The Effects of Sulphur Dioxide on Phloem Transport in Two Cereals

Abstract
Gould, R. P., Minchin, P. E. H. and Young, P. C. 1988. The effects of sulphur dioxide on phloem transport in two cereals.—J. exp. BoL 39: 997–1007. In vivo investigations using 11C-labelled photosynthate revealed that there is a change in the patterns of tracer profiles when cereal leaves are exposed to SO2. The change after exposure to SO2 was interpreted in terms of a decrease in lateral water flow into the sieve tubes brought about by reduced phloem loading along the length of a leaf. Analysis also revealed that the speed of translocation was reduced, as expected by the Munch model of phloem transport.