The present book is divided into five sections. The first section deals with the methodology and bioresource generation, techniques related to genetic engineering and gene transfer to the nuclear genome and chloroplast genome. The new techniques of genome profiling and gene silencing are also present. The second section of the book deals with the classical aspects of plant biotechnology tissue culture and Micropropagation. Use of genetic engineering via. Agrobacterium and direct transfer of DNA via particle bombardment to develop transformed plants in Artemesia, castor and orchids, and production of recombinant proteins in plant cells have been dealt with in the third section. The fourth section deals with the abiotic and biotic stress tolerance in plants. The basic biology of some of the stress responses, and designing plants for stress tolerance is discussed in this section. The fifth section deals with medicinal plants and alkaloid production.