For Corydalis plants, we have suggested a possible explanation for this transport inhibition based
on the study of developmental and carbohydrate changes in tubers growing under natural autumn and
winter temperatures (from 10 °C to −10 °C) and in tubers cultivated during the same period in a
greenhouse at 18 °C [11,12]. We have shown that low temperature activates the apoplastic route for
sugar movement from the storage parenchyma cells into the apoplastic region of the bulb. Apoplastic
sugars are then loaded to phloem and transferred to the developing bud.