Tomato fruit (Lycopersicum esculentum), injected with [35S] methionine at harvest and subjected to 38°C for 48 h, accumulated high levels of specific radiolabeled proteins as visualized on 2-D gels, which were not present if the fruit was held at 20°C. These proteins remained labeled for up to 21 days if the fruit was held at 2°C, while the label declined within 4 days if the fruit was transferred to 20°C after heating. Heated fruit held for 20°C for 4 days before being put in low temperature were sensitive to chilling injury, while heated fruit transferred immediately to low temperature were not. This is the first report showing a relationship between the persistence of heat shock proteins and chilling tolerance in a plant tissue. |
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