Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation
<i>Syzygium maire</i> 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, the...
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| Format: | Article |
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MDPI AG
2022-04-01
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| Series: | Plants |
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| Online Access: | https://www.mdpi.com/2223-7747/11/8/1056 |
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| author | Karin van der Walt David J. Burritt Jayanthi Nadarajan |
| author_facet | Karin van der Walt David J. Burritt Jayanthi Nadarajan |
| author_sort | Karin van der Walt |
| collection | DOAJ |
| description | <i>Syzygium maire</i> 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 <i>S. maire</i> EA viability loss is due to oxidative stress rather than structural impacts. |
| first_indexed | 2024-03-09T10:29:58Z |
| format | Article |
| id | doaj.art-3b02f522e5734fb49f29e807f5d1fc01 |
| institution | Directory Open Access Journal |
| issn | 2223-7747 |
| language | English |
| last_indexed | 2024-03-09T10:29:58Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Plants |
| spelling | doaj.art-3b02f522e5734fb49f29e807f5d1fc012023-12-01T21:19:43ZengMDPI AGPlants2223-77472022-04-01118105610.3390/plants11081056Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for CryopreservationKarin van der Walt0David J. Burritt1Jayanthi Nadarajan2Ōtari Native Botanic Garden, Wellington City Council, 150 Wilton Road, Wellington 6012, New ZealandDepartment of Botany, University of Otago, Dunedin 9016, New ZealandFitzherbert Science Centre, The New Zealand Institute for Plant and Food Research Limited, Batchelar Road, Palmerston North 4474, New Zealand<i>Syzygium maire</i> 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 <i>S. maire</i> EA viability loss is due to oxidative stress rather than structural impacts.https://www.mdpi.com/2223-7747/11/8/1056critically endangereddifferential scanning calorimetryrecalcitrantROSTEMthermal transitions |
| spellingShingle | Karin van der Walt David J. Burritt Jayanthi Nadarajan Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation Plants critically endangered differential scanning calorimetry recalcitrant ROS TEM thermal transitions |
| title | Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation |
| title_full | Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation |
| title_fullStr | Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation |
| title_full_unstemmed | Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation |
| title_short | Impacts of Rapid Desiccation on Oxidative Status, Ultrastructure and Physiological Functions of <i>Syzygium maire</i> (Myrtaceae) Zygotic Embryos in Preparation for Cryopreservation |
| title_sort | impacts of rapid desiccation on oxidative status ultrastructure and physiological functions of i syzygium maire i myrtaceae zygotic embryos in preparation for cryopreservation |
| topic | critically endangered differential scanning calorimetry recalcitrant ROS TEM thermal transitions |
| url | https://www.mdpi.com/2223-7747/11/8/1056 |
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