OsMADS50 functions as a LD-specific flowering activator.
OsMADS50 functions as a LD-specific flowering activator that functions only under LD conditions.
OsMADS50 encodes MIKC-type MADS-box proteins . MADS-box genes play important roles in several developmental processes, e.g. control of flowering time, floral organ identity and fruit developmen.
OsMADS50 serves as a flowering activator by controlling various floral regulators such as OsMADS1, OsMADS14, OsMADS15, OsMADS18 and Hd3a.It causing early flowering when overexpressed and delayed flowering when suppressed.OsMADS50 activates Ehd1 expression, and in turn Ehd1 activates RFT1 expression. RFT1 acts as the LD-specific florigen(from reference ).
OsMADS50 KO plants
RNA gel blot analysis revealed that OsMADS50 was variably expressed in most organs (Figure 6a). This gene was detected at a low level during the seedling stage, with transcripts increasing as the plant matured. In young panicles, expression was initially low, and continued to decline as these organs matured. RT-PCR analysis of leaves at four developmental stages confirmed the RNA gel blot analysis (Figure 6b). OsMADS50 transcript was detected at all four stages, with the expression level slightly increasing in 49-day-old plants compared with those that were 20 days old. The transcripts of Hd3a, OsMADS14, OsMADS15, and OsMADS18 increased gradually, reaching a maximum at 80 days.
In rice, OsMADS50 is the protein most homologous with SOC1/AGL20, showing 50.6% identity, whereas OsMADS56 has 48.3% identity. Genome-wide phylogenic analysis showed that OsMADS50 is clustered with the SOC1-group MADS-box proteins.
OsMADS50 is the putative ortholog of SOC1/AGL20.
OsMADS50 is upstream of OsMADS1, OsMADS14, OsMADS15, and OsMADS18.Expression analyses of the MADS-box genes in WT plants demonstrated that
OsMADS50 acts upstream of the other MADS-box genes.
OsMADS50 physically interacts with OsMADS56.Because both OsMADS50 and OsMADS56 appear to function as LD-specific regulators,the OsMADS50 KC region indeed binds to the OsMADS56 KC.
OsMADS50 is epistatic to Hd3a.Three genes, OsGI, Hd1, and Hd3a, play major roles in the photoperiodic flowering pathway.The expression of OsGI and Hd1 was not affected by OsMADS50, thereby indicating that they act upstream of or in parallel with OsMADS50. In contrast, Hd3a was downregulated in the OsMADS50 KO plants, implying that OsMADS50 is epistatic to Hd3a.
Labs working on this gene
Department of Life Science and Functional Genomic Center, Pohang University of Science and Technology (POSTECH)
National Key Laboratory for Crop Genetics and Germplasm Enhancement, Jiangsu Plant Gene Engineering Research Center,Nanjing Agricultural University
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- Lee S Y, Jang S H, Jun S H, et al. Functional analysis of MADS-box genes expressed preferentially in vegetative tissues[C]//Advances in rice genetics, Los Baños, Laguna, Philippines, 22-27 October 2000. World Scientific Publishing Co. Pte. Ltd, 2003: 414-416.