缺磷胁迫对甘蔗悬浮细胞磷素吸收特性和相关酶活性的影响

Effects of Phosphorus-deficiency on Phosphorus Uptake of Suspension-culturedCells and Relative Enzyme Activities of Sugarcane (Saccharum officinarum)

在初始磷浓度为1.25 mmolL-1的MS培养基中,甘蔗悬浮细胞在继代后的1 d之内几乎将磷完全吸收。此后,细胞在数天内仍能继续生长。缺磷细胞对磷的吸收动力学参数Imax增加,Km减少。在培养过程中,缺磷细胞的无机磷含量变化不大,但随着培养时间的延长,细胞酸性磷酸酶活性逐渐升高,且在培养的第8 天,活性增加4倍。甘蔗悬浮细胞中不仅有植酸酶的存在,且在培养的第8 天,缺磷细胞植酸酶活性比不缺磷的增高2.5倍。

During the exponential growth phase, exposed to normal P conditions(KH2PO4 initial concentration1.25 mmolL-1) , cells were able to consume all of the phosphorus in MS medium within 1 d. And cells could stillcontinuously grow after that. In comparison with the normal cells, Imax was increased whereas Km was decreasedin 0 P treated cells, which indicated that both the rates and the affinity to P increased. Acid phosphatase (APase)and phytase activities were induced by P-deficiency. At 8 d after the treatment, APase and phytase activities inthe 0 P treated cells were 4 times and 2.5 times higher than the control, respectively.