GRAS transcription factor PINNATE-LIKE PENTAFOLIATA2 controls compound leaf morphogenesis in Medicago truncatula

• DOI: 10.1093/plcell/koae033
• Publication Date: 2024-02-06T12:57:29Z
• Authors: Liangliang He; Ye Liu; Yawen Mao; Xinyuan Wu; Xiaoling Zheng; Weiyue Zhao; Xiaoyu Mo; Ruoruo Wang; Qinq Wu; Dongfa Wang; Youhan Li; Yuanfan Yang; Quanzi Bai; Xiaojia Zhang; Shaoli Zhou; Baolin Zhao; Changning Liu; Yu Liu; Million Tadege; Jianghua Chen
• Keywords: Medicago truncatula; Medicago; Transcription

Abstract The milestone of compound leaf development is the generation separate leaflet primordia during early stages, which involves two linked but distinct morphogenetic events: initiation and boundary establishment for separation. Although some progress in understanding regulatory pathways each event have been made, it unclear how they are intrinsically coordinated. Here, we identify PINNATE-LIKE PENTAFOLIATA2 (PINNA2) gene encoding a newly identified GRAS transcription factor Medicago truncatula. PINNA2 transcripts preferentially detected at organ boundaries. Its loss-of-function mutations convert trifoliate leaves into pinnate pentafoliate pattern. directly binds to promoter region LEAFY orthologue SINGLE LEAFLET1 (SGL1), encodes key positive regulator initiation, downregulates its expression. Further analysis revealed that synergizes with other repressors SGL1 expression, BEL1-like homeodomain protein PINNA1 C2H2 zinc finger PALMATE-LIKE PENTAFOLIATA1 (PALM1), precisely define spatiotemporal expression primordia, thereby maintaining proper pattern initiation. Moreover, showed enriched leaflet-to-leaflet boundaries positively regulated by boundary-specific MtNAM, essential formation. Together, these results unveil pivotal role boundary-expressed regulating providing molecular insights coordination intricate developmental processes underlying