Abstract
Plants have developed many strategies, such as secretion of acid phosphatase (APase) and organic acids, to utilize unavailable P under P-deficient conditions. Part of the plants, such as lupin and Hakea, can develop unique roots so-called cluster roots under P-deficiency to elevate secretion abilities, however, information on the distribution of APase within tissues was missing. This study aimed to understand the role of APase and cluster roots by histochemical staining of APase in roots.
Cluster roots and normal roots of lupin were sliced and stained APase activities using ELF97-phosphate as a substrate. APase activity was observed whole root tissues, especially in epidermal tissues and root tips of cluster roots under P-deficient conditions. APase activities of Hakea were also observed in root tips and epidermal cells. These results suggest that cluster roots are efficient morphologies to utilize unavailable P by APase and they play important role under P-deficient conditions.
