Microelectrodes were used for measurements of oxygen, ammonium, potassium and calcium concentrations within gonidial zones of Cycas revoluta coralloid roots. Gonidial zone segments contained an oxygen pressure of 85% with respect to its concentration in the atmosphere. Dissolved ammonium was detected in concentrations between × 10−3 M and 4 × 10−3 M. The highest ammonium concentration was in intermedial segments and it could cause the decrease of nitrogenase activity. Potassium concentration was in the range 5.5–9 × 10−3 M; calcium concentration was 10−6 M in apical and subapical segments, it reached 1–2 × 10−5 M in the intermedial and basal segments. Calcium concentrations could affect heterocyst differentiation, nitrogen fixation and mucilage composition of coralloid roots.
Canini, A., Grilli Caiola, M. (1993). Characterization of gonidial zone of Cycas revoluta coralloid roots by means of microelectrodes. FEMS MICROBIOLOGY LETTERS, 109, 75-80 [10.1111/j.1574-6968.1993.tb06146.x].
Characterization of gonidial zone of Cycas revoluta coralloid roots by means of microelectrodes
CANINI, ANTONELLA;
1993-01-01
Abstract
Microelectrodes were used for measurements of oxygen, ammonium, potassium and calcium concentrations within gonidial zones of Cycas revoluta coralloid roots. Gonidial zone segments contained an oxygen pressure of 85% with respect to its concentration in the atmosphere. Dissolved ammonium was detected in concentrations between × 10−3 M and 4 × 10−3 M. The highest ammonium concentration was in intermedial segments and it could cause the decrease of nitrogenase activity. Potassium concentration was in the range 5.5–9 × 10−3 M; calcium concentration was 10−6 M in apical and subapical segments, it reached 1–2 × 10−5 M in the intermedial and basal segments. Calcium concentrations could affect heterocyst differentiation, nitrogen fixation and mucilage composition of coralloid roots.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
