Tension wood(TW)is a specialized xylem tissue formed in angiosperm trees under gravitational stimulus or mechanical stresses(e.g.,bending).The genetic regulation that underlies this important mechanism remains poorly ...Tension wood(TW)is a specialized xylem tissue formed in angiosperm trees under gravitational stimulus or mechanical stresses(e.g.,bending).The genetic regulation that underlies this important mechanism remains poorly understood.Here,we used laser capture microdissection of stem xylem cells coupled with full transcriptome RNA-sequencing to analyze TW formation in Populus trichocarpa.After tree bending,PtrLBD39 was the most significantly induced transcription factor gene;it has a phylogenetically paired homolog,PtrLBD22.CRISPR-based knockout of PtrLBD39/22 severely inhibited TW formation,reducing cellulose and increasing lignin content.Transcriptomic analyses of CRISPR-based PtrLBD39/22 double mutants showed that these two genes regulate a set of TW-related genes.Chromatin immunoprecipitation sequencing(ChIP-seq)was used to identify direct targets of PtrLBD39.We integrated transcriptomic analyses and ChIP-seq assays to construct a transcriptional regulatory network(TRN)mediated by PtrLBD39.In this TRN,PtrLBD39 directly regulates 26 novel TW-responsive transcription factor genes.Our work suggests that PtrLBD39 and PtrLBD22 specifically control TW formation by mediating a TW-specific TRN in Populus.展开更多
The DNA binding with one finger(Dof)proteins are plant-specific transcription factors involved in a variety of biological processes.However,little is known about their functions in fruit ripening,a flowering-plant-spe...The DNA binding with one finger(Dof)proteins are plant-specific transcription factors involved in a variety of biological processes.However,little is known about their functions in fruit ripening,a flowering-plant-specific process that is required for seed maturation and dispersal.Here,we found that the tomato Dof transcription factor SlDof1,is necessary for normal fruit ripening.Knockdown of SlDof1 expression by RNA interference delayed ripening-related processes,including lycopene synthesis and ethylene production.Transcriptome profiling indicated that SlDof1 influences the expression of hundreds of genes,and a chromatin immunoprecipitation sequencing revealed a large number of SlDof1 binding sites.A total of 312 genes were identified as direct targets of SlDof1,among which 162 were negatively regulated by SlDof1 and 150 were positively regulated.The SlDof1 target genes were involved in a variety of metabolic pathways,and follow-up analyses verified that SlDof1 directly regulates some well-known ripening-related genes including ACS2 and PG2A as well as transcriptional repressor genes such as SlIAA27.Our findings provide insights into the transcriptional regulatory networks underlying fruit ripening and highlight a gene potentially useful for genetic engineering to control ripening.展开更多
基金This work was supported by the National Key Research and Development Program of China(no.2016YFD0600106)We also acknowledge financial support from the National Natural Science Foundation of China(grant nos.32001332 and 32001331)+1 种基金the Fundamental Research Funds for the Central Universities of China(grant nos.2572018CL01 and 2572018CL02)the Heilongjiang Touyan Innovation Team Program(Tree Genetics and Breeding Innovation Team).
文摘Tension wood(TW)is a specialized xylem tissue formed in angiosperm trees under gravitational stimulus or mechanical stresses(e.g.,bending).The genetic regulation that underlies this important mechanism remains poorly understood.Here,we used laser capture microdissection of stem xylem cells coupled with full transcriptome RNA-sequencing to analyze TW formation in Populus trichocarpa.After tree bending,PtrLBD39 was the most significantly induced transcription factor gene;it has a phylogenetically paired homolog,PtrLBD22.CRISPR-based knockout of PtrLBD39/22 severely inhibited TW formation,reducing cellulose and increasing lignin content.Transcriptomic analyses of CRISPR-based PtrLBD39/22 double mutants showed that these two genes regulate a set of TW-related genes.Chromatin immunoprecipitation sequencing(ChIP-seq)was used to identify direct targets of PtrLBD39.We integrated transcriptomic analyses and ChIP-seq assays to construct a transcriptional regulatory network(TRN)mediated by PtrLBD39.In this TRN,PtrLBD39 directly regulates 26 novel TW-responsive transcription factor genes.Our work suggests that PtrLBD39 and PtrLBD22 specifically control TW formation by mediating a TW-specific TRN in Populus.
基金This work was supported by the National Natural Science Foundation of China(grant Nos.31925035,31930086,and 31572174).
文摘The DNA binding with one finger(Dof)proteins are plant-specific transcription factors involved in a variety of biological processes.However,little is known about their functions in fruit ripening,a flowering-plant-specific process that is required for seed maturation and dispersal.Here,we found that the tomato Dof transcription factor SlDof1,is necessary for normal fruit ripening.Knockdown of SlDof1 expression by RNA interference delayed ripening-related processes,including lycopene synthesis and ethylene production.Transcriptome profiling indicated that SlDof1 influences the expression of hundreds of genes,and a chromatin immunoprecipitation sequencing revealed a large number of SlDof1 binding sites.A total of 312 genes were identified as direct targets of SlDof1,among which 162 were negatively regulated by SlDof1 and 150 were positively regulated.The SlDof1 target genes were involved in a variety of metabolic pathways,and follow-up analyses verified that SlDof1 directly regulates some well-known ripening-related genes including ACS2 and PG2A as well as transcriptional repressor genes such as SlIAA27.Our findings provide insights into the transcriptional regulatory networks underlying fruit ripening and highlight a gene potentially useful for genetic engineering to control ripening.
