镧对水稻根质膜透性和根分泌物中几种营养离子含量的影响

Effects of lanthanum on root membrane permeability and nutrient contents in root exudate of rice.

通过水培实验 ,研究了系列浓度La在不同处理时间内对水稻根质膜透性和根分泌物中几种营养离子含量的影响 .结果表明 ,La在低浓度时 (≤ 5 0 μg·ml-1) ,可以稳定细胞膜 ,减少电解质外渗率 .在此浓度下 ,根系分泌物中K+ 、Ca2 + 、P和H+ 的含量比对照低 .La的浓度升高 (10 0～ 4 0 0 μg·ml-1) ,随着处理时间的延长 ,电解质外渗率呈现短时间抑制 ,长时间促进的规律 .La在高浓度时 (c≥ 5 0 0 μg·ml-1) ,即使短时间的处理 ,也会使根细胞原生质膜破坏 ,电解质外渗率提高 .此时根分泌物中K+ 、Ca2 + 、P和H+ 含量均比对照高 .由此可以得出在水培条件下 ,La3 + ≤ 5 0

This study showed that when lanthanum was in lower concentration (≤50μg·ml -1),the membrane permeability of rice root was stabilized by decreasing the electrolyte exosmosis,and the contents of K +,Ca 2+,P and H + in root exudate were lower than the control;while the concentration of La 3+ was in the range of 100～400 μg·ml -1,the electrolyte exosmosis was reduced in the first 6 hours,and then significantly increased.When the concentration of La 3+ was over 500 μg·ml -1,the electrolyte exosmosis was continuously enlarged because of the destruction of the membrane. Under this condition,K +,Ca 2+,P and H + in root exudate were higher than the control.It could be concluded that the concentration of 50 μg·ml -1 La 3+ was safe to rice growing.