An autoactive NB-LRR gene causes Rht13 dwarfism in wheat.

Semidwarfing genes have greatly increased wheat yields globally, yet the widely used gibberellin (GA)-insensitive genes and have disadvantages for seedling emergence. Use of the GA-sensitive semidwarfing gene avoids this pleiotropic effect. Here, we show that encodes a () gene. A point mutation in the semidwarf allele autoactivates the gene and causes a height reduction comparable with and in diverse genetic backgrounds. The autoactive allele leads to transcriptional up-regulation of pathogenesis-related genes including class III peroxidases associated with cell wall remodeling. represents a new class of reduced height () gene, unlike other genes, which encode components of the GA signaling or metabolic pathways. This discovery opens avenues to use autoactive genes as semidwarfing genes in a range of crop species, and to apply in wheat breeding programs using a perfect genetic marker.