Relationship of Boron to Gibberellic Acid-Induced Proliferation in Debudded Tobacco Plants

Stem applications of gibberellic acid (GA) to debudded tobacco plants ( Nicotiona tabacum L., var. One Sucker) produce stem swellings that involve intense proliferation of, primarily, xylem tissue. Withholding boron from GA-treated debudded plants greatly reduces the GA-induced proliferation. This response offers a system for directly demonstrating the effect of boron on xylem formation and lignification that is unconfounded by the effect of boron on elongation growth.