| Abstract: | The effects of growth-inhibiting substances from young cotton bolls on phosphorylation in both intact cotton plant and tissue slices of young cotton bolls were determined using 32P as a tracer. The results showed that the incorporation of 32P into the various organic phosphates including high-energy phosphate compounds, were decreased in abscissing bolls to about 1/2 as that of developing bolls. Infiltration of the growth-inhibiting substances into normal boll tissue caused a marked increase in respiration intensity, the synthesis of high-energy phosphate compouds was, however, decreased to 39% of that of the control tissue. When 10 ppm NAA was applied tvabscissing young cotton bolls, the incorporation of 32P into various fractions of organic phosphates increased, although never to the level of developing bolls. The above results suggested that uncoupling of respiration and oxidative phosphorylation might be one of the important effects of the growth-inhibiting substances in inducing the abscission of cotton bolls. |
