This book discusses genetic engineering of both plants and microbes for making agricultural practices more productive and sustainable. It chapters explore the understanding of the interaction between plants and microbes, and genomic information to modify the metabolism of plants or microbes to further enhance the beneficial interaction. The book covers the development of commercial inoculants including selection of appropriate plant growth-promoting rhizobacteria/ phosphate solubilize bacteria based on target host plant, soil type, indigenous microbial communities, environmental conditions, inoculant density, suitability of carriers and compatibility with integrated crop management. This is a relevant content for scientists and researchers working on soil biology, sustainable agricultural and plant physiology. Also, this book is a useful read for graduate and post graduate students of agriculture, botany and microbiology.