Genetic architecture of flowering-time variation in grasses

Genetic architecture of flowering-time variation in grasses

New insights into the genetic control of natural variation in flowering time in Brachypodium distachyon.

The Science

To explore the genetic architecture of flowering time, we developed a recombinant inbred line population from a cross between two diverse accessions of the grass Brachypodium distachyon that have different flowering behavior. We then used a genotyping-by-sequencing approach to identify six quantitative trait locis that control differences in flowering time.

The Impact

Increasing biomass yield could improve the economics of biomass as an energy source. By furthering the molecular-level understanding of the flowering regulatory network in the model grass Brachypodium distachyon, we are advancing the potential to manipulate flowering time in bioenergy grass crops to increase biomass yield.

Summary

The transition to reproductive development is a crucial step in the plant life cycle, and the timing of this transition is an important factor in crop yields. Here, we report new insights into the genetic control of natural variation in flowering time in Brachypodium distachyon, a non-domesticated pooid grass closely related to cereals such as wheat and barley. A recombinant inbred line population derived from a cross between the rapid-flowering accession Bd21 and the delayed-flowering accession Bd1-1 were grown in a variety of environmental conditions to enable exploration of the genetic architecture of flowering time. A genotyping-by-sequencing approach was used to develop SNP markers for genetic map construction, and quantitative trait loci (QTLs) that control differences in flowering time were identified. Many of the flowering-time QTLs are detected across a range of photoperiod and vernalization conditions, suggesting that the genetic control of flowering within this population is robust. The two major QTLs identified in undomesticated B. distachyon colocalize with VERNALIZATION1/PHYTOCHROME C and VERNALIZATION2, loci identified as flowering regulators in the domesticated crops wheat and barley. This suggests that variation in flowering time is controlled in part by a set of genes broadly conserved within pooid grasses.

Contacts (BER PM)

N. Kent Peters
Program Manager, Office of Biological and Environmental Research
kent.peters@science.doe.gov, 301-903-5549

(PI Contact)

Richard M. Amasino
University of Wisconsin - Madison
amasino@biochem.wisc.edu

Funding

This work was funded by: the National Science Foundation under grant no. IOS-1258126; the Great Lakes Bioenergy Research Center (Department of Energy Biological and Environmental Research Office of Science grant no. DE-FCO2 07ER64494); the U.S. Department of Energy Joint Genome Institute (a Department of Energy Office of Science User Facility), which is supported under contract no. DE-AC02-05CH11231, with additional funding provided by Office of Biological and Environmental Research, Office of Science, U.S. Department of Energy, under interagency agreement no. DE-SC0006999; USDA-ARS CRIS project no. 5062-21000-030-00D; a National Institutes of Health-sponsored predoctoral training fellowship to the University of Wisconsin Genetics Training Program; and a post doctoral fellowship from the Belgian American Educational Foundation (BAEF).

Publications

Woods, D.P. et al. “Genetic architecture of flowering-time variation in Brachypodium distachyon.” Plant Physiology 173, 269-279 (2017) [DOI: 10.1104/pp.16.01178]. 

Related Links

http://www.plantphysiol.org/content/173/1/269.full.pdf+html

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