Biology subjects

Sedbrook, J. C.

Publications and source records attributed to Sedbrook, J. C..

4 recordsLinked to original sources

bioRxiv2025

Creating a new oilseed crop, pennycress, by combining key domestication traits using CRISPR genome editing

Considerable offseason farmland lays fallow because there are few crops that can profitably fit between primary crops. To remedy, we employed CRISPR genome editing to the freeze-tolerant, rapid cycling wild Brassica, Thlaspi arvense L. (field pennycress). High-yielding domesticated pennycress varieties were created having seed compositions comparable to "double low" canola (low erucic acid and glucosinolate). Seed glucosinolate content was reduced 75 % by combining mutations in R2R3-MYB (MYB28) and bHLH MYC (MYC3) transcription factors. Pennycress weediness was greatly reduced by knockout of the bHLH transcription factor TRANSPARENT TESTA8 (TT8), lowering seed dormancy and seed coat protections thereby mitigating pennycress re-emergence in fields. Domesticated pennycress offers farmers a profitable, low-carbon-intensity intermediate crop that confers ecosystem benefits while producing grain for renewable fuels and enhanced food security.

genetics↗

bioRxiv2025

A pennycress transparent testa 8 knockout mutant has drastic changes in seed coat anatomy and chemical compositions

Pennycress is a winter annual intermediate crop with approximately 30% seed oil content suitable for producing biofuels. Here, we evaluated seed development, anatomy, and agronomically relevant traits of a transparent testa 8 knockout mutant (tt8-2bp) generated by CRISPR genome editing to improve seed quality. We performed histochemical analyses on wild-type and tt8-2bp seeds at different developmental stages. No visible anatomical defects were observed in embryos and endosperm of tt8-2bp seeds. However, tt8-2bp seed coats completely lost proanthocyanidins which were accumulated in an inner integument cell layer and in the thickened cell wall of an outer integument cell layer of wild-type seed coats. Based on spatial metabolomic and solid-state NMR analyses, tt8-2bp seed coats had decreased aromatic compounds and cell wall polysaccharides compared to wild-type seed coats. Additionally, tt8-2bp seeds had reduced seed coat dry weights and increased embryo dry weights compared to wild-type seeds, indicating changes in macronutrient partitioning during seed development. Mature tt8-2bp seeds exhibited increased imbibition rates and seed coat permeability to water-soluble molecules, suggesting a higher seed coat hydrophilicity than wild-type seeds. In conclusion, we did not find defects in tt8-2bp mutant seeds that were unfavorable agronomically, supporting that TT8 is an attractive target for pennycress domestication. HighlightHistochemical analyses of pennycress seeds revealed a complete loss of proanthocyanidins in tt8-2bp seed coats accompanied by increased seed imbibition rates and seed coat permeability compared to wild-type seeds.

plant biology↗

bioRxiv2019

Progress toward the identification and stacking of crucial domestication traits in pennycress

The oilseed species Thlaspi arvense (pennycress) is being domesticated as a new crop that can provide both important ecosystem services and intensify farmland output. Through the use of high throughput sequencing and phenotyping, along with classical mutagenesis key traits needed for pennycress domestication have been identified. Domestication traits identified herein include reduced pod shatter, early maturity, reduced seed glucosinolate levels, and improved oil fatty acid content. By taking advantage of pennycress close genetic relationship with Arabidopsis thaliana, the causative mutations responsible for each of these traits have been identified. These mutations have been used to develop molecular markers to begin to stack the traits into individual lines.

plant biology↗

bioRxiv2017

CLASP stabilizes microtubule plus ends after severing to facilitate light-induced microtubule reorientation

Central to building and reorganizing cytoskeletal arrays is the creation of new polymers. While nucleation has been the major focus of study for new microtubule generation, severing has been proposed as an alternative mechanism to create new polymers, a mechanism recently shown to drive the reorientation of cortical arrays of higher plants in response to blue light perception. As severing produces new plus ends behind the stabilizing GTP-cap, an important and unanswered question is how these are stabilized in vivo to promote net microtubule generation. Here we identify the conserved protein CLASP as a potent stabilizer of new plus ends created by katanin severing and find that CLASP is required for rapid cortical array reorientation. In clasp mutants both rescue of shrinking plus ends and the regrowth of plus ends immediately after severing are reduced, computational modeling reveals that it is the specific stabilization of severed ends that explains CLASPs function in promoting microtubule amplification by severing and cortical array reorientation.

cell biology↗