A. Shukla

Transgenic tomato plants resistant to fruit borer (Helicoverpa armigera Hubner)

Abstract A synthetic cry 1 Ac gene coding for an insecticidal crystal protein (ICP) of Bacillus thuringiensis ( Bt ) was transferred to tomato by cocultivating cotyledonary explants with Agrobacterium tumefaciens . Transformant plants resistant to kanamycin were regenerated. Hybridization experiments demonstrated gene integration and gene copy number in the transgenic plants. Double-antibody sandwich ELISA analysis revealed high levels of Bt ICP expression in the leaves of transgenic plants. The expression resulted in a high level of protection of transgenic plant leaves and fruits against the larvae of tomato fruit borer ( Helicoverpa armigera ). Limited field trial of the transgenic plants (T 1 generation) confirmed the high levels of insect protection.

Polaron-electron assisted giant dielectric dispersion in SrZrO3 high-k dielectric

The SrZrO3 is a well known high-k dielectric constant (∼22) and high optical bandgap (∼5.8 eV) material and one of the potential candidates for future generation nanoelectronic logic elements (8 nm node technology) beyond silicon. Its dielectric behavior is fairly robust and frequency independent till 470 K; however, it suffers a strong small-polaron based electronic phase transition (Te) linking 650 to 750 K. The impedance spectroscopy measurements revealed the presence of conducting grains and grain boundaries at elevated temperature which provide energetic mobile charge carriers with activation energy in the range of 0.7 to 1.2 eV supporting the oxygen ions and proton conduction. X-ray photoemission spectroscopy measurements suggest the presence of weak non-stoichiometric O2− anions and hydroxyl species bound to different sites at the surface and bulk. These thermally activated charge carriers at elevated temperature significantly contribute to the polaronic based dielectric anomaly and conductivity. O...