N. Tominaga et al., EFFECTS OF NACL AND KNO(3) CONCENTRATIONS ON THE ABSCISIC-ACID CONTENT OF DUNALIELLA SP (CHLOROPHYTA), Hydrobiologia, 267(1-3), 1993, pp. 163-168
Abscisic acid (ABA) is a hormone which has a number of roles during th
e life cycle of a plant. We demonstrated the occurrence of ABA in a ha
lotolerant green alga, Dunaliella sp. isolated from a salt pond near A
delaide, South Australia, using thin layer chromatography (TLC), high
performance liquid chromatography (HPLC) and gas chromatography-mass s
pectrometry (GC-MS). The variation of cellular ABA and protein content
during the growth of an axenic clonal culture of Dunaliella sp. was i
nvestigated under different concentrations of NaCl and KNO3. Experimen
tal results can be summarized as follow: (1) ABA content was changed w
ith the growth stage of culture: A rapid increase in ABA content was o
bserved in the logarithmic phase. After this, the content rapidly decr
eased to very low values. (2) ABA content was also affected by the NaC
l concentration. The content had a minimum value at the NaCl concentra
tion (15%) where growth rate was maximal, and higher values at higher
or lower concentrations of NaCl. (3) The ABA content also increased wi
th decreasing nitrogen concentration of the medium.