Some observations on the role of ATP in sieve tube translocation

✍ Scribed by D. C. J. Gardner; A. J. Peel

• Publisher: Springer-Verlag
• Year: 1972
• Tongue: English
• Weight: 662 KB
• Volume: 107
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00397937

✦ Synopsis

Using the aphid stylet technique 14C ATP was shown to be readily taken up into the sieve elements of willow. At the same time this compound was found to be metabolised during uptake resulting in labelled ADP and AMP appearing in the styler exudate. Longitudinal movement of labelled ATP was also found to occur.

Measurement of the levels of ATP and ADP in styler exudate showed that both were present in high concentrations. The ratio ATP/ADP varied between 2.0 and 5.3.

The effect of certain inhibitors of oxidative phosphorylation (oligomyein and DNP) and glycolysis (fluoride) on the rate of styler exudation was studied. All three inhibitors caused a cessation of exudation but this did not occur until several hours after inhibitor application. Oligomycin and DNP had no effect on the concentration of ATP in the sap. Fluoride however, appeared in some cases to reduce the ATP concentration to a low level an hour or more before exudation finally stopped.

Incorporation of 32pi into organic phosphate esters present in styler exudate was found to occur within 15 minutes of the application of the tracer to a bark strip. Labelling of organic phosphates also took place, at a slower rate, when 82p inorganic phosphate was incubated with styler exudate.