Physiology and Biochemistry Department, Experiment Station, Hawaiian Sugar Planters' Association, Honolulu, Hawaii 96822.
Plant Physiol. 1970 Sep;46(3):419-22. doi: 10.1104/pp.46.3.419.
Withholding nitrogen decreased the percentages of nitrogen and chlorophyll in the blades; reduced the total fixation of radioactive carbon dioxide at 15, 37, and 178 seconds; and changed the relative composition of fixation products. Translocation of radioactive photosynthate from the fed part down the attached blade and into the stalk was less in the plants deprived of nitrogen than in the control plants supplied with nitrogen. Both the percentage of total activity translocated and the velocity of transport were decreased by nitrogen deficiency. During a translocation period of 90 minutes the minus nitrogen blade retained more (14)C-sucrose than the control in the fed part and the blade below the fed part, but it sent less (14)C-sucrose to the sheath of the fed leaf. Thus translocation decreased with nitrogen deficiency not for lack of sucrose but for some other reason. Although withholding nitrogen decreased translocation of labeled carbon in and from attached blades, there was no effect upon transport in detached blades. The effect of nitrogen deficiency upon translocation may be indirect and secondary to the effect upon growth of the plant as a whole.
氮的截留降低了叶片中的氮和叶绿素的百分比；减少了在 15、37 和 178 秒时放射性二氧化碳的总固定量；并改变了固定产物的相对组成。与供应氮的对照植物相比，从供食部分向下延伸到附着叶片并进入茎中的放射性光合作用产物的易位在缺乏氮的植物中较少。氮缺乏会降低放射性物质的总活性转移百分比和运输速度。在 90 分钟的易位期间，缺氮叶片在供食部分和供食叶片以下的部分保留的 14C-蔗糖比对照叶片多，但它向供食叶片叶鞘输送的 14C-蔗糖较少。因此，易位减少不是因为缺乏蔗糖，而是由于其他原因。尽管氮的截留减少了附着叶片中标记碳的易位，但对离体叶片的运输没有影响。氮缺乏对易位的影响可能是间接的，是对整个植物生长的影响的结果。
