摘要
用０．５ ｍ ｍ ｏｌ／Ｌ ＫＣＮ 或０．０１ ｍ ｍ ｏｌ／Ｌ ＮａＮ３ 预处理继代培养２５ ｄ 的“甘肃黄花烟草”（Ｎｉｃｏｔｉａｎａ ｒｕｓｔｉｃａ Ｌ． ｃｖ． Ｇａｎｓｕ ｙｅｌｌｏｗ ｆｌｏｗ ｅｒ）愈伤组织对其呼吸作用有明显的影响。ＫＣＮ 和ＮａＮ３ 预处理１２ ｈ 可分别使愈伤组织的总呼吸速率下降１２％ 和１７％ ，细胞色素途径的实际运行量分别下降２２％ 和２８％ ；抗氰交替途径在最大容量（Ｖａｌｔ）基本不变的情况下，实际运行量（ρ·Ｖａｌｔ）不但未随总呼吸速率和细胞色素途径运行量的下降而降低，反而还略有上升。结果导致细胞色素途径对总呼吸的贡献下降而抗氰交替途径对总呼吸的贡献上升。ＫＣＮ 预处理２４ ｈ，细胞色素途径的实际运行量虽略有回升，但仍低于对照；ＮａＮ３ 预处理２４ ｈ 则使细胞色素途径运行继续下降而交替途径运行持续上升。上述结果表明，在继代培养的烟草愈伤组织中，当细胞色素主路途径被部分抑制后交替途径的电子流量明显加强。
The effects of KCN (0 5 mmol/L) and NaN 3 (0 01 mmol/L) pretreatment on the operation of the alternative pathway in subcultured tobacco (Nicotiana rustica L. cv. Gansu yellow flower) callus were analyzed. After treatment with KCN and NaN 3 for 12 h, the total respiration rate (V T) decreased by 12% and 17%, whereas oxygen consuption by the cytochrome pathway decreased by 22% and 28% respectively. The capacity of the alternative pathway (V alt ) remained constant, while the activity of the alternative pathway (ρ·V alt ) inreased slightly. This changing pattern led to a declined contribution of the cytochrome pathway to the total respiration rate and an increased activity of the alternative pathway. Treatment with KCN for 24 h brought about a slight rise of oxygen consumption by the cytochrome pathway as compared with that in callus treated for 12 h, but the oxygen consumption was still lower than that in the untreated callus. Treatment with NaN 3 for 24 h resulted in a profound decrease of the cytochrome pathway operation and a continuing increase of the alternative pathway operation. These data indicated that the enhanced operation of the alternative pathway played a compensatory role to the total respiration when the cytochrome pathway was partially inhibited in tobacco callus.
基金
高等学校博士学科点专项科研基金
关键词
烟草
抗氰呼吸
KCNC
预处理
NAN3
愈伤组织
Cyanide resistant respiration
Pretreatment with KCN
Pretreatment with NaN_3
Tobacco callus
