Isolation and expression analysis of a LEAFY/FLORICAULA homolog and its promoter from London plane (Platanus acerifolia Willd.)

Abstract

The LEAFY/FLORICAULA (LFY/FLO) homologous genes are necessary for normal flower development in diverse angiosperm species. To understand the genetic and molecular mechanisms underlying floral initiation and development in Platanaceae, an early divergent eudicot family consisting of large monoecious trees, we isolated a homolog of LFY/FLO, PlacLFY, and its promoter from London plane (Platanus acerifolia). PlacLFY is 1,419 bp in length, with an ORF of 1,122 bp encoding a predicted polypeptide of 374 amino acids and 5'/3'-UTR of 54 and 213 bp, respectively. The putative PlacLFY protein showed a high degree of identity (56-84 %) with LFY/FLO homologs from other species, including two highly conserved regions, the N and C domains, and a less conserved amino-terminal proline-rich region. Real-time PCR analysis showed that PlacLFY was expressed mainly in male inflorescences from May of the first year to March of next year, with the highest expression level in December, and in female inflorescences from June to April of next year. PlacLFY mRNA was also detected strongly in subpetiolar buds of December from 4-year-old and adult trees, and slightly in stem of young seedling and young leaf of adult plant. Additionally, we cloned 1,138 bp promoter sequence of PlacLFY and we drove GUS expression in transgenic tobacco by the chimerical pPlacLFY::GUS construction. Histological GUS staining analysis indicated that PlacLFY promoter can drive GUS gene expression in shoot apex, stem, young leaf and petiole, flower stalk, petal tip, and young/semi-mature fruits of transgenic tobacco, which is almost identical to the expression pattern of PlacLFY in London plane. The results revealed that the PlacLFY gene isolated from London plane is expressed not only in reproductive organ but also in vegetative organs. Moreover, this expression pattern is consistent with the expression pattern in tobacco of a GUS reporter gene under the control of the potential promoter region of PlacLFY.

Detoxification strategies and regulation of oxygen production and flowering of Platanus acerifolia under lead (Pb) stress by transcriptome analysis

“…The tree also has some undesirable traits, such as abundant pollens from mature male flowers and numerous stiff hairs of broken seed balls that pollute the environment (Lu et al 2012). This can cause severe pollinosis (Lu et al 2012) and has been reported to aggravate breathing difficulties in asthma patients (Subiza et al 1994;Varela et al 1997). The leaf structure, pest control, pollen, and cold resistance of P. acerifolia have all been reported (Li et al 2007;Lu et al 2012Lu et al , 2014Mimet et al 2009;Zhang et al 2011).…”

“…In addition, P. acerifolia shows innate disease resistance (Lu et al 2012). The tree also has some undesirable traits, such as abundant pollens from mature male flowers and numerous stiff hairs of broken seed balls that pollute the environment (Lu et al 2012). This can cause severe pollinosis (Lu et al 2012) and has been reported to aggravate breathing difficulties in asthma patients (Subiza et al 1994;Varela et al 1997).…”

“…This can cause severe pollinosis (Lu et al 2012) and has been reported to aggravate breathing difficulties in asthma patients (Subiza et al 1994;Varela et al 1997). The leaf structure, pest control, pollen, and cold resistance of P. acerifolia have all been reported (Li et al 2007;Lu et al 2012Lu et al , 2014Mimet et al 2009;Zhang et al 2011). Genetic engineering approaches have focused on breeding nonflowering or fruitless varieties through overexpressing a flowering repressor gene (Jensen CS 2004).…”

“…Platanus acerifolia (London plane tree) is a hybrid of Platanus occidentalis and Platanus orientalis (Li et al 2007;Lu et al 2012Lu et al , 2014Mimet et al 2009;Zhang et al 2011) and is an avenue tree in temperate and subtropical regions (Lu et al 2012). P. acerifolia has many desirable characteristics, such as root compaction, rapid growth, and tolerance to pruning and atmospheric pollution (Li et al 2007;Zhang et al 2011).…”

“…P. acerifolia has many desirable characteristics, such as root compaction, rapid growth, and tolerance to pruning and atmospheric pollution (Li et al 2007;Zhang et al 2011). In addition, P. acerifolia shows innate disease resistance (Lu et al 2012). The tree also has some undesirable traits, such as abundant pollens from mature male flowers and numerous stiff hairs of broken seed balls that pollute the environment (Lu et al 2012).…”