Submitted to: American Phytopathological Society Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2011
Publication Date: 6/1/2011
Citation: Yin, C., Wan, A., Chen, X., Hulbert, S. 2011. An effector of Puccinia striiformis f. sp. tritici is expressed in haustoria and required for avirulence on wheat cultivar carrying resistance gene YrTr. American Phytopathological Society Annual Meeting. 101:S198. Interpretive Summary:
Technical Abstract: Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating fungal diseases that threaten wheat production worldwide. Genetic resistance is the preferred method to control the disease, but the effectiveness of race specific resistance is typically not durable due to the genetic plasticity of rust populations. In this study, we identified a Pst effector (PSTeTr) that was highly expressed in haustoria. The PSTeTr gene delivered by modified Pseudomonas fluorescens strain EtHAn into leaves of wheat cultivar Tres, which has resistance genes YrTr1 and YrTr2, induced noticeably more callose depositions than the empty pEDV6 vector and the vector inserted with other two Pst genes (Pstha2A5 and Pstha5A23). Silencing PSTeTr in leaves of Tres through BSMV-VIGS produced abundant uredia in most leaves inoculated with a Tres-avirulent race, while the leaves infected by BSMV::MCS with the control constructs with no Pst gene and with PSTha12O3 sporulated sporadically. In contrast, silencing PSTeTr in other resistant wheat cultivars with Yr5 or Yr10 did not change the resistance reactions. The results indicate that PSTeTr is required for avirulence on wheat cultivar Tres.