A cis-acting bidirectional transcription switch controls sexual dimorphism in the liverwort.
Plant life cycles alternate between haploid gametophytes and diploid sporophytes. While regulatory factors determining male and female sexual morphologies have been identified for sporophytic reproductive organs, such as stamens and pistils of angiosperms, those regulating sex-specific traits in the haploid gametophytes that produce male and female gametes and hence are central to plant sexual reproduction are poorly understood. Here, we identified a MYB-type transcription factor, MpFGMYB, as a key regulator of female sexual differentiation in the haploid-dominant dioicous liverwort, Marchantia polymorpha MpFGMYB is specifically expressed in females and its loss resulted in female-to-male sex conversion. Strikingly, MpFGMYB expression is suppressed in males by a cis-acting antisense gene SUF at the same locus, and loss-of-function suf mutations resulted in male-to-female sex conversion. Thus, the bidirectional transcription module at the MpFGMYB/SUF locus acts as a toggle between female and male sexual differentiation in M. polymorpha gametophytes. Arabidopsis thaliana MpFGMYB orthologs are known to be expressed in embryo sacs and promote their development. Thus, phylogenetically related MYB transcription factors regulate female gametophyte development across land plants.
['Hisanaga|Tetsuya|T|0000-0002-2834-7044', 'Okahashi|Keitaro|K|', 'Yamaoka|Shohei|S|0000-0003-4154-9967', 'Kajiwara|Tomoaki|T|', 'Nishihama|Ryuichi|R|0000-0002-7032-732X', 'Shimamura|Masaki|M|0000-0002-5665-5116', 'Yamato|Katsuyuki T|KT|0000-0002-7130-0911', 'Bowman|John L|JL|0000-0001-7347-3691', 'Kohchi|Takayuki|T|0000-0002-9712-4872', 'Nakajima|Keiji|K|0000-0002-1580-3354']
D017360:Arabidopsis D029681:Arabidopsis Proteins D056130:Gametogenesis, Plant D018506:Gene Expression Regulation, Plant D055993:Germ Cells, Plant D035926:Hepatophyta D010802:Phylogeny D010940:Plant Proteins D020598:Proto-Oncogene Proteins c-myb D050436:Regulatory Elements, Transcriptional D012727:Sex Characteristics D014157:Transcription Factors D014158:Transcription, Genetic
sexual differentiation Marchantia polymorpha R2R3 MYB‐type transcription factor antisense transcription lncRNA