Author
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MIBEL, ELIAS - Jomo Kenyatta University |
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OWINO, WILLIS - Jomo Kenyatta University |
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AMBOLO, JANE - University Of Nairobi |
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Giovannoni, James |
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ONYANGO, ARNOLD - Jomo Kenyatta University |
Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 5/28/2017 Publication Date: 8/3/2017 Citation: Mibel, E., Owino, W., Ambolo, J., Giovannoni, J.J., Onyango, A. 2017. Metabolomic analysis to evaluate the effects of drought stress on selected African eggplant accessions. Journal of the Science of Food and Agriculture. doi:10.1002/jsfa.8458. Interpretive Summary: Eggplant is an important source of vegetable and nutrients on the African continent. The analysis of plant metabolites contributes to the understanding of stress biology of plants through the identification of the compounds and the part they play in acclimation or tolerance. Here we provide evidence of drought and oxidative stress responses in African eggplant accessions. The study displayed differences in the levels of organic acids, sugars and amino acids in response to drought stress and this was dependent on genotype. Some of the observed metabolite compositional changes are related to known phenomena associated with development, stress and photosynthetic activity. The findings of this study illustrate the common effects associated with drought stress on vegetable quality, including stunted growth, leaf color, shape and size as well as change in metabolite composition. This work adds value to the study of stress tolerance and acclimation in crops and contributes to the understanding of the metabolic basis of stress biology in plants. Specifically, we provide evidence that proline, glutamate, sucrose, fructose, trehalose and citric acid are positively associated with stress tolerance in African eggplant. In addition to stress tolerance, the observed metabolites may also contribute to nutritional value since amino acids and sugars are the precursors for nutritional biomolecules such as proteins and carbohydrates, respectively. Technical Abstract: Drought stress is one of the main abiotic stresses that affect crops. It leads to biochemical changes that can have adverse effects on plant growth, development and productivity. African eggplants are important vegetable and fruit crops reported to adapt and thrive well under drought stress. The diversified metabolites arising due to stress have not been well defined. A gas chromatographic–mass spectrometric metabolomic approach was applied to characterize the effect of drought stress on metabolites at different stages of growth. Nineteen accessions were selected for analysis and drought was imposed by withholding water until soil moisture reached 60% field capacity. Fresh leaf tissues were sampled before stress, 2 and 4'weeks after stress and metabolite profiling done. |