Submitted to: Plant Cell Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2006
Publication Date: 2/1/2007
Citation: Tobias, D.J., Manoharan, M., Pritsch, C., Dahleen, L.S. 2007. Co-bombardment, integration and expression of rice chitinase and thaumatin-like protein genes in barley (hordeum vulgare cv. conlon). Plant Cell Reports. Interpretive Summary: Plants produce a variety of proteins when they are attacked by fungi, which can help protect the plants from diseases. Two of these proteins are chitinase and thaumatin-like protein. We have inserted genes for these two proteins from rice into barley and tested to see whether the genes produced the proper proteins in leaves and spikes. Three independent gene insertions were recovered. Testing of plants containing these insertions showed that the progeny of one plant produced both the chitinase and the thaumatin-like protein, while the progeny of the other two plants only produced the chitinase protein. The next step with these plants is to test the effects of the inserted genes on a variety of fungal diseases that attack barley to see if they can be used to increase disease resistance.
Technical Abstract: Pathogenesis-related (PR) proteins associated with degradation of structural components of pathogenic filamentous fungi were overexpressed in the two-rowed malting barley (Hordeum vulgare L.) cultivar Conlon. Transgenes were introduced by co-bombardment with two plasmids, one carrying a rice (Oryza sativa L.) chitinase gene (chi11) and another carrying a rice thaumatin-like protein gene (tlp). Each gene was under the control of the maize ubiquitin (Ubi1) promoter. Fifty-eight primary transformants from three independent transformation events were regenerated. T1 plants with high rice chi and tlp protein expression levels were advanced to identify T2 homozygotes by herbicide spray and subjected to further molecular analyses. T3 progeny from one event (E2) had stable integration and expression of the rice chi and tlp while those from the other events (E1 and E3) showed stable integration only of tlp. The successful production of these lines overexpressing the antifungal chi and tlp proteins provides materials to test the effects of these genes on a variety of fungal diseases that attack barley and to serve as potential additional sources of disease resistance.