Development of a plum chromosome doubling method and proteomics and biochemical characterization

dc.contributor.advisorNdimba, Bongani
dc.contributor.advisorMansvelt, Lucienne
dc.contributor.advisorKlein, Ashwil
dc.contributor.authorMabiya, Thembeka
dc.date.accessioned2016-04-05T13:57:39Z
dc.date.accessioned2024-05-09T07:45:22Z
dc.date.available2016-04-05T13:57:39Z
dc.date.available2024-05-09T07:45:22Z
dc.date.issued2015
dc.description>Magister Scientiae - MScen_US
dc.description.abstractChromosome doubling has become an important tool in breeding programmes as it offers the ability of introducing novel traits into existing plants. Doubled haploid plants are highly valued by both consumers and breeders as these plants usually show larger flower, leaves and fruit, thus making them more marketable. Marianna open pollinated plum rootstocks’ adaptability to different soil types and moisture conditions has been favoured in polyploidy studies as parental material in breeding programmes. The potential of the microtubule depolymerizing herbicide (oryzalin) for in vitro chromosome doubling were investigated by optimizing the concentration and incubation time of plant shoots to the antimitotic agent. Meristem tissues were treated for two time intervals (24 and 48 h) with five different concentrations of oryzalin (50, 75, 100, 150 or 200 μM) in liquid Murashige and Skoog (MS) medium. After treatment, plants were allowed to grow under a 16/8 h light/dark photoperiod at 24±2˚C for 4 weeks. One and two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry (MS) was used to separate, visualise and identify differently expressed proteins. Furthermore, changes in ROS accumulation, photosynthetic pigmentation, lipid peroxidation and antioxidant enzyme activity (SOD, APX and GR) were investigated. Flow cytometry results revealed that treatment of plants with oryzalin concentrations ranging from 75 to 150 μM induced ploidy after 24 h exposure whereas, 200 μM produced mixoploids containing both tetraploid and octoploids plants after 24 h exposure. Longer incubations of 48 h were detrimental to plant tissues as complete mortality was observed in the higher concentration (100 to 200 μM) treatments. Mass spectrometry analysis identified 14 differentially expressed protein spots that were characterized into different functional categories. ROS accumulation, the extent of lipid peroxidation and antioxidant capacity were differentially regulated in response to oryzalin treatment whereas photosynthetic pigments were significantly enhanced. The results suggests that oryzalin-induced proteins may act as potential biomarkers to improve fruit characteristics in future breeding programs whereas antioxidant enzymes play an important role in scavenging ROS in plants to enhance their adaptability to different environmental conditions.en_US
dc.identifier.urihttps://hdl.handle.net/10566/13322
dc.language.isoenen_US
dc.publisherUniversity of the Western Capeen_US
dc.rights.holderUniversity of the Western Capeen_US
dc.subjectAntioxidantsen_US
dc.subjectFlow cytometryen_US
dc.subjectPlant breedingen_US
dc.subjectMariannaen_US
dc.subject2D SDS-PAGEen_US
dc.titleDevelopment of a plum chromosome doubling method and proteomics and biochemical characterizationen_US

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Mabiya_t_msc_ns_2015.pdf
Size:
6.02 MB
Format:
Adobe Portable Document Format
Description:
Thesis
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.62 KB
Format:
Plain Text
Description: