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: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.
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: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).