藻状菌游动孢子梗对氧气部分耗尽的生长速度适应。

Growth-rate adaptation of Phycomyces sporangiophores to partial depletion of oxygen.

机构信息

Abteilung Trautner, Max Planck Institut für Molekulare Genetik, Ihnestraße 63-73, D-1000, Berlin-West 33, Germany.

出版信息

Planta. 1984 May;161(2):137-41. doi: 10.1007/BF00395473.

Abstract

The growth rate of Phycomyces blakesleeanus sporangiophores was found to be very sensitive to sudden changes in the oxygen concentration. A change from 20% to 15% oxygen elicits a transient decrease in the growth rate which returns to normal 10 min after altering the concentration. After a step change to 10% oxygen, the growth rate shows two minima at 6-8 and 30-35 min and it reaches about 80% of its original value 50 min after this change. A threshold curve for this negative growth response shows that sporangiophores begin to sense a decrease in the oxygen concentration from 20% to 17%. Seven phototropically abnormal mutants with defects in the genes madA to madG were tested for the oxygen response. Two strains, C149madD120 and C316madF48, were found to have recoveries different from those of the wild type after step changes from 20% to 10% oxygen.

摘要

研究发现，水玉霉游动孢子梗的生长速率对氧气浓度的突然变化非常敏感。从 20%氧气变化到 15%氧气，会引起生长速率的短暂下降，在改变浓度 10 分钟后恢复正常。在氧浓度骤降至 10%后，生长速率在 6-8 和 30-35 分钟出现两个最小值，在这种变化后 50 分钟，生长速率达到其原始值的约 80%。该负生长反应的阈值曲线表明，游动孢子梗开始从 20%氧气中感知到氧气浓度的下降。对 madA 到 madG 基因有缺陷的 7 个光形态异常突变体进行了氧气响应测试。发现两种菌株 C149madD120 和 C316madF48 在从 20%氧骤降至 10%氧后，其恢复情况与野生型不同。