Effects of excess concentrations of boron on major cell wall components of tobacco cells(Nicotiana tabacum L. cv. Burley 21) were studied. Pectin, xyloglucan, hydroxyproline-richglycoproteins (extensin), and arabinogalactan proteins were characterized. Results showedthat increased boron supply resulted in significant decrease in cell and cell wall dry weights.Also, high concentrations of boron ...