温度对雌雄葎草生理代谢及保护酶系统影响的性别差异

以雌雄异株攀援草本植物葎草为材料,依据野生资源主要分布地域的平均温度,设置3个温度(15,20,25℃)为变量,通过测定光合指标、代谢指标、抗氧化酶活性指标和细胞膜完整性指标,分析温度对葎草光合作用、呼吸作用及抗逆性影响的生理变化,研究温度对雌雄葎草生理代谢及保护酶系统影响的性别差异。结果表明,温度显著影响葎草叶中的叶绿素含量,Pn和单株生物量随温度下降显著减小(P0.05),♀株的潜在P_n显著大于♂株(P0.05);♂株的糖代谢和呼吸作用显著高于♀株(P0.05),氮代谢性别间无显著差异(P0.05),温度对可溶性糖(SS)、丙酮酸(PA)含量和硝酸还原酶(NR)有显著影响(P0.05),随温度下降SS含量逐步增加(P0.05),NR活性逐步降低(P0.05),温度对代谢速率影响远大于性别间的差异。温度对SOD和POD活性有极显著影响(P0.01),对CAT活性有显著影响(P0.05),随温度降低3种酶活性均不断增加,♀株中SOD和POD含量显著高于♂株(P0.05),性别间CAT含量无差异。温度对细胞膜完整性物质含量的影响,远大于性别间差异,随温度降低葎草体内H_2O_2、丙二醛(MDA)、脯氨酸(Pro)和可溶性蛋白(SP)含量均显著增加,♂株中H_2O_2和SP含量显著高于♀株(P0.05),♀株中MDA和Pro含量显著大于♂株。温度对光合作用、呼吸作用、抗氧化酶系统及细胞膜完整性的影响有显著的性别差异,♀株比♂株有更强的适应温度胁迫的生理基础。

Gender differences in physiology and enzyme activity in response to temperature in Humulus scandens

The purpose of the study was to explore gender differences in physiology and protective enzyme activity of dioecious plant species at different temperatures.Seed of the dioecious climbing herb Humulus scandens were planted in pots;at the 1-2 true leaf stage seedlings were moved to an incubator with three temperature settings (15,20,25 ℃) based on the mean temperature of the area of seed provenance origin.Photosynthesis,metabolism,antioxidant enzyme activity and cell membrane integrity were measured.The effect of temperature on photosynthesis,respiration and resistance of H.scandens to temperature was determined.Temperature significantly affected leaf chlorophyll content,light-saturated photosynthetic rate (Pn) and biomass which significantly decreased with decreasing temperature.The Pn of female plants was always significantly higher than that of males (P＜0.05).Soluble sugar (SS) and pyruvic acid (PA) contents and nitrate reductase activity (NRA) were also affected by temperature change (P＜0.05);SS content was lower but NRA higher with decreasing temperature.Sugar metabolism and respiration rate of males was significantly higher than females (P＜0.05),while nitrogen metabolism was not influenced by gender.Temperature affected metabolism more than gender.Temperature significant affected superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT) (P＜0.05) activity which increased with decreasing temperature;SOD and POD activity in females plants were significant higher than those of males (P＜0.05) but CAT activity was not influenced by gender.The effect of temperature on cell membrane traits was greater than that of gender.H2O2,malondialdehyde (MDA),proline (Pro) and soluble protein (SP) content also increased significantly with decreasing temperature.Higher H2O2 and SP but lower MDA and Pro were observed in male compared to female plants.Our results indicated that gender differences in photosynthesis,respiration,antioxidant enzyme system and cell membrane integrity response to low temperature were of less importance than differences due to temperature.