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16 results on '"Bester, Cecilia"'

7. Analysis of the Differentially Expressed Proteins and Metabolic Pathways of Honeybush (Cyclopia subternata) in Response to Water Deficit Stress.

Author

Mahlare, Mary-Jane S., Husselmann, Lizex, Lewu, Muinat N., Bester, Cecilia, Lewu, Francis B., and Caleb, Oluwafemi James

Subjects
PROTEINS, FISHER exact test, BETA-glucans, WATER supply, BIOSYNTHESIS, POTTED plants
Abstract

Honeybush (Cyclopia spp.) is a rich source of antioxidant properties and phenolic compounds. Water availability plays a crucial role in plant metabolic processes, and it contributes to overall quality. Thus, this study aimed to investigate changes in molecular functions, cellular components, and biological processes of Cyclopia subternata exposed to different water stress conditions, which include well-watered (as Control, T1), semi-water stressed (T2), and water-deprived (T3) potted plants. Samples were also collected from a well-watered commercial farm first cultivated in 2013 (T13) and then cultivated in 2017 (T17) and 2019 (T19). Differentially expressed proteins extracted from C. subternata leaves were identified using LC-MS/MS spectrometry. A total of 11 differentially expressed proteins (DEPs) were identified using Fisher's exact test (p < 0.00100). Only α-glucan phosphorylase was found to be statistically common between T17 and T19 (p < 0.00100). Notably, α-glucan phosphorylase was upregulated in the older vegetation (T17) and downregulated in T19 by 1.41-fold. This result suggests that α-glucan phosphorylase was needed in T17 to support the metabolic pathway. In T19, five DEPs were upregulated, while the other six were downregulated. Based on gene ontology, the DEPs in the stressed plant were associated with cellular and metabolic processes, response to stimulus, binding, catalytic activity, and cellular anatomical entity. Differentially expressed proteins were clustered based on the Kyoto Encyclopedia of Genes and Genomes (KEGG), and sequences were linked to metabolic pathways via enzyme code and KEGG ortholog. Most proteins were involved in photosynthesis, phenylpropanoid biosynthesis, thiamine, and purine metabolism. This study revealed the presence of trans-cinnamate 4-monooxygenase, an intermediate for the biosynthesis of a large number of substances, such as phenylpropanoids and flavonoids. [ABSTRACT FROM AUTHOR]

Published
2023
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11. Lessons from invasion biology: Can eco-evolutionary experience sustain benefits from mycorrhizal fungi and rhizobia in plant production?

Author

Ramoneda, Josep, Le Roux, Johannes, Frossard, Emmanuel, Bester, Cecilia, Oettle, Noel, Frey, Beat, and Gamper, Hannes Andres

Subjects
Crop plant domestication, Range expansion, Root microbiomes, fungi, Ecological fitting, food and beverages, Co-introductions, Plant-icrobe interactions, Crop breeding, Adaptation, Biological invasions, Crop wild relative
Abstract

Mutualistic plant–microbial functioning relies on co-adapted symbiotic partners as well as conducive environmental conditions. Choosing particular plant genotypes for domestication and subsequent cultivar selection can narrow the gene pools of crop plants to a degree that they are no longer able to benefit from microbial mutualists. Elevated mineral nutrient levels in cultivated soils also reduce the dependence of crops on nutritional support by mutualists such as mycorrhizal fungi and rhizobia. Thus, current ways of crop production are predestined to compromise the propagation and function of microbial symbionts, limiting their long-term benefits for plant yield stability. The influence of mutualists on non-native plant establishment and spread, i.e. biological invasions, provides an unexplored analogue to contemporary crop production that accounts for mutualistic services from symbionts like rhizobia and mycorrhizae. The historical exposure of organisms to biotic interactions over evolutionary timescales, or so-called eco-evolutionary experience (EEE), has been used to explain the success of such invasions. In this paper, we stress that consideration of the EEE concept can shed light on how to overcome the loss of microbial mutualist functions following crop domestication and breeding. We propose specific experimental approaches to utilize the wild ancestors of crops to determine whether crop domestication compromised the benefits derived from root microbial symbioses or not. This can predict the potential for success of mutualistic symbiosis manipulation in modern crops and the maintenance of effective microbial mutualisms over the long term., AoB Plants, 11 (6), ISSN:2041-2851

Published
2019
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13. Honeybush (Cyclopiaspp.) anther-stigma distance and intraspecies cross compatibilities

Author

Koen, Jenifer, Slabbert, Martha M., Booyse, Mardé, and Bester, Cecilia

Abstract

Species of Cyclopiaare used to produce honeybush tea, a uniquely South African beverage that is rapidly growing in popularity locally and abroad. In response to warnings about ecological sustainability, the honeybush industry is transitioning from a wild-harvested source model to one relying primarily on commercial farming. To this end, honeybush genotypes are needed with improved homogeneity, sensory qualities, productivity, vigour and resistance to such pest and disease conditions as may arise in massed plantings. In support of existing honeybush breeding programmes, studies have been undertaken to answer pressing questions about honeybush reproductive anatomy and sexual compatibility. Anther-stigma distance was measured within and between honeybush genotypes in order to rule out flower heteromorphism as a cause for low seed set following hand pollination. Continuous variation in anther-stigma distance was observed for the homomorphic, leguminous flowers, suggesting the existence of a mixed-mating system. Diallel crosses were then performed by hand pollination between genotypes within three honeybush species. All three species were found to be partially self-compatible, with large variations in self-incompatibility between genotypes within species. This study provides practical recommendations with regard to the sexual propagation of select honeybush species and expands the platform of scientific research available to honeybush breeders.

Published
2021
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16. Heuningbos (Cyclopia spp.) volwasse embrioweefselkultuur en die effek van peulposisie op saadkleur.

Author

Koen, Jenifer, Slabbert, Martha M., Booyse, Mardé, and Bester, Cecilia

Abstract

Plants (different genotypes) of Cyclopia, used for production of South African honeybush tea (a herbal tisane product), are being improved through breeding for largescale cultivation, but seed dimorphism and dormancy negatively affect germination percentage. In order to increase the percentage of plants that can be obtained from a batch of seed, mature embryo culture and the influence of pod position on seed colour were investigated for C. longifolia, C. maculata and C. subternata. Mature embryos were excised and cultured in vitro at 25 °C ± 1 °C, 24-hour photoperiod, with and without prior cold treatment. The culture of mature embryos proved to be very successful, consistently resulting in more plantlets than conventional sowing. Mature honeybush pods were also collected from the upper, middle and lower-third foliar portions of honeybush shrubs to determine the number of green/indeterminate/brown seeds produced in each position. However, the ratio of dimorphic seed colours produced could not be predicted by pod position. [ABSTRACT FROM AUTHOR]

Published
2021
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