Pagter Majken, Jensen Christian R, Petersen Karen K, Liu Fulai, Arora Rajeev
Department of Horticulture, University of Aarhus, Kirstinebjergvej 10, DK-5792 Aarslev, Denmark.
Physiol Plant. 2008 Nov;134(3):473-85. doi: 10.1111/j.1399-3054.2008.01154.x. Epub 2008 Aug 14.
Cold injury is frequently seen in the commercially important shrub Hydrangea macrophylla but not in Hydrangea paniculata. Cold acclimation and deacclimation and associated physiological adaptations were investigated from late September 2006 to early May 2007 in stems of field-grown H. macrophylla ssp. macrophylla (Thunb.) Ser. cv. Blaumeise and H. paniculata Sieb. cv. Kyushu. Acclimation and deacclimation appeared approximately synchronized in the two species, but they differed significantly in levels of mid-winter cold hardiness, rates of acclimation and deacclimation and physiological traits conferring tolerance to freezing conditions. Accumulation patterns of sucrose and raffinose in stems paralleled fluctuations in cold hardiness in both species, but H. macrophylla additionally accumulated glucose and fructose during winter, indicating species-specific differences in carbohydrate metabolism. Protein profiles differed between H. macrophylla and H. paniculata, but distinct seasonal patterns associated with winter acclimation were observed in both species. In H. paniculata concurrent increases in xylem sap abscisic acid (ABA) concentrations (ABA) and freezing tolerance suggests an involvement of ABA in cold acclimation. In contrast, ABA from the root system was seemingly not involved in cold acclimation in H. macrophylla, suggesting that species-specific differences in cold hardiness may be related to differences in ABA. In both species a significant increase in stem freezing tolerance appeared long after growth ceased, suggesting that cold acclimation is more regulated by temperature than by photoperiod.
冷害在具有重要商业价值的灌木大花绣球中很常见，但圆锥绣球中却没有。2006年9月下旬至2007年5月初，对田间种植的大花绣球亚种大花绣球（Thunb.）Ser. cv. Blaumeise和圆锥绣球Sieb. cv. Kyushu的茎进行了冷驯化、去驯化及相关生理适应性研究。两个物种的驯化和去驯化过程似乎大致同步，但它们在冬季中期的抗寒水平、驯化和去驯化速率以及赋予冷冻条件耐受性的生理特征方面存在显著差异。两个物种茎中蔗糖和棉子糖的积累模式与抗寒能力的波动平行，但大花绣球在冬季还额外积累了葡萄糖和果糖，这表明碳水化合物代谢存在物种特异性差异。大花绣球和圆锥绣球的蛋白质谱不同，但两个物种均观察到与冬季驯化相关的明显季节性模式。在圆锥绣球中，木质部汁液脱落酸（ABA）浓度（ABA）和抗冻性同时增加，表明ABA参与了冷驯化。相比之下，根系中的ABA似乎未参与大花绣球的冷驯化，这表明抗寒能力的物种特异性差异可能与ABA的差异有关。在两个物种中，茎的抗冻性在生长停止很久之后才出现显著增加，这表明冷驯化更多地受温度而非光周期的调节。
