The increasement of the operation (ρValt) and the capacity of the alternative pathway (Valt) in tobacco (Nicotiana rustica L. cv. Gansu Yellow Flower) callus that treated by low temperature (4 ℃) were observed. The two electron transport pathways were changed alternatively, the cyanide-resistant respiration was the main respiratory pathway from the 2nd day to the 5th day, while the cytochrome pathway was the main pathway consistently in control callus. Cycloheximide and chloramphenicol treatment which inhibited protein synthesis resulted in dramatic and partly inhibition of Valt induced by low temperature respectively. This further proved above result that low temperature induced Valt. The same result was found when two inhibitors were used together. The analysis of heat production of callus indicated that the operation of the alternative pathway could be regulated to improve the micro-environmental temperature of tobacco callus to adapt to low temperature. The possible participation of the alternative pathway in the response to low temperature and its physiological roles were discussed.
低温胁迫下甘肃黄花烟草愈伤组织的抗氰呼吸
周功克1 李红玉2 文江祁2 孔英珍1 梁厚果2*
（1. 兰州大学干旱农业生态国家重点实验室，兰州730000；2. 兰州大学生命科学学院，兰州730000)
摘要：继代培养的Nｉｃｏｔｉｏｎｏ ｒｕｓｉｔｏａ Ｌ．ｃｖ．Ｇａｎｓｕ Ｙｅｌｌｏｗ Ｆｌｏｗｅｒ）愈伤组织经低温（４℃）处理后，交替途径容量９Ｖａｌｔ）和实际运行量（ρＶａｈ）均被显著地诱导，同时其电子传递途径也在发生交替变化。低温胁迫开始时以细胞色素途径为主，至第２天时则以交替途径为主，并一直持续到第５天，以后则又转为经细胞色素途径为主，而对照却始终以细胞色素途径为主。经放红菌酮或氯霉素处理后，受低温诱导的Valt分别被显著或部分抑制，进一步表明低温诱导了Valt。用两种抑制剂共同处理也得到相同的结论。愈伤组织产热分析表明，低温胁迫下愈伤组织可调节ρVakt以提高其微环境的温度来适应低温。讨论了抗氰呼吸参与低温反应的可能生理作用。
关键词： 低温；烟草；愈伤组织；抗氰呼吸；交替途径；产热
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