Gene Details:

Functional Descriptions:

  • RT-PCR analyses of the OsMADS50 KO and ubiquitin (ubi):OsMADS50 plants showed that OsMADS50 is an upstream regulator of OsMADS1, OsMADS14, OsMADS15, OsMADS18, and Hd (Heading date)3a, but works either parallel with or downstream of Hd1 and O.
  • These results suggest that OsMADS50 is an important flowering activator that controls various floral regulators in rice.
  • We previously reported that OsMADS50, which is highly homologous to Arabidopsis SOC1, functions as a positive regulator for flowering.
  • Knock-out of OsMADS50 caused a late-flowering phenotype only under LD conditions.
  • These observations imply that OsMADS50 and OsMADS56 function antagonistically through OsLFL1-Ehd1 in regulating LD-dependent flowering.
  • OsMADS50 and OsMADS56 function antagonistically in regulating long day (LD)-dependent flowering in rice.
  • In these transgenics, the expression levels of known flowering time genes reveal RFL as a regulator of OsSOC1 (OsMADS50), an activator of flowering.
  • OsSOC1 is expressed in vegetative tissues, and expression is elevated at the time of floral initiation, 40-50 days after sowing, and remains uniformly high thereafter, similar to the expression pattern of AtSOC1.
  • Among them, the OsMADS50 and Heading date1 pathways were not affected by the mutation.
  • By analyzing a large F2 population from NIL x DJY1, the locus DTH3 (QTL for days to heading on chromosome 3) controlling early heading date in DJY1 was fine mapped to a 64-kb segment which contained only one annotated gene, a MIKC-type MADS-box protein.
  • The Early heading date 1 (Ehd1) which promotes the RFT1, was up-regulated by DTH3 in both LD and SD conditions.
  • Heading date gene, DTH3 controlled late flowering in O. Glaberrima Steud. by down-regulating Ehd1.
  • In a screen for MADS box genes which activate and/or repress flowering in rice, we identified a gene encoding a MADS domain protein (OsSOC1) related to the Arabidopsis gene AtSOC1.
  • The constitutive expression of OsSOC1 in Arabidopsis results in early flowering, suggesting that the rice gene is a functional equivalent of AtSOC1.
  • We were not able to identify FLC-like sequences in the rice genome; however, we show that ectopic expression of the Arabidopsis FLC delays flowering in rice, and the up-regulation of OsSOC1 at the onset of flowering initiation is delayed in the AtFLC transgenic lines.
  • Reciprocal control of flowering time by OsSOC1 in transgenic Arabidopsis and by FLC in transgenic rice.
  • Furthermore, mutants in OsMADS50, a rice ortholog of Arabidopsis SUPPRESOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) did not flower up to 300 days after sowing under LD conditions, indicating that OsMADS50, which acts upstream of RFT1, promotes flowering under LD conditions.
  • We propose that both positive (OsMADS50 and Ehd1) and negative (Hd1, phyB and Ghd7) regulators of RFT1 form a gene network that regulates LD flowering in rice.
  • The expression of Hd3a and FTL decreased in these transgenic plants, whereas the expression of Hd1, Early heading date 1 (Ehd1), OsMADS51, and OsMADS50 did not significantly change.
  • OsSOC1 is located on top of the short arm of chromosome 3, tightly linked to the heading date locus, Hd9.
  • We detected a 6-bp deletion and a single base substitution in the C-domain by sequencing DTH3 in DJY1 compared with DTH3 in NIL, and overexpression of DTH3 caused early flowering in callus.
  • DTH3 affected flowering time and had no significant effect on the main agronomic traits.
  • Functional analyses of the flowering time gene OsMADS50, the putative SUPPRESSOR OF OVEREXPRESSION OF CO 1/AGAMOUS-LIKE 20 (SOC1/AGL20) ortholog in rice.
  • While overexpression of OsMADS50 caused extremely early flowering at the callus stage, OsMADS50 RNAi plants exhibited phenotypes of late flowering and an increase in the number of elongated internodes.

Literature:

Gene Resources:

Sequences:

cDNA Sequence
  • >LOC_Os03g03070.1
    AATAAGCATATATAAGATCCCTGCACTGAAGCAGGGACAGTACTATTTTTAAGACAAAGAAAATCAGATGTATTCTAGACTTTTAAGAATCAGTTTTCAATTCACCAAGGATGTGCATAGTCTTCGAGATTATGCAAGTAAAAGCTGACGCTGATGGTTTGGCAAAGAAACTTGAAGCTCTTGAAACTTACAAAAGAAAACTGCTGGGTGAAAAGTTGGATGAATGTTCTATTGAAGAACTGCATAGCCTGGAGGTCAAGCTGGAGAGAAGCCTCATTAGCATCAGGGGAAGGAAGACAAAGCTGCTTGAGGAGCAGGTTGCCAAACTGAGAGAGAAGGAGATGAAGCTGCGCAAGGACAATGAAGAGTTACGCGAAAAGTGTAAGAATCAGCCTCCCTTGTCTGCTCCTTTGACTGTCCGGGCCGAAGATGAGAACCCGGACCGTAACATCAACACCACCAACGACAACATGGATGTCGAAACTGAGCTATTCATAGGGCTGCCTGGCAGAAGTCGCTCCAGCGGCGGTGCTGCAGAAGATAGCCAAGCGATGCCCCATTCTTAAGTAACAGGCCAGGAATAAGCTGGATCTCTGCGTTGAGAAAGGAGATGATGCTAGGCATGCAATGACACCAAACCATCCTAAAAACAGACCACGCTGTATATTTTACTTACCCGTATTGTCGTCCATGGATGCGAAATGCTAGACGCATATGCACCCACCCATTCAGCACCACCAGGCAGAAACCCTTCGATCGGCAGACTCCACTACCCATCTAAATCTAAATCGAGAGATCTCAAGTGCATACTTGTACTCCTGCTTGATTGTGGCTTGGTATTTGATGTGATGTTGGAGCAAACATATGCTGAACATATCTCAGTTGAGATTCTCTGCACAAGGCCGGAACGGGAGGAAGACGAAAGGAGGAGTTTTAAAGAGGGAGGGAGTACATTCAGGTGACAGATCGCTTTGACCTGTACCCCTGTTGTATATGACGCGCTATGCTGGTATTGGTCGACGTTTCGATCTCTTGAATGCTACCTGTGGTCGACGTGTCGATTGGGCAGTGGAAGCCGAGGAGACTTATGGACCCTTATCCCCATCGCTTCTAGTAGTATCCCTCGATTCGGTGCGTGATAACGGTTTTTGCTTGCAAAGCCGCGATGTGATTTTTCCAACTCTGGAGTCTGAAGTAGTAGTAGTATATTTCTCTTTACAGCGAGTATATATGGAATTTTTTTGAGAATTAATATTATTTTTATGGAAAATCGCAAAA
CDS Sequence
  • >LOC_Os03g03070.1
    ATGTGCATAGTCTTCGAGATTATGCAAGTAAAAGCTGACGCTGATGGTTTGGCAAAGAAACTTGAAGCTCTTGAAACTTACAAAAGAAAACTGCTGGGTGAAAAGTTGGATGAATGTTCTATTGAAGAACTGCATAGCCTGGAGGTCAAGCTGGAGAGAAGCCTCATTAGCATCAGGGGAAGGAAGACAAAGCTGCTTGAGGAGCAGGTTGCCAAACTGAGAGAGAAGGAGATGAAGCTGCGCAAGGACAATGAAGAGTTACGCGAAAAGTGTAAGAATCAGCCTCCCTTGTCTGCTCCTTTGACTGTCCGGGCCGAAGATGAGAACCCGGACCGTAACATCAACACCACCAACGACAACATGGATGTCGAAACTGAGCTATTCATAGGGCTGCCTGGCAGAAGTCGCTCCAGCGGCGGTGCTGCAGAAGATAGCCAAGCGATGCCCCATTCTTAA
Protein Sequence
  • >LOC_Os03g03070.1
    MCIVFEIMQVKADADGLAKKLEALETYKRKLLGEKLDECSIEELHSLEVKLERSLISIRGRKTKLLEEQVAKLREKEMKLRKDNEELREKCKNQPPLSAPLTVRAEDENPDRNINTTNDNMDVETELFIGLPGRSRSSGGAAEDSQAMPHS*