Browsing by Author "Hogg, Andrew C."

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Creation and Characterization of a Double Null Puroindoline Genotype in Spring Wheat
(2017-09) Martin, John M.; Hogg, Andrew C.; Webster, Richard W.; Giroux, Michael J.
Wheat (Triticum aestivum L.) grain hardness is controlled by the Ha locus, which is composed of two closely linked genes, Puroindoline a (Pina) and Puroindoline b (Pinb). Hard grain results from mutations in either of the Pin genes. Previous results have shown that the Pina-D1b (Pina null) allele has harder grain than other naturally occurring Pin alleles. Our goal was to create, identify, and characterize a double null Pin genotype by identifying a Pinb null mutation in a variety carrying the Pina-D1l null allele. Seeds of Fortuna, which has a premature stop codon in Pina, were treated with ethyl methanesulfonate. Two premature stop codon mutations were identified in Pinb using direct sequencing. The double null Pin haplotype was characterized after backcrossing to the parent variety Fortuna to create Pina null populations segregating for the presence of Pinb. The double null group was 6 units harder than the single null with no difference in other kernel characteristics. The milling characteristics differed between the two classes; the double null class had less break flour with a greater fraction of large and a smaller fraction of small flour particles compared with the single null class. Neither water absorption nor loaf volume was impacted by the change in grain hardness; however, Na2CO3 tests indicated greater starch damage in the double nulls. The double null Pin genotype may find a niche in hard wheat products for which flours with larger particle size are desired.
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.
Evaluating the impact of Rht hypomorphic mutations in durum wheat
(Wiley, 2021-12) Brown, McKenna M.; Martin, John M.; Jobson, Emma M.; Hogg, Andrew C.; Carr, Patrick M.; Giroux, Michael J.
Increasing the yield of wheat (Triticum spp.) requires identifying new allelic combinations by crossing or by creating useful variation in yield limiting genes. Wheat yield is impacted by many factors, including tiller number and seeds per tiller, both of which are impacted by the Reduced height (Rht) gene. Durum wheat [T. turgidum L. subsp. durum (Desf.) van Slageren] varieties are either standard height, wild type for Rht (Rht-B1a), or are semidwarf and carry the Rht-B1b allele. Rht-B1b increases productive tillers but can result in plants too short for easy harvest in the northern United States and shorter coleoptiles that reduce dry soil germination. In this study, durum plants varying for Rht alleles created by ethyl methanesulfonate (EMS) mutagenesis were studied to determine the impact of each allele upon agronomic and seed traits. The projects’ goal is to increase durum wheat yield through the development of a plant with height intermediate between current full-height and semidwarf varieties. Experiments included field trials, coleoptile length and gibberellic acid (GA) responsiveness assays, and an in vitro test to determine the impact of each Rht mutation upon binding to Gibberellin Insensitive Dwarf1 (GID1). It was found that the Rht-B1b-E529K allele conferred plant height and coleoptile length intermediate between Rht-B1b and Rht-B1a containing plants, while two Rht-A1 alleles had lesser impacts with trends toward intermediate-height plants. The results of this research demonstrate that hypomorphic Rht alleles that alter Rht binding to GID1 may prove useful in optimizing durum wheat height to increase yield across different growing conditions.
Missense alleles of the HMW glutenin subunits Dx5 and Dy10 have small changes in function relative to missense changes in Puroindoline a and b
(Wiley, 2022-12) Martin, John M.; Zhang, Jinrui; Hogg, Andrew C.; Giroux, Michael J.
Background and Objectives. The high molecular weight glutenin subunit genes (HMW-GS) in wheat (Triticum aestivum L.) play a key role in determining dough functionality. More specifically allelic variation for the Glu-D1 subunit loci is consistently associated with bread making quality. Since much of the hard wheat germplasm is fixed for the more favorable 1Dx5 + 1Dy10 haplotype, our goal was to identify allelic variation in 1Dx5 and 1Dy10 HMW-GS genes using an ethyl methanesulfonate (EMS) mutagenized population in the soft white spring wheat cultivar “Alpowa.” The same source population was previously used in screening for creating novel alleles in Puroindoline a (Pina) and Puroindoline b (Pinb) which are responsible for grain hardness variation. Direct sequencing of 384 M3 families identified 135 point mutations equally dispersed across 1Dx5 and 1Dy10. The mutation discovery rate was 1/12.7 kb of DNA, equal to that found in the Pin loci. Mutation carrying plants were crossed to the nonmutagenized Alpowa parent to create F2 populations segregating for the induced EMS HMW Glutenin mutations. Swelling index of gluten (SIG) was measured from seed from field grown plants to assess the impact of each EMS mutation upon Glutenin function. Findings. Nonsense mutations in both 1Dx5 and 1Dy10 reduced SIG values, indicating both 1Dx5 and 1Dy10 are needed for gluten functionality. Missense mutations did not alter SIG values compared to their wild type counterparts. In contrast missense mutations within the tryptophan-rich region of both PINS increased grain hardness pointing to the importance of this protein region. No such region in 1Dx5 or 1Dy10 was found indicating these proteins are structurally stable and tolerant of amino acid substitution. Conclusions. Results from the Glu-D1 subunit and Pin loci show that useful phenotypic variation can be created using EMS mutagenesis for genes where naturally occurring mutations occur from amino substitutions as is the case for the Pin loci. Significance and Novelty. EMS induced mutations are useful for creating new alleles in storage proteins with much greater impacts in genes that have a defined active site as for the Pin loci than in genes such as the HMW Glu-1 genes which have a long repetitive region.
Registration of ‘Lustre’ durum wheat
(Wiley, 2022-08) Hogg, Andrew C.; Carr, Patrick; Eberly, Jed; Chen, Chengci; Kowatch‐Carlson, Calla; Crutcher, Frankie; Lamb, Peggy F.; McNamara, Kyla; Haney, Eleri; Kephart, Ken D.
‘Lustre’ (Reg. no. CV-1193, PI 695072) is a spring durum wheat [Triticum turgidum L. ssp. durum (Desf.)] developed by the Montana Agricultural Experiment Station and released in 2020. Lustre was bred using the single seed descent method and was selected for its yield performance under dryland conditions across Montana, low grain Cd accumulation, good pasta firmness, high grain protein, high yellow semolina color, and low semolina ash. Lustre performs well in both the north central and northeast regions of Montana, where most Montana durum is produced and intended for pasta production. Lustre has similar stripe rust tolerance and susceptibility as top-grown durum cultivars in the state with susceptibility at the seedling stage and high-temperature adult-plant resistance. Lustre is moderately susceptible to Fusarium head blight like other durum cultivars. Lustre is resistant to the predominant races of stem and leaf rust and is moderately tolerant to fungal leaf spot complex. Lustre is approximately 89 cm tall, with a yellow green color and a heading date 1 d later than the cultivar ‘Mountrail’. Lustre has an erect flag leaf and an erect tapering head having white glumes and awns.