Re-evaluation of characteristics of a carrot cell line previously selected as aluminum-tolerant cells

A carrot ( Daucus carota L. cv. MS Yonsun) cell line previously selected to be tolerant to Al supply was re-evaluated by culturing with hardly soluble or ionic Al. When insoluble Al-phosphate (2.0 m M ) was supplied as a sole source of phosphate at an initial pH of 5.6, the selected cell line, but not wild-type cells, grew normally corresponding to the growth of the cells supplied with Na-phosphate in the absence of Al Under these conditions, the selected cells excreted large amounts of citrate into the medium. Insoluble Fe-phosphate could also be utilized as a phosphate source by the selected cells. Excretion of citrate was, however, not detected when the cells were cultured in the absence of insoluble phosphate. The selected cells were less tolerant against soluble. Al ions than the wild-type cells.