Acoustic Characteristics Of Plant Leaves Using Ultrasonic Transmission Waves

Abstract

It is my privilege to contribute the foreword for this unique volume entitled: “Plant Tissue Culture Engineering,” edited by S. Dutta Gupta and Y. Ibaraki. While there have been a number of volumes published regarding the basic methods and applications of plant tissue and cell culture technologies, and even considerable attention provided to bioreactor design, relatively little attention has been afforded to the engineering principles that have emerged as critical contributions to the commercial applications of plant biotechnologies. This volume, “Plant Tissue Culture Engineering,” signals a turning point: the recognition that this specialized field of plant science must be integrated with engineering principles in order to develop efficient, cost effective, and large scale applications of these technologies. I am most impressed with the organization of this volume, and the extensive list of chapters contributed by expert authors from around the world who are leading the emergence of this interdisciplinary enterprise. The editors are to be commended for their skilful crafting of this important volume. The first two parts provide the basic information that is relevant to the field as a whole, the following two parts elaborate on these principles, and the last part elaborates on specific technologies or applications. Part 1 deals with machine vision, which comprises the fundamental engineering tools needed for automation and feedback controls. This section includes four chapters focusing on different applications of computerized image analysis used to monitor photosynthetic capacity of micropropagated plants, reporter gene expression, quality of micropropagated or regenerated plants and their sorting into classes, and quality of cell culture proliferation. Some readers might be surprised by the use of this topic area to lead off the volume, because many plant scientists may think of the image analysis tools as merely incidental components for the operation of the bioreactors. The editors properly focus this introductory section on the software that makes the real differences in hardware performance and which permits automation and efficiency. As expected the larger section of the volume, Part 2 covers Bioreactor Technologythe hardware that supports the technology. This section includes eight chapters addressing various applications of bioreactors for micropropagation, bioproduction of proteins, and hairy root culture for production of medicinal compounds. Various engineering designs are discussed, along with their benefits for different applications, including airlift, thin-film, nutrient mist, temporary immersion, and wave bioreactors. These chapters include discussion of key bioprocess control points and how they are handled in various bioreactor designs, including issues of aeration, oxygen transport, nutrient transfer, shear stress, mass/energy balances, medium flow, light, etc. Part 3 covers more specific issues related to Mechanized Micropropagation. The two chapters in this section address the economic considerations of automated micropropagation systems as related to different types of tissue proliferation, and the use of robotics to facilitate separation of propagules and reduce labour costs. Part 4, Engineering Cultural Environment, has six chapters elaborating on engineering issues related to closed systems, aeration, culture medium gel hardness, dissolved oxygen,photoautotrophic micropropagation and temperature distribution inside the culture vessel. The last part (Part 5) includes four chapters that discuss specific applications in Electrophysiology, Ultrasonics, and Cryogenics. Benefits have been found in the use of both electrostimulation and ultrasonics for manipulation of plant regeneration. Electrostimulation may be a useful tool for directing signal transduction within and between cells in culture. Ultrasound has also applications in monitoring tissue quality, such as state of hyperhydricity. Finally the application of engineering principles has improved techniques and hardware used for long-term cryopreservation of plant stock materials. Readers of this volume will find a unique collection of chapters that will focus our attention on the interface of plant biotechnologies and engineering technologies. I look forward to the stimulation this volume will bring to our colleagues and to this emerging field of research and development!