A carbohydrate-binding protein, FLOURY ENDOSPERM 6 influences the initiation of A- and B-type starch granules in wheat

Previously, we identified a quantitative trait locus on the group 4 chromosomes of Aegilops and bread wheat that controls B-type starch-granule content. Here, we identify a candidate gene by fine-mapping in Aegilops and confirm its function using wheat TILLING mutants. This gene is orthologous to the FLOURY ENDOSPERM 6 (FLO6) gene of rice and barley and the PTST2 gene of Arabidopsis. In Triticeae endosperm, reduction in the gene dose of functional FLO6 alleles results in reduction, or loss, of B-granules. This is due to repression of granule initiation in late-grain development, but has no deleterious impact on the synthesis of A-granules. The complete absence of functional FLO6, however, results in reduced numbers of normal A-type and B-type granules and the production of highly-abnormal granules that vary in size and shape. This polymorphous starch seen in a wheat flo6 triple mutant is similar to that observed in the barley mutant Franubet. Analysis of Franubet (fractured Nubet) starch suggests that the mutant A-granules are not fractured but compound, due to stimulation of granule initiation in plastids during early-grain development. Thus, in different situations in Triticeae, FLO6 either stimulates or represses granule initiation.

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  • Name: Chia, Tansy, Type: Corresponding Author,
  • Name: Chirico, Marcella, Type: Author,
  • Name: King, Rob, Type: Author,
  • Name: Ramirez-Gonzalez, Ricardo, Type: Author,
  • Name: Saccomanno, Benedetta, Type: Author,
  • Name: Seung, David, Type: Author,
  • Name: Simmonds, James, Type: Author,
  • Name: Trick, Martin, Type: Author,
  • Name: Uauy, Cristobal, Type: Author,
  • Name: Verhoeven, Tamara, Type: Author,
  • Name: Trafford, Kay, Type: Author,
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Article Host Type publisher
Article Is Open Access true
Article License Type cc-by-nc-nd
Article Version Type publishedVersion
Citation Report https://scite.ai/reports/10.1101/643759
DFW Organisation NIAB
DFW Work Package 2
DOI 10.1101/643759
Date Last Updated 2019-07-09T05:10:07.396155
Evidence open (via page says license)
Journal Is Open Access false
Open Access Status hybrid
PDF URL https://www.biorxiv.org/content/biorxiv/early/2019/05/23/643759.full.pdf
Publisher URL https://doi.org/10.1101/643759