Graduation dhr. J. Ramos Escribano
Supervisor(s): prof.dr. A.H.J. Bisseling (Molecular Biology - Development Biology of Plants)
Co-supervisor(s):

Towards a better understanding of the role of reactive oxygen species in legume root nodules

Date: Tuesday, September 28, 2004
Time: 16:00 hrs
Place: Aula (gebouw 362), Gen. Foulkesweg 1, Wageningen
Contact: judith.barendsen@wur.nl

Description:
In legumes the process of N2 fixation occurs in specialized organs, called nodules, These are formed as a result of a symbiotic interaction with Rhizobium bacteria These enter the plant by infection threads formed in root hairs. It is shown that reactive oxygen species (ROS) are involved in different steps of nodule formation. We have devised three strategies for cellular and molecular studies of symbiosis and in particular of ROS metabolism in nodules. First, we report a novel method that allows the isolation of root hairs from the model legume Medicago truncatula. We also found in Medicago a protein, MtRH2, specifically localized in the root epidermis and the encoding gene can be used for specific expression in root hairs. A second strategy that may be helpful to study the function of ROS is gene inactivation. We show that A. rhizogenes-mediated RNA interference (RNAi) is an effective tool for this purpose. A third strategy is the overexpression of important