NUTRIENT AVAILABILITY AND GENE EXPRESSION IN RESPONSE TO NANOPARTICLES IN RICE (Oryza sativa)

Abstract

Nanotechnology is a fast growing industry now-a-days which is having considerable impacts on society, economy, and also on environment. Present study was designed to assess the effects of TNP on Oryza sativa for an exposure time of 70 days. The core objectives were; i) to identify the best respondent genotype of Oryza sativa in response to TNP, ii) to determine the growth parameters and phosphorus availability in soil medium and iii) identification of genes involved in phosphorus uptake in Oryza sativa. TNP were synthesized by Liquid Impregnation method and characterized via SEM, EDX and XRD. Six concentration levels (0, 100, 200, 300, 400, 500 mg L−1) were used in seed germination test and applied to five Oryza sativa genotypes. Seeds of Super Basmati treated with TNP showed better response in germination percentage, shoot length stress index (SLSI), root length stress index (RLSI), seedling vigor index (SVI) and plant height stress tolerance index (PHSTI) as compared to other four genotypes. In soil medium, Super Basmati was treated with six concentration levels of TNP (0, 100, 200, 300, 400, 500 mg kg−1). In comparison with control, plants treated with TNP showed 15 and 35% improvement in shoot length and shoot biomass, respectively at 400 mg kg−1. Whereas 18% increase in root length and 73% improvement in root biomass was recorded at 400 mg kg−1. Availability of phosphorus also improved to 0.38 folds in shoots while 1.3 folds in roots at 500 mg kg−1. Morphological differences were found among treated and control plants that were confirmed by Scanning Electron Microscopy analysis. It was observed that there was significant increase in silica bodies in treated shoots, which enhances the plant strength against fungal attack and pests. In silico study was done by blasting the Phosphate Transporter gene (OsPT1) with other cereal crops and Arabidopsis thaliana. Sequences were retrieved from different databases and it was confirmed that there was great similarity between all studied cereal crops in terms of phosphate transporters (PiTs) genes with respect to rice. Results indicate towards the advantageous characteristics of TNP along with environmental benefits which encourage its application on cereal crops.