Plant organ size is an important agronomic trait that makes a significant contribution to plant yield.Despite its central importance,the genetic and molecular mechanisms underlying organ size control remain to be full...Plant organ size is an important agronomic trait that makes a significant contribution to plant yield.Despite its central importance,the genetic and molecular mechanisms underlying organ size control remain to be fully clarified.Here,we report that the trithorax group protein ULTRAPETALA1(ULT1)interacts with the TEOSINTE BRANCHED1/CYCLOIDEA/PCF14/15(TCP14/15)transcription factors by antagonizing the LIN-11,ISL-1,and MEC-3(LIM)peptidase DA1,thereby regulating organ size in Arabidopsis.Loss of ULT1 function significantly increases rosette leaf,petal,silique,and seed size,whereas overexpression of ULT1 results in reduced organ size.ULT1 associates with TCP14 and TCP15 to co-regulate cell size by affecting cellular endoreduplication.Transcriptome analysis revealed that ULT1 and TCP14/15 regulate common target genes involved in endoreduplication and leaf development.ULT1 can be recruited by TCP14/15 to promote lysine 4 of histone H3 trimethylation at target genes,activating their expression to determinefinal cell size.Furthermore,we found that ULT1 influences the interaction of DA1 and TCP14/15 and antagonizes the effect of DA1 on TCP14/15 degradation.Collectively,ourfindings reveal a novel epigenetic mechanism underlying the regulation of organ size in Arabidopsis.展开更多
基金supported by the National Natural Science Foundation of China (31872805)the Fundamental Research Funds for Central NonProfit of the Chinese Academy of Agricultural Sciences (CAASZDRW202109 and Y2023PT20)the Nanfan Special Project of the Chinese Academy of Agricultural Sciences (YBXM15).
文摘Plant organ size is an important agronomic trait that makes a significant contribution to plant yield.Despite its central importance,the genetic and molecular mechanisms underlying organ size control remain to be fully clarified.Here,we report that the trithorax group protein ULTRAPETALA1(ULT1)interacts with the TEOSINTE BRANCHED1/CYCLOIDEA/PCF14/15(TCP14/15)transcription factors by antagonizing the LIN-11,ISL-1,and MEC-3(LIM)peptidase DA1,thereby regulating organ size in Arabidopsis.Loss of ULT1 function significantly increases rosette leaf,petal,silique,and seed size,whereas overexpression of ULT1 results in reduced organ size.ULT1 associates with TCP14 and TCP15 to co-regulate cell size by affecting cellular endoreduplication.Transcriptome analysis revealed that ULT1 and TCP14/15 regulate common target genes involved in endoreduplication and leaf development.ULT1 can be recruited by TCP14/15 to promote lysine 4 of histone H3 trimethylation at target genes,activating their expression to determinefinal cell size.Furthermore,we found that ULT1 influences the interaction of DA1 and TCP14/15 and antagonizes the effect of DA1 on TCP14/15 degradation.Collectively,ourfindings reveal a novel epigenetic mechanism underlying the regulation of organ size in Arabidopsis.
