Modulation of physiological responses with TiO2 nano-particle in Azolla pinnata R.Br. under 2,4-D toxicity

Abstract

The present work is emphasised with the herbicidal tolerance of Azolla pinnata R.Br. and its modulation with TiO nano-particle. Both carbohydrate and nitrogen metabolism were effected with 2,4-D as herbicide and in few cases TiO-NP had recovered few detrimental effects. From the nutrient status in Azolla it recorded the recovery of nitrogen as well as potassium by TiO-NP but not in case of phosphorus. However, a conversion of nitrate to ammonium was more induced by TiO-NP under herbicidal toxicity. Similar results were obtained for inter-conversion of amino acid-nitrate pool, but no changes with glutamine synthase activity with TiO-NP. Initially, the effects of 2,4-D was monitored with changes of chlorophyll content but had not been recovered with nanoparticle. Photosynthetic reserves expressed as both total and reducing sugar were insensitive to TiO-NP interference but activity of soluble and wall bound invertase was in reverse trend as compared to control. The 2,4-D mediated changes of redox and its oxidative stress was ameliorated in plants with over expressed ADH activity. As a whole the Azolla bio system with TiO supplementation may be useful in sustenance against 2,4-D toxicity through recovery of nitrogen metabolism. Thus, Azolla-TiO-NP bio system would be realised to monitor the herbicidal toxicity in soil and its possible bioremediation.

Titanium and Zinc Based Nanomaterials in Agriculture: A Promising Approach to Deal with (A)biotic Stresses?

“…Besides metal contaminants, nTiO 2 was able to mitigate some effects of 2,4dichlorophenoxyacetic acid (2,4-D), a systemic herbicidal, and tetracycline, an antibiotic widely used in agriculture and livestock industries. In the case of 2,4-D, nTiO 2 increased the biomass, promoted the accumulation of N and K, despite reducing P content, upregulated the activity of soluble invertase to values closer to the control (despite decreasing the amount of cell wall bounded invertase), and promoted the nitrogen metabolism by increasing nitrate reductase and glutamine 2-oxoglutarate amino transferase activities [167]. Concerning the tetracycline, nTiO 2 application alleviated the negative effects on plant/pod biomass in Arabidopsis [161] and rice [160] grown in hydroponics.…”

Application of Polypodiopsida Class in Nanotechnology–Potential towards Development of More Effective Bioactive Solutions

“…Four of the studied species were affected by the high and medium doses of herbicides, and three of them were more sensitive than the flowering species Rumex acetosa . Similar studies, regarding the toxicity different pesticides were performed by Liu et al [ 149 ] (evaluating the glyphosate effect on Salvinia natans (L.) All) and by De et al [ 150 ] (evaluating the 2,4-Dichloro-phenoxy acetic acid effect on A. pinnata in the presence of TiO 2 nanoparticles). Their conclusions, that TiO 2 nanoparticles may alleviate the toxic effects, were also confirmed by Spanò et al [ 151 ], who used A. filiculoides pre-treated with TiO 2 NPs and evaluated the Cd-induced injuries in the model fern.…”