Effect of Ozone on Induction of Resistance in Rhinacanthus nasutus (L.) Kurz. against Acute Ozone Exposure

Authors : N SUDHAKAR, D Nagendra PRASAD, N MOHAN, K MURUGESAN

Pages : 135-141

View : 18 | Download : 11

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Studies were undertaken for induction of resistance against acute ozone exposure in Rhinacanthus nasutus insert ignore into journalissuearticles values(L.); Kurz. plants using ozone. Callus induced from Rhinacanthus nasutus leaf explants on Murashige & Skoog`s insert ignore into journalissuearticles values(MS); medium supplemented with 3.40 µM of 2,4-dichlorophenoxy acetic acid insert ignore into journalissuearticles values(2,4-D); were treated with different concentrations of ozone insert ignore into journalissuearticles values(T1 = 1.0 µmol mol-1 insert ignore into journalissuearticles values(±0.2);, T2 = 1.5 µmol mol-1 insert ignore into journalissuearticles values(±0.2);, T3 = 2.0 µmol mol-1 insert ignore into journalissuearticles values(±0.2););, and for the control insert ignore into journalissuearticles values(C); filtered air was supplied. Regeneration of shoots was obtained by culturing ozone-treated calli on MS medium supplemented with 5.57 µM of kinetin insert ignore into journalissuearticles values(KIN); and 1.30 µM of gibberellic acid insert ignore into journalissuearticles values(GA3);. The frequency of regeneration of shoots from the callus was T1 = 60%, T2 = 49%, T3 = 32%, but for the control 81% regeneration was obtained. Regenerated shoots were rooted in half-strength MS medium containing 4.92 µM of indole-3 butyric acid insert ignore into journalissuearticles values(IBA); and successfully acclimatised. The seedlings regenerated from ozone treated calli are referred to as T1, T2 and T3 seedlings and the seedlings regenerated from filtered air-treated callus are referred to as control seedlings. T1 seedlings hold remarkably more total soluble phenol content than T2 and T3 compared to the control seedlings. T1 seedlings developed more resistance to withstand acute ozone exposure by increased phenylalanine ammonia-lyase activity and possessed more chlorophyll pigments and decreased H2O2 content relative to T2 and T3 seedlings compared to control seedlings.
Keywords : Callus, chlorophyll, soluble phenol, phenylalanine ammonia lyase PAL,