Čeština
EnglishStacked mutations in wheat homologues of rice SEMI-DWARF1 confer a novel semi-dwarf phenotype
Ndreca B., Huttly A., Bibi S., Bayon C., Lund G., Hernandez A., Lund G., Ham J., Alarcón-Reverte R., Addy J., Tarkowská D., Pearce S., Hedden P., Thomas S., Phillips A.
BMC PLANT BIOLOGY 24: 384, 2024
Keywords: wheat, gibberellin, dwarfing alleles, TILLING, green revolution
Abstract: Semi-dwarfing alleles are used widely in cereals to confer improved lodging resistance and assimilate partitioning. The most widely deployed semi-dwarfing alleles in rice and barley encode the gibberellin (GA)-biosynthetic enzyme GA 20-OXIDASE2 (GA20OX2). The hexaploid wheat genome carries three homoeologous copies of GA20OX2, and because of functional redundancy, loss-of-function alleles of a single homoeologue would not be selected in wheat breeding programmes. Instead, approximately 70% of wheat cultivars carry gain-of-function mutations in REDUCED HEIGHT 1 (RHT1) genes that encode negative growth regulators and are degraded in response to GA. Semi-dwarf Rht-B1b or Rht-D1b alleles encode proteins that are insensitive to GA-mediated degradation. However, because RHT1 is expressed ubiquitously, these alleles have pleiotropic effects that confer undesirable traits in some environments.
DOI: 10.1186/s12870-024-05098-1 IEB authors: Peter Hedden, Danuše Tarkowská
BMC PLANT BIOLOGY 24: 384, 2024
Keywords: wheat, gibberellin, dwarfing alleles, TILLING, green revolution
Abstract: Semi-dwarfing alleles are used widely in cereals to confer improved lodging resistance and assimilate partitioning. The most widely deployed semi-dwarfing alleles in rice and barley encode the gibberellin (GA)-biosynthetic enzyme GA 20-OXIDASE2 (GA20OX2). The hexaploid wheat genome carries three homoeologous copies of GA20OX2, and because of functional redundancy, loss-of-function alleles of a single homoeologue would not be selected in wheat breeding programmes. Instead, approximately 70% of wheat cultivars carry gain-of-function mutations in REDUCED HEIGHT 1 (RHT1) genes that encode negative growth regulators and are degraded in response to GA. Semi-dwarf Rht-B1b or Rht-D1b alleles encode proteins that are insensitive to GA-mediated degradation. However, because RHT1 is expressed ubiquitously, these alleles have pleiotropic effects that confer undesirable traits in some environments.
DOI: 10.1186/s12870-024-05098-1 IEB authors: Peter Hedden, Danuše Tarkowská