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Diantina S, McGill C, McCormick AC, Millner J, Pritchard HW, Nadarajan J. Comparative seed cryopreservation of indonesian and new zealand epiphytic and terrestrial orchids. Cryo Letters 2023; 44:197-207. [PMID: 37883137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
BACKGROUND The atypical seed storage behaviour reported in several orchid species justifies cryopreservation as a complementary conservation strategy to conventional seed banking. OBJECTIVE This study aimed to assess the seed cryopreservation potential of five orchid species; two tropical epiphytic, Indonesian species (Dendrobium strebloceras, D. lineale), one temperate epiphytic, New Zealand species (D. cunninghamii) and two temperate terrestrial, New Zealand species (Pterostylis banksii, Thelymitra nervosa). MATERIALS AND METHODS Seeds were cryopreserved by direct immersion in liquid nitrogen (LN) and through the application of a cryoprotectant vitrification method. For the latter, seeds were exposed to Plant Vitrification Solution 2 (PVS2) for 0, 20, 50, and 70 min, at either room temperature or on ice, prior to immersion in LN. RESULTS Seeds of all the studied species germinated well following direct cooling in LN. There was no difference in the seedling development capability between cryopreserved and non-cryopreserved seeds of both tropical epiphytic species and direct immersion in LN enhanced seed germination and shoot formation in both temperate terrestrials. CONCLUSION Through a range of analyses of germination and post-germination growth, our study shows the potential for cryopreserving epiphytic or terrestrial orchids from tropical and temperate regions. Doi: 10.54680/fr23410110312.
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Affiliation(s)
- S Diantina
- School of Agriculture and Environment, Massey University, New Zealand. Indonesia Agency for Agricultural Research and Development (IAARD), Jakarta Selatan, Indonesia. Research Center for Plant Conservation, Botanic Garden and Forestry, National Research and Innovation Agency, West Java, Indonesia.
| | - C McGill
- School of Agriculture and Environment, Massey University, Tennent Drive, 4410 Palmerston North, New Zealand
| | - A C McCormick
- School of Agriculture and Environment, Massey University, Tennent Drive, 4410 Palmerston North, New Zealand
| | - J Millner
- School of Agriculture and Environment, Massey University, Tennent Drive, 4410 Palmerston North, New Zealand
| | - H W Pritchard
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, West Sussex RH17 6TN, UK Chinese Academy of Sciences, Kunming Institute of Botany, 132 Lanhei Road, Heilongtan, Kunming, Yunnan 650201, China
| | - J Nadarajan
- The New Zealand Institute for Plant and Food Research Limited, New Zealand.
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Nadarajan J, Esfandiari A, Mathew L, Divinagracia J, Wiedow C, Morgan E. Development, Management and Utilization of a Kiwifruit ( Actinidia spp.) In Vitro Collection: A New Zealand Perspective. Plants (Basel) 2023; 12:2009. [PMID: 37653926 PMCID: PMC10222645 DOI: 10.3390/plants12102009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 09/02/2023]
Abstract
The New Zealand Institute for Plant and Food Research Limited (PFR) supports a large kiwifruit breeding program that includes more than twenty Actinidia species. Almost all the kiwifruit accessions are held as field collections across a range of locations, though not all plants are at multiple locations. An in vitro collection of kiwifruit in New Zealand was established upon the arrival of Pseudomonas syringae pv. Actinadiae-biovar 3 in 2010. The value of an in vitro collection has been emphasized by restrictions on importation of new plants into New Zealand and increasing awareness of the array of biotic and abiotic threats to field collections. The PFR in vitro collection currently holds about 450 genotypes from various species, mostly A. chinensis var. chinensis and A. chinensis var. deliciosa. These collections and the in vitro facilities are used for germplasm conservation, identification of disease-free plants, reference collections and making plants available to users. Management of such a diverse collection requires appropriate protocols, excellent documentation, training, sample tracking and databasing and true-to-type testing, as well as specialized facilities and resources. This review also discusses the New Zealand biosecurity and compliance regime governing kiwifruit plant movement, and how protocols employed by the facility aid the movement of pathogen-free plants within and from New Zealand.
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Affiliation(s)
- Jayanthi Nadarajan
- Food Industry Science Centre, The New Zealand Institute for Plant and Food Research Limited, Palmerston North 4410, New Zealand
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van der Walt K, Nadarajan J. Seed Storage Physiology of Lophomyrtus and Neomyrtus, Two Threatened Myrtaceae Genera Endemic to New Zealand. Plants (Basel) 2023; 12:1067. [PMID: 36903930 PMCID: PMC10005796 DOI: 10.3390/plants12051067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/24/2023] [Accepted: 02/24/2023] [Indexed: 06/18/2023]
Abstract
There is no published information on the seed germination or seed storage physiology of Lophomyrtus bullata, Lophomyrtus obcordata, and Neomyrtus pedunculata. This lack of information is hampering conservation efforts of these critically endangered species. This study investigated the seed morphology, seed germination requirements, and long-term seed storage methods for all three species. The impact of desiccation, desiccation and freezing, as well as desiccation plus storage at 5 °C, -18 °C, and -196 °C on seed viability (germination) and seedling vigour was assessed. Fatty acid profiles were compared between L. obcordata and L. bullata. Variability in storage behaviour between the three species was investigated through differential scanning calorimetry (DSC) by comparing thermal properties of lipids. L. obcordata seed were desiccation-tolerant and viability was retained when desiccated seed was stored for 24 months at 5 °C. L. bullata seed was both desiccation- and freezing-sensitive, while N. pedunculata was desiccation-sensitive. DSC analysis revealed that lipid crystallisation in L. bullata occurred between -18 °C and -49 °C and between -23 °C and -52 °C in L. obcordata and N. pedunculata. It is postulated that the metastable lipid phase, which coincides with the conventional seed banking temperature (i.e., storing seeds at -20 ± 4 °C and 15 ± 3% RH), could cause the seeds to age more rapidly through lipid peroxidation. Seeds of L. bullata, L. obcordata and N. pedunculata are best stored outside of their lipid metastable temperature ranges.
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Affiliation(s)
- Karin van der Walt
- Ōtari Native Botanic Garden, Wellington City Council, 150 Wilton Road, Wellington 6012, New Zealand
- School of Agriculture and Environment, Massey University, Palmerston North 4410, New Zealand
| | - Jayanthi Nadarajan
- The New Zealand Institute for Plant and Food Research Limited, Fitzherbert Science Centre, Batchelar Road, Palmerston North 4474, New Zealand
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Nadarajan J, Walters C, Pritchard HW, Ballesteros D, Colville L. Seed Longevity-The Evolution of Knowledge and a Conceptual Framework. Plants (Basel) 2023; 12:471. [PMID: 36771556 PMCID: PMC9919896 DOI: 10.3390/plants12030471] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 06/18/2023]
Abstract
The lifespan or longevity of a seed is the time period over which it can remain viable. Seed longevity is a complex trait and varies greatly between species and even seed lots of the same species. Our scientific understanding of seed longevity has advanced from anecdotal 'Thumb Rules,' to empirically based models, biophysical explanations for why those models sometimes work or fail, and to the profound realisation that seeds are the model of the underexplored realm of biology when water is so limited that the cytoplasm solidifies. The environmental variables of moisture and temperature are essential factors that define survival or death, as well as the timescale to measure lifespan. There is an increasing understanding of how these factors induce cytoplasmic solidification and affect glassy properties. Cytoplasmic solidification slows down, but does not stop, the chemical reactions involved in ageing. Continued degradation of proteins, lipids and nucleic acids damage cell constituents and reduce the seed's metabolic capacity, eventually impairing the ability to germinate. This review captures the evolution of knowledge on seed longevity over the past five decades in relation to seed ageing mechanisms, technology development, including tools to predict seed storage behaviour and non-invasive techniques for seed longevity assessment. It is concluded that seed storage biology is a complex science covering seed physiology, biophysics, biochemistry and multi-omic technologies, and simultaneous knowledge advancement in these areas is necessary to improve seed storage efficacy for crops and wild species biodiversity conservation.
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Affiliation(s)
- Jayanthi Nadarajan
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North 4410, New Zealand
| | - Christina Walters
- USDA—Agricultural Research Service, National Laboratory for Genetic Resources Preservation, Fort Collins, CO 80521, USA
| | - Hugh W. Pritchard
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, Haywards Heath RH17 6TN, UK
- Chinese Academy of Sciences, Kunming Institute of Botany, Kunming 650201, China
| | - Daniel Ballesteros
- Faculty of Farmacy, Department of Botany and Geology, University of Valencia, Av. Vicent Estelles s/n, 46100 Valencia, Spain
| | - Louise Colville
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, Haywards Heath RH17 6TN, UK
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Bettoni JC, Mathew L, Pathirana R, Wiedow C, Hunter DA, McLachlan A, Khan S, Tang J, Nadarajan J. Eradication of Potato Virus S, Potato Virus A, and Potato Virus M From Infected in vitro-Grown Potato Shoots Using in vitro Therapies. Front Plant Sci 2022; 13:878733. [PMID: 35665190 PMCID: PMC9161163 DOI: 10.3389/fpls.2022.878733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
Certain viruses dramatically affect yield and quality of potatoes and have proved difficult to eradicate with current approaches. Here, we describe a reliable and efficient virus eradication method that is high throughput and more efficacious at producing virus-free potato plants than current reported methods. Thermotherapy, chemotherapy, and cryotherapy treatments were tested alone and in combination for ability to eradicate single and mixed Potato virus S (PVS), Potato virus A (PVA), and Potato virus M (PVM) infections from three potato cultivars. Chemotherapy treatments were undertaken on in vitro shoot segments for four weeks in culture medium supplemented with 100 mg L-1 ribavirin. Thermotherapy on in vitro shoot segments was applied for two weeks at 40°C (day) and 28°C (night) with a 16 h photoperiod. Plant vitrification solution 2 (PVS2) and cryotherapy treatments included a shoot tip preculture followed by exposure to PVS2 either without or with liquid nitrogen (LN, cryotherapy) treatment. The virus status of control and recovered plants following therapies was assessed in post-regeneration culture after 3 months and then retested in plants after they had been growing in a greenhouse for a further 3 months. Microtuber production was investigated using in vitro virus-free and virus-infected segments. We found that thermotherapy and cryotherapy (60 min PVS2 + LN) used alone were not effective in virus eradication, while chemotherapy was better but with variable efficacy (20-100%). The most effective result (70-100% virus eradication) was obtained by combining chemotherapy with cryotherapy, or by consecutive chemotherapy, combined chemotherapy and thermotherapy, then cryotherapy treatments irrespective of cultivar. Regrowth following the two best virus eradication treatments was similar ranging from 8.6 to 29% across the three cultivars. The importance of virus removal on yield was reflected in "Dunluce" free of PVS having higher numbers of microtubers and in "V500' free of PVS and PVA having a greater proportion of microtubers > 5 mm. Our improved procedure has potential for producing virus-free planting material for the potato industry. It could also underpin the global exchange of virus-free germplasm for conservation and breeding programs.
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Affiliation(s)
- Jean Carlos Bettoni
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
| | - Liya Mathew
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
| | - Ranjith Pathirana
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
| | - Claudia Wiedow
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
| | - Donald A. Hunter
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
| | - Andrew McLachlan
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
| | - Subuhi Khan
- Plant Health and Environment Laboratory, Ministry for Primary Industries, Auckland, New Zealand
| | - Joe Tang
- Plant Health and Environment Laboratory, Ministry for Primary Industries, Auckland, New Zealand
| | - Jayanthi Nadarajan
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Palmerston North, New Zealand
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van der Walt K, Burritt DJ, Nadarajan J. Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of Syzygium maire (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation. Plants (Basel) 2022; 11:1056. [PMID: 35448783 PMCID: PMC9028110 DOI: 10.3390/plants11081056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 06/14/2023]
Abstract
Syzygium maire is a highly threatened Myrtaceae tree species endemic to New Zealand. Due to its recalcitrant seed storage behaviour, cryopreservation is the only viable long-term ex situ conservation option for this species. This study investigated viability, oxidative stress, thermal properties, and ultrastructure of zygotic embryo axes (EAs) desiccated to various moisture contents (MC). Fresh EAs had a MC of c. 1.9 g/g with 100% viability but rapid desiccation to MC < 0.3 g/g significantly reduced viability and decreased the activities of the enzymatic antioxidants superoxide dismutase, catalase and glutathione peroxidase, with a sevenfold increase in the production of protein carbonyls and lipid peroxides. Differential Scanning Calorimetry analysis showed no thermal events in EAs desiccated to a MC of <0.2 g/g, indicating that all freezable water had been removed, but this was lethal to both EAs and enzymatic antioxidants. The ultrastructure of desiccated EAs showed signs of plasmolysis, while fully hydrated EAs exposed to cryogenic temperature had ultrastructural disintegration and membrane damage. The decline in enzymatic antioxidant activities and the increase in lipid peroxidation suggest that S. maire EA viability loss is due to oxidative stress rather than structural impacts.
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Affiliation(s)
- Karin van der Walt
- Ōtari Native Botanic Garden, Wellington City Council, 150 Wilton Road, Wellington 6012, New Zealand
- School of Agriculture and Environment, Massey University, Palmerston North 4410, New Zealand
| | - David J. Burritt
- Department of Botany, University of Otago, Dunedin 9016, New Zealand;
| | - Jayanthi Nadarajan
- Fitzherbert Science Centre, The New Zealand Institute for Plant and Food Research Limited, Batchelar Road, Palmerston North 4474, New Zealand;
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Diantina S, McGill C, Millner J, Nadarajan J, Pritchard HW, Colville L, Clavijo McCormick A. Seed viability and fatty acid profiles of five orchid species before and after ageing. Plant Biol (Stuttg) 2022; 24:168-175. [PMID: 34724312 DOI: 10.1111/plb.13345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 06/24/2020] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
Changes in seed lipid composition during ageing are associated with seed viability loss in many plant species. However, due to their small seed size, this has not been previously explored in orchids. We characterized and compared the seed viability and fatty acid profiles of five orchid species before and after ageing: one tropical epiphytic orchid from Indonesia (Dendrobium strebloceras), and four temperate species from New Zealand, D. cunninghamii (epiphytic), and Gastrodia cunninghamii, Pterostylis banksii and Thelymitra nervosa (terrestrial). Seeds were aged under controlled laboratory conditions (3-month storage at 60% RH and 20 °C). Seed viability was tested before and after ageing using tetrazolium chloride staining. Fatty acid methyl esters from fresh and aged seeds were extracted through trans-esterification, and then analysed using gas chromatography-mass spectrometry. All species had high initial viability (>80%) and experienced significant viability loss after ageing. The saturated, polyunsaturated, monounsaturated and total fatty acid content decreased with ageing in all species, but this reduction was only significant for D. strebloceras, D. cunninghamii and G. cunninghamii. Our results suggest that fatty acid degradation is a typical response to ageing in orchids, albeit with species variation in magnitude, but the link between fatty acid degradation and viability was not elucidated. Pterostylis banksii exemplified this variation; it showed marked viability loss despite not having a significant reduction in its fatty acid content after ageing. More research is required to identify the effect of ageing on fatty acid composition in orchids, and its contribution to seed viability loss.
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Affiliation(s)
- S Diantina
- School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
- Indonesia Agency for Agricultural Research and Development (IAARD), Jakarta Selatan, Indonesia
| | - C McGill
- School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - J Millner
- School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - J Nadarajan
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North, New Zealand
| | - H W Pritchard
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, West Sussex, UK
| | - L Colville
- Royal Botanic Gardens, Kew, Wakehurst, Ardingly, West Sussex, UK
| | - A Clavijo McCormick
- School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
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Michalak M, Plitta-Michalak BP, Nadarajan J, Colville L. Volatile signature indicates viability of dormant orthodox seeds. Physiol Plant 2021; 173:788-804. [PMID: 34008870 DOI: 10.1111/ppl.13465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 05/11/2021] [Indexed: 06/12/2023]
Abstract
All seeds eventually die even under optimal storage conditions. The moment of viability loss is difficult to predict and detect. In order to differentiate between dead and viable dormant orthodox seeds, GC-MS analysis was used to non-invasively evaluate the volatile signature of seeds of Pyrus communis L. and Sorbus aucuparia L. Dormant seeds are capable of extended metabolic depression. However, their low metabolic rate remains largely unquantified, and there are no measurements of metabolites, i.e. volatile organic compounds (VOC) for physiologically dormant seeds during storage. Therefore, to address this issue, seeds were stored at a broad range of moisture content (MC) ranging from 2 to 30% under cryogenic (-196°C), cool (5°C) and elevated (40°C) temperatures. Volatile emission was highly dependent on seed MC and storage temperature and was higher under conditions associated with seed viability loss. However, changes in the emission of volatiles entrapped in seeds and released during 24 h after storage were detected for all conditions, providing insight into the processes occurring in dry dormant seeds. Among the 36 volatiles identified, three (acetaldehyde, ethanol, ethyl acetate) were highly correlated with seed germinability and show potential for the non-invasive screening of viability. Significantly, all three VOC are derived mostly from glycolysis and peroxidation and were detected even under very low moisture and temperature storage conditions. This is the first study to report on VOC accumulation and emission from physiologically dormant seeds and provide a broader view into their viability.
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Affiliation(s)
- Marcin Michalak
- Department of Plant Physiology, Genetics and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - Beata P Plitta-Michalak
- Department of Plant Physiology, Genetics and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
- Institute of Dendrology, Polish Academy of Sciences, Kórnik, Poland
| | - Jayanthi Nadarajan
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, UK
- The New Zealand Institute for Plant and Food Research Limited, Food Industry Science Centre, Fitzherbert Science Centre, Palmerston North, New Zealand
| | - Louise Colville
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, UK
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van der Walt K, Kemp P, Sofkova-Bobcheva S, Burritt D, Nadarajan J. Evaluation of droplet-vitrification, vacuum infiltration vitrification and encapsulation-dehydration for cryopreservation of Syzygium maire zygotic embryos. Cryo Letters 2021; 42:202-209. [PMID: 35363839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
BACKGROUND Syzygium maire is a threatened tree species with limited information on long-term storage options for its recalcitrant seed. OBJECTIVE To evaluate the cryopreservation of S. maire zygotic embryo axes (EA) using dehydration, encapsulation-dehydration as well as PVS2 vitrification using droplet vitrification (DV) and the novel droplet vacuum infiltration vitrification (DVIV) methods. MATERIALS AND METHODS Excised naked and sodium alginate encapsulated EA were desiccated to various moisture contents (MC) using a laminar flow cabinet. Moisture content, embryo survival and plantlet formation, before and after cryopreservation, were assessed at 1 h intervals during the desiccation period (0-6 h). The influence of PVS2, using DV and DVIV, was assessed for various desiccation times and temperatures. RESULTS Encapsulated EA desiccated to 31% and 37% MC survived but no plantlets formed following cryopreservation. Exposure to PVS2 using the DV method had a negative impact on embryo survival and plantlet formation, while DVIV resulted in improved results for non-cryopreserved EA. However, neither PVS2 vitrification method resulted in embryo survival following cryopreservation. CONCLUSION S. maire embryos are sensitive to desiccation and likely require physical, chemical or a combination of protection methods to increase embryo survival and plantlet formation following cryopreservation.
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Affiliation(s)
- K van der Walt
- Otari Native Botanic Garden and Wilton's Bush Reserve, Wellington City Council, 160 Wilton Road, Wellington; Massey University of New Zealand, Private Bag 11222, Palmerston North, New Zealand.
| | - P Kemp
- Massey University of New Zealand, Private Bag 11222, Palmerston North, New Zealand
| | - S Sofkova-Bobcheva
- Massey University of New Zealand, Private Bag 11222, Palmerston North, New Zealand
| | - D Burritt
- University of Otago, Department of Botany, P.O. Box 56, Dunedin, New Zealand
| | - J Nadarajan
- Massey University of New Zealand, Private Bag 11222, Palmerston North; the New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North, New Zealand
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Smith GR, Ganley BJ, Chagné D, Nadarajan J, Pathirana RN, Ryan J, Arnst EA, Sutherland R, Soewarto J, Houliston G, Marsh AT, Koot E, Carnegie AJ, Menzies T, Lee DJ, Shuey LS, Pegg GS. Resistance of New Zealand Provenance Leptospermum scoparium, Kunzea robusta, Kunzea linearis, and Metrosideros excelsa to Austropuccinia psidii. Plant Dis 2020; 104:1771-1780. [PMID: 32272027 DOI: 10.1094/pdis-11-19-2302-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Resistance to the pandemic strain of Austropuccinia psidii was identified in New Zealand provenance Leptospermum scoparium, Kunzea robusta, and K. linearis plants. Only 1 Metrosideros excelsa-resistant plant was found (of the 570 tested) and no resistant plants of either Lophomyrtus bullata or L. obcordata were found. Three types of resistance were identified in Leptospermum scoparium. The first two, a putative immune response and a hypersensitive response, are leaf resistance mechanisms found in other myrtaceous species while on the lateral and main stems a putative immune stem resistance was also observed. Both leaf and stem infection were found on K. robusta and K. linearis plants as well as branch tip dieback that developed on almost 50% of the plants. L. scoparium, K. robusta, and K. linearis are the first myrtaceous species where consistent infection of stems has been observed in artificial inoculation trials. This new finding and the first observation of significant branch tip dieback of plants of the two Kunzea spp. resulted in the development of two new myrtle rust disease severity assessment scales. Significant seed family and provenance effects were found in L. scoparium, K. robusta, and K. linearis: some families produced significantly more plants with leaf, stem, and (in Kunzea spp.) branch tip dieback resistance, and provenances provided different percentages of resistant families and plants. The distribution of the disease symptoms on plants from the same seed family, and between plants from different seed families, suggested that the leaf, stem, and branch tip dieback resistances were the result of independent disease resistance mechanisms.
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Affiliation(s)
- Grant R Smith
- The New Zealand Institute for Plant and Food Research Limited, Lincoln 7608, New Zealand
| | - Beccy J Ganley
- The New Zealand Institute for Plant and Food Research Limited, Te Puke 3182, New Zealand
| | - David Chagné
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North 4410, New Zealand
| | - Jayanthi Nadarajan
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North 4410, New Zealand
| | - Ranjith N Pathirana
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North 4410, New Zealand
| | - Julie Ryan
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North 4410, New Zealand
| | - Elise A Arnst
- Manaaki Whenua Landcare Research, Lincoln 7608, New Zealand
| | | | | | - Gary Houliston
- Manaaki Whenua Landcare Research, Lincoln 7608, New Zealand
| | - Alby T Marsh
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North 4410, New Zealand
| | - Emily Koot
- The New Zealand Institute for Plant and Food Research Limited, Palmerston North 4410, New Zealand
| | - Angus J Carnegie
- Forest Science, Department of Primary Industries-Forestry, Parramatta, NSW 2150 Australia
| | - Tracey Menzies
- The Queensland Department of Agriculture and Fisheries, Brisbane, Queensland 4001, Australia
| | - David J Lee
- The University of the Sunshine Coast, Maroochydore, Queensland 4558, Australia
| | - Louise S Shuey
- The Queensland Department of Agriculture and Fisheries, Brisbane, Queensland 4001, Australia
| | - Geoff S Pegg
- The Queensland Department of Agriculture and Fisheries, Brisbane, Queensland 4001, Australia
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Diantina S, McGill C, Millner J, Nadarajan J, W. Pritchard H, Clavijo McCormick A. Comparative Seed Morphology of Tropical and Temperate Orchid Species with Different Growth Habits. Plants (Basel) 2020; 9:E161. [PMID: 32013075 PMCID: PMC7076704 DOI: 10.3390/plants9020161] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/13/2020] [Accepted: 01/17/2020] [Indexed: 11/18/2022]
Abstract
Seed morphology underpins many critical biological and ecological processes, such as seed dormancy and germination, dispersal, and persistence. It is also a valuable taxonomic trait that can provide information about plant evolution and adaptations to different ecological niches. This study characterised and compared various seed morphological traits, i.e., seed and pod shape, seed colour and size, embryo size, and air volume for six orchid species; and explored whether taxonomy, biogeographical origin, or growth habit are important determinants of seed morphology. We investigated this on two tropical epiphytic orchid species from Indonesia (Dendrobium strebloceras and D. lineale), and four temperate species from New Zealand, terrestrial Gastrodia cunnninghamii, Pterostylis banksii and Thelymitra nervosa, and epiphytic D. cunninghamii. Our results show some similarities among related species in their pod shape and colour, and seed colouration. All the species studied have scobiform or fusiform seeds and prolate-spheroid embryos. Specifically, D. strebloceras, G. cunninghamii, and P. banksii have an elongated seed shape, while T. nervosa has truncated seeds. Interestingly, we observed high variability in the micro-morphological seed characteristics of these orchid species, unrelated to their taxonomy, biogeographical origin, or growth habit, suggesting different ecological adaptations possibly reflecting their modes of dispersal.
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Affiliation(s)
- Surya Diantina
- School of Agriculture and Environment, Massey University, Tennent Drive, 4410 Palmerston North, New Zealand; (C.M.); (J.M.); (A.C.M.)
- Indonesia Agency for Agricultural Research and Development (IAARD), Jl. Ragunan 29, Pasar Minggu, Jakarta Selatan 12540, Indonesia
| | - Craig McGill
- School of Agriculture and Environment, Massey University, Tennent Drive, 4410 Palmerston North, New Zealand; (C.M.); (J.M.); (A.C.M.)
| | - James Millner
- School of Agriculture and Environment, Massey University, Tennent Drive, 4410 Palmerston North, New Zealand; (C.M.); (J.M.); (A.C.M.)
| | - Jayanthi Nadarajan
- The New Zealand Institute for Plant and Food Research Limited, Batchelar Road, Fitzherbert, 4474 Palmerston North, New Zealand;
| | - Hugh W. Pritchard
- Royal Botanic Gardens Kew, Wellcome Trust Millennium Building, Wakehurst, Ardingly, West Sussex RH17 6TN, UK;
| | - Andrea Clavijo McCormick
- School of Agriculture and Environment, Massey University, Tennent Drive, 4410 Palmerston North, New Zealand; (C.M.); (J.M.); (A.C.M.)
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Nadarajan J, Benson EE, Xaba P, Harding K, Lindstrom A, Donaldson J, Seal CE, Kamoga D, Agoo EMG, Li N, King E, Pritchard HW. Comparative Biology of Cycad Pollen, Seed and Tissue - A Plant Conservation Perspective. Bot Rev 2018; 84:295-314. [PMID: 30174336 PMCID: PMC6105234 DOI: 10.1007/s12229-018-9203-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Cycads are the most endangered of plant groups based on IUCN Red List assessments; all are in Appendix I or II of CITES, about 40% are within biodiversity 'hotspots,' and the call for action to improve their protection is long-standing. We contend that progress in this direction will not be made until there is better understanding of cycad pollen, seed and tissue biology, which at the moment is limited to relatively few (<10%) species. We review what is known about germplasm (seed and pollen) storage and germination, together with recent developments in the application of contemporary technologies to tissues, such as isotype labelling, biomolecular markers and tissue culture. Whilst progress is being made, we conclude that an acceleration of comparative studies is needed to facilitate the integration of in situ and ex situ conservation programmes to better safeguard endangered cycads.
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Affiliation(s)
- J. Nadarajan
- Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN UK
- Present Address: The New Zealand Institute for Plant & Food Research Ltd, Private Bag 11600, Palmerston North, 4442 New Zealand
| | - E. E. Benson
- Damar Research Scientists, Damar, Cuparmuir, Fife, KY15 5RJ UK
| | - P. Xaba
- South African National Biodiversity Institute, Kirstenbosch National Botanical Garden, Cape Town, Republic of South Africa
| | - K. Harding
- Damar Research Scientists, Damar, Cuparmuir, Fife, KY15 5RJ UK
| | - A. Lindstrom
- Nong Nooch Tropical Botanical Garden, Chonburi, 20250 Thailand
| | - J. Donaldson
- South African National Biodiversity Institute, Kirstenbosch National Botanical Garden, Cape Town, Republic of South Africa
| | - C. E. Seal
- Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN UK
| | - D. Kamoga
- Joint Ethnobotanical Research Advocacy, P.O.Box 27901, Kampala, Uganda
| | | | - N. Li
- Fairy Lake Botanic Garden, Shenzhen, Guangdong People’s Republic of China
| | - E. King
- UNEP-World Conservation Monitoring Centre, Cambridge, UK
| | - H. W. Pritchard
- Royal Botanic Gardens, Kew, Wakehurst Place, Ardingly, West Sussex RH17 6TN UK
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Pritchard H, Nadarajan J, Ballesteros D, Thammasiri K, Prasongsom S, Malik S, Chaudhury R, Kim HH, Lin L, Li WQ, Yang XY, Popova E. Cryobiotechnology of tropical seeds – scale, scope and hope. Acta Hortic 2017:37-48. [DOI: 10.17660/actahortic.2017.1167.6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/19/2023]
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Wade EM, Nadarajan J, Yang X, Ballesteros D, Sun W, Pritchard HW. Plant species with extremely small populations (PSESP) in China: A seed and spore biology perspective. Plant Divers 2016; 38:209-220. [PMID: 30159468 PMCID: PMC6112217 DOI: 10.1016/j.pld.2016.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 09/06/2016] [Accepted: 09/07/2016] [Indexed: 05/08/2023]
Abstract
Approximately one fifth of the world's plants are at risk of extinction. Of these, a significant number exist as populations of few individuals, with limited distribution ranges and under enormous pressure due to habitat destruction. In China, these most-at-risk species are described as 'plant species with extremely small populations' (PSESP). Implementing conservation action for such listed species is urgent. Storing seeds is one of the main means of ex situ conservation for flowering plants. Spore storage could provide a simple and economical method for fern ex situ conservation. Seed and spore germination in nature is a critical step in species regeneration and thus in situ conservation. But what is known about the seed and spore biology (storage and germination) of at-risk species? We have used China's PSESP (the first group listing) as a case study to understand the gaps in knowledge on propagule biology of threatened plant species. We found that whilst germination information is available for 28 species (23% of PSESP), storage characteristics are only known for 8% of PSESP (10 species). Moreover, we estimate that 60% of the listed species may require cryopreservation for long-term storage. We conclude that comparative biology studies are urgently needed on the world's most threatened taxa so that conservation action can progress beyond species listing.
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Affiliation(s)
- Ellie Merrett Wade
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Jayanthi Nadarajan
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Xiangyun Yang
- The Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, PR China
| | - Daniel Ballesteros
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
| | - Weibang Sun
- Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, Yunnan, PR China
| | - Hugh W. Pritchard
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, Wakehurst Place, Ardingly, West Sussex, RH17 6TN, UK
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Nadarajan J, Pritchard HW. Biophysical characteristics of successful oilseed embryo cryoprotection and cryopreservation using vacuum infiltration vitrification: an innovation in plant cell preservation. PLoS One 2014; 9:e96169. [PMID: 24788797 PMCID: PMC4006905 DOI: 10.1371/journal.pone.0096169] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/03/2014] [Indexed: 12/05/2022] Open
Abstract
Heterogeneity in morphology, physiology and cellular chemistry of plant tissues can compromise successful cryoprotection and cryopreservation. Cryoprotection is a function of exposure time × temperature × permeability for the chosen protectant and diffusion pathway length, as determined by specimen geometry, to provide sufficient dehydration whilst avoiding excessive chemical toxicity. We have developed an innovative method of vacuum infiltration vitrification (VIV) at 381 mm (15 in) Hg (50 kPa) that ensures the rapid (5 min), uniform permeation of Plant Vitrification Solution 2 (PVS2) cryoprotectant into plant embryos and their successful cryopreservation, as judged by regrowth in vitro. This method was validated on zygotic embryos/embryonic axes of three species (Carica papaya, Passiflora edulis and Laurus nobilis) up to 1.6 mg dry mass and 5.6 mm in length, with varying physiology (desiccation tolerances) and 80 °C variation in lipid thermal profiles, i.e., visco-elasticity properties, as determined by differential scanning calorimetry. Comparisons between the melting features of cryoprotected embryos and embryo regrowth indicated an optimal internal PVS2 concentration of about 60% of full strength. The physiological vigour of surviving embryos was directly related to the proportion of survivors. Compared with conventional vitrification, VIV-cryopreservation offered a ∼ 10-fold reduction in PVS2 exposure times, higher embryo viability and regrowth and greater effectiveness at two pre-treatment temperatures (0 °C and 25 °C). VIV-cryopreservation may form the basis of a generic, high throughput technology for the ex situ conservation of plant genetic resources, aiding food security and protection of species from diverse habitats and at risk of extinction.
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Affiliation(s)
- Jayanthi Nadarajan
- Seed Conservation Department, Royal Botanic Gardens Kew, Wellcome Trust Millennium Building, Ardingly, West Sussex, United Kingdom
| | - Hugh W. Pritchard
- Seed Conservation Department, Royal Botanic Gardens Kew, Wellcome Trust Millennium Building, Ardingly, West Sussex, United Kingdom
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Chen H, Pritchard HW, Seal CE, Nadarajan J, Li W, Yang S, Kranner I. Post desiccation germination of mature seeds of tea (Camellia sinensis L.) can be enhanced by pro-oxidant treatment, but partial desiccation tolerance does not ensure survival at -20°C. Plant Sci 2012; 184:36-44. [PMID: 22284708 DOI: 10.1016/j.plantsci.2011.12.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Revised: 12/06/2011] [Accepted: 12/09/2011] [Indexed: 05/31/2023]
Abstract
The maximal potential desiccation tolerance (MPDT) of tea (Camellia sinensis) seeds has been a matter of debate for decades. Here we assessed the ability of tea seeds from three sites in China to germinate after desiccation. Desiccation tolerance was greatest in Kunming, followed by Puer and Lincang, with Kunming seeds tolerating drying to 8% moisture content (MC), or ∼0.5 water activity (a(w)). Such tolerance was observed in Lincang seeds only when hydrogen peroxide (H₂O₂) at 0.5 or 1M was applied to seeds, indicating a stimulatory role for H₂O₂ in post-desiccation germination. Puer seeds exhibited MPDT of 16% MC (∼0.7 a(w)). Therefore, seeds from all three sites were not recalcitrant. The length of the dry season after dispersal and the high ratio of seed coat to seed mass (>0.3) support the observation of non-recalcitrant behaviour. The seeds were not immature, as the lipid signal in embryonic axes mirrored that of the cotyledons (30% oil). Even after high survival [>60% total germination (TG)] on drying to 10-13% MC, no Kunming seeds tolerated 1 month storage at -20 °C coinciding with lipid transitional changes at this temperature. The results indicate that tea seeds from China are neither recalcitrant nor storable at -20 °C.
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Affiliation(s)
- Hongying Chen
- Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, China
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Pritchard HW, Kranner I, Nadarajan J. 18. FROZEN PLANeT – The biobanking of plants. Cryobiology 2010. [DOI: 10.1016/j.cryobiol.2010.10.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Nadarajan J, Mansor M, Krishnapillay B, Staines HJ, Benson EE, Harding K. Applications of differential scanning calorimetry in developing cryopreservation strategies for Parkia speciosa, a tropical tree producing recalcitrant seeds. Cryo Letters 2008; 29:95-110. [PMID: 18516340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Shoot-tips of Parkia speciosa, a recalcitrant seed producing tropical leguminous tree withstood cryopreservation using encapsulation-vitrification in combination with trehalose preculture. Differential scanning calorimetry (DSC) revealed that trehalose moderated the thermal characteristics of the shoot-tips. A 30 min PVS2 treatment had the lowest glass transition temperature (Tg) (-50.2 +/- 1.1 degree C) when applied in combination with 5% (w/v) trehalose. The Tg increased to -40.2 +/- 1.0 degree C as the sugar concentration was decreased to 2.5 percent (w/v). Tg heat capacity for shoot-tips treated with 2.5 percent and 5 percent (w/v) trehalose and exposed to PVS2 for 30 min increased from 0.17 +/ 0.05 to 0.23 +/- 0.01 J per gram, respectively. Enthalpies of the melt-endotherm varied in proportion to trehalose concentration, for the 30 min PVS2 treatment, whereas the melt enthalpy for control shoots was greater than 150 J per gram and decreased to ca. 60 J per gram with 2.5 percent (w/v) trehalose. For 5 percent and 10 percent (w/v) trehalose treatments, enthalpy declined to ca. 24 and 12 J per gram respectively and freezing points were depressed to -75 degree C and -85 degree C with 2.5 percent and 5 percent trehalose (w/v), respectively. DSC elucidated the critical points at which vitrification occurred in germplasm exposed to trehalose and PVS2. A 60 min PVS2 treatment supporting ca. 70 percent survival was found optimal for stable glass formation during cooling and on rewarming.
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Johnston JW, Dussert S, Gale S, Nadarajan J, Harding K, Benson EE. Optimisation of the azinobis-3-ethyl-benzothiazoline-6-sulphonic acid radical scavenging assay for physiological studies of total antioxidant activity in woody plant germplasm. Plant Physiol Biochem 2006; 44:193-201. [PMID: 16762559 DOI: 10.1016/j.plaphy.2006.04.005] [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: 08/15/2005] [Indexed: 05/10/2023]
Abstract
A robust spectroscopic method for determining total antioxidant activity in aqueous extractions has been applied to tissues from diverse woody plant species, including seeds of Coffea arabica and in vitro shoots from Ribes nigrum, Picea sitchensis and Shorea leprosula. The assay involves scavenging of an ABTS [2,2'-azinobis-(3-ethyl-benzothiazoline-6-sulphonic acid)] radical generated by the reaction of potassium persulphate with ABTS to produce an ABTS*(+) chromophore (lambda=734 nm). Antioxidants reduce ABTS*(+) back to ABTS with a concomitant decrease in absorbance. Aqueous extractions from C. arabica and S. leprosula had considerably higher (110-205 micromol Trolox eq. g(-1) FW) total antioxidant activities than P. sitchensis and R. nigrum (6-11 micromol Trolox eq. g(-1) FW). Further studies in two of these species showed that the inclusion of water-insoluble polyvinylpyrrolidone during aqueous tissue extraction enabled the combined phenolic and alkaloid antioxidant activity to be determined. These fractions accounted for 85% and 60% of total antioxidant activity for C. arabica seeds and R. nigrum shoots, respectively. The ABTS radical scavenging assay is presented herein as a robust method for determining total antioxidant activity in germplasm from diverse woody plant tissues and species. Its applicability to study oxidative stress in tissue cultures and germplasm employed in plant biotechnology, breeding and stress physiology programmes is discussed.
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Affiliation(s)
- Jason W Johnston
- Plant Conservation Group, School of Contemporary Science, University of Abertay Dundee, Kydd Building, Bell St, Dundee, DD1 1HG, UK.
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