biostudies-literatureSakai YSuntory Foundation for Life SciencesKyoto University FoundationMinistry of Education, Culture, Sports, Science and TechnologyAsahi Glass FoundationYamada Science FoundationOhsumi Frontier Science FoundationJapan Science and Technology AgencyJapan Society for the Promotion of Science2678-2696https://www.ebi.ac.uk/biostudies/studies/S-EPMC12371152biostudies-literatureUnknown247(6)Many plants reproduce asexually by generating clonal progeny from vegetative tissues, a process known as vegetative reproduction. This reproduction mode contrasts with sexual reproduction, which enhances genetic diversity. The bryophyte Marchantia polymorpha L. adjusts its reproductive strategy in response to seasonal environmental cues, transitioning between vegetative and sexual reproduction. In this study, we identified a gene encoding the R2R3-MYB transcription factor SHOT GLASS (MpSTG) as a critical regulator of gemma cup development. MpSTG was predominantly expressed in the gemma cup, apical notch, and sexual reproductive organs (gametangiophores). MpSTG mutation resulted in the formation of abnormal shot-glass-shaped structures lacking gemmae, which replaced functional gemma cups. Additionally, MpSTG-disrupted plants failed to develop sexual reproductive organs, even under inductive conditions. In Arabidopsis thaliana, the MpSTG ortholog LATERAL ORGAN FUSION1 (AtLOF1) plays a pivotal role in lateral bud formation. We demonstrated that MpSTG can partially compensate for AtLOF1's function in lateral bud formation in A. thaliana. Our findings suggest that MpSTG is a key regulator of vegetative and sexual reproduction in M. polymorpha, and illustrate that evolutionarily conserved developmental mechanisms may function in both the gametophyte generation of bryophytes and the sporophyte generation of angiosperms.The New phytologistSHOT GLASS, an R2R3-MYB transcription factor, promotes gemma cup and gametangiophore development in Marchantia polymorpha.PMC12371152KAKENHI 21K15125KAKENHI 15H01233KAKENHI 15H04391KAKENHI 19H05673KAKENHI 19H05670J-PEAKSKAKENHI 20H05780KAKENHI 17H06472KAKENHI25K09689KAKENHI 19H03247KAKENHI 21J40092J‐PEAKSKAKENHI 25119711JPMJGX23B0Kato HFukaki HSakai YKohchi TYamaoka SIshizaki KTakami HfalseSHOT GLASS, an R2R3-MYB transcription factor, promotes gemma cup and gametangiophore development in Marchantia polymorpha.Many plants reproduce asexually by generating clonal progeny from vegetative tissues, a process known as vegetative reproduction. This reproduction mode contrasts with sexual reproduction, which enhances genetic diversity. The bryophyte Marchantia polymorpha L. adjusts its reproductive strategy in response to seasonal environmental cues, transitioning between vegetative and sexual reproduction. In this study, we identified a gene encoding the R2R3-MYB transcription factor SHOT GLASS (MpSTG) as a critical regulator of gemma cup development. MpSTG was predominantly expressed in the gemma cup, apical notch, and sexual reproductive organs (gametangiophores). MpSTG mutation resulted in the formation of abnormal shot-glass-shaped structures lacking gemmae, which replaced functional gemma cups. Additionally, MpSTG-disrupted plants failed to develop sexual reproductive organs, even under inductive conditions. In Arabidopsis thaliana, the MpSTG ortholog LATERAL ORGAN FUSION1 (AtLOF1) plays a pivotal role in lateral bud formation. We demonstrated that MpSTG can partially compensate for AtLOF1's function in lateral bud formation in A. thaliana. Our findings suggest that MpSTG is a key regulator of vegetative and sexual reproduction in M. polymorpha, and illustrate that evolutionarily conserved developmental mechanisms may function in both the gametophyte generation of bryophytes and the sporophyte generation of angiosperms.2025-01-01T00:00:00Z2025 Sep2026-05-08T10:53:15.728Z2026-05-03T03:06:15.237ZS-EPMC123711524073422910.1111/nph.70337