School of Biological Sciences & Center for Plant Science and Innovation, University of Nebraska, Lincoln, NE 68588, USA. byu3@unl.edu.|School of Biological Sciences & Center for Plant Science and Innovation, University of Nebraska, Lincoln, NE 68588, USA. byu3@unl.edu.|Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA. lqzhang@cs.vt.edu.