MicroRNAs are a class of endogenous small non-coding RNAs,some of which can trigger phased secondary small interfering RNA(phasiRNA)production from target genes.Mitochondrial transcription termination factors(mTERFs),...MicroRNAs are a class of endogenous small non-coding RNAs,some of which can trigger phased secondary small interfering RNA(phasiRNA)production from target genes.Mitochondrial transcription termination factors(mTERFs),mainly localized in chloroplasts and/or mitochondria,play critical roles in plant development and stress responses.We report here the identification of 63 mTERFs and a 22 nt novel miRNA(smi-miRmTERF),which directly cleave SmmTERF33 and SmmTERF45 transcripts to trigger phasiRNA biogenesis.The generated phasiRNAs could further trigger phasiRNA biogenesis from SmmTERF26 and regulated a subset of lineage-specific SmmTERFs.MIRmTERF widely existed in Nepetoideae plants and SmmTERF33 and SmmTERF45 proteins were localized in chloroplasts,mitochondria,and the cytoplasm.Smi-miRmTERF overexpression(MIRMTERF#OE)resulted in a dwarfing phenotype with severe defects in chloroplast and mitochondrial morphogenesis.Transcriptomic analysis showed up-regulation of defenserelated and down-regulation of photosynthesis-related genes in MIRMTERF#OE plants.Under norflurazon and lincomycin treatments,MIRMTERF#OE plants displayed a gun phenotype,indicating the role of smi-miRmTERF in retrograde signaling.Furthermore,MIRMTERF#OE plants showed increased contents of phenolic acids,monoterpenoids,and sesquiterpenoids and reduced susceptibility to pathogenic bacteria Pst DC3000.The results suggest that smimiRmTERF is a significant regulator of chloroplast and mitochondrial development,retrograde signaling,secondary metabolism,and immunity in S.miltiorrhiza.展开更多
基金supported by the CAMS Innovation Fund for Medical Sciences(CIFMS)(2022-I2M-2–001).
文摘MicroRNAs are a class of endogenous small non-coding RNAs,some of which can trigger phased secondary small interfering RNA(phasiRNA)production from target genes.Mitochondrial transcription termination factors(mTERFs),mainly localized in chloroplasts and/or mitochondria,play critical roles in plant development and stress responses.We report here the identification of 63 mTERFs and a 22 nt novel miRNA(smi-miRmTERF),which directly cleave SmmTERF33 and SmmTERF45 transcripts to trigger phasiRNA biogenesis.The generated phasiRNAs could further trigger phasiRNA biogenesis from SmmTERF26 and regulated a subset of lineage-specific SmmTERFs.MIRmTERF widely existed in Nepetoideae plants and SmmTERF33 and SmmTERF45 proteins were localized in chloroplasts,mitochondria,and the cytoplasm.Smi-miRmTERF overexpression(MIRMTERF#OE)resulted in a dwarfing phenotype with severe defects in chloroplast and mitochondrial morphogenesis.Transcriptomic analysis showed up-regulation of defenserelated and down-regulation of photosynthesis-related genes in MIRMTERF#OE plants.Under norflurazon and lincomycin treatments,MIRMTERF#OE plants displayed a gun phenotype,indicating the role of smi-miRmTERF in retrograde signaling.Furthermore,MIRMTERF#OE plants showed increased contents of phenolic acids,monoterpenoids,and sesquiterpenoids and reduced susceptibility to pathogenic bacteria Pst DC3000.The results suggest that smimiRmTERF is a significant regulator of chloroplast and mitochondrial development,retrograde signaling,secondary metabolism,and immunity in S.miltiorrhiza.
