Abstract
1Department of Biology, University of Houston, Houston, Texas 77204-5934, and Botanisches Institut, Mikrobiologie, Universität Tübingen, D-7400 Tübingen, Germany
2Department of Biochemical and Biophysical Sciences, University of Houston, Houston, Texas 77204-5934, and Botanisches Institut, Mikrobiologie, Universität Tübingen, D-7400 Tübingen, Germany
3University of Houston, Houston, Texas 77204-5934, and Botanisches Institut, Mikrobiologie, Universität Tübingen, D-7400 Tübingen, Germany