Glaubitz Ulrike, Li Xia, K Hl Karin I, van Dongen Joost T, Hincha Dirk K, Zuther Ellen
Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, D-14476 Potsdam, Germany.
Funct Plant Biol. 2014 Apr;41(4):437-448. doi: 10.1071/FP13132.
Global climate change is leading to asymmetric atmospheric warming with reduced temperature differences between day and night. This has an increasing influence on crop plants. However, little is known about the physiology of high night temperature (HNT) effects and natural variation in HNT susceptibility. Twelve rice cultivars were investigated under HNT (30°C day/28°C night) and control (28°C day/21°C night) conditions. Chlorosis was observed under HNT and used to classify relative sensitivity of cultivars. The resulting mean sensitivity rank correlated significantly with seed yield under HNT (r=-0.547). Wide variability in HNT tolerance led to an increase in shoot FW and DW in tolerant, but decreased plant growth in sensitive cultivars. Growth parameters correlated negatively with HNT sensitivity. Respiration rate was significantly increased under HNT at the end of night for several cultivars 34 DAS and 41 DAS and for all cultivars 66 DAS whereas photosynthetic quantum yield was not influenced. Negative correlations of sensitivity rank with respiration rate at two time points under HNT (r=-0.305; r=-0.265) exclude higher respiration rates in sensitive cultivars as a primary cause for HNT sensitivity. Monosaccharide and starch concentrations of leaves were increased after 16 days of HNT, while sucrose was not affected. Additionally tolerant cultivars showed a higher increase of monosaccharide concentrations during the day under HNT compared with control conditions. While HNT did not lead to carbon depletion in rice leaves, tolerant cultivars coped better with HNT, enabling them to accumulate more carbohydrates than sensitive cultivars with leaves affected by chlorosis.
全球气候变化正导致大气不对称变暖，昼夜温差减小。这对农作物的影响日益增大。然而，关于高夜温（HNT）效应的生理学以及HNT敏感性的自然变异，我们所知甚少。在HNT（白天30°C/夜间28°C）和对照（白天28°C/夜间21°C）条件下对12个水稻品种进行了研究。在HNT条件下观察到了叶片黄化现象，并据此对品种的相对敏感性进行分类。所得的平均敏感性排名与HNT条件下的种子产量显著相关（r = -0.547）。HNT耐受性的广泛变异导致耐受性品种的地上部鲜重和干重增加，但敏感性品种的植株生长下降。生长参数与HNT敏感性呈负相关。在34日龄和41日龄时，几个品种在夜间结束时HNT条件下呼吸速率显著增加，在66日龄时所有品种呼吸速率均显著增加，而光合量子产量未受影响。在HNT条件下两个时间点敏感性排名与呼吸速率呈负相关（r = -0.305；r = -0.265），排除了敏感性品种较高的呼吸速率是HNT敏感性的主要原因。HNT处理16天后，叶片中单糖和淀粉浓度增加，而蔗糖不受影响。此外，与对照条件相比，耐受性品种在HNT条件下白天单糖浓度的增加幅度更大。虽然HNT并未导致水稻叶片碳亏缺，但耐受性品种能更好地应对HNT，使其比受黄化影响的敏感性品种积累更多的碳水化合物。
