Me. Lenoble et al., PREVENTION OF ALUMINUM TOXICITY WITH SUPPLEMENTAL BORON .1. MAINTENANCE OF ROOT ELONGATION AND CELLULAR STRUCTURE, Plant, cell and environment, 19(10), 1996, pp. 1132-1142
Aluminium toxicity is an important factor limiting plant growth on aci
d soils. Symptoms of B deficiency and Al toxicity are very similar and
generally associated with impaired membrane function and root growth.
Thus the objective of this study was to determine whether supplementa
l B prevents Al inhibition of root growth and development. Squash (Cuc
urbita pepo L. cv. Sunbar) was grown in hydroponic nutrient media with
43 mmol m(-3) free Al and B concentrations extending from 5 to 100 mm
ol m(-3). Our results establish that B protects against Al inhibition
of root growth. Protection was apparent at all levels of organization
examined: primary root and lateral root lengths; primary root cell elo
ngation, cell production rate, tissue organization and cell structure;
primary root morphology and maturation. Protection against Al inhibit
ion was also apparent for shoot growth. These studies were undertaken
in solution culture to limit the variables examined; however, the unde
rlying motivation for this study is the problem of worldwide Al toxici
ty in soils. Therefore. the effect of adding additional B to a high-Al
soil was also investigated and is the subject of the companion paper
(Le Noble, Blevins &: Miles 1996, Plant, Cell and Environment 19, 1143
-1148).