Boron mobility in two coniferous species

In contrast to earlier beliefs, it is now known that baron (B) can be retranslocated complexed with sugar alcohols in some plant species. Conifers had been thought not to translocate sugar alcohols in the phloem. However, 1 d after applying B-10 enriched boric acid to shoots of Scots pine and Norway spruce seedlings, we found increases in both the amount and proportion of B-10 in the root systems in both species. We conclude that B is translocated in the phloem from shoots to roots in spruce and pine, and therefore it is possible that these species retranslocate B. (C) 2000 Annals of Botany Company.