Related Experiment Video
Updated: Apr 28, 2026

Direct Agroinoculation of Maize Seedlings by Injection with Recombinant Foxtail Mosaic Virus and Sugarcane Mosaic Virus Infectious Clones
Published on: February 27, 2021
CONSTANS is a photoperiod regulated activator of flowering in sorghum
Shanshan Yang, Brock D Weers, Daryl T Morishige
1Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX 77843-2128, USA. jmullet@neo.tamu.edu.
Background:
Sorghum genotypes used for grain production in temperate regions are photoperiod insensitive and flower early avoiding adverse environments during the reproductive phase. In contrast, energy sorghum hybrids are highly photoperiod sensitive with extended vegetative phases in long days, resulting in enhanced biomass accumulation. SbPRR37 and SbGHD7 contribute to photoperiod sensitivity in sorghum by repressing expression of SbEHD1 and FT-like genes, thereby delaying flowering in long days with minimal influence in short days (PNAS_108:16469-16474, 2011; Plant Genome_in press, 2014). The GIGANTEA (GI)-CONSTANS (CO)-FLOWERING LOCUS T (FT) pathway regulates flowering time in Arabidopsis and the grasses (J Exp Bot_62:2453-2463, 2011). In long day flowering plants, such as Arabidopsis and barley, CONSTANS activates FT expression and flowering in long days. In rice, a short day flowering plant, Hd1, the ortholog of CONSTANS, activates flowering in short days and represses flowering in long days.
Results:
Quantitative trait loci (QTL) that modify flowering time in sorghum were identified by screening Recombinant Inbred Lines (RILs) derived from BTx642 and Tx7000 in long days, short days, and under field conditions. Analysis of the flowering time QTL on SBI-10 revealed that BTx642 encodes a recessive CONSTANS allele containing a His106Tyr substitution in B-box 2 known to inactivate CONSTANS in Arabidopsis thaliana. Genetic analysis characterized sorghum CONSTANS as a floral activator that promotes flowering by inducing the expression of EARLY HEADING DATE 1 (SbEHD1) and sorghum orthologs of the maize FT genes ZCN8 (SbCN8) and ZCN12 (SbCN12). The floral repressor PSEUDORESPONSE REGULATOR PROTEIN 37 (PRR37) inhibits sorghum CONSTANS activity and flowering in long days.
Conclusion:
Sorghum CONSTANS is an activator of flowering that is repressed post-transcriptionally in long days by the floral inhibitor PRR37, contributing to photoperiod sensitive flowering in Sorghum bicolor, a short day plant.
More Related Videos
10:10Investigating Tissue- and Organ-specific Phytochrome Responses using FACS-assisted Cell-type Specific Expression Profiling in Arabidopsis thaliana
Published on: May 29, 2010
10:29Measuring Gene Expression in Bombarded Barley Aleurone Layers with Increased Throughput
Published on: March 30, 2018
Related Concept Videos
Biological Clocks and Seasonal Responses
Photoreceptors and Plant Responses to Light
Cell Signaling in Plants
Gene Regulation During Sporulation
Regulation of Transpiration by Stomata
Morphogenesis