【摘要】 本试验对于不同基质与抑制剂对白兰瓜果实蔗糖合成与呼吸强度的影响进行了测定,对不同发育时期果实中有机磷化物含量及高能磷化物生成速率也进行了观察。果实切片当渗入无机磷酸盐与ATP以后,分别使蔗糖合成与呼吸作用有不同程度的提高,提高的程度ATP大于无机磷酸盐。发育后期的果实对上述处理的反应远远超过前期的果实。当渗入KCN之后,则使果实的蔗糖合成与呼吸作用受到不同程度的抑制作用,但前期果实的抑制程度远此后期为高。后期果实的有机磷化物含量及高能磷化物生成的速率都比前期为高。上述结果证明磷酸化作用在前期与后期果实中对蔗糖合成作用都有密切关系。但是前期果实蔗糖合成能力较低的主要原因还不是由于磷酸化作用的限制,很可能植物体内的代谢机制的发展是随着发育时期而改变的,在发育前期果实中所建立的机制可以使能量与代谢物质的利用导向与生长有关的代谢轨道中去,在发育后期则又使它们转入到与蔗糖合成及累积有关的代谢轨道。更多还原

【Abstract】 The effects of respiratory inhibitors and various substrates on the biosynthesis of sucrose and the respiratory activity of Bai-Lan melon fruits were investigated.The content of organic phosphate and the rate of high-energy phosphate formation were also determined at different stages of fruit development. After infiltrating the fruit slices with inorganic phosphate and adenosine triphosphate, the rate of sucrose synthesis and the respiratory activity were increased to different extents, the effectiveness of ATP in increasing sucrose synthesis and respiration was higher than inorganic phosphate.Fruits at later stage of development showed a greater response to the above treatments than those at early stage.When KCN was added to the substrates,synthesis of sucrose and the intensity of respiration were reduced,but the fruits at early stage were more susceptible to it than those at later stage. The content of organic phosphates and the rate of high-energy phosphate formation were higher in fruits at later stage than those at early stage. The above results show that phosphorylation is closely connected with the synthesis of sucrose in fruits at both stages of development.The low rate of phosphorylation is, however,not the principal factor responsible for the lower capacity of sucrose synthesis in fruits at early stage.It is very possible that the metabolic mechanism is different at different stages of development and it is this mechanism which allows the energy and metabolites to be flowed into canals of growth and associated processes in fruits at early stage,and to be switched to canals of sucrose synthesis and related processes at later stage of fruit development.The implications of this suggestion is briefly discussed.更多还原