Recension of Stuart Card to: Eckhard Koch,Petra Zink,Cornelia I. Ullrich,Regina G. Kleespies, 2018:Light microscopic studies on the development of Beauveria bassiana and other putative endophytes in leaf tissues

Microscopic organisms associate with the majority of plant species found on planet Earth, including those in wild and managed ecosystems. Plant associated microorganisms are no longer viewed purely as agents of disease but are now considered by many researchers as intrinsic plant-partners with fossil evidence indicating their role in early plant transitions from aquatic to terrestrial environments (REMY et al., 1994; TAYLOR et al., 1995). Furthermore a particular group of microbial species, termed endophytes, are regarded as extremely important plant symbionts that can directly or indirectly improve plant growth, increase yield, reduce disease symptoms caused by plant pathogens, improve plant performance under low water availability and heavy metal pollution, solubilise phosphate and contribute assimilable nitrogen to their hosts and deter herbivorous insects and animals. Some researchers now believe that the low stress tolerance exhibited by many axenic plants is partly due to the absence of mutualistic endophytes (HALLMANN et al., 1997). However, it is only recently that these endophytic microorganisms including their bioactive products, have received deserving attention from the scientific community. Since then, a multitude of manuscripts have been published on this fascinating and intriguing subject. These papers cover the full breadth of scientific endeavours from the discovery of new species and behaviours to investigating fundamental biological processes to the development and commercialisation of endophyte products.