Plant migration and gene flow from genetically modified or exotic trees to nearby lands or by crossing with wild relatives is a major public and regulatory concern.Many genetic strategies exist to mitigate potential g...Plant migration and gene flow from genetically modified or exotic trees to nearby lands or by crossing with wild relatives is a major public and regulatory concern.Many genetic strategies exist to mitigate potential gene flow;however,the long delay in onset of flow-ering is a severe constraint to research progress.We used heat-induced FT overexpression to speed assessment of the expected floral phenotypes after CRISPR knockout of poplar homologs of the key floral genes,LEAFY and AGAMOUS.We selected events with previously characterized CRISPR-Cas9 induced biallelic changes then re-transformed them with the Arabidopsis thaliana FLOWERING LOCUS T(AtFT)gene under control of either a strong constitutive promoter or a heat-inducible promoter.We successfully obtained flowering in both a male and female clone of poplar,observing a wide range of inflorescence and floral forms among flowers,ramets,and insertion events.Overall,flowers obtained from the selected LFY and AG targeted events were consistent with what would be predicted for loss-of-function of these genes.LFY-targeted events showed small catkins with leaf-like organs,AG-targeted events had nested floral organs consistent with reduction in floral determinacy and absence of well-formed carpels or anthers.These findings demonstrate the great developmental plasticity of Populus flowers during genetically accelerated flowering,which may be of horticultural value.They also provide an informative early view of floral phenotypes and apparent sterility from knockouts of both these gene targets.展开更多
Amaryllidaceae, a monocot plant family, consists of many important ornamental bulb flower species. Chinese narcissus （Narcissus tazetta var. chinensis Roem）, its flowers developed at high temperatures and bloomed at...Amaryllidaceae, a monocot plant family, consists of many important ornamental bulb flower species. Chinese narcissus （Narcissus tazetta var. chinensis Roem）, its flowers developed at high temperatures and bloomed at lower temperatures during the Chinese Spring Festival, is a traditional Chinese flower with high economic and ornamental value. To study its flower development, a full length cDNA containing MADS box domain from narcissus was isolated by a reverse transcription polymerase chain reaction （RT-PCR） with degenerate oligo-nucleotide primers derived from a conserved MADS- and K-box domain sequence. The 5＇ and the 3＇ regions of the gene were amplified using the PCR protocol for the rapid amplification of cDNA ends （RACE）. The 690 bp open reading frame encodes 230 amino acid residues. A comparison of the deduced amino acid sequence of NTAG with the sequence of other MADS box proteins showed 91.3% amino acid identities with HAG （Hyacinthus orientalis）. Sequence analysis and alignment showed significant similarity with other AG homologues. RNA blot analysis indicated that the narcissus NTAG gene was expressed only in reproductive organs, especially in stamens and carpels. These results indicated that the NTAG gene was an AG homologue and that the AG genes appeared to be structurally and functionally conserved between dicots and monocots.展开更多
Dear Editor,In eukaryotes, mature m RNAs have a tripartite structure consisting of a 5′-untranslated region(5′-UTR), a coding region and a 3′-untranslated region(3′-UTR). Though the coding region encodes the prote...Dear Editor,In eukaryotes, mature m RNAs have a tripartite structure consisting of a 5′-untranslated region(5′-UTR), a coding region and a 3′-untranslated region(3′-UTR). Though the coding region encodes the protein sequence.展开更多
基金We thank the Tree Biosafety and Genomics Research Cooperative(TBGRC)at Oregon State University,the USDA(award 2011-68005-30407,System for Advanced Biofuels Production From Woody Biomass In The Pacific Northwest)USDA Biotechnology Risk Assessment Grants(2011-68005-30407 and 2010-33522-21736)the NSF I/UCRC Center for Advanced Forestry(0736283).
文摘Plant migration and gene flow from genetically modified or exotic trees to nearby lands or by crossing with wild relatives is a major public and regulatory concern.Many genetic strategies exist to mitigate potential gene flow;however,the long delay in onset of flow-ering is a severe constraint to research progress.We used heat-induced FT overexpression to speed assessment of the expected floral phenotypes after CRISPR knockout of poplar homologs of the key floral genes,LEAFY and AGAMOUS.We selected events with previously characterized CRISPR-Cas9 induced biallelic changes then re-transformed them with the Arabidopsis thaliana FLOWERING LOCUS T(AtFT)gene under control of either a strong constitutive promoter or a heat-inducible promoter.We successfully obtained flowering in both a male and female clone of poplar,observing a wide range of inflorescence and floral forms among flowers,ramets,and insertion events.Overall,flowers obtained from the selected LFY and AG targeted events were consistent with what would be predicted for loss-of-function of these genes.LFY-targeted events showed small catkins with leaf-like organs,AG-targeted events had nested floral organs consistent with reduction in floral determinacy and absence of well-formed carpels or anthers.These findings demonstrate the great developmental plasticity of Populus flowers during genetically accelerated flowering,which may be of horticultural value.They also provide an informative early view of floral phenotypes and apparent sterility from knockouts of both these gene targets.
文摘Amaryllidaceae, a monocot plant family, consists of many important ornamental bulb flower species. Chinese narcissus （Narcissus tazetta var. chinensis Roem）, its flowers developed at high temperatures and bloomed at lower temperatures during the Chinese Spring Festival, is a traditional Chinese flower with high economic and ornamental value. To study its flower development, a full length cDNA containing MADS box domain from narcissus was isolated by a reverse transcription polymerase chain reaction （RT-PCR） with degenerate oligo-nucleotide primers derived from a conserved MADS- and K-box domain sequence. The 5＇ and the 3＇ regions of the gene were amplified using the PCR protocol for the rapid amplification of cDNA ends （RACE）. The 690 bp open reading frame encodes 230 amino acid residues. A comparison of the deduced amino acid sequence of NTAG with the sequence of other MADS box proteins showed 91.3% amino acid identities with HAG （Hyacinthus orientalis）. Sequence analysis and alignment showed significant similarity with other AG homologues. RNA blot analysis indicated that the narcissus NTAG gene was expressed only in reproductive organs, especially in stamens and carpels. These results indicated that the NTAG gene was an AG homologue and that the AG genes appeared to be structurally and functionally conserved between dicots and monocots.
基金supported by the National Natural Science Foundation of China (31671356)the Beijing Municipal Government Science Foundation (IDHT20170513)
文摘Dear Editor,In eukaryotes, mature m RNAs have a tripartite structure consisting of a 5′-untranslated region(5′-UTR), a coding region and a 3′-untranslated region(3′-UTR). Though the coding region encodes the protein sequence.
