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Salt‐induced inhibition of phosphate uptake in plants of cotton ( Gossypium hirsutum L.)
Author(s) -
MARTINEZ V.,
LÄUCHLI A.
Publication year - 1994
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.1469-8137.1994.tb02955.x
Subject(s) - salinity , shoot , phosphate , gossypium hirsutum , salt (chemistry) , chemistry , gossypium , malvaceae , botany , horticulture , biology , biochemistry , ecology
SUMMARY Radio‐labelled phosphate ( 32 P) was used to study the effect of 150 mM NaCl on P 1 uptake and P distribution in the roots of cotton plants (Gossypium hirsutum L. cv Alcala SJ‐2), Salinity inhibited P, uptake more severely at low P 1 concentration (30μM) than at high P, concentration (1 niM). Data of 32 P 1 uptake at low P 1 concentration μM range) in the nutrient solution showed a typical Michaelis‐Menten hyperbolic curve (uptake rate VS max concentration). NaCl increased the apparent K m (from 2.23 to 4.73 μM and decreased the apparent V max (from 1.18 to 0.87 μmol g −1 f. wt h −1 ). High NaCl inhibited P, uptake in the mature root zone. However, salinity enhanced P, uptake in the root tips. We speculate that salinity may induce alkalinization of the cytoplasm in root tips cells, increasing the transmembrane pH gradient and therefore P, uptake. Our results showed an inhibition of 32 P transport within the roots and from the roots to the shoots m the salt treatment.