Boron Mobility in Two Coniferous Species

In contrast to earlier beliefs, it is now known that boron (B)can be retranslocated complexed with sugar alcohols in someplant species. Conifers had been thought not to translocatesugar alcohols in the phloem. However, 1 d after applying¹⁰Benriched boric acid to shoots of Scots pine and Norway spruceseedlings, we found increases in both the amount and proportionof¹⁰B in the root systems in both species. We conclude thatB is translocated in the phloem from shoots to roots in spruceand pine, and therefore it is possible that these species retranslocateB. Copyright 2000 Annals of Botany Company Scots pine, Pinus sylvestris, Norway spruce, Picea abies, conifers, boron retranslocation, roots, stable isotopes, sugar alcohols, boron complexes, mineral nutrition, forest trees