甘肃黄花烟草愈伤组织抗氰呼吸的研究

根据呼吸抑制剂试验和氧肟酸滴定法测定结果表明,甘肃黄花烟草愈伤组织呼吸中有明显的抗氰交替途径运行,平均占总呼吸的31%;但仍以细胞色素途径为主,平均占总呼吸的46%;还有23%不受 KCN 加 m-CLAM 抑制的未知剩余呼吸。改变培养基的激素成分和浓度,在不引起愈伤组织发生明显分化条件下,愈伤组织的生长和呼吸速率虽有不同,但抗氰交替途径和细胞色素途径对总呼吸的相对贡献程度和二者的变化趋势基本一致。

STUDIES ON THE CN-RESISTANT RESPIRATION IN CALLUS OF NICOTIANA RUSTICA,GANSU YELLOW FLOWER

In attempting to examine whether CN-resistant respiratory pathway is present in callus culture,we used tobacco callus cultures grown on different media.The M-1 medium contained the mineral and organic elements of MS medium and was sup- plemented with 6-BA (0.5 mg/l) and 2,4-D (2 mg/l),and M-2 medium with 6-BA (2mg/l) and IAA (1 mg/l).No differentiation was observed in both of them. The respiration of M-1 callus was partly resistant to CN,and was markedly inhi- bited by m-CLAM in the presence or absence of CN.Experiments of m-CLAM titra- tion showed that the averages of relative contribution of alternative and cytochroe pathway in M-1 callus were 31% anf 46% of the total respiration respectively during the culture period of 25 days. A same experiment was made on the M-2 callus.It was found that the percentages of relative contributions of the two eIectron transport pathways to the total respiration were approximately the same as those of the M-1,callus,although the respiratory rate was higher in M-2 callus. The above results showed that the bulk of respiratory electron flux was mediated by the cytochrome pathway,although the alternative pathway was operative in callus of tobacco.The change of exogenous hormones added in the medium could not produce significant effects on the degree of relative contribution of two electron transport pa- thways under non-differentiation conditions.