Bioreduction of gold metal to nanoparticles by tea (Camellia sinensis) plant extracts

Tremendous health benefits of the chemical cocktails present within the tea plant may also possess reduction potential, which will reduce gold salts into gold nanoparticles for the potential medical and technological applications. Reduction of gold salts using toxic chemicals cause problem in the environment. As the nano-revolution progresses, demand for environmentally benign and biologically friendly green synthesis process will rise. We present an approach to produce gold nanoparticles using aqueous extract from different parts of tea plant. Gold metal in this phytochemically induced reduction leads to generation of nanoparticles with definite shape and properties. Various phytochemicals present in tea plant extract provided robust coating and stabilized the synthesized nanoparticles. Reduction of gold salts by the tea plant extracts paves the way for plenty of opportunities for their application in imaging and therapy of serious disease like cancer. Surface plasmon resonance (SPR) bands observed in the gold nanoparticles solution at 540 nm indicated spherical nanoparticles formation. The morphology and size of gold nanoparticles were also determined by transmission electron microscopic (TEM) images. Under TEM, spherical nanoparticles with size ranges from 11 nm to 40 nm were observed. The potential application of gold nanoparticles synthesized using the principles of green chemistry has been discussed

A rapid and simple chitinase assay to screen tea genotypes for resistance against blister blight

Plant naturally responds to fungal attack by a complex network of defense mechanisms. Among these, production of pathogenesis related (PR) proteins is an important mode of resistance against pathogen invasion. Chitinase is one such PR protein and a potent biomarker for the identification of promising resistant germplasm. In this study, Gram’s iodine based detection assay for chitinase production in tea cultivars has been attempted to screen and validate the data available on the resistance level of the cultivars against blister blight disease. Small wells in the glycol-chitin-agarose/agar plates were loaded with enzyme extract and flooded with Gram’s iodine after 24h. The glycol-chitin formed a bluish complex with iodine, whereas the areas around the wells showed a sharp and distinct clearance zone, against the blue background. The diameter of the zone increased with increased amount of chitinase present in the sample. These observations were validated with field data on blister blight disease incidence in these cultivars and discussed. The new approach is an easy, reproducible, cost effective, user and environmental friendly qualitative method for rapid screening of the tea cultivars in breeding program