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Rht18 Semidwarfism in Wheat Is Due to Increased GA 2-oxidaseA9 Expression and Reduced GA Content

Ford, Brett; Foo, Eloise; Sharwood, Robert; Karafiatova, Miroslava; Vrána, Jan; MacMillan, Colleen; Nichols, David; Steuernagel, Burkhard; Uauy, Cristobal; Dolezel, Jaroslav; Chandler, Peter

Description

Semidwarfing genes have improved crop yield by reducing height, improving lodging resistance, and allowing plants to allocate more assimilates to grain growth. In wheat (Triticum aestivum), the Rht18 semidwarfing gene was identified and deployed in durum wheat before it was transferred into bread wheat, where it was shown to have agronomic potential. Rht18, a dominant and gibberellin (GA) responsive mutant, is genetically and functionally distinct from the widely used GA-insensitive...[Show more]

dc.contributor.authorFord, Brett
dc.contributor.authorFoo, Eloise
dc.contributor.authorSharwood, Robert
dc.contributor.authorKarafiatova, Miroslava
dc.contributor.authorVrána, Jan
dc.contributor.authorMacMillan, Colleen
dc.contributor.authorNichols, David
dc.contributor.authorSteuernagel, Burkhard
dc.contributor.authorUauy, Cristobal
dc.contributor.authorDolezel, Jaroslav
dc.contributor.authorChandler, Peter
dc.date.accessioned2019-05-10T05:25:45Z
dc.identifier.issn0032-0889
dc.identifier.urihttp://hdl.handle.net/1885/161492
dc.description.abstractSemidwarfing genes have improved crop yield by reducing height, improving lodging resistance, and allowing plants to allocate more assimilates to grain growth. In wheat (Triticum aestivum), the Rht18 semidwarfing gene was identified and deployed in durum wheat before it was transferred into bread wheat, where it was shown to have agronomic potential. Rht18, a dominant and gibberellin (GA) responsive mutant, is genetically and functionally distinct from the widely used GA-insensitive semidwarfing genes Rht-B1b and Rht-D1b. In this study, the Rht18 gene was identified by mutagenizing the semidwarf durum cultivar Icaro (Rht18) and generating mutants with a range of tall phenotypes. Isolating and sequencing chromosome 6A of these “overgrowth” mutants showed that they contained independent mutations in the coding region of GA2oxA9. GA2oxA9 is predicted to encode a GA 2-oxidase that metabolizes GA biosynthetic intermediates into inactive products, effectively reducing the amount of bioactive GA (GA1). Functional analysis of the GA2oxA9 protein demonstrated that GA2oxA9 converts the intermediate GA12 to the inactive metabolite GA110. Furthermore, Rht18 showed higher expression of GA2oxA9 and lower GA content compared with its tall parent. These data indicate that the increased expression of GA2oxA9 in Rht18 results in a reduction of both bioactive GA content and plant height. This study describes a height-reducing mechanism that can generate new genetic diversity for semidwarfism in wheat by combining increased expression with mutations of specific amino acid residues in GA2oxA9.
dc.format.mimetypeapplication/pdf
dc.language.isoen_AU
dc.publisherAmerican Society of Plant Biologists
dc.rights© 2018 American Society of Plant Biologists
dc.sourcePlant Physiology
dc.titleRht18 Semidwarfism in Wheat Is Due to Increased GA 2-oxidaseA9 Expression and Reduced GA Content
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume177
dc.date.issued2018
local.identifier.absfor060705 - Plant Physiology
local.identifier.ariespublicationu5786633xPUB425
local.publisher.urlhttp://www.aspbjournals.org/
local.type.statusPublished Version
local.contributor.affiliationFord, Brett, CSIRO Agriculture and Food
local.contributor.affiliationFoo, Eloise, University of Tasmania
local.contributor.affiliationSharwood, Robert, College of Science, ANU
local.contributor.affiliationKarafiatova, Miroslava, Centre of the Region Haná for Biotechnological and Agricultural Research
local.contributor.affiliationVrána, Jan, Centre of the Region Haná for Biotechnological and Agricultural Research
local.contributor.affiliationMacMillan, Colleen, CSIRO Agriculture and Food
local.contributor.affiliationNichols, David, University of Tasmania
local.contributor.affiliationSteuernagel, Burkhard, John Innes Centre
local.contributor.affiliationUauy, Cristobal, John Innes Centre
local.contributor.affiliationDolezel, Jaroslav, Institute of Experimental Botany
local.contributor.affiliationChandler, Peter, CSIRO
local.description.embargo2037-12-31
local.bibliographicCitation.issue1
local.bibliographicCitation.startpage168
local.bibliographicCitation.lastpage180
local.identifier.doi10.1104/pp.18.00023
local.identifier.absseo970106 - Expanding Knowledge in the Biological Sciences
dc.date.updated2019-03-12T07:39:04Z
CollectionsANU Research Publications

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