Abstract
Wall-associated kinases (WAKs) have recently been identified as major components of fungal and bacterial disease resistance in several cereal crop species. However, the molecular mechanisms of WAK-mediated resistance remain largely unknown.
\nHere, we investigated the function of the maize gene ZmWAK-RLK1 (Htn1) that confers quantitative resistance to northern corn leaf blight (NCLB) caused by the hemibiotrophic fungal pathogen Exserohilum turcicum.
\nZmWAK-RLK1 was found to localize to the plasma membrane and its presence resulted in a modification of the infection process by reducing pathogen penetration into host tissues. A large-scale transcriptome analysis of near-isogenic lines (NILs) differing for ZmWAK-RLK1 revealed that several differentially expressed genes are involved in the biosynthesis of the secondary metabolites benzoxazinoids (BXs). The contents of several BXs including DIM2BOA-Glc were significantly lower when ZmWAK-RLK1 is present. DIM2BOA-Glc concentration was significantly elevated in ZmWAK-RLK1 mutants with compromised NCLB resistance. Maize mutants that were affected in overall BXs biosynthesis or content of DIM2BOA-Glc showed increased NCLB resistance.
\nWe conclude that Htn1-mediated NCLB resistance is associated with a reduction of BX secondary metabolites. These findings suggest a link between WAK-mediated quantitative disease resistance and changes in biochemical fluxes starting with indole-3-glycerol phosphate.
Original language | English (US) |
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Pages (from-to) | 976-987 |
Number of pages | 12 |
Journal | New Phytologist |
Volume | 221 |
Issue number | 2 |
DOIs | |
State | Published - Sep 4 2018 |