This volume reviews various facets of Agrobacterium biology, from modern aspects of taxonomy and bacterial ecology to pathogenesis, bacterial cell biology, plant and fungal transformation, natural transgenics, and biotechnology. Agrobacterium-mediated transformation is the most extensively utilized platform for generating transgenic plants, but modern biotechnology applications derive from more than 40 years of intensive basic scientific research. Many of the biological principles established by this research have served as models for other bacteria, including human and animal pathogens. Written by leading experts and highlighting recent advances, this volume serves both as an introduction to Agrobacterium biology for students as well as a more comprehensive text for research scientists.

Agrobacterium is a plant pathogen which causes the “crown-gall” disease, a neoplastic growth that results from the transfer of a well-defined DNA segment (“transferred DNA”, or “T-DNA”) from the bacterial Ti (tumor-inducing) plasmid to the host cell, its integration into the host genome, and the expression of oncogenes contained on the T-DNA. The molecular machinery, needed for T-DNA generation and transport into the host cell and encoded by a series of chromosomal (chv) and Ti-plasmid virulence (vir) genes, has been the subject of numerous studies over the past several decades. Today, Agrobacterium is the tool of choice for plant genetic engineering with an ever expanding host range that includes many commercially important crops, flowers, and tree species. Furthermore, its recent application for the genetic transformation of non-plant species, from yeast to cultivated mushrooms and even to human cells, promises this bacterium a unique place in the future of biotechnological applications. The book is a comprehensive volume describing Agrobacterium's biology, interactions with host species, and uses for genetic engineering.

The broad host range pathogenic bacterium Agrobacterium tumefaciens has been widely studied as a model system to understand horizontal gene flow, secretion of effector proteins into host cells, and plant-pathogen interactions. Agrobacterium-mediated plant transformation also is the major method for generating transgenic plants for research and biotechnology purposes. Agrobacterium species have the natural ability to conduct interkingdom genetic transfer from bacteria to eukaryotes, including most plant species, yeast, fungi, and even animal cells. In nature, A. tumefaciens causes crown gall disease resulting from expression in plants of auxin and cytokinin biosynthesis genes encoded by the transferred (T-) DNA. Gene transfer from A. tumefaciens to host cells requires virulence (vir) genes that reside on the resident tumor-inducing (Ti) plasmid. In addition to T-DNA, several Virulence (Vir) effector proteins are also translocated to host cells through a bacterial type IV secretion system. These proteins aid in T-DNA trafficking through the host cell cytoplasm, nuclear targeting, and T-DNA integration. Genes within native T-DNAs can be replaced by any gene of interest, making Agrobacterium species important tools for plant research and genetic engineering. In this research topic, we provided updated information on several important areas of Agrobacterium biology and its use for biotechnology purposes.

Agrobacterium tumefaciens is a soil bacterium that for more than a century has been known as a pathogen causing the plant crown gall disease. Unlike many other pathogens, Agrobacterium has the ability to deliver DNA to plant cells and permanently alter the plant genome. The discovery of this unique feature 30 years ago has provided plant scientists with a powerful tool to genetically transform plants for both basic research purposes and for agric- tural development. Compared to physical transformation methods such as particle bomba- ment or electroporation, Agrobacterium-mediated DNA delivery has a number of advantages. One of the features is its propensity to generate single or a low copy number of integrated transgenes with defined ends. Integration of a single transgene copy into the plant genome is less likely to trigger “gene silencing” often associated with multiple gene insertions. When the first edition of Agrobacterium Protocols was published in 1995, only a handful of plants could be routinely transformed using Agrobacterium. Ag- bacterium-mediated transformation is now commonly used to introduce DNA into many plant species, including monocotyledon crop species that were previously considered non-hosts for Agrobacterium. Most remarkable are recent devel- ments indicating that Agrobacterium can also be used to deliver DNA to non-plant species including bacteria, fungi, and even mammalian cells.

This anthology traces the fascinating progress from plant pathology to biotechnology through 38 scientific papers on Agrobacterium, published over the past century. Included are the seminal scientific papers on the biology and application of Agrobacterium with introductory commentaries mostly by those involved in the original work. The commentaries give background to the papers and explain the problems faced and the techniques used, providing insight into the way fundamental research progresses.Agrobacterium tumefaciens has played a major role in the astounding advances that have been made over the past several decades in the areas of plant genetics, plant molecular biology, and plant genetic engineering. The papers included in this book were integral to the current understanding of the interaction of Agrobacterium with its hosts, its development into a major player in the genetic engineering of plants, and the biological control of crown gall.Agrobacterium tumefaciens: From Plant Pathology to Biotechnology is divided into five sections. The first section begins with 1904 when Erwin F. Smith began detailed work on crown gall and considered it to be a plant pathological problem. It explores many of the biological discoveries made over the past century, including the pivotal moment when Armin C. Braun discovered that crown gall was a plant cancer. Other papers cover the beginnings of T-DNA research and the development of vectors to improve the process of transferring T-DNA from bacterium to plant cell. The second section delves further into vector systems and genetic coding for disease and insect resistance, exploring the evolution of genetic engineering in crops.The final three sections deal with themes developed from crown gall studies, including ?quorum sensing? or population density, the DNA sequencing of one strain of A. tumefaciens, and the first genetically engineered organism, strain K1026, released for commercial use.According to Editor, Eugene Nester, ?This book should serve as a testimony to the 100 years of research on this remarkable organism, as well as to an international group of investigators who helped reveal secrets of this natural genetic engineer.? Students, professors, plant pathologists, microbiologists, or anyone interested in research and/or the history of plant pathology and biotechnology, will find this collection of papers an intriguing read.From the Preface: ??the journey is not over. As the commentary by Paul Hooykaas indicates, it looks as though T-DNA will insert into any cell, be it plant, fungal or even mammalian. Is there a possibility of using Agro?bacterium in gene therapy? Will Agrobacterium prove to be as useful a tool in fungal genetics as it has been in plant genetics? Its potential is mind-boggling.?

"This excellent book should be present in all central libraries and in those of plant biology institutions. The book is recommended to advanced students and researchers".Journal of Plant Physiology, 1999