Maturity2, a novel regulator of flowering time in Sorghum bicolor, increases expression of SbPRR37 and SbCO in long days delaying flowering

Anna L Casto; Ashley J Mattison; Sara N Olson; Manish Thakran; William L Rooney; John E Mullet

doi:10.1371/journal.pone.0212154

Maturity2, a novel regulator of flowering time in Sorghum bicolor, increases expression of SbPRR37 and SbCO in long days delaying flowering

PLoS One. 2019 Apr 10;14(4):e0212154. doi: 10.1371/journal.pone.0212154. eCollection 2019.

Authors

Anna L Casto¹, Ashley J Mattison¹, Sara N Olson¹, Manish Thakran¹, William L Rooney², John E Mullet¹

Affiliations

¹ Biochemistry and Biophysics Department, Texas A&M University, College Station, TX, United States of America.
² Soil and Crop Science Department, Texas A&M University, College Station, TX, United States of America.

Abstract

Sorghum bicolor is a drought-resilient facultative short-day C4 grass that is grown for grain, forage, and biomass. Adaptation of sorghum for grain production in temperate regions resulted in the selection of mutations in Maturity loci (Ma1 -Ma6) that reduced photoperiod sensitivity and resulted in earlier flowering in long days. Prior studies identified the genes associated with Ma1 (PRR37), Ma3 (PHYB), Ma5 (PHYC) and Ma6 (GHD7) and characterized their role in the flowering time regulatory pathway. The current study focused on understanding the function and identity of Ma2. Ma2 delayed flowering in long days by selectively enhancing the expression of SbPRR37 (Ma1) and SbCO, genes that co-repress the expression of SbCN12, a source of florigen. Genetic analysis identified epistatic interactions between Ma2 and Ma4 and located QTL corresponding to Ma2 on SBI02 and Ma4 on SBI10. Positional cloning and whole genome sequencing identified a candidate gene for Ma2, Sobic.002G302700, which encodes a SET and MYND (SYMD) domain lysine methyltransferase. Eight sorghum genotypes previously identified as recessive for Ma2 contained the mutated version of Sobic.002G302700 present in 80M (ma2) and one additional putative recessive ma2 allele was identified in diverse sorghum accessions.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Circadian Rhythm Signaling Peptides and Proteins / genetics
Flowers / genetics
Flowers / growth & development*
Gene Expression Regulation, Plant*
Genes, Plant
Photoperiod
Plant Proteins / genetics
Quantitative Trait Loci*
Sorghum / genetics
Sorghum / growth & development*

Substances

Circadian Rhythm Signaling Peptides and Proteins
Plant Proteins

Grants and funding

This research was supported by the Perry Adkisson Chair in Agricultural Biology (awarded to JEM) and by the Agriculture and Food Research Initiative Competitive Grant 2016-67013-24617 from the USDA National Institute of Food and Agriculture (awarded to JEM, https://nifa.usda.gov/program/agriculture-and-food-research-initiative-afri). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.