The rice blast resistance gene Ptr encodes an atypical protein required for broad-spectrum disease resistance

Abstract

Plant resistance genes typically encode proteins with nucleotide binding site-leucine rich repeat (NLR) domains. Here we show that Ptr is an atypical resistance gene encoding a protein with four Armadillo repeats. Ptr is required for broad-spectrum blast resistance mediated by the NLR R gene Pi-ta and by the associated R gene Pi-ta2. Ptr is expressed constitutively and encodes two isoforms that are mainly localized in the cytoplasm. A two base pair deletion within the Ptr coding region in the fast neutron-generated mutant line M2354 creates a truncated protein, resulting in susceptibility to M. oryzae. Targeted mutation of Ptr in a resistant cultivar using CRISPR/Cas9 leads to blast susceptibility, further confirming its resistance function. The cloning of Ptr may aid in the development of broad spectrum blast resistant rice.

Genome‐wide association study identifies an NLR gene that confers partial resistance to Magnaporthe oryzae in rice

“…In the reference genome of Nipponbare (NPB), six NLR genes ( Os04g52970 , Os04g53000 , Os04g53030 , Os04g53050 , Os04g53120 and Os04g53160 ) form a tandem‐repeat R ‐gene cluster in the LABR12 region. LABR27 is co‐localized with two cloned R genes, Pita (Bryan et al , ) and Ptr (Zhao et al , ), and a previously identified R locus (Kang et al , ). Among the 27 LABRs, 5 are co‐localized with previously mapped or cloned R genes, and the other 22 are new (Table , Figure ).…”

A Toolbox for Managing Blast and Sheath Blight Diseases of Rice in the United States of America

“…The genetic markers linked or derived from the cloned R genes were developed to predict resistance function and to monitor the existence of each of the R genes [31][32][33][44][45][46][47][48][49][50][51][52]. Differential blast races were identified ( Table 2) and have been used to validate their predicted resistance efficacies.…”

“…Further analysis of Katy revealed that there are three linked blast R genes, Pi-ta and Pi-ta2/Ptr genes near the centromere of rice chromosome 12. Pi-ta is a classical R gene with NBS-LRR [63] and Ptr, which is allelic to Pi-ta2, encodes a predicted protein with four armadillo repeats [52]. Ptr was shown to confer resistance to a wide range of blast races except for IE1k and help Pi-ta with unknown mechanisms [52].…”

“…Pi-ta is a classical R gene with NBS-LRR [63] and Ptr, which is allelic to Pi-ta2, encodes a predicted protein with four armadillo repeats [52]. Ptr was shown to confer resistance to a wide range of blast races except for IE1k and help Pi-ta with unknown mechanisms [52]. To date, a handful of rice varieties with the Pita, Pita2/Ptr cluster in a linkage block including Katy, Drew, Madison, Kaybonnet, Cybonnet, Banks, Ahrent, Catahoula, and Templeton have been released in the Southern US since 1990 [64][65][66].…”

Identification of the blast resistance gene Picl(t) from Chaling common wild rice (Oryza rufipogon Griff.)

“…Discovering rice blast resistance ( R ) genes is the premise of disease resistance breeding. To date, over 100 rice blast R genes have been identified and 36 of them were cloned (Wang, Ebbole, & Wang, 2017; Zhao et al, 2018). All of these genes encode nucleotide‐binding leucine‐rich repeat (NLR) proteins, except Pid2 , pi21 and Ptr , which encode a β‐lectin receptor‐like kinase, a heavy metal transport/detoxification protein and an Armadillo (ARM) repeat protein, respectively (Chen et al, 2006; Fukuoka et al, 2009; Zhao et al, 2018).…”