3. Influence of Color Light on Callus InductionLight is an important physical factor, which influences growth, development, and the formation Sorafenib Raf-1 of primary and secondary metabolites [25]. In the present study, color light was also one of the most important factors in inducing and maintaining GC nature of the cells on G. sylvestre callus (Figure 4(d)). The analysis of G. sylvestre callus growth in batch culture under blue light conditions showed that GC callus yielded higher biomass (DW-172mg/L) at the stationary phase of 35�C45 days of culture (Figure 4(a)). In general, the optimal flux of blue light for leaf explants is about 10�C15% of the total photosynthetically active radiation. Moreover, the higher flux of blue light is essential for normal carbohydrate metabolism, photosynthetic assimilating, and transport from leaves.

Cryptochrome wave length (450nm), was closed to the blue light, and in this condition more Pr transformed into Pfr for phenylethanoid glycoside production [26]. Figure 4(b) callus growth on red light was, however, extremely slow, and growth curve values of only 31mg/L, 59mg/L, 85mg/L, 122mg/L and 102mg/L of dry weight could be registered after 15, 25, 35, 45, and 55 days of the growth. In comparison, MS medium + OPGRs with green light supported maximum GA accumulation in callus harvested on 35�C45 days of incubation, respectively, (DW 116mg/L; Figure 4(c)).Figure 4MS medium supplemented with OPGRs, physical and chemical treatments on leaf explants of Gymnema sylvestre induced callus after 45 days incubation. (a) Blue light (1.8x); (b) red light (1.

8x); (c) green light (1.6x); (d) color light setup; (e) 30��C …3.4. Influence of Temperature on Callus InductionTemperature has many effects on the mechanisms of metabolic regulation, permeability, nutritional needs, and the rate of intracellular reactions in plant cell cultures [27]. 30��C increased the callus biomass and decreased the GA content (2.9mg/gd.w) than the control (25 �� 2��C) in 35�C45 days of stationary phase. Thus, changing the culture temperature may change the physiology and metabolism of cultured cells and subsequently affect callus growth and secondary metabolite production. The callus culture exposed to the lower temperature (20 �� 2��C) showed decrease in callus biomass (DW-45mg/L) and GA content (0.03mg/gd.w) (Figure 4(e)).

MS medium supplemented with OPGRs kept under 30��C induced GFC (Figure 4(f)) and biomass (DW-150mg/L) in G. sylvestre. However, each plant species may favour a different temperature. For strawberry callus culture, maximum anthocyanin content was obtained at 15��C and it was about 13 fold higher than that obtained at 35��C [27]. Anacetrapib The cultures incubated at 35 �� 2��C had lower callus biomass (DW-125mg/L) and GA (1.4mg/gd.w) (Figure 4(g)), respectively. For Asclepiadaceae species, callus biomass increased at 31��C, more than at 25��C, hence gagaminine content was higher at 25��C in Cynanchum wilfordii [24].3.5.