不同盐处理对玉米幼苗根系质子分泌及细胞膜透性的影响

以玉米品种郑单958为实验材料,分别用100 mmol/L NaCl、100 mmol/L KCl和50 mmol/L Na2CO3处理其幼苗3 d,研究不同盐类对玉米根系质子分泌和细胞膜透性的影响.结果表明:不同盐处理都显著抑制玉米幼苗根系的生长,抑制程度依次为Na2CO3>KCl>NaCl;不同盐处理均使玉米幼苗根系Na 含量显著增加,NaCl和Na2CO3处理显著降低根系K 含量而导致其Na /K 升高,但KCl处理却显著提高根系K 含量使其Na /K 降低;不同盐处理均能显著增加细胞膜透性而降低根系质子分泌能力,影响程度依次为Na2CO3>KCl>NaCl.研究发现,相同阳离子浓度条件下,KCl处理对玉米根系质子分泌的抑制作用强于NaCl,碱性盐的抑制作用大于中性盐;盐胁迫可能通过改变玉米幼苗根系质膜的稳定性来影响质子分泌,从而抑制根系生长.

Effects of Different Salt Treatments on the Root Proton Extrusion and Membrane Permeability of Zea mays Seedlings

The effects of different salt stress on the root proton extrusion and membrane permeability of Zea mays(cv.Zhengdan No.958) seedlings treated with 100 mmol/L NaCl,100 mmol/L KCl and 50 mmol/L Na2CO3 for 3 d were examined.The results indicated that different salt treatments significantly inhibited Zea mays roots growth,and the inhibitory degree was Na2CO3>KCl>NaCl.The treatments of NaCl and Na2CO3 markedly reduced root K content and increased Na content,leading to a significant increase of the ratio of Na /K .However,KCl treatment just resulted in an opposite trend.Different salt treatments significantly enhanced the plasma membrane permeability and inhibited the proton extrusion ability of the Z.mays roots,and the influence degree was Na2CO3>KCl>NaCl.These results suggest that:under the same cation concentration condition,the inhibitory effect of KCl on the roots proton extrusion was much more than that of NaCl treatment,and alkaline salt more than neutral salt.Salt tress possibly regulates the proton extrusion of Z.mays roots by altering the stability of plasma membrane,leading to the growth inhibition of the roots.