ISOLATION, STABILITY AND BIOCHEMISTRY OF A P-FLUOROPHENYLALANINE-RESISTANT CELL LINE OF ACER PSEUDOPLATANUS L.

Cell lines resistant to growth inhibition by 10 μM DL-p-fiuorophenylalanine (PFP) have been isolated from a stock cell suspension culture line of Acer pseudoplatanus L. One of the lines (Xs) retained its resistance when serially subcultured in the absence of PFP. X[SUB8] could not be distinguished from the parent line in growth rate and biomass yield but in mixed cultures of the two lines, X8 cells progressively declined as a fraction of the cell population during serial subculture in the absence of PFP. The X[SUB8] line could be recovered from such mixed cultures by subculture to medium containing 10 μM PFP. Line X[SUB8] resembled the parent cell line in phenylalanine (PA) pool size and in showing no evidence of discrimination between PA and PFP in protein synthesis. It differed from the parent line in exhibiting lower uptake of PFP and PA; at an appropriate level PA almost completely suppressed PFP uptake. X[SUB8] cells had a higher content of phenols and higher extractable activity of phenylalanine ammonia lyase (PAL); they actively degraded absorbed PFP. The problem of isolation of biochemical mutants from plant cell cultures is discussed. [ABSTRACT FROM AUTHOR]