铜镉复合胁迫下温度对小麦幼苗生长及其对铜、镉和矿质营养元素吸收与各元素在亚细胞分布的影响

为了研究重金属复合胁迫下温度变化对陆生植物的毒性效应的影响,实验采用水培的方法,设置对照和Cu-Cd复合胁迫(10 μmol·L1 Cu+10μmol·L-1Cd)2个处理,每个处理分别设置3个不同的培养温度(8/4℃、25/20℃和35/30℃),对小麦进行48 h的暴露实验,测定小麦幼苗的生长及其对重金属和矿质营养...

Uptake, Subcellular Distributions of Cu, Cd and Mineral Elements, and Plant Growth for Wheat Seedlings under Stress of Cu and Cd as affected by Temperature

To study the effect of temperature on the ecotoxic response of terrestrial plants under combined stress of copper and cadmium,wheat seedlings were exposed to the combined stress of copper and cadmium(10 mol·L-1 Cu+10 mol·L-1 Cd) under three different temperatures(8/4 ℃,25/20 ℃ and 35/30 ℃)for 48 h using hydroponic methods.The indicators of wheat seedlings growth and the uptake and subcellular distribution of heavy metals and mineral elements were measured.The results indicated that the combined treatment of Cu and Cd at different temperatures did not inhibit the growth of wheat seedlings.However,temperature significantly influenced the uptake and subcellular distributions of Cu and Cd in wheat seedlings.It appeared that the contents of Cu and Cd in wheat seedlings increased with temperature elevation,and the distribution of Cu and Cd increased in soluble fraction but decreased in cell wall fraction in wheat seedling roots with temperature elevation.Both temperature treatment and combined stress of Cu and Cd could exert significant effect on the uptake of mineral elements by wheat seedlings.The uptake of micro-mineral elements(Fe,Mn and Zn) by wheat seedlings was more significantly affected by temperature than the uptake of macro-mineral elements(K,Ca and Zn).The interaction of temperature and combined stress of Cu and Cd was strong,especially on the uptake of micro-mineral elements by wheat seedling roots.Furthermore,the subcellular distributions of Fe,Mn and Zn in wheat seedling roots were significantly affected by the combined stress of Cu and Cd,as well as temperature.In general,with temperature elevation,the distributions of Fe,Mn and Zn in soluble fractions increased,while the distributions in cell wall significantly decreased.Thus,it is indicated that temperature as an important environmental factor can obviously influence the ecotoxic response of wheat seedlings under combined stress of heavy metals.