1. Department of Chemistry, Texas A&M University, College Station, TX, USA 77840;
2. 清华大学化学系 北京 100084;
3. Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX, USA 77840;
4. University of Wisconsin-Madison, Madison, WI, USA 53706;
5. Division of Biological Science, University of California San Diego, La Jolla, USA 92093