Endophytic Bacteria in Tree Shoot Tissues and Their Effects on Host

Abstract

The interactions between the plant and endophytic bacteria in the shoots likely differ to some extent from those in the roots. Shoot endophytic bacteria are typically isolated during plant tissue culture started from shoot tips (buds) or embryos. With methods such as in situ hybridization and transmission electron microscopy, endophytic bacteria have been localized in buds, seeds, and flowers of forest trees, and GFP tagging has been used to observe colonization of seedlings by endophytic bacteria. Vertical transmission of endophytic bacteria has been suggested. Shoot endophytic bacteria share many plant growth-promoting effects with the root endophytes, the ability of producing plant growth hormones and nitrogen fixation being the most common ones. In addition, some shoot endophytes may affect plant growth through production of adenine derivatives and vitamin B 12 . Many more likely remain to be determined by powerful methods such as genomics and metabolomics, which will be valuable tools for describing the significance of endophytic bacteria for forest trees in the future.