Wheat powdery mildew resistance gene Pm13 encodes a mixed lineage kinase domain-like protein

Abstract

Wheat powdery mildew is one of the most destructive diseases threatening global wheat production. The wild relatives of wheat constitute rich sources of diversity for powdery mildew resistance. Here, we report the map-based cloning of the powdery mildew resistance gene Pm13 from the wild wheat species Aegilops longissima. Pm13 encodes a mixed lineage kinase domain-like (MLKL) protein that contains an N-terminal-domain of MLKL (MLKL_NTD) domain in its N-terminus and a C-terminal serine/threonine kinase (STK) domain. The resistance function of Pm13 is validated by mutagenesis, gene silencing, transgenic assay, and allelic association analyses. The development of introgression lines with significantly reduced chromosome segments of Ae. longissima encompassing Pm13 enables widespread deployment of this gene into wheat cultivars. The cloning of Pm13 may provide valuable insights into the molecular mechanisms underlying Pm13-mediated powdery mildew resistance and highlight the important roles of kinase fusion proteins (KFPs) in wheat immunity.

A membrane associated tandem kinase from wild emmer wheat confers broad-spectrum resistance to powdery mildew

“…To date, eighteen powdery mildew resistance ( Pm ) genes, Pm1a 4 , Pm2 5 , Pm3 6 , Pm4 7 , Pm5e 8 , Pm8 9 , Pm12 10 , Pm13 11 , Pm17 12 , Pm21 13 , 14 , Pm24 15 , Pm38/Yr18/Lr34/Sr57 16 , Pm41 17 , Pm46 / Yr46 / Lr67 / Sr55 18 , Pm57 19 , Pm60 20 , Pm69 21 and WTK4 22 have been cloned in wheat and its wild relatives. Most of them encode coiled coil nucleotide-binding leucine-rich-repeat (NLR) proteins, except for Pm4 , Pm13 , Pm24 , WTK4 , Pm57 , Pm38/Yr18/Lr34/Sr57 , and Pm46 / Yr46 / Lr67 / Sr55 .…”

“…Pm4 encodes a putative chimeric protein of a serine/threonine kinase, multiple C2 domains, and transmembrane regions that mediate race-specific resistance 7 . Pm13 from Aegilops longissimi encodes a unique mixed lineage kinase domain-like protein 11 . Pm24 from Chinese wheat landrace Hulutou, WTK4 from Aegilops tauschii , and Pm57 from Aegilops searsii encode tandem kinase protein (TKP) 15 , 19 , 22 .…”

Pm57 from Aegilops searsii encodes a tandem kinase protein and confers wheat powdery mildew resistance

“…Thirteen of these 20 genes, i.e., Pm3 12 , Pm8 13 (ortholog of Pm3 ), Pm2 14 , Pm60 15 , Pm17 16 (allele of Pm8 ), Pm21 17 , 18 , Pm41 19 , Pm5e 20 , Pm1a 21 , MlIW172 / MlWE18 22 (allelic to Pm60 ), Pm12 23 (ortholog of Pm21 ), Pm69 24 , and Pm55 25 , encode nucleotide-binding leucine-rich repeat (NLR) immune receptors. Among the remaining seven Pm genes, Pm24 , WTK4 , and Pm36 encode tandem kinases 26 – 28 , Pm4 and Pm13 encode kinase fusion proteins 29 , 30 , and the two broad-spectrum resistance genes Pm38/Yr18/Lr34/Sr57 and Pm46/Yr46/Lr67/Sr55 encode an ABC transporter and a hexose transporter, respectively 31 , 32 .…”

“…Although Pm genes from wild relatives play an important role in breeding for disease resistance, it is very difficult to fine-map and clone alien genes from secondary or tertiary gene pools in the wheat background compared to those from common wheat due to homoeologous recombination suppression, lack of alien chromosome-specific markers and the unavailability of annotated reference genomes. To date, only six Pm genes have been cloned from wild relatives of wheat in secondary and tertiary gene pools including recently reported Pm55 25 ( Dasypyrum villosum L.) and Pm13 30 ( Ae . longissima ); for the other four genes, Pm12 ( Ae .…”

Genetic Basis Identification of a NLR Gene, TaRGA5-like, That Confers Partial Powdery Mildew Resistance in Wheat SJ106

“…Pm4 encodes a chimeric protein recognized as a serine/threonine kinase, which contains multiple C2 structural domains and transmembrane regions [ 17 ]. Pm13 and Pm36 encode kinase fusion proteins [ 18 , 19 ]. Pm38 ( Lr34 / Yr18 / Sr57 , ABC transporter) and Pm46 ( Lr67 / Yr46 / Sr55 , hexose transporter) show a broad spectrum of resistance to powdery mildew and rust with broad-spectrum adult plant resistance [ 20 , 21 ].…”