Identification of novel nonhost resistance genes in the interaction between Arabidopsis thaliana and Asian soybean rust

  • Identifizierung von Genen mit einer Funktion in der Nichtwirt-Resistenz von Arabidopsis thaliana gegen Phakopsora pachyrhizi

Langenbach, Caspar; Göllner, Katharina (Thesis advisor)

Aachen : Publikationsserver der RWTH Aachen University (2013)
Dissertation / PhD Thesis

Aachen, Techn. Hochsch., Diss., 2013

Abstract

Nonhost resistance (NHR) is the most durable form of plant immunity and is effective against all genetic variants of a pathogen. NHR wards off non-adapted pathogens using pre- and postinvasion defenses. In Arabidopsis, PEN2 is required for preinvasion resistance to the Asian soybean rust fungus Phakopsora pachyrhizi while PEN2, PAD4, and SAG101 together are needed for postinvasion NHR in the mesophyll. Transcriptional profiling of infected and mock-treated Arabidopsis wild type, pen2 and pen2 pad4 sag101 mutants identified 24 novel putative NHR genes whose expression is specifically associated with postinvasion mesophyll resistance to P. pachyrhizi. In the Arabidopsis pen2 mutant, individual silencing or mutation of candidate NHR genes CL4, CL7, CL15, CL16 (BRT1; UGT84A2), CL22 and CL23 attenuated postinvasion mesophyll resistance to P. pachyrhizi. Furthermore, stable overexpression of individual candidate genes (CL4, CL7, CL13,CL22 and CL24) in the soybean host conferred enhanced immunity to the rust fungus. Hence, evidence is provided that transfer of Arabidopsis NHR genes can significantly improve pathogen resistance of crop plants. Genes identified in this study will be used in future breeding programs for production of soybean varieties with durable resistance to Asian soybean rust.

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