摘要
玉米(Zea mays L.)根相对伸长速率(RER)、质膜H^+分泌速率和Fe(CN)_6^(3-)还原速率均随NaCl浓度的增加而下降。随着胁迫时间的延长,H^+分泌速率又有不同程度恢复,Fe(CN)_6^(3-)还原速率则随胁迫时间的延长而下降。NaCl胁迫时间在12h前,随着NaCl浓度的增加NADH的氧化速率也增加,超过12h明显下降。在同一NaCl浓度下,NADH氧化速率随胁迫时间的延长而下降。统计结果表明,盐胁迫下BER与H^+分泌速率的相关系数为0.9998。所以,盐胁迫对根伸长生长的抑制可能与质膜H^+-ATPase和氧化还原系统等H^+分泌过程的抑制有关。
Four-day-old corn ( Zea mays L.) seedlings, which had grown in aerated 0.5× Hoagland solution (pH 5.7) in dark were stressed by 50, 100 and 150 nunol/L NaCl solution for 6, 12 and 24 h respectively. The root segments (0 to 20 mm from the tip) were sampled for study. The results showed that the relative elongation rate (RER), H+ -extrusion rate and Fe(CN)63- reduction rate of the roots declined with the increase of NaCl concentration, but H+ -extrusion rate restored somewhat with the time course. NADH oxidation rate increased up to 12 h with the increase of NaCl concentration and then decreased significantly, while under the same concentration of NaCl NADH oxidation rate decreased with the time course. The relative coeffecient (r) of RER and H+ -extrusion rate under NaCl stress was 0.999 8. Therefore, it is suggested that the inhibition of the elongation growth by NaCl stress is closely related to the inhibition of redox system and H+ -ATPase activity of plasma membrane.
基金
山东省自然科学基金
