Introduction

In the preceding seven chapters of this book, the biology including structural details of hydathodes and the quantification, physiology, chemistry, phytopathology, mechanism, and regulation of guttation were discussed. In the light of these studies, the implications of guttation for soil–plant– animal–environment systems, ranging from the maintenance of soil fertility and its moisture build-up through plant biomass and crop productivity enhancement and pasture and rangeland management to ecosystem sustainability, were highlighted. Now, in this chapter, the significance of guttation and root secretion in the production of drugs, medicines, including recombinant proteins and vaccines, and other important commercial products for veterinary and human healthcare for a happy and healthy life are described.

Pharmaceutical implications

Medicinal plants have been used since the beginning of human evolution till recent times. Most of the available drugs are derived from plant extracts (Raskin et al. 2002). In 1983, heterologous gene expression in plant cells was detected. In 1989, the first ever recombinant human serum albumin was expressed in tobacco and potato plants (Sijmons et al. 1990). During the same year, the expression of recombinant antibodies by the plants was also shown (Hiatt et al. 1989). This sector of scientific studies progressed so rapidly that within a few years nearly 100 therapeutic and diagnostic recombinant proteins and vaccines were produced from a variety of plants (Ma et al. 2003; Twyman et al. 2005). The obvious reasons for this momentum are that plants are considered highly productive as compared with traditional production systems that follow microbial or mammalian cell systems (Fischer et al. 2004; Twyman et al. 2006, 2007). Many agencies are exploiting many recombinant antibodies and vaccines derived from plants. For example, vaccine against Newcastle disease obtained from tobacco plant, which was approved by the United States Department of Agriculture (USDA) in February 2006, was used in the poultry industry. Another such recombinant antibody was used against hepatitis B virus surface antigen, which was approved by the Center for State Control of Medication Quality (CECMED), Cuba in June 2006 (Fischer et al. 2007). The CECMED has approved, both, the production of the antibody through field-grown crops and the process in which these drugs are used. Many pharmaceutical proteins derived from plants are under clinical trials and on the regulatory approval list.