Project description:Onion is regarded as non-climacteric. In onion, ethylene can suppress sprouting however, the ethylene binding inhibitor, 1-MCP can also suppress sprout growth although it is unknown how ethylene and 1-MCP elicit the same response. In this study, onion bulbs were treated with 10 μL L-1 ethylene or 1 μL L-1 1-MCP individually or in combination for 24 h at 20°C before or after curing (six weeks) at 20 or 28°C then stored at 1°C. Following curing, a subset of these same onion bulbs was stored separately under continuous air or ethylene (10 μL L-1) at 1°C
Project description:Background: Human intestinal tissue samples are barely accessible to study potential health benefits of nutritional compounds. Numbers of animals used in animal trials, however, need to be minimalized. Therefore, in this study we explored the applicability of an in vitro model, namely human intestinal Caco-2 cells, to study the effect of food compounds on (intestinal) health. In vitro digested yellow (YOd) and white onion extracts (WOd) were used as model food compounds and transcriptomics was applied to obtain more insight into their mode of actions in the intestinal cells. Methods: Caco-2 cells were incubated with in vitro digested onion extracts for 6 hours, total RNA was extracted and Affymterix Human Gene 1.1 ST arrays were used to analyze the gene expression profiles. To identify onion-induced gene expression profiles in Caco-2 cells, digested yellow onion and white onion samples were compared to a digest control samples. Results: We found that yellow onion (n=5586, p<0.05) had a more pronounced effect on gene expression than white onion (n=3688, p<0.05). However, a substantial number of genes (n=3281, p<0.05) were affected by both onion variants in the same direction. Pathway analyses revealed that mainly processes related to oxidative stress, and especially the Keap1-Nrf2 pathway, were affected by onions. Our data fit with previous in vivo studies showing that the beneficial effects of onions are mostly linked to their antioxidant properties. Conclusion: our data indicate that the in vitro Caco-2 intestinal model can be used to determine modes of action of nutritional compounds and can thereby reduce the number of animals used in conventional nutritional intervention studies.
Project description:Background: Human intestinal tissue samples are barely accessible to study potential health benefits of nutritional compounds. Numbers of animals used in animal trials, however, need to be minimalized. Therefore, in this study we explored the applicability of an in vitro model, namely human intestinal Caco-2 cells, to study the effect of food compounds on (intestinal) health. In vitro digested yellow (YOd) and white onion extracts (WOd) were used as model food compounds and transcriptomics was applied to obtain more insight into their mode of actions in the intestinal cells. Methods: Caco-2 cells were incubated with in vitro digested onion extracts for 6 hours, total RNA was extracted and Affymterix Human Gene 1.1 ST arrays were used to analyze the gene expression profiles. To identify onion-induced gene expression profiles in Caco-2 cells, digested yellow onion and white onion samples were compared to a digest control samples. Results: We found that yellow onion (n=5586, p<0.05) had a more pronounced effect on gene expression than white onion (n=3688, p<0.05). However, a substantial number of genes (n=3281, p<0.05) were affected by both onion variants in the same direction. Pathway analyses revealed that mainly processes related to oxidative stress, and especially the Keap1-Nrf2 pathway, were affected by onions. Our data fit with previous in vivo studies showing that the beneficial effects of onions are mostly linked to their antioxidant properties. Conclusion: our data indicate that the in vitro Caco-2 intestinal model can be used to determine modes of action of nutritional compounds and can thereby reduce the number of animals used in conventional nutritional intervention studies.
Project description:Physiological and biochemical changes occur in onion (Allium cepa L.) bulbs during the transition from dormancy to sprout suppression and subsequent sprout growth. These include changes in the concentrations of flavor compounds, carbohydrates, mineral elements and plant growth regulators (PGRs). Detailed analyses of these changes and the impact of different post-harvest techniques, designed to prolong storage life, have not been undertaken. We developed the first onion oligonucleotide microarray to determine differential gene expression in onion during curing and storage, with transcriptional changes supporting biochemical and physiological analyses.
Project description:High-quality chromosome-level genome assemblies of onion, garlic, Welsh onion and African lily, Global studies of Allium crops and their trait evolution.
Project description:Physiological and biochemical changes occur in onion (Allium cepa L.) bulbs during the transition from dormancy to sprout suppression and subsequent sprout growth. These include changes in the concentrations of flavor compounds, carbohydrates, mineral elements and plant growth regulators (PGRs). Detailed analyses of these changes and the impact of different post-harvest techniques, designed to prolong storage life, have not been undertaken. We developed the first onion oligonucleotide microarray to determine differential gene expression in onion during curing and storage, with transcriptional changes supporting biochemical and physiological analyses. Samples of RNA were prepared from onions of two cultivars, ‘Wellington’ (brown, long-storing) and ‘Sherpa’ (brown, average-storing), grown according to normal commercial practice at various physiological ages, viz, freshly harvested, cured, pre-sprouting and sprouting. Three biological replicates for each time (harvest, cured, before sprouting, sprouting), curing temperature (20, 28°C) and cultivar (Wellington, Sherpa) combination (n = 42).
Project description:Onion is regarded as non-climacteric. In onion, ethylene can suppress sprouting however, the ethylene binding inhibitor, 1-MCP can also suppress sprout growth although it is unknown how ethylene and 1-MCP elicit the same response. In this study, onion bulbs were treated with 10 μL L-1 ethylene or 1 μL L-1 1-MCP individually or in combination for 24 h at 20°C before or after curing (six weeks) at 20 or 28°C then stored at 1°C. Following curing, a subset of these same onion bulbs was stored separately under continuous air or ethylene (10 μL L-1) at 1°C Six treatments were chosen for microarray analysis; four samples were taken before curing immediately after treatment with ethylene or 1-MCP or ethylene and 1-MCP in combination for 24 h at 20°C. The other two samples and two were taken at the end of storage following 6 weeks curing at 28°C andafter 29 weeks cold storage (1°C) in continuous air or continuous ethylene totalling 35 weeks storage. The four pre-curing samples used were untreated (control) or treated with EB, MB or EMB and the two samples after storage were control bulbs stored in continuous ethylene or air at 1°C. There were three biological replicates of each of the six treatments making 18 samples in total.