Wheat powdery mildew is an important fungal disease that seriously jeopardizes wheat production, which poses a serious threat to food safety. SJ106 is a high-quality, disease-resistant spring wheat variety; this disease resistance is derived from Wheat-wheatgrass 33. In this study, the powdery mildew resistance genes in SJ106 were located at the end of chromosome 6DS, a new disease resistance locus tentatively named PmSJ106 locus. This interval was composed of a nucleotide-binding leucine-rich repeat (NLR) gene cluster containing 19 NLR genes. Five NLRs were tandem duplicated genes, and one of them (a coiled coil domain–nucleotide binding site–leucine-rich repeat (CC-NBS-LRR; CNL) type gene, TaRGA5-like) expressed 69–836-fold in SJ106 compared with the susceptible control. The genome DNA and cDNA sequences of TaRGA5-like were amplified from SJ106, which contain several nucleotide polymorphisms in LRR regions compared with susceptible individuals and Chinese Spring. Overexpression of TaRGA5-like significantly increased resistance to powdery mildew in susceptible receptor wheat Jinqiang5. However, Virus induced gene silence (VIGS) of TaRGA5-like resulted in only a small decrease of SJ106 in disease resistance, presumably compensated by other NLR duplicated genes. The results suggested that TaRGA5-like confers partial powdery mildew resistance in SJ106. As a member of the PmSJ106 locus, TaRGA5-like functioned together with other NLR duplicated genes to improve wheat resistance to powdery mildew. Wheat variety SJ106 would become a novel and potentially valuable germplasm for powdery mildew resistance.

Wheat powdery mildew, caused by Blumeria graminis f. sp. tritici, represents one of the most threatening biotic stresses of this crop. The cultivated wheat variety ‘Brock’ exhibits resistance not only to rust but also to powdery mildew, making it a valuable resource for exploitation in wheat disease-resistant breeding. This study identified a novel gene in ‘Brock’ distinct from Pm2. In order to identify the disease resistance gene in ‘Brock’, genetic mapping was performed using F₂ and F_2:3 populations derived from the cross ‘Jing411/Brock’. The candidate powdery mildew resistance gene was located within a 6.88 Mb physical interval on chromosome 2D, which harbors a highly expressed gene, TaRPM1-2D. The protein encoded by TaRPM1-2D possesses a typical nucleotide binding, leucine-rich repeat receptor (NLR) domain, and its sequence significantly differs among ‘Jing411’, ‘BJ-1’, and ‘Brock’. Expression of TaRPM1-2D was markedly higher in resistant wheat ‘Brock’ and ‘BJ-1’ compared to the susceptible ‘Jing411’. Both overexpression and gene silencing experiments demonstrated that TaRPM1-2D contributes to enhance resistance against powdery mildew in wheat. These findings reveal the function of TaRPM1-2D in conferring powdery mildew resistance in ‘Brock’ and provide a candidate gene for disease-resistance breeding.