Nanoparticle effect on degradation of vanillic acid, a germination inhibiting dormancy factor present in Cyperus rotundus

Abstract

Cyperus rotundus is one of the most invasive perennial sedge weed considered as the world's worst weed. The tubers of the weed remain viable for more than three years and pass over the harsh weather period by preventing the germination of buds present in the tubers. Due to dormancy, the tubers may sustain in the soil for longer and interfere with the crops raised in the following season. Phenols are considered as the major factor of dormancy in Cyperus rotundus tubers. Among different phenolic acids, vanillic acid is dominated, found under long and continuous stress. Nanoparticles are capable to degrade the phenols. In order to confirm whether the nanoparticles have effect on degradation of phenol present in Cyperus rotundus, the dominant phenol present in the tuber i.e., vanillic acid was chosen. Experiment was conducted at the department of Nano Science and Technology, Tamil Nadu Agricultural University, Coimbatore to find the effect of different nanoparticles such as iron oxide, silver, titanium dioxide and zinc oxide on commercially available vanillic acid degradation during 2013–15. The maximum degradation of vanillic acid was observed with iron oxide nanoparticles at 25 mg i.e., 60.6% degradation compared to control. Titanium dioxide, zinc oxide and silver nanoparticles at 25 mg recorded the 54.5, 49.3 and 24.8% degradation, respectively The purple nutsedge (Cyperus rotundus) causes serious problems in many crops all over the world than any other weed (Kadir et al. 2000). Often forms dense colonies and greatly reduces the crop yields. The sedge weed propagates mainly by producing a complex underground system of rhizomes, basal bulbs and tubers (Stoller 1975). The tubers remain viable for more than three years and pass over the harsh weather period by preventing the germination of buds present in the tubers. Jangaard et al (1971) reported that increasing phenolic compounds and abscissic acids in the tubers reduced the sprouting. C. rotundus tubers contain vanillic, coumaric, ferulic, hydroxybenzoic and protochatechuic acids (Komai et al. 1991). Among these, vanillic acid is dominant. Due to its highest free radical scavenging potential, vanillic acid is expected to protect plant roots from the adverse effects produced by free radicals (Swigonska et al. 2014). Due to dormancy, the tubers may sustain in the soil for longer time and interfere with the crops raised in the following season. Under this situation, new strategies have to be designed to break the dormancy of the tubers.