Jp. Albano et Wb. Miller, IRON-DEFICIENCY STRESS INFLUENCES PHYSIOLOGY OF IRON ACQUISITION IN MARIGOLD (TAGETES-ERECTA L), Journal of the American Society for Horticultural Science, 121(3), 1996, pp. 438-441
Excised roots of 'First Lady' marigold (Tagetes erecta L.) grown in an
aerated 0 Fe nutrient solution hall Fe(III)DTPA reductase activity 14
-fold greater, and an enhanced ability to acidify the rhizosphere than
plants grown in a solution containing 0.018 mM (1 ppm) Fe-DTPA. Reduc
tase activity and rhizosphere acidification of plants grown in 0.018 a
nd 0.09 mM Fe-DTPA were similar. Manganese concentration in leaves of
plants grown in the 0 Fe treatment was 2-fold greater than in leaves o
f plants grown in the 0.018 mM Fe-DTPA treatment. These results indica
ted that 'First Lady' marigold is an Fe-efficient plant that possesses
both an inducible or adaptive reductase system and the ability to aci
dify the rhizosphere, and that these Fe-efficiency reactions do not oc
cur when Fe is sufficient. Chemical name used: ferric diethylenetriami
nepentaacetic acid, monosodium salt (Fe-DTPA).