|Murphy, Rebecca -|
|Morishige, Daryl -|
|Brady, Jeff -|
|Rooney, William -|
|Miller, Frederick -|
|Dugas, Diana -|
|Klein, Patricia -|
|Mullet, John -|
Submitted to: Proceedings of the National Academy of Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 3, 2011
Publication Date: September 27, 2011
Citation: Murphy, R.L., Klein, R.R., Morishige, D.T., Brady, J.A., Rooney, W.L., Miller, F.R., Dugas, D.V., Klein, P.E., Mullet, J.E. 2011. Coincident light and clock regulation of pseudoresponse regulator protein 37 (PRR37) controls photoperiodic flowering in sorghum. Proceedings of the National Academy of Sciences. 108(39):16469-16474. Interpretive Summary: Major advancements in science hinge on the identification of genes controlling plant and animal traits that are critically important to agriculture. Genes are tiny packets of genetic blueprint material that are found inside the cells of all plants and animals and control all of the physical characteristics of these organisms. Our work focuses on improving major grain crops and, with gene sequences, the genetic blueprint will be visible and this information can make improving the plants more efficient. This study details the isolation of a major plant gene, named Ma1 that controls flowering date in sorghum. The cloning of this gene and understanding how this gene controls flowering through the plant biological clock will allow scientists to understand those key features of the genetic blueprint that make sorghum's physical appearance differ from that of other cereals. Information will be primarily used by fellow scientists, but the work should ultimately result in better adapted, higher producing crop varieties available to American farmers.
Technical Abstract: Variation in flowering time was essential during widespread crop domestication and optimal timing of reproduction remains critical to modern agriculture. Ma1, the major repressor of flowering in sorghum in long days, was identified as the pseudo-response regulator protein PRR37. Three prr37 alleles were found with mutations in the PRR37 protein that are likely the causal basis for photoperiod insensitivity. SbPRR37 represses flowering by activating expression of the floral inhibitor CONSTANS, and by inhibiting expression of the floral activators EARLY HEADING DATE 1 and FLOWERING LOCUS T. Expression of SbPRR37 is light dependent and regulated by the circadian clock, with peaks of RNA abundance in the morning and evening in long days. In short days, expression of SbPRR37 in the evening is eliminated allowing sorghum to initiate flowering.