AUTHOR=Vaz Patto Maria Carlota , Rubiales Diego 

TITLE=Unveiling common responses of Medicago truncatula to appropriate and inappropriate rust species

JOURNAL=Frontiers in Plant Science

VOLUME=5

YEAR=2014

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2014.00618

DOI=10.3389/fpls.2014.00618

ISSN=1664-462X

ABSTRACT=<p>Little is known about the nature of effective defense mechanisms in legumes to pathogens of remotely related plant species. Some rust species are among pathogens with broad host range causing dramatic losses in various crop plants. To understand and compare the different host and nonhost resistance (NHR) responses of legume species against rusts, we characterized the reaction of the model legume <italic>Medicago truncatula</italic> to one appropriate (<italic>Uromyces striatus</italic>) and two inappropriate (<italic>U. viciae-fabae</italic> and <italic>U. lupinicolus</italic>) rusts. We found that similar pre and post-haustorial mechanisms of resistance appear to be operative in <italic>M. truncatula</italic> against appropriate and inappropriate rust fungus. The appropriate <italic>U. striatus</italic> germinated better on <italic>M. truncatula</italic> accessions then the inappropriate <italic>U. viciae-fabae</italic> and <italic>U. lupinicolus</italic>, but once germinated, germ tubes of the three rusts had a similar level of success in finding stomata and forming an appressoria over a stoma. However, responses to different inappropriate rust species also showed some specificity, suggesting a combination of non-specific and specific responses underlying this legume NHR to rust fungi. Further genetic and expression analysis studies will contribute to the development of the necessary molecular tools to use the present information on host and NHR mechanisms to breed for broad-spectrum resistance to rust in legume species.</p>