Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a serious threat to wheat production, and the application of fungicides is one of the most important means for controlling the disease. The purpose of this study is to determine the effects of a new succinate dehydrogenase inhibitor (SDHI) fungicide, flubeneteram, on reducing stripe rust. The baseline sensitivity of 173 Pst isolates from 13 provinces of China to flubeneteram was determined. Flubeneteram displayed significant effects on inhibiting SDH enzymes of Pst. Histological observations showed that after flubeneteram application, the formation and development of Pst hyphae and haustoria were significantly inhibited, and the structures were destroyed. Flubeneteram primed wheat for salicylic acid-induced defenses via upregulating pathogenesis-related genes (PR1 and PR2). Altogether, our study is the first to provide evidence that flubeneteram induces wheat defense against Pst infection. The findings indicate that flubeneteram could be an effective fungicide for managing stripe rust.
Keywords: flubeneteram; histochemistry; induced systemic resistance; ultrastructure; wheat stripe rust.