Department of Plant Physiology, Facultad de Ciencias, University of Granada, Fuentenueva s/n, 18071 Granada, Spain.
Department of Plant Physiology, Facultad de Ciencias, University of Granada, Fuentenueva s/n, 18071 Granada, Spain.
Plant Sci. 2014 Mar;217-218:78-86. doi: 10.1016/j.plantsci.2013.12.004. Epub 2013 Dec 14.
The postharvest handling of zucchini fruit includes low-temperature storage, making cold stress unavoidable. We have investigated the changes of soluble carbohydrates under this stress and its relation with weight loss and chilling injury in zucchini fruit during postharvest storage at 4 °C and 20 °C for up to 14 days. Two varieties with different degrees of chilling tolerance were compared: Natura, the more tolerant variety, and Sinatra, the variety that suffered more severe chilling-injury symptoms and weight loss. In both varieties, total soluble carbohydrates, reducing soluble carbohydrates and polyols content was generally higher during storage at 4 °C than at 20 °C, thus these parameters are related to the physiological response of zucchini fruit to cold stress. However, the raffinose content increased in Natura and Sinatra fruits during storage at 4 °C and 20 °C, although at 20 °C the increase in raffinose was more remarkable than at 4 °C in both varieties, so that the role of raffinose could be more likely related to dehydration than to chilling susceptibility of zucchini fruit. Glucose, fructose, pinitol, and acid invertase activity registered opposite trends in both varieties against chilling, increasing in Natura and decreasing in Sinatra. The increase in acid invertase activity in Natura fruit during cold storage could contribute in part to the increase of these reducing sugars, whose metabolism could be involved in the adaptation to postharvest cold storage.
西葫芦果实的采后处理包括低温贮藏，这不可避免地会造成冷胁迫。我们研究了在 4°C 和 20°C 下贮藏至 14 天期间，这种胁迫下可溶性碳水化合物的变化及其与失重和冷害的关系。比较了两个具有不同耐冷性的品种：Natura，更耐冷的品种，和 Sinatra，受冷害症状和失重更严重的品种。在这两个品种中，总可溶性碳水化合物、还原可溶性碳水化合物和多元醇含量在 4°C 贮藏时通常高于 20°C，因此这些参数与西葫芦果实对冷胁迫的生理反应有关。然而，在 4°C 和 20°C 贮藏过程中，Natura 和 Sinatra 果实中的棉子糖含量增加，尽管在这两个品种中，20°C 时棉子糖的增加比 4°C 时更为显著，因此棉子糖的作用可能更与脱水有关，而不是与西葫芦果实的冷敏性有关。葡萄糖、果糖、松醇和酸性转化酶活性在两个品种中对冷胁迫的反应相反，在 Natura 中增加，在 Sinatra 中减少。在冷贮藏过程中，Natura 果实中酸性转化酶活性的增加可能部分导致这些还原糖的增加，其代谢可能参与了对采后冷贮藏的适应。
