Distribution of Calcium and Boron in the Pectin Fraction of Tomato Leaf Cell Wall

Calcium was present in the pectin fraction of tomato leaf cell wall in association with pectin constituents and with a pectin-protein complex. Boron deficiency induced a decrease in the amount of Ca associated with pectin constituents. Most of the boron in the pectin fraction obtained by pectinase treatment was in a free form. These results suggest that boron plays an important role in Ca metabolism in the cell wall.