Buss Wolfram, Ford Brett A, Foo Eloise, Schnippenkoetter Wendelin, Borrill Philippa, Brooks Brenton, Ashton Anthony R, Chandler Peter M, Spielmeyer Wolfgang
CSIRO Agriculture and Food, Canberra, ACT, Australia.
The School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia.
J Exp Bot. 2020 Dec 31;71(22):7171-7178. doi: 10.1093/jxb/eraa443.
The induced dwarf mutant Rht12 was previously shown to have agronomic potential to replace the conventional DELLA mutants Rht-B1b/Rht-D1b in wheat. The Rht12 dwarfing gene is not associated with reduced coleoptile length (unlike the DELLA mutants) and it is dominant, characteristics which are shared with the previously characterized dwarfing genes Rht18 and Rht14. Using the Rht18/Rht14 model, a gibberellin (GA) 2-oxidase gene was identified in the Rht12 region on chromosome 5A. A screen for suppressor mutants in the Rht12 background identified tall overgrowth individuals that were shown to contain loss-of-function mutations in GA2oxidaseA13, demonstrating the role of this gene in the Rht12 dwarf phenotype. It was concluded that Rht12, Rht18, and Rht14 share the same height-reducing mechanism through the increased expression of GA 2-oxidase genes. Some of the overgrowth mutants generated in this study were semi-dwarf and taller than the original Rht12 dwarf, providing breeders with new sources of agronomically useful dwarfism.
诱导型矮秆突变体Rht12先前已被证明具有农学潜力，可替代小麦中传统的DELLA突变体Rht - B1b/Rht - D1b。Rht12矮化基因与胚芽鞘长度缩短无关（与DELLA突变体不同），且它是显性的，这些特征与先前鉴定的矮化基因Rht18和Rht14相同。利用Rht18/Rht14模型，在5A染色体的Rht12区域鉴定出一个赤霉素（GA）2 -氧化酶基因。在Rht12背景下对抑制突变体进行筛选，鉴定出了高大过度生长个体，这些个体被证明在GA2氧化酶A13中含有功能丧失突变，证明了该基因在Rht12矮化表型中的作用。得出的结论是，Rht12、Rht18和Rht14通过GA 2 -氧化酶基因表达的增加共享相同的降低株高机制。本研究中产生的一些过度生长突变体是半矮秆的，且比原始的Rht12矮秆更高，为育种者提供了具有农学利用价值的矮化新资源。
