title: MPF2-like MADS-box genes affecting expression of SOC1 and MAF1 are recruited to control flowering time.
abstract: A complex and intricate network of genes responding to various developmental and environmental signals control floral transition in plants. MADS-box genes are the key regulators and major contributors with regard to flowering time determination. Previously, MPF2-like genes belonging to the STMADS11 superclade were duplicated into MPF2-like-A and MPF2-like-B in Withania (WSA206 and WSB206) and Tubocapsicum (TAB 201). The present study was conducted to determine the effect of MPF2-like genes on flowering time by analyzing 35S:MPF2-like transgenic Arabidopsis plants as well as to probe their effects on the expression of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1, a floral promoter) and MADS AFFECTING FLOWERING 1 (MAF1, a floral repressor) genes. The overexpression of WSA206 (35S:MPF2-like-A) moderately promoted flowering, while that of WSB206 and TAB 201 (35S:MPF2-like-B) exhibited no effects on floral transition. Concomitantly, an elevation in SOC1 transcript abundance and a reduction for MAF1 transcript levels were observed in 35S:WSA206 transgenic plants. Nucleotide diversity analysis indicated an extraordinary 8 aa extension at the C-terminus of the WSA206 protein. Ectopic expression of a truncated WSA206-version without these 8 aa (WSA206ΔC246) and of MPF2-like-B-versions elongated by these 8 aa (WSB206∇C257 and TAB 201∇C257) in Arabidopsis revealed an ambiguous role of the 8 aa signature in floral transition. It may influence a protein's ability to modulate flowering time but is neither sufficient nor strictly necessary for early flowering. Nevertheless, the 8 aa extension influences the expression of SOC1 and MAF1 in MPF2-like derivative constructs. Our studies provide insight into the role of MPF2-like genes in phase transition by interacting with SOC1 and MAF1 genes, thereby also pointing to their significance as potential candidates for modifying flowering in crop plants in the future.
authors.affiliation: National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Center, Park Road, Islamabad, Pakistan. rkhan_75@yahoo.com
authors.forename: Muhammad Ramzan
authors.initials: MR
authors.lastname: Khan
authors.forename: Irfan Ullah
authors.initials: IU
authors.lastname: Khan
authors.forename: Ghulam Muhammad
authors.initials: GM
authors.lastname: Ali
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics*; D035264:Flowers / Q000235:genetics / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D030821:Plants, Genetically Modified / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid
chemical_list: C419046:AGL20 protein, Arabidopsis; D029681:Arabidopsis Proteins; D026161:MADS Domain Proteins; D010940:Plant Proteins