title: Isolation of a LEAFY homolog from Populus tomentosa: expression of PtLFY in P. tomentosa floral buds and PtLFY-IR-mediated gene silencing in tobacco (Nicotiana tabacum).
abstract: To understand the genetic and molecular mechanisms underlying floral development in Populus tomentosa, we isolated PtLFY, a LEAFY homolog, from a P. tomentosa floral bud cDNA library. DNA gel blot analysis showed that PtLFY is present as a single copy in the genomes of both male and female individuals of P. tomentosa. The genomic copy is composed of three exons and two introns. Relative expression levels of PtLFY in tissues of P. tomentosa were estimated by RT-PCR; our results revealed that PtLFY mRNA is highly abundant in roots and both male and female floral buds. A low level of gene expression was detected in stems and vegetative buds, and no PtLFY-specific transcripts were detected in leaves. PtLFY expression patterns were analyzed during the development of both male and female floral buds in P. tomentosa via real-time quantitative RT-PCR. Continuous, stable and high-level expression of PtLFY-specific mRNA was detected in both male and female floral buds from September 13th to February 25th, but the level of PtLFY transcripts detected in male floral buds was considerably higher than in female floral buds. Our results also showed an inverted repeat PtLFY fragment (PtLFY-IR) effectively blocked flowering of transgenic tobacco plants, and that this effect appeared to be due to post-transcriptional silencing of the endogenous tobacco LFY homologs NFL1 and NFL2.
authors.affiliation: National Engineering Laboratory for Tree Breeding, Beijing Forestry University, Beijing 100083, People's Republic of China.
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: An
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Wang
authors.forename: Ze-Liang
authors.initials: ZL
authors.lastname: Wang
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Wen-Hao
authors.initials: WH
authors.lastname: Bo
authors.forename: Guan-Lin
authors.initials: GL
authors.lastname: Cao
authors.forename: Zhi-Yi
authors.initials: ZY
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003433:Crosses, Genetic; D018744:DNA, Plant / Q000235:genetics; D035264:Flowers / Q000235:genetics*; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D055029:Inverted Repeat Sequences / Q000235:genetics; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D032107:Populus / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014026:Nicotiana / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins