MicroRNA390(miR390)is involved in plant growth and development by down-regulating the expression of the downstream genes trans-acting short interfering RNA3(TAS3)and AUXIN RESPONSE FACTORs(ARFs).There is a scarcity of...MicroRNA390(miR390)is involved in plant growth and development by down-regulating the expression of the downstream genes trans-acting short interfering RNA3(TAS3)and AUXIN RESPONSE FACTORs(ARFs).There is a scarcity of research on the involvement of the miR390-TAS3-ARFs pathway in the stem development of Populus.Here,differentially expressedmiRNAs during poplar stem development were screened by small RNA sequencing analysis,and a novel function of miR390b in stem development was revealed.Overexpression of miR390b(OE-miR390b)resulted in a large increase in the number of xylem fiber cells and a slight decrease in the cell length at the longitudinal axis.Overall increases in stem elongation and plant height were observed in the OE-miR390b plants.According to transcriptome sequencing results and transient co-expression analysis,TAS3.1 and TAS3.2 were identified as the target genes of miR390 in poplar and were negatively regulated by miR390 in the apex.The transcription levels of ARF3.2 and ARF4 were significantly repressed in OE-miR390b plants and strongly negatively correlatedwith the number of xylem fiber cells along the longitudinal axis.These findings indicate that the conserved miR390-TAS3-ARFs pathway in poplar is involved in stem elongation and plant height growth.展开更多
基金supported by the National Natural Science Foundation of China(32171821 and 31770639)Science and Technology Projects of Shennongjia Academy of Forestry,Hubei,China(Grant number:SAF202107)the Project 2662022YLYJ009 supported by the Fundamental Research Funds for the Central Universities.We are grateful to Professor Feng Li(Huazhong Agricultural University)for providing the vector pMS4v2,and Dr Kebing Du(Huazhong Agricultural University)for supplying the P.deltoides clones.
文摘MicroRNA390(miR390)is involved in plant growth and development by down-regulating the expression of the downstream genes trans-acting short interfering RNA3(TAS3)and AUXIN RESPONSE FACTORs(ARFs).There is a scarcity of research on the involvement of the miR390-TAS3-ARFs pathway in the stem development of Populus.Here,differentially expressedmiRNAs during poplar stem development were screened by small RNA sequencing analysis,and a novel function of miR390b in stem development was revealed.Overexpression of miR390b(OE-miR390b)resulted in a large increase in the number of xylem fiber cells and a slight decrease in the cell length at the longitudinal axis.Overall increases in stem elongation and plant height were observed in the OE-miR390b plants.According to transcriptome sequencing results and transient co-expression analysis,TAS3.1 and TAS3.2 were identified as the target genes of miR390 in poplar and were negatively regulated by miR390 in the apex.The transcription levels of ARF3.2 and ARF4 were significantly repressed in OE-miR390b plants and strongly negatively correlatedwith the number of xylem fiber cells along the longitudinal axis.These findings indicate that the conserved miR390-TAS3-ARFs pathway in poplar is involved in stem elongation and plant height growth.