Search

The extensive use of nanoparticles (NPs) in various industrial and household products pose a threat of their release into the environment. Plants being sessile are prone to be directly affected by these nanomaterials in polluted soils, which may represent possible risks to food safety and human health. In the present study, we compared the phytotoxic effects of metal oxide NPs namely nickel oxide (NiO), copper oxide (CuO) and zinc oxide (ZnO) NPs at four varying concentrations (100, 250, 500 and 1000 mg/L) on in-vitro grown seedlings of Abelmoschus esculentus (okra). All the NPs tested demonstrated a suppressed plant growth in a concentration-dependent manner which was evidenced from the repression of shoot and root length. A decrease in chlorophyll content was recorded in the NP-treated plants. Anthocyanin contents, total phenolic and total flavonoid contents were significantly altered in the NP-treated plants. Moreover, reactive oxygen species (ROS) generation was monitored in the roots of NP-treated plants using 4-nitro blue tetrazolium chloride (NBT) and 3, 3'-diaminobenzidine (DAB) staining, demonstrated an increase in ROS production in a dose-dependent manner in plants exposed to all three NPs. Enhanced ROS and malondialdehyde (MDA) production was recorded in A. esculentus seedlings when exposed to NPs. Among the three metal oxide NPs compared in the study, NiO NPs were found to be more toxic than CuO and ZnO ones. [ABSTRACT FROM AUTHOR]

Significant efforts are being directed towards the improvement of rice using genetic manipulations. A good and reproducible system for recovering fertile Indica rice plants is imperative. The aim of this study was to study the influence of initial cell density on growth dynamics of suspension cultures. The cultures were initiated from 3-week-old embryogenic calli derived from mature seeds of Indica rice cultivars ASD16 and Pusa basmati. Growth kinetics of the rice cell suspensions were measured and the obtained data reveal that viable cells at 3% PCV using 20 ml liquid (N6D) medium and sub-culturing at 7-day intervals resulted in rapid increase in fresh and dry weights and the embryogenic competency of the cells were found to be high. The growth kinetics analysis revealed that ASD16 showed better efficiency for high frequency and viable somatic embryo formation as compared to Pusa basmati. The technique was found to be suitable for developing somatic embryos for both cultivars ASD16 and Pusa basmati, which can be used for many important applications including micropropagation and secondary metabolites production. [ABSTRACT FROM AUTHOR]