Browsing by Author "Tillet, Brandon J."

Now showing 1 - 2 of 2

Dosage response to reduced height‐1 (Rht‐1) loss‐of‐function mutations and characterization of slender phenotype in hexaploid wheat
(Wiley, 2023-10) Ugrin, Josey M.; Hogg, Andrew C.; Tracy, Emma M.; Tillet, Brandon J.; Cook, Jason P.; Martin, John M.; Giroux, Michael J.
The reduced height (Rht-1) genes in wheat (Triticum aestivum L.) are integral in controlling plant height. Previous studies in other plant species have demonstrated that loss-of-function mutations in their orthologous Rht-1 genes results in plants with a slender phenotype illustrated by increased plant heights, sterility, and a constitutive gibberellic acid (GA3) response; however, this phenotype has not been described in wheat. In this study, nonsense alleles occurring in the GRAS domain of Rht-A1, B1, and D1 were combined to create single, double, and triple Rht-1 mutants. Homozygous lines possessing none, one, two, or three Rht-1 stop mutations were grown in replicated field trials in three environments to assess agronomic traits. Germination tests to measure GA3 responsiveness and gene expression analysis via RNA-seq were also performed. Rht-1 triple mutants exhibited a slender phenotype characterized by rapid growth, elongated coleoptiles and internodes, elongated spikes, decreased tiller and spikelet number, and sterile heads. The presence of a single functional Rht-1 gene resulted in a normal phenotype. Differences in plant height among the Rht-1 double mutants, Rht-1 single mutants, and Rht-1 all wild-type dosages trended toward increased plant height with increased Rht-1 stop mutation dosage. Differences in Rht-1 homeolog gene expression did not equate to differences in plant height between the different Rht-1 stop mutations.
Novel alleles of MFT‐A and MFT‐B1 appear to impact wheat preharvest sprouting in Triticum aestivum and Triticum turgidum ssp. durum
(Wiley, 2024-05) Tillet, Brandon J.; Vetch, Justin M.; Martin, John M.; Giroux, Michael J.
Background and Objectives. Preharvest sprouting (PHS) is the premature germination of seeds, which is often caused by late-season rains after seeds reach physiological maturity. PHS negatively impacts grain yield and end-use quality. Previous studies in spring bread wheat (Triticum aestivum) and durum wheat (Triticum turgidum) have identified that some mutations in the mother of FT and TFL1 gene (MFT) coding sequence decrease seed dormancy and increase wheat PHS. Findings. Here, we report two novel alleles for the MFT-A and two novel alleles for the MFT-B1 homologs in spring bread wheat and durum wheat. Conclusions. A haplotype analysis suggests that TaMFT-3A1b (OQ729929), TaMFT-3B1b (OQ729932) and TdMFT-3B1b (OQ729937) increase PHS susceptibility. It is expected that functional copies of MFT promote seed dormancy. Variant analysis of the novel MFT-A and MFT-B1 alleles in both spring and durum wheat suggest impairment of protein function, therefore a negative impact on seed dormancy. Significance and Novelty: Previously unassessed durum wheat varieties were examined for PHS susceptibility. The information in this study can serve as a resource for spring and durum wheat breeders to make selections for alleles of MFT that impact susceptibility to PHS.