中文摘要：

以‘辽园多丽’番茄幼苗为试材，采用营养液栽培模式，以夜温15℃为对照，对夜间低温（6℃）影响番茄幼苗磷素吸收及转运过程的因素进行研究。结果显示：（1）夜间低温胁迫导致番茄幼苗根系活力受到显著抑制。（2）夜间低温条件下，番茄幼苗根系中酸性磷酸酶活性无明显变化，而其地上部酸性磷酸酶活性增强，且以叶片中活性增加较大。（3）夜间低温胁迫使根系中磷酸盐转运蛋白基因LePT1和LePT2的相对表达量较对照增加，地上部磷酸盐转运蛋白基因LePT1的表达受到抑制，且叶片中受到的抑制作用更显著。（4）夜间低温胁迫处理营养液中剩余磷素含量始终多于对照；其番茄幼苗地下部和地上部中磷素绝对含量均下降，且叶片比茎的下降幅度更大。（5）夜间低温胁迫使番茄幼苗伤流强度下降，伤流液中磷素含量随着处理天数的增加而增加，在处理第9天时极显著高于对照。研究表明，夜间低温导致番茄幼苗根系活力降低，诱导植株中磷酸盐转运蛋白基因LePT1的表达下调以及伤流强度降低，从而引起磷素由茎向叶片中的转运过程受到明显抑制。

英文摘要：

With Tomato ‘Liaoyuan Duoli’ as the materials of this experiment, using the mode of nutrient solution cultivation, the compared seedlings was cultivated as normal temperature as 15 ℃ of nighttime, set the temperature of nighttime as low as 6 ℃ to cultivate seedlings, we analyzed the factors affecting the absorption and transport processes of phosphorus of tomato seedlings in low night temperature. Results showed that： （1） the root activity of tomato seedlings was significantly inhibited by low temperature stress at night; （2） Under the condition of low temperature, there is no apparent change in the activity of acid phosphatase in the root of tomato seedlings, but the activity of acid phosphatase has strengthened in the aboveground parts and the activity of leaves increased significantly; （3） The relative expression of tomato phosphate transporter gene LEPT1 and LEPT2 increased in the roots by low temperature at night, LEPT1 phosphate transporter gene expression is suppressed in the aboveground, which is more apparent in leaves; （4） The P residue is higher than that in the control under treatment of low temperature stress at night; the concentration of phosphorus in the parts of seedling either underground or aboveground decreased, Such decline in the leaves is higher than that of the stems; （5） The bleeding intensity of tomato seedling decreased; P concentration in the bleeding sap increased with experiment period and significantly higher than that of control in the 9th day. These results showed that the root activity of tomato seedlings significantly decreased by low temperature at night; the low temperature made phosphate transporter gene LePT1 expression and the intensity of the bleeding sap decreased, which caused the transport of phosphorus from the stem to the leaf was inhibited.