4.Bacteria in infection thread grow toward root cell Infection thread Invaded plant cells and those nearby are stimulated to divide 5.Formation of bacteroid state within plant cell 6.Continued plant and Nodules bacterial cell division Figure 19-61 part 2 Brock Biology of Microorganisms 11/e 17 2006 Pearson Prentice Hall,Inc. Micropioiogy,Snangnai Jiao i ong University17 Microbiology, Shanghai Jiao Tong University