Current Research on Plant-Growth Promoting Rhizobacteria in Latin America: Meeting Report from the 2nd Latin American PGPR Workshop

Abstract

Crop performance depends, to a large degree, on biological activities taking place in the root environment. By the early twentieth century, it was already recognized that plants exert key effects on the soil space just outside the root surface. This led to the concept of the rhizosphere, that is, the portion of the soil that is directly influenced by the root (Hiltner 1904). The rhizosphere contains diverse microorganisms that induce beneficial, neutral, or deleterious effects on plant growth. The beneficial rhizosphere bacteria were deemed plant-growth promoting rhizobacteria (PGPR) (Kloepper and Schroth 1978). The rhizosphere was then recognized to be an active microbial habitat with complex and multitrophic biological interactions among microbes and eukaryotic organisms, and focused studies on these interactions began. The applications of such knowledge were of direct economical relevance given that PGPRs may be utilized as agronomic inputs to increase crop yields. This gave rise to a community of scientists interested in elucidating the mechanisms displayed by PGPR species and understanding the role of the plant in shaping the microbial community of the rhizosphere. In parallel, a number of private companies started to commercialize PGPR-based products for a range of agronomical applications worldwide, with Latin American countries taking the lead in this field. With these interests in mind, the International PGPR Workshop was first held in Canada in 1987 and since then, the workshop has been held every 3 years at different locations around the world (Switzerland, Australia, Japan, Argentina, India, The Netherlands, USA and Colombia). With the selection of a Latin American venue for the last international PGPR workshop and based on a regional demand for exchange of basic and applied information about the biology of PGPR and its applications, Quirama (Medellin, Colombia) hosted the 1st official Latin American PGPR meeting as a branch of the International edition. At that time, it was decided that the Latin American PGPR would be held every two years, and that the next venue would be Argentina.