Haustorial Initiation in Agalinis

1. Agalinis purpurea. This species has served as a model organism for studies of haustorial initiation in the lab of Dr. James Riopel, University of Virginia. Photo by Lytton J. Musselman.
2. Agalinis purpurea root, 18 hours after being induced to form a haustorium by xenognosins. The epidermal cells become densely cytoplasmic and cell divisions begin. Photo by J. Riopel.
3. Agalinis purpurea root, 3 days after being induced to form a haustorium by xenognosins. Swelling begins below the densely staining epidermal cells. Photo by J. Riopel.
4. Agalinis purpurea root, 6 days after being induced to form a haustorium by xenognosins. A large swelling is apparent as well as haustorial hairs. Photo by J. Riopel.
5. Agalinis purpurea. Scanning electron microscope (SEM) picture of haustorial root attaching to a host root. Photo by Wm. Vance Baird.
6. Agalinis purpurea. SEM pictures showing series of developmental stages of haustoria. Photo by Wm. Vance Baird.
7. Aureolaria flava - mature haustorium in section. Host root is to the right. Photo by L. J. Musselman.

A related scroph, Triphysaria versicolor, is being used as a model organism in John Yoder's lab, University of California, Davis. On this page you can watch a movie of the timecourse of haustorial development in Triphysaria in response to maize root exudate.