany, University of Melbourne, 3010 VIC, Australia
| | - Ed Newbigin
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, 3010 VIC, Australia
| | - Mark Tester
- Australian Centre for Plant Functional Genomics, University of Adelaide, Waite Campus, Glen Osmond, 5064 SA, Australia
| | - Antony Bacic
- Australian Centre for Plant Functional Genomics, School of Botany, University of Melbourne, 3010 VIC, Australia
| | - Ute Roessner
- Australian Centre for Plant Functional Genomics, School of Botany, University of Melbourne, 3010 VIC, Australia
| |
Collapse
|
19
|
Doblin MS, Pettolino FA, Wilson SM, Campbell R, Burton RA, Fincher GB, Newbigin E, Bacic A. A barley cellulose synthase-like CSLH gene mediates (1,3;1,4)-beta-D-glucan synthesis in transgenic Arabidopsis. Proc Natl Acad Sci U S A 2009; 106:5996-6001. [PMID: 19321749 PMCID: PMC2667043 DOI: 10.1073/pnas.0902019106] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Indexed: 11/18/2022] Open
Abstract
The walls of grasses and related members of the Poales are characterized by the presence of the polysaccharide (1,3, 1,4)-beta-D-glucan (beta-glucan). To date, only members of the grass-specific cellulose synthase-like F (CSLF) gene family have been implicated in its synthesis. Assuming that other grass-specific CSL genes also might encode synthases for this polysaccharide, we cloned HvCSLH1, a CSLH gene from barley (Hordeum vulgare L.), and expressed an epitope-tagged version of the cDNA in Arabidopsis, a species with no CSLH genes and no beta-glucan in its walls. Transgenic Arabidopsis lines that had detectable amounts of the epitope-tagged HvCSLH1 protein accumulated beta-glucan in their walls. The presence of beta-glucan was confirmed by immunoelectron microscopy (immuno-EM) of sectioned tissues and chemical analysis of wall extracts. In the chemical analysis, characteristic tri- and tetra-saccharides were identified by high-performance anion-exchange chromatography and MALDI-TOF MS following their release from transgenic Arabidopsis walls by a specific beta-glucan hydrolase. Immuno-EM also was used to show that the epitope-tagged HvCSLH1 protein was in the endoplasmic reticulum and Golgi-associated vesicles, but not in the plasma membrane. In barley, HvCSLH1 was expressed at very low levels in leaf, floral tissues, and the developing grain. In leaf, expression was highest in xylem and interfascicular fiber cells that have walls with secondary thickenings containing beta-glucan. Thus both the CSLH and CSLF families contribute to beta-glucan synthesis in grasses and probably do so independently of each other, because there is no significant transcriptional correlation between these genes in the barley tissues surveyed.
Collapse
Affiliation(s)
- Monika S. Doblin
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Filomena A. Pettolino
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Sarah M. Wilson
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Rebecca Campbell
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Rachel A. Burton
- Australian Centre for Plant Functional Genomics, School of Agriculture and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia; and
| | - Geoffrey B. Fincher
- Australian Centre for Plant Functional Genomics, School of Agriculture and Wine, University of Adelaide, Waite Campus, Glen Osmond, SA 5064, Australia; and
| | - Ed Newbigin
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | - Antony Bacic
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
- Australian Centre for Plant Functional Genomics, School of Botany, University of Melbourne, Victoria 3010, Australia
| |
Collapse
|
20
|
Abstract
Many plants have a genetically determined self-incompatibility system in which the rejection of self pollen grains is controlled by alleles of an S locus. A common feature of these S loci is that separate pollen- and style-expressed genes (pollen S and style S, respectively) determine S allele identity. The long-held view has been that pollen S and style S must be a coevolving gene pair in order for allelic recognition to be maintained as new S alleles arise. In at least three plant families, the Solanaceae, Rosaceae, and Plantaginaceae, the style S gene has long been known to encode an extracellular ribonuclease called the S-RNase. Pollen S in these families has more recently been identified and encodes an F-box protein known as either SLF or SFB. In this perspective, we describe the puzzling evolutionary relationship that exists between the SLF/SFB and S-RNase genes and show that in most cases cognate pairs of genes are not coevolving in the expected manner. Because some pollen S genes appear to have arisen much more recently than their style S cognates, we conclude that either some pollen S genes have been falsely identified or that there is a major problem with our understanding of how the S locus evolves.
Collapse
Affiliation(s)
- Ed Newbigin
- School of Botany, University of Melbourne, VIC 3010, Australia.
| | | | | |
Collapse
|
21
|
Brownfield L, Wilson S, Newbigin E, Bacic A, Read S. Molecular control of the glucan synthase-like protein NaGSL1 and callose synthesis during growth of Nicotiana alata pollen tubes. Biochem J 2008; 414:43-52. [PMID: 18462191 DOI: 10.1042/bj20080693] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
The protein NaGSL1 (Nicotiana alata glucan synthase-like 1) is implicated in the synthesis of callose, the 1,3-beta-glucan that is the major polysaccharide in the walls of N. alata (flowering tobacco) pollen tubes. Here we examine the production, intracellular location and post-translational processing of NaGSL1, and relate each of these to the control of pollen-tube callose synthase (CalS). The 220 kDa NaGSL1 polypeptide is produced after pollen-tube germination and accumulates during pollen-tube growth, as does CalS. A combination of membrane fractionation and immunoelectron microscopy revealed that NaGSL1 was present predominantly in the endoplasmic reticulum and Golgi membranes in younger pollen tubes when CalS was mostly in an inactive (latent) form. In later stages of pollen-tube growth, when CalS was present in both latent and active forms, a greater proportion of NaGSL1 was in intracellular vesicles and the plasma membrane, the latter location being consistent with direct deposition of callose into the wall. N. alata CalS is activated in vitro by the proteolytic enzyme trypsin and the detergent CHAPS, but in neither case was activation associated with a detectable change in the molecular mass of the NaGSL1 polypeptide. NaGSL1 may thus either be activated by the removal of a few amino acids or by the removal of another protein that inhibits NaGSL1. These findings are discussed in relation to the control of callose biosynthesis during pollen germination and pollen-tube growth.
Collapse
Affiliation(s)
- Lynette Brownfield
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, VIC 3010, Australia
| | | | | | | | | |
Collapse
|
22
|
Wheeler D, Newbigin E. Expression of 10 S-class SLF-like genes in Nicotiana alata pollen and its implications for understanding the pollen factor of the S locus. Genetics 2007; 177:2171-80. [PMID: 17947432 PMCID: PMC2219507 DOI: 10.1534/genetics.107.076885] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Accepted: 10/03/2007] [Indexed: 11/18/2022] Open
Abstract
The S locus of Nicotiana alata encodes a polymorphic series of ribonucleases (S-RNases) that determine the self-incompatibility (SI) phenotype of the style. The pollen product of the S locus (pollen S) in N. alata is unknown, but in species from the related genus Petunia and in self-incompatible members of the Plantaginaceae and Rosaceae, this function has been assigned to an F-box protein known as SLF or SFB. Here we describe the identification of 10 genes (designated DD1-10) encoding SLF-related proteins that are expressed in N. alata pollen. Because our approach to cloning the DD genes was based on sequences of SLFs from other species, we presume that one of the DD genes encodes the N. alata SLF ortholog. Seven of the DD genes were exclusively expressed in pollen and a low level of sequence variation was found in alleles of each DD gene. Mapping studies confirmed that all 10 DD genes were linked to the S locus and that at least three were located in the same chromosomal segment as pollen S. Finally, the different topologies of the phylogenetic trees produced using available SLF-related sequences and those produced using S-RNase sequences suggests that pollen S and the S-RNase have different evolutionary histories.
Collapse
Affiliation(s)
- David Wheeler
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria 3010, Australia
| | | |
Collapse
|
23
|
Erbas B, Chang JH, Newbigin E, Dhamarge S. Modelling atmospheric concentrations of grass pollen using meteorological variables in Melbourne, Australia. Int J Environ Health Res 2007; 17:361-368. [PMID: 17924264 DOI: 10.1080/09603120701628693] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
This study aims to develop models that may be used to describe the relationship between meteorological variables and ambient concentrations of pollen. We used daily ambient concentrations of grass pollen during the pollen season (October to December) of 2004 in Melbourne, Australia. During this period, daily levels of meteorological data including average relative humidity, mean temperature, rain fall, wind speed, and wind direction were entered as predictors in the models. A generalized additive model (GAM) was used to assess the relationship between daily levels of meteorological variables and ambient concentrations of grass pollen. The relationship between average temperature, rain fall, wind speed, relative humidity and pollen were nonlinear and smooth terms were highly significant (p < 0.001). Nonlinear statistical methods such as the GAM approach have the potential to accurately predict ambient concentrations of pollen during the pollen season.
Collapse
Affiliation(s)
- Bircan Erbas
- Centre for Molecular Environmental Genetic Analytic Epidemiology, School of Population Health, University of Melbourne, Victoria, Australia.
| | | | | | | |
Collapse
|
24
|
Brownfield L, Ford K, Doblin MS, Newbigin E, Read S, Bacic A. Proteomic and biochemical evidence links the callose synthase in Nicotiana alata pollen tubes to the product of the NaGSL1 gene. Plant J 2007; 52:147-56. [PMID: 17666022 DOI: 10.1111/j.1365-313x.2007.03219.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The NaGSL1 gene has been proposed to encode the callose synthase (CalS) enzyme from Nicotiana alata pollen tubes based on its similarity to fungal 1,3-beta-glucan synthases and its high expression in pollen and pollen tubes. We have used a biochemical approach to link the NaGSL1 protein with CalS enzymic activity. The CalS enzyme from N. alata pollen tubes was enriched over 100-fold using membrane fractionation and product entrapment. A 220 kDa polypeptide, the correct molecular weight to be NaGSL1, was specifically detected by anti-GSL antibodies, was specifically enriched with CalS activity, and was the most abundant polypeptide in the CalS-enriched fraction. This polypeptide was positively identified as NaGSL1 using both MALDI-TOF MS and LC-ESI-MS/MS analysis of tryptic peptides. Other low-abundance polypeptides in the CalS-enriched fractions were identified by MALDI-TOF MS as deriving from a 103 kDa plasma membrane H+-ATPase and a 60 kDa beta-subunit of mitochondrial ATPase, both of which were deduced to be contaminants in the product-entrapped material. These analyses thus suggest that NaGSL1 is required for CalS activity, although other smaller (<30 kDa) or low-abundance proteins could also be involved.
Collapse
Affiliation(s)
- Lynette Brownfield
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | | | | | | | | | | |
Collapse
|
25
|
Erbas B, Chang JH, Dharmage S, Ong EK, Hyndman R, Newbigin E, Abramson M. Do levels of airborne grass pollen influence asthma hospital admissions? Clin Exp Allergy 2007; 37:1641-7. [PMID: 17877763 DOI: 10.1111/j.1365-2222.2007.02818.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND The effects of environmental factors and ambient concentrations of grass pollen on allergic asthma are yet to be established. OBJECTIVE We sought to estimate the independent effects of grass pollen concentrations in the air over Melbourne on asthma hospital admissions for the 1992-1993 pollen season. METHODS Daily grass pollen concentrations were monitored over a 24-h period at three stations in Melbourne. The outcome variable was defined as all-age asthma hospital admissions with ICD9-493 codes. The ambient air pollutants were average daily measures of ozone, nitrogen dioxide and sulphur dioxide, and the airborne particle index representing fine particulate pollution. Semi-parametric Poisson regression models were used to estimate these effects, adjusted for air temperature, humidity, wind speed, rainfall, day-of-the-week effects and seasonal variation. RESULTS Grass pollen was a strong independent non-linear predictor of asthma hospital admissions in a multi-pollutant model (P=0.01). Our data suggest that grass pollen had an increasing effect on asthma hospital admissions up to a threshold of 30 grains/m3, and that the effect remains stable thereafter. CONCLUSION Our findings suggest that grass pollen levels influence asthma hospital admissions. High grass pollen days, currently defined as more than 50 grains/m3, are days when most sensitive individuals will experience allergic symptoms. However, some asthmatic patients may be at a significant risk even when airborne grass pollen levels are below this level. Patients with pollen allergies and asthma would be advised to take additional preventive medication at lower ambient concentrations.
Collapse
Affiliation(s)
- B Erbas
- Centre for Molecular Environmental Genetic Analytic Epidemiology, School of Population Health, University of Melbourne, Carlton, Vic., Australia.
| | | | | | | | | | | | | |
Collapse
|
26
|
Newbigin E, Uyenoyama MK. The evolutionary dynamics of self-incompatibility systems. Trends Genet 2005; 21:500-5. [PMID: 16023253 DOI: 10.1016/j.tig.2005.07.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Revised: 06/02/2005] [Accepted: 07/03/2005] [Indexed: 10/25/2022]
Abstract
Self-incompatible flowering plants reject pollen that expresses the same mating specificity as the pistil (female reproductive tract). In most plant families, pollen and pistil mating specificities segregate as a single locus, the S locus. In at least two self-incompatibility systems, distinct pollen and pistil specificity genes are embedded in an extensive nonrecombining tract. To facilitate consideration of how new S locus specificities arise in systems with distinct pollen and pistil genes, we present a graphical model for the generation of hypotheses. It incorporates the evolutionary principle that nonreciprocal siring success (cross-pollinations between two plants produce seeds in only one direction) tends to favor the rejecting partner. This model suggests that selection within S-allele specificity classes could accelerate the rate of nonsynonymous (amino acid-changing) substitutions, with periodic selective sweeps removing segregating variation within classes. Accelerated substitution within specificity classes could also promote the origin of new S-allele specificities.
Collapse
Affiliation(s)
- Ed Newbigin
- School of Botany, University of Melbourne, Victoria 3010, Australia
| | | |
Collapse
|
27
|
Abstract
Features common to many mating-type regions include recombination suppression over large genomic tracts and cosegregation of genes of various functions, not necessarily related to reproduction. Model systems for homomorphic self-incompatibility (SI) in flowering plants share these characteristics. We introduce a method for the exact computation of the joint probability of numbers of neutral mutations segregating at the determinant of mating type and at a linked marker locus. The underlying Markov model incorporates strong balancing selection into a two-locus coalescent. We apply the method to obtain a maximum-likelihood estimate of the rate of recombination between a marker locus, 48A, and S-RNase, the determinant of SI specificity in pistils of Nicotiana alata. Even though the sampled haplotypes show complete allelic linkage disequilibrium and recombinants have never been detected, a highly significant deficiency of synonymous substitutions at 48A compared to S-RNase suggests a history of recombination. Our maximum-likelihood estimate indicates a rate of recombination of perhaps 3 orders of magnitude greater than the rate of synonymous mutation. This approach may facilitate the construction of genetic maps of regions tightly linked to targets of strong balancing selection.
Collapse
Affiliation(s)
- Naoki Takebayashi
- Department of Biology, Duke University, Durham, North Carolina 27708-0338, USA
| | | | | |
Collapse
|
28
|
Maćasev D, Whelan J, Newbigin E, Silva-Filho MC, Mulhern TD, Lithgow T. Tom22', an 8-kDa trans-Site Receptor in Plants and Protozoans, Is a Conserved Feature of the TOM Complex That Appeared Early in the Evolution of Eukaryotes. Mol Biol Evol 2004; 21:1557-64. [PMID: 15155803 DOI: 10.1093/molbev/msh166] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
One of the earliest events in the evolution of mitochondria was the development a means to translocate proteins made in the cytosol into the "protomitochondrion." How this was achieved remains uncertain, and the nature of the earliest version of the protein translocation machinery is not known. Comparative sequence analysis suggests three subunits, Tom40, Tom7, and Tom22 as common elements of the protein translocase in the mitochondrial outer membrane in diverse extant eukaryotes. Tom22, the 22-kDa subunit, plays a critical role in the function of this complex in fungi and animals, and we show that an 8-kDa subunit of the plant translocase is a truncated form of Tom22. It has a single transmembrane segment conforming in sequence to the same region of Tom22 from other eukaryotic lineages and a short carboxy-terminal trans domain located in the mitochondrial intermembrane space. The trans domain from the Arabidopsis thaliana protein functions in yeast lacking their own Tom22 by complementing protein import defects and restoring cell growth. Moreover, we have identified orthologs of Tom22, Tom7, and Tom40 in diverse eukaryotes such as the diatom Phaeodactylum tricornutum, the amoebic slime Dictyostelium discoideum, and the protozoan parasite Plasmodium falciparum. This finding strongly suggests these subunits as the core of the protein translocase in the earliest mitochondria.
Collapse
Affiliation(s)
- Diana Maćasev
- Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Australia
| | | | | | | | | | | |
Collapse
|
29
|
Abstract
Diverse self-incompatibility (SI) mechanisms permit flowering plants to inhibit fertilization by pollen that express specificities in common with the pistil. Characteristic of at least two model systems is greatly reduced recombination across large genomic tracts surrounding the S-locus, which regulates SI. In three angiosperm families, including the Solanaceae, the gene that controls the expression of gametophytic SI in the pistil encodes a ribonuclease (S-RNase). The gene that controls pollen SI expression is currently unknown, although several candidates have recently been proposed. Although each candidate shows a high level of polymorphism and complete allelic disequilibrium with the S-RNase gene, such properties may merely reflect tight linkage to the S-locus, irrespective of any functional role in SI. We analyzed the magnitude and nature of nucleotide variation, with the objective of distinguishing likely candidates for regulators of SI from other genes embedded in the S-locus region. We studied the S-RNase gene of the Solanaceae and 48A, a candidate for the pollen gene in this system, and we also conducted a parallel analysis of the regulators of sporophytic SI in Brassica, a system in which both the pistil and pollen genes are known. Although the pattern of variation shown by the pollen gene of the Brassica system is consistent with its role as a determinant of pollen specificity, that of 48A departs from expectation. Our analysis further suggests that recombination between 48A and S-RNase may have occurred during the interval spanned by the gene genealogy, another indication that 48A may not regulate SI expression in pollen.
Collapse
|
30
|
|
31
|
Thompson C, Thompson B, Ades P, Cousens R, Garnier-Gere P, Landman K, Newbigin E, Burgman M. Model-based analysis of the likelihood of gene introgression from genetically modified crops into wild relatives. Ecol Modell 2003. [DOI: 10.1016/s0304-3800(02)00347-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
32
|
Golz JF, Oh HY, Su V, Kusaba M, Newbigin E. Genetic analysis of Nicotiana pollen-part mutants is consistent with the presence of an S-ribonuclease inhibitor at the S locus. Proc Natl Acad Sci U S A 2001; 98:15372-6. [PMID: 11752474 PMCID: PMC65036 DOI: 10.1073/pnas.261571598] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2001] [Accepted: 10/26/2001] [Indexed: 11/18/2022] Open
Abstract
Self-incompatibility (SI) is a genetic mechanism that restricts inbreeding in flowering plants. In the nightshade family (Solanaceae) SI is controlled by a single multiallelic S locus. Pollen rejection in this system requires the interaction of two S locus products: a stylar (S)-RNase and its pollen counterpart (pollen S). pollen S has not yet been cloned. Our understanding of how this gene functions comes from studies of plants with mutations that affect the pollen but not the stylar SI response (pollen-part mutations). These mutations are frequently associated with duplicated S alleles, but the absence of an obvious additional allele in some plants suggests pollen S can also be deleted. We studied Nicotiana alata plants with an additional S allele and show that duplication causes a pollen-part mutation in several different genetic backgrounds. Inheritance of the duplication was consistent with a competitive interaction model in which any two nonmatching S alleles cause a breakdown of SI when present in the same pollen grain. We also examined plants with presumed deletions of pollen S and found that they instead have duplications that included pollen S but not the S-RNase gene. This finding is consistent with a bipartite structure for the S locus. The absence of pollen S deletions in this study and perhaps other studies suggests that pollen S might be required for pollen viability, possibly because its product acts as an S-RNase inhibitor.
Collapse
Affiliation(s)
- J F Golz
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | | | | | | | | |
Collapse
|
33
|
Ida K, Norioka S, Yamamoto M, Kumasaka T, Yamashita E, Newbigin E, Clarke AE, Sakiyama F, Sato M. The 1.55 A resolution structure of Nicotiana alata S(F11)-RNase associated with gametophytic self-incompatibility. J Mol Biol 2001; 314:103-12. [PMID: 11724536 DOI: 10.1006/jmbi.2001.5127] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The crystal structure of Nicotiana alata (ornamental tobacco) S(F11)-RNase, an S-allelic glycoprotein associated with gametophytic self-incompatibility, was determined by X-ray diffraction at 1.55 A resolution. The protein has a tertiary structure typical of members of the RNase T(2) family as it consists of a variant of the (alpha+beta) fold and has eight helices and seven strands. A heptasaccharide moiety is also present, and amino acid residues that serve as the catalytic acid and base can be assigned to His32 and His91, respectively. Two "hypervariable" regions, known as HVa and HVb, are the proposed sites of S-allele discrimination during the self-incompatibility reaction, and in the S(F11)-RNase these are well separated from the active site. HVa and HVb are composed of a long, positively charged loop followed by a part of an alpha-helix and short, negatively charged alpha-helix, respectively. The S(F11)-RNase structure shows both regions are readily accessible to the solvent and hence could participate in the process of self/non-self discrimination between the S-RNase and an unknown pollen S-gene product(s) upon pollination.
Collapse
Affiliation(s)
- K Ida
- Graduate School of Integrated Science, Yokohama City University, Tsurumi-ku, Yokohama 230-0045, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Doblin MS, De Melis L, Newbigin E, Bacic A, Read SM. Pollen tubes of Nicotiana alata express two genes from different beta-glucan synthase families. Plant Physiol 2001; 125:2040-52. [PMID: 11299383 PMCID: PMC88859 DOI: 10.1104/pp.125.4.2040] [Citation(s) in RCA: 103] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2000] [Revised: 11/21/2000] [Accepted: 12/22/2000] [Indexed: 05/18/2023]
Abstract
The walls deposited by growing pollen tubes contain two types of beta-glucan, the (1,3)-beta-glucan callose and the (1,4)-beta-glucan cellulose, as well as various alpha-linked pectic polysaccharides. Pollen tubes of Nicotiana alata Link et Otto, an ornamental tobacco, were therefore used to identify genes potentially encoding catalytic subunits of the callose synthase and cellulose synthase enzymes. Reverse transcriptase-polymerase chain reactions (RT-PCR) with pollen-tube RNA and primers designed to conserved regions of bacterial and plant cellulose synthase (CesA) genes amplified a fragment that corresponded to an abundantly expressed cellulose-synthase-like gene named NaCslD1. A fragment from a true CesA gene (NaCesA1) was also amplified, but corresponding cDNAs could not be identified in a pollen-tube library, consistent with the very low level of expression of the NaCesA1 gene. RT-PCR with pollen-tube RNA and primers designed to regions conserved between the fungal FKS genes [that encode (1,3)-beta-glucan synthases] and their presumed plant homologs (the Gsl or glucan-synthase-like genes) amplified a fragment that corresponded to an abundantly expressed gene named NaGsl1. A second Gsl gene detected by RT-PCR (NaGsl2) was expressed at low levels in immature floral organs. The structure of full-length cDNAs of NaCslD1, NaCesA1, and NaGsl1 are presented. Both NaCslD1 and NaGsl1 are predominantly expressed in the male gametophyte (developing and mature pollen and growing pollen tubes), and we propose that they encode the catalytic subunits of two beta-glucan synthases involved in pollen-tube wall synthesis. Different beta-glucans deposited in one cell type may therefore be synthesized by enzymes from different gene families.
Collapse
Affiliation(s)
- M S Doblin
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Victoria 3010, Australia
| | | | | | | | | |
Collapse
|
35
|
Abstract
Self-incompatibility (SI) in flowering plants entails the inhibition of fertilization by pollen that express specificities in common with the pistil. In species of the Solanaceae, Rosaceae, and Scrophulariaceae, the inhibiting factor is an extracellular ribonuclease (S-RNase) secreted by stylar tissue. A distinct but as yet unknown gene (provisionally called pollen-S) appears to determine the specific S-RNase from which a pollen tube accepts inhibition. The S-RNase gene and pollen-S segregate with the classically defined S-locus. The origin of a new specificity appears to require, at minimum, mutations in both genes. We explore the conditions under which new specificities may arise from an intermediate state of loss of self-recognition. Our evolutionary analysis of mutations that affect either pistil or pollen specificity indicates that natural selection favors mutations in pollen-S that reduce the set of pistils from which the pollen accepts inhibition and disfavors mutations in the S-RNase gene that cause the nonreciprocal acceptance of pollen specificities. We describe the range of parameters (rate of receipt of self-pollen and relative viability of inbred offspring) that permits the generation of a succession of new specificities. This evolutionary pathway begins with the partial breakdown of SI upon the appearance of a mutation in pollen-S that frees pollen from inhibition by any S-RNase presently in the population and ends with the restoration of SI by a mutation in the S-RNase gene that enables pistils to reject the new pollen type.
Collapse
Affiliation(s)
- M K Uyenoyama
- Department of Biology, Duke University, Durham, North Carolina 27708-0338, USA.
| | | | | |
Collapse
|
36
|
MacIntosh GC, Bariola PA, Newbigin E, Green PJ. Characterization of Rny1, the Saccharomyces cerevisiae member of the T2 RNase family of RNases: unexpected functions for ancient enzymes? Proc Natl Acad Sci U S A 2001; 98:1018-23. [PMID: 11158587 PMCID: PMC14701 DOI: 10.1073/pnas.98.3.1018] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The T(2) family of nonspecific endoribonucleases (EC ) is a widespread family of RNases found in every organism examined thus far. Most T(2) enzymes are secretory RNases and therefore are found extracellularly or in compartments of the endomembrane system that would minimize their contact with cellular RNA. Although the biological functions of various T(2) RNases have been postulated on the basis of enzyme location or gene expression patterns, the cellular roles of these enzymes are generally unknown. In the present work, we characterized Rny1, the only T(2) RNase in Saccharomyces cerevisiae. Rny1 was found to be an active, secreted RNase whose gene expression is controlled by heat shock and osmotic stress. Inactivation of RNY1 leads to unusually large cells that are temperature-sensitive for growth. These phenotypes can be complemented not only by RNY1 but also by both structurally related and unrelated secretory RNases. Additionally, the complementation depends on RNase activity. When coupled with a recent report on the effect of specific RNAs on membrane permeability [Khvorova, A., Kwak, Y-G., Tamkun, M., Majerfeld, I. & Yarus, M. (1999) Proc. Natl. Acad. Sci. USA 96, 10649-10654], our work suggests an unexpected role for Rny1 and possibly other secretory RNases. These enzymes may regulate membrane permeability or stability, a hypothesis that could present an alternative perspective for understanding their functions.
Collapse
Affiliation(s)
- G C MacIntosh
- Departments of Energy Plant Research Laboratory and Biochemistry, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | |
Collapse
|
37
|
Ida K, Shinkawa T, Norioka S, Newbigin E, Clarke AE, Sakiyama F, Sato M. Crystallization and preliminary X-ray crystallographic analysis of S-allelic glycoprotein S(F11)-RNase from Nicotiana alata. Acta Crystallogr D Biol Crystallogr 2001; 57:143-4. [PMID: 11134938 DOI: 10.1107/s0907444900014050] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2000] [Accepted: 10/09/2000] [Indexed: 02/18/2023]
Abstract
Nicotiana alata S(F11)-RNase is an S-glycoprotein associated with gametophytic self-incompatibility. Crystals of S(F11)-RNase have been grown at room temperature using polyethylene glycol as a precipitant. A crystal diffracted to better than 1.4 A resolution at 100 K at the SPring-8 synchrotron-radiation source, indicating that it is very suitable for high-resolution structure analysis. The crystal belongs to the space group P2(1), with unit-cell parameters a = 65.86 (11), b = 44.73 (5), c = 64.36 (7) A, beta = 90.27 (9) degrees. The asymmetric unit contains two monomers, giving a crystal volume per protein mass (V(M)) of 2.05 A(3) Da(-1) and a solvent content of 39.6% by volume. A full set of X-ray diffraction data was collected to 1.55 A resolution with a completeness of 97.4%. A heavy-atom derivative has been successfully prepared with ethylmercury thiosalicylate (EMTS) and structure analysis is in progress.
Collapse
Affiliation(s)
- K Ida
- Graduate School of Integrated Science, Yokohama City University, Kanazawa-ku, Yokohama 236-0027, Japan
| | | | | | | | | | | | | |
Collapse
|
38
|
Macasev D, Newbigin E, Whelan J, Lithgow T. How do plant mitochondria avoid importing chloroplast proteins? Components of the import apparatus Tom20 and Tom22 from Arabidopsis differ from their fungal counterparts. Plant Physiol 2000; 123:811-6. [PMID: 10889230 PMCID: PMC1539262 DOI: 10.1104/pp.123.3.811] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Affiliation(s)
- D Macasev
- Russell Grimwade School of Biochemistry and Molecular Biology, University of Melbourne, Parkville 3010, Victoria, Australia
| | | | | | | |
Collapse
|
39
|
Affiliation(s)
- Marcy K. Uyenoyama
- Department of Zoology Box 90325 Duke University Durham, NC 27708-0325 e-mail:
| | - Ed Newbigin
- School of Botany University of Melbourne Victoria 3010 Australia e-mail:
| |
Collapse
|
40
|
Abstract
Mutations affecting the self-incompatibility response of Nicotiana alata were generated by irradiation. Mutants in the M1 generation were selected on the basis of pollen tube growth through an otherwise incompatible pistil. Twelve of the 18 M1 plants obtained from the mutagenesis screen were self-compatible. Eleven self-compatible plants had mutations affecting only the pollen function of the S locus (pollen-part mutants). The remaining self-compatible plant had a mutation affecting only the style function of the S locus (style-part mutant). Cytological examination of the pollen-part mutant plants revealed that 8 had an extra chromosome (2n + 1) and 3 did not. The pollen-part mutation in 7 M1 plants was followed in a series of crosses. DNA blot analysis using probes for S-RNase genes (encoding the style function of the S locus) indicated that the pollen-part mutation was associated with an extra S allele in 4 M1 plants. In 3 of these plants, the extra S allele was located on the additional chromosome. There was no evidence of an extra S allele in the 3 remaining M1 plants. The breakdown of self-incompatibility in plants with an extra S allele is discussed with reference to current models of the molecular basis of self-incompatibility.
Collapse
Affiliation(s)
- J F Golz
- Plant Cell Biology Research Center, School of Botany, University of Melbourne, Parkville, Victoria 3052, Australia
| | | | | | | |
Collapse
|
41
|
Dodds PN, Ferguson C, Clarke AE, Newbigin E. Pollen-expressed S-RNases are not involved in self-incompatibility in Lycopersicon peruvianum. ACTA ACUST UNITED AC 1999. [DOI: 10.1007/s004970050175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
42
|
Abstract
We surveyed ribonuclease activity in the styles of Nicotiana spp. and found little or no activity in self-compatible species and in a self-compatible accession of a self-incompatible species. All self-incompatible species had high levels of ribonuclease activity in their style. Interestingly, one self-compatible species, N. sylvestris, had a level of stylar ribonuclease activity comparable to that of some self-incompatible Nicotiana species. A ribonuclease with biochemical properties similar to those of the self-incompatibility (S-)RNases of N. alata was purified from N. sylvestris styles. The N-terminal sequence of this protein was used to confirm the identity of a cDNA corresponding to the stylar RNase. The amino acid sequence deduced from the cDNA was related to those of the S-RNases and included the five conserved regions characteristic of these proteins. It appears that the N. sylvestris RNase may have evolved from the S-RNases and is an example of a 'relic S-RNase'. A number of features distinguish the N. sylvestris RNase from the S-RNases, and the role these may have played in the presumed loss of the self-incompatibility response during the evolution of this species are discussed.
Collapse
Affiliation(s)
- J F Golz
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria, Australia
| | | | | | | |
Collapse
|
43
|
Parry S, Newbigin E, Craik D, Nakamura KT, Bacic A, Oxley D. Structural analysis and molecular model of a self-incompatibility RNase from wild tomato. Plant Physiol 1998; 116:463-469. [PMID: 9489006 PMCID: PMC35102 DOI: 10.1104/pp.116.2.463] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/1997] [Accepted: 10/14/1997] [Indexed: 05/22/2023]
Abstract
Self-incompatibility RNases (S-RNases) are an allelic series of style glycoproteins associated with rejection of self-pollen in solanaceous plants. The nucleotide sequences of S-RNase alleles from several genera have been determined, but the structure of the gene products has only been described for those from Nicotiana alata. We report on the N-glycan structures and the disulfide bonding of the S3-RNase from wild tomato (Lycopersicon peruvianum) and use this and other information to construct a model of this molecule. The S3-RNase has a single N-glycosylation site (Asn-28) to which one of three N-glycans is attached. S3-RNase has seven Cys residues; six are involved in disulfide linkages (Cys-16-Cys-21, Cys-46-Cys-91, and Cys-166-Cys-177), and one has a free thiol group (Cys-150). The disulfide-bonding pattern is consistent with that observed in RNase Rh, a related RNase for which radiographic-crystallographic information is available. A molecular model of the S3-RNase shows that four of the most variable regions of the S-RNases are clustered on one surface of the molecule. This is discussed in the context of recent experiments that set out to determine the regions of the S-RNase important for recognition during the self-incompatibility response.
Collapse
Affiliation(s)
- S Parry
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, VIC, Australia
| | | | | | | | | | | |
Collapse
|
44
|
Parry S, Newbigin E, Currie G, Bacic A, Oxley D. Identification of active-site histidine residues of a self-incompatibility ribonuclease from a wild tomato. Plant Physiol 1997; 115:1421-1429. [PMID: 9414554 PMCID: PMC158607 DOI: 10.1104/pp.115.4.1421] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The style component of the self-incompatibility (S) locus of the wild tomato Lycopersicon peruvianum (L.) Mill. is an allelic series of glycoproteins with ribonuclease activity (S-RNases). Treatment of the S3-RNase from L. peruvianum with iodoacetate at pH 6.1 led to a loss of RNase activity. In the presence of a competitive inhibitor, guanosine 3'-monophosphate (3'-GMP), the rate of RNase inactivation by iodoacetate was reduced significantly. Analysis of the tryptic digestion products of the iodoacetate-modified S-RNase by reversed-phase high-performance liquid chromatography and electrospray-ionization mass spectrometry showed that histidine-32 was preferentially modified in the absence of 3'-GMP. Histidine-88 was also modified, but this occurred both in the presence and absence of 3'-GMP, suggesting that this residue is accessible when 3'-GMP is in the active site. Cysteine-150 was modified by iodoacetate in the absence of 3'-GMP and, to a lesser extent, in its presence. The results are discussed with respect to the related fungal RNase T2 family and the mechanism of S-RNase action.
Collapse
Affiliation(s)
- S Parry
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | | |
Collapse
|
45
|
Dodds PN, Clarke AE, Newbigin E. Molecular characterisation of an S-like RNase of Nicotiana alata that is induced by phosphate starvation. Plant Mol Biol 1996; 31:227-38. [PMID: 8756589 DOI: 10.1007/bf00021786] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We characterised a cDNA encoding an S-like RNase (RNase NE) from the styles of the self-incompatible plant, Nicotiana alata. RNase NE is 86% identical to an extracellular RNase from tomato cell cultures, RNase LE. DNA hybridisation experiments indicate that there are ca. 5-6 sequences related to RNase NE in the N. alata genome and that RNase NE is not linked to the self-incompatibility (S) locus. RNase NE is expressed in the styles, petals and immature anthers but not in the vegetative tissues of N. alata plants under normal growth conditions. Under phosphate-limited conditions, RNase NE expression is induced in roots but not leaves of N. alata. A transcript hybridising to RNase NE is also induced in N. plumbaginifolia cell cultures in response to phosphate starvation. RNase NE is likely to play a role in the response of N. alata to phosphate limitation, possibly by scavenging phosphate from sources of RNA in the root environment. We also discuss the evolutionary relationships between the S- and S-like RNase genes in plants.
Collapse
Affiliation(s)
- P N Dodds
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria, Australia
| | | | | |
Collapse
|
46
|
Affiliation(s)
- P N Dodds
- Plant Cell Biology Research Centre School of Botany, University of Melbourne Parkville, Vic, Australia
| | | | | |
Collapse
|
47
|
Royo J, Nass N, Matton DP, Okamoto S, Clarke AE, Newbigin E. A retrotransposon-like sequence linked to the S-locus of Nicotiana alata is expressed in styles in response to touch. Mol Gen Genet 1996; 250:180-8. [PMID: 8628217 DOI: 10.1007/bf02174177] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have identified a family of repetitive sequences in the genome of Nicotiana alata named Tna1 (Transposon of N. alata). The first element we characterised was a genomic clone for the N. alata s6-ribonuclease (S6-RNase), a gene required for self-incompatibility in this species. The DNA sequence of this element resembles the integrase domain of retrotransposons of the gypsy class and is most similar to a retrotransposon from Lilium henryi. A transcript present in N.alata styles (self-incompatibility genotype S6S6) hybridized to Tna1 and accumulated in the style following either pollination or touching. This transcript was cloned from a cDNA library and was encoded by second, partial Tna1 elements. Neither the transcribed sequence nor the original Tna1 element contain an open reading frame or is likely to be able to transpose. The second element was mapped using a population of N.alata plants segregating for alleles of the self-incompatibility locus and is closely linked to the S6-allele. The Tna1 element is present in a number of Nicotiana species and appears to have been active at least twice during the evolution of this genus.
Collapse
Affiliation(s)
- J Royo
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | | | | |
Collapse
|
48
|
Abstract
Fertilization in flowering plants begins with a pollen grain bearing the male gametes landing on the female stigma. Several mechanisms enable the stigma to discriminate between the different types of pollen that it may receive, of which the best studied is self-incompatibility. The molecules that regulate self-incompatibility are well characterized in two plant families, the Solanaceae and Brassicaceae. This list has recently been extended to include candidates for self-incompatibility molecules from the Rosaceae, Papaveraceae and Poaceae. The information provided by the sequences of these molecules gives insight into the mechanisms and evolution of self-incompatibility in the different families of flowering plants.
Collapse
Affiliation(s)
- J F Golz
- Plant Cell Biology Research Centre, University of Melbourne, Australia
| | | | | |
Collapse
|
49
|
Matton DP, Mau SL, Okamoto S, Clarke AE, Newbigin E. The S-locus of Nicotiana alata: genomic organization and sequence analysis of two S-RNase alleles. Plant Mol Biol 1995; 28:847-58. [PMID: 7640357 DOI: 10.1007/bf00042070] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Genomic clones encoding the S2- and S6-RNases of Nicotiana alata Link and Otto, which are the allelic stylar products of the self-incompatibility (S) locus, were isolated and sequenced. Analysis of genomic DNA by pulsed-field gel electrophoresis and Southern blotting indicates the presence of only a single S-RNase gene in the N. alata genome. The sequences of the open-reading frames in the genomic and corresponding cDNA clones were identical. The organization of the genes was similar to that of other S-RNase genes from solanaceous plants. No sequence similarity was found between the DNA flanking the S2- and S6-RNase genes, despite extensive similarities between the coding regions. The DNA flanking the S6-RNase gene contained sequences that were moderately abundant in the genome. These repeat sequences are also present in other members of the Nicotianae.
Collapse
Affiliation(s)
- D P Matton
- Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria, Australia
| | | | | | | | | |
Collapse
|
50
|
Read SM, Newbigin E, Clarke AE, McClure BA, Kao T. Disputed Ancestry: Comments on a Model for the Origin of Incompatibility in Flowering Plants. Plant Cell 1995; 7:661-664. [PMID: 12242380 PMCID: PMC160812 DOI: 10.1105/tpc.7.6.661] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|