Premium
Citrate exudation from white lupin induced by phosphorus deficiency differs from that induced by aluminum
Author(s) -
Wang B. L.,
Shen J. B.,
Zhang W. H.,
Zhang F. S.,
Neumann G.
Publication year - 2007
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2007.02206.x
Subject(s) - phosphorus deficiency , lupinus , elongation , phosphorus , seedling , efflux , chemistry , biophysics , biology , botany , biochemistry , organic chemistry , materials science , ultimate tensile strength , metallurgy
Summary• Both phosphorus (P) deficiency and aluminum (Al) toxicity induce root exudation of carboxylates, but the relationship between these two effects is not fully understood. Here, carboxylate exudation induced by Al in Lupinus albus (white lupin) was characterized and compared with that induced by P deficiency. • Aluminum treatments were applied to whole root systems or selected root zones of plants with limited (1 µ m ) or sufficient (50 µ m ) P supply. • Aluminum stimulated citrate efflux after 1–2 h; this response was not mimicked by a similar trivalent cation, La 3+ . P deficiency triggered citrate release from mature cluster roots, whereas Al stimulated citrate exudation from the 5‐ to 10‐mm subapical root zones of lateral roots and from mature and senescent cluster roots. Al‐induced citrate exudation was inhibited by P limitation at the seedling stage, but was stimulated at later growth stages. Citrate exudation was sensitive to anion‐channel blockers. Al treatments did not affect primary root elongation, but inhibited the elongation of lateral roots. • The data demonstrate differential patterns of citrate exudation in L. albus , depending on root zone, developmental stage, P nutritional status and Al stress. These findings are discussed in terms of possible functions and underlying mechanisms.