烟草愈伤组织分化和芽原基形成期间呼吸代谢途径的改变

接种在继代培养基上的柳叶烟草愈伤组织,未观察到组织分化和芽原基形成。在分化培养基上生长的愈伤组织,接种后第6天可见拟分生组织和管胞分化,9—12天有芽原基形成,15—18天可观察到苗端结构。根据碘乙酸、Na_3PO_4和丙二酸抑制试验,以及3-磷酸甘油醛脱氢酶与琥珀酸脱氢酶活性测定结果,初步表明烟草愈伤组织呼吸中存在有EMP、HMP和TCAC代谢途径.在发生输导组织和芽原基分化的愈伤组织中(接种后第6—12天),HMP途径的运行程度较高;而芽原基的继续生长(培养12天以后),则与EMP途径的增加有关;分化培养基上生长的愈伤组织,始终较继代培养愈伤组织具有较高的FCAC活性水平。

CHANGES OF RESPIRATORY METABOLISM PATHWAY DURING THE TISSUE DIFFERENTIATION AND BUD FORMATION IN TOBACCO CALLUS CULTURES

The respiratory metabolism of plant andits relation to some physiological processeshad been extensively studied.However,thereare only few reports on the respiratorymetabolism of plant callus.In this paper,the callus cultures of Nicotiana tabacum (cv.Willow leaf) was used as experimental ma-terials and to elucidate the pathways of res-piratory metabolism and their changes duringtissue differentiation and organ formation oftobacco callus.The results were summarizedas following: Tissue differentiation and bud primordiaformation were not observed in the calluscultured on the subculture medium.However,a great deal of meristemoid and tracheid dif-ferentiation was occurred on the 6 th day inthe callus cultured on differentiation medium,from the 9 th to 12 th day bud primordiaformed and shoot apex structures could beobserved from the 15th to 18th day.Accor-ding to the results of inhibition experimentswith iodoacetic acid,Na_3PO_4 and the deter-mination of 3-phosphoglyceradehyde dehy-drogenase activity,it was shown that the EMPand HMP pathways were both participant in therespiration of tobacco callus.When bud primor-dia continued to grow and differentiate intoshoot apex structures,the more participationdegree of EMP pathway was observed thanthat of HMP.The results of inhibition exper-iment with malonate and the determinationof the succinic dehydrogenase activity indi-cated that the activity of TCAC in the calluscultures which showed tissue differentiationand bud primordia formation was much higherthan that of the subculture callus throughoutthe experiment period.