Bacterial endophytes, bacteria residing within plants, play an important role in the growth and development of plants and their ability to thrive under adverse conditions. The endophytes of Acer negundo, Ulmus pumila and Ulmus parvifolia trees sampled from a hydrocarbon-contaminated site were analyzed for variation between seasons and plant species. Branches from the same trees over a span of 3 seasons were collected and analyzed via culture dependent and culture independent methods. Numerous culture independent approaches were tested, culminating in the development of a new method for the amplification of endophytic bacterial ribosomal DNA that excludes plastid DNA. Community analyses using this new method in combination with T-RFLP showed significant differences between the endophytic communities of different plants species and of the same species growing in different seasons. The proposed technique can be used for the future study of endophytic communities of plants.

Bacterial endophytes, bacteria residing within plants, play an important role in the growth and development of plants and their ability to thrive under adverse conditions. The endophytes of Acer negundo, Ulmus pumila and Ulmus parvifolia trees sampled from a hydrocarbon-contaminated site were analyzed for variation between seasons and plant species. Branches from the same trees over a span of 3 seasons were collected and analyzed via culture dependent and culture independent methods. Numerous culture independent approaches were tested, culminating in the development of a new method for the amplification of endophytic bacterial ribosomal DNA that excludes plastid DNA. Community analyses using this new method in combination with T-RFLP showed significant differences between the endophytic communities of different plants species and of the same species growing in different seasons. The proposed technique can be used for the future study of endophytic communities of plants.