Beneficial Effects of Bacterial Endophytes on Forest Tree Species

Since their discovery, beneficial bacteria living inside the plant tissues (known as bacterial endophytes) have been studied widely in agricultural crop species. But their ecology and effects on tree species in a forest ecosystem could be very different yet intriguing. In this chapter, studies highlighting the isolation of bacterial endophytes, re-inoculation and detection of the endophytic population in the host tree, and benefits provided to the host tree through direct and indirect mechanisms have been reviewed. Important tree species including those belonging to the genus Pinus, Populus, and Picea have been reported widely to harbor bacterial endophytes belonging to the genus Bacillus, Paenibacillus, and Pseudomonas and possibly obtain benefits like nitrogen fixation and increased biomass production from them. Nitrogen-fixing bacterial endophytes are the most commonly studied beneficial microbes of forest tree species, and thus have been reviewed in detail in this chapter.