Seedlings of Ravuolfia tetraphylla L. were grown, transplanted and acclimatized for 60 days at different altitudes gradient (250, 400 and 1600 m) in Yercaud, Salem, Tamil Nadu, India. Response to shift in altitude was observed in the test plants. Shoot length decreased with the increase in the altitude, while increase in the root length was directly proportional to the increase in the altitudinal gradient. Biomass accumulation in roots of R. tetraphylla recorded the maximum at high altitude at the same time shoot biomass was maximum at an intermediate height (400m), thereafter reduction in biomass was observed with the increase in the altitude. Total soluble protein content was significantly high at low altitude in the shoot while it followed a reverse trend in the roots. Likewise, free tissue ammonia level in this species showed positive correlation with increase in the altitude. Ammonium assimilatory enzymes viz., glutamine synthetase (GS), glutamate synthase (GOGAT) and glutamate dehydrogenase (GDH) were analyzed. GS/ GOGAT activity and specific activity were altitude sensitive, whereas GDH activity exhibited inverse trend. A positive shift in ammonium assimilatory pathway in test plants growing at high altitude was observed in R. tetraphylla.
Rajasekaran, C.; Kalaivani, T.; Jayakumararaj, R.; Singh, Abhijeet; Pusalkar, V. R.; and Marimuthu, R.
"Impact of Altitudinal Gradient on Ammonium Assimilatory Enzymes in Rauvolfia teraphylla L. (Apocyanaceae) – A Perennial Medicinal Herb,"
3, Article 4.
Available at: http://opensiuc.lib.siu.edu/ebl/vol2009/iss3/4