Nitrate, Ammonium and Kinetin Effects on Growth and Enzyme Activities of Paul's Scarlet Rose Callus

Abstract

Factorial experiments using the three variables nitrate, ammonium, and kinetin at six different concentrations each (nitrate 4.64 to 215 mM; ammonium 2.15 to 100 mM; and kinetin 0.1 to 4.64 mg/1) were set up to measure the effects of each of these factors, and their interactions, on the fresh weight, protein, and enzyme activities of callus of Paul's Scarlet Rose. Optimum fresh weight values were obtained with nitrate at 46.4 mM. Ammonium inhibited growth at concentrations above 2.15 mM, and kinetin had no significant effect. Significant interaction between nitrate and ammonium effects on growth was found. Kinetin did not interact significantly with either nitrate or ammonium to influence the fresh weight. The specific activity of glutamate dehydrogenase (NAD) in the aminating reaction increased with increasing ammonium concentrations to 21.5; at higher concentrations the activity remained high. Giutamine synthetase specific activity was constant over a large range of nitrate and ammonium concentrations, increasing only when nitrate went from 46.4 to 100 mM. Giutamine synthetase was sensitive to the nitrate: ammonium interaction. Specific activity decreased at progressively higher ammonium levels when nitrate concentration increased. No glutamate synthase activity was detected at optimal nitrate concentrations.

Effect of carbon and nitrogen growth limitation upon nutrient uptake and metabolism in batch cultures of Catharanthus roseus (L) G. Don

“…The possibility that nitrate reductase activity and protein synthesis were regulated to some extent by the availability of carbon supply to N30 cultures is suggested by the fact that zero nitrate reductase and maximum protein/ml culture on day 12 coincided with the final depletion of medium monosaccharides. This result agrees with the observation that little change in the activity of glutamine synthetase in Paul's Scarlet Rose callus cultures could be induced by varying the medium nitrate level between 10-100 mM (Caldas and Caldas, 1976). The profiles of enzyme activity were almost identical in N5 and N30 cultures under the conditions used in this experiment,indicating that the regulation of glutamine synthetase was not dependent upon medium nitrate availability.…”

Nitrate assimilation in suspension cultures of Paul's scarlet rose

“…Cell cultures of several plants, including Paul's scarlet rose, have been shown to grow better with NO3-+ NH4+ than with NO3-alone (2,4,9,38). This was most pronounced when cells were grown in media possessing low concentrations of NO3-.…”

“…1A) Can. 3,4) showed that after day 3, NO3-+ NH4+ cultures achieved much higher NR activities than NO3-cultures. Downloaded from www.nrcresearchpress.com by Depository Services Program on 11/16/14 For personal use only.…”