Improvement of Morphological and Biochemical Traits of In vitro Antigonon leptopus Plant Grown under Drought Conditions

The micropropagation ability of Antigonon leptopus plant under drought stress was examined using three levels (0, 1, 2%) of polyethylene glycol (PEG) with additive two concentrations (1 and 2gl-1) of potassium silicate (K2SiO3) as well as silica nanoparticles (SiO2-NPs) at 2.5 and 5 mgl-1 as protectants to mitigate drought stress. Most treatments of the two sources of silicate enhanced the ability of explants to survive highly as compared to those grown under drought condition only. Adding 1gl-1 of K2SiO3 or 2.5mgl-1 of SiO2-NPs positively affected the morphological characters and all estimated pigments content under various levels of PEG (0, 1 and 2%) in the culture medium. High level (2%) of PEG without any additive augmented the phenolic compounds (Tannins, flavonoids and phenols) as well as proline and catalase activity. The total soluble sugar was increased under high levels of PEG (2%) and/or K2SiO3 (2gl-1) individually or interacted as compared with other treatments. The fractionation of phenolic compounds by HPLC showed an increment in some components at 2% PEG such as apigenin, cinnamic acid and ellagic acid compared to the control.