Distribution of Boron in Cells of Dicotyledonous Plants in Relation to Growth.

Boron determinations were made on intracellular fractions separated by differential centrifugation. Mitochondria and microsomes were found to be lower in boron than nuclei, plastids and dialyzed supernatant fractions. The boron content of the nondialyzable supernatant fraction does not change in response to decreasing amounts of available boron accompanied by the appearance of boron deficiency symptoms. The boron content of the dialyzable portion of the supernatant fraction, however, declines when supplies of available boron decline and it finally reaches zero in this fraction when plants exhibit pronounced boron deficiency symptoms. (auth)