Generation and Analysis of Expressed Sequence Tags fromChimonanthus praecox(Wintersweet) Flowers for Discovering Stress-Responsive and Floral Development-Related Genes

Abstract

<jats:p>A complementary DNA library was constructed from the flowers of<jats:italic>Chimonanthus praecox</jats:italic>, an ornamental perennial shrub blossoming in winter in China. Eight hundred sixty-seven high-quality expressed sequence tag sequences with an average read length of 673.8 bp were acquired. A nonredundant set of 479 unigenes, including 94 contigs and 385 singletons, was identified after the expressed sequence tags were clustered and assembled. BLAST analysis against the nonredundant protein database and nonredundant nucleotide database revealed that 405 unigenes shared significant homology with known genes. The homologous unigenes were categorized according to Gene Ontology hierarchies (biological, cellular, and molecular). By BLAST analysis and Gene Ontology annotation, 95 unigenes involved in stress and defense and 19 unigenes related to floral development were identified based on existing knowledge. Twelve genes, of which 9 were annotated as “cold response,” were examined by real-time RT-PCR to understand the changes in expression patterns under cold stress and to validate the findings. Fourteen genes, including 11 genes related to floral development, were also detected by real-time RT-PCR to validate the expression patterns in the blooming process and in different tissues. This study provides a useful basis for the genomic analysis of<jats:italic>C. praecox</jats:italic>.</jats:p>

Generation and Analysis of Expressed Sequence Tags (ESTs) from Halophyte Atriplex canescens to Explore Salt-Responsive Related Genes

“…Heat-shock protein, glyceraldehyde-3-phosphate dehydrogenase, S -adenosylmethionine synthase, eukaryotic elongation factor, transforming growth factor and others were response to abiotic stresses [6,9,24]. …”

Effects of Hormone Treatments on Cut Flower Opening and Senescence in Wintersweet (Chimonanthus praecox)

“…Concolor Makino (the local leading cultivar) was collected from an outdoor nursery in Jingguan, Chongqing, China. Wintersweet flower opening stages have been described previously (Sui et al, 2012;Wu and Hu, 1995): stage 1, bud scales loosen; stage 2, flower buds turn green; stage 3, flower buds enlarge and turn yellow; stage 4, fragrance emerges; stage 5, flowers fully open with strong fragrance; stage 6, petals begin withering. In this experiment, we added a stage 7, the complete senescence period at which the petals turned brown, lost turgidity, and shriveled.…”

“…Our previous research indicated that the expression level of CpSRG1 (SRG1) from wintersweet was significantly high during flower senescence, whereas it was very low at other stages of flower development. The results showed an association with flower senescence (Sui et al, 2012), so it provided us with a useful molecular tool with which to research the senescence of wintersweet.…”

Cloning of an Expansin Gene from Chimonanthus praecox Flowers and Its Expression in Flowers Treated with Ethephon or 1-Methylcyclopropene

“…Total RNA and library construction through directional cloning of cDNAs into the lTriplEx2 vector were performed using the SMART cDNA Library Construction Kit. A total of 867 random cDNA clones were successfully sequenced to generate high-quality expressed sequence tags (ESTs) (Sui et al, 2012).…”

“…A comparative Ct method (2 -DDCt ) of relative quantification (Livak and Schmittgen, 2001) was used to analyze the real-time quantitative PCR data using Bio-Rad CFX Manager Software Version 1.6. The genes for actin and tubulin (Sui et al, 2012) were used for the calculation of the relative transcript abundance. The sizes of the amplified products were confirmed through gel electrophoresis.…”