BackgroundThe petal senescence of ethylene insensitive species has not been investigated thoroughly while little is known about the temporal and tissue specific expression patterns of transcription factors (TFs) in this developmental process. Even less is known on flower senescence of the ornamental pot plant Gardenia jasminoides, a non climacteric flower with significant commercial value.ResultsWe initiated a de novo transcriptome study to investigate the petal senescence in four developmental stages of cut gardenia flowers considering that the visible symptoms of senescence appear within 4 days of flower opening. De novo assembly of transcriptome sequencing resulted in 102,263 contigs with mean length of 360 nucleotides that generated 57,503 unigenes. These were further clustered into 20,970 clusters and 36,533 singletons. The comparison of the consecutive developmental stages resulted in 180 common, differentially expressed unigenes. A large number of Simple Sequence Repeats were also identified comprising a large number of dinucleotides and trinucleotides. The prevailing families of differentially expressed TFs comprise the AP2/EREBP, WRKY and the bHLH. There are 81 differentially expressed TFs when the symptoms of flower senescence become visible with the most prevailing being the WRKY family with 19 unigenes. No other WRKY TFs had been identified up to now in petal senescence of ethylene insensitive species. A large number of differentially expressed genes were identified at the initiation of visible symptoms of senescence compared to the open flower stage indicating a significant shift in the expression profiles which might be coordinated by up-regulated and/or down-regulated TFs. The expression of 16 genes that belong to the TF families of WRKY, bHLH and the ethylene sensing pathway was validated using qRT – PCR.ConclusionThis de novo transcriptome analysis resulted in the identification of TFs with specific temporal expression patterns such as two WRKYs and one bHLH, which might play the role of senescence progression regulators. Further research is required to investigate their role in gardenia flowers in order to develop tools to delay petal senescence.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-554) contains supplementary material, which is available to authorized users.

The Greek lentil landrace ‘Eglouvis’ is cultivated continuously at the Lefkada island for more than 400 years. It has great taste, high nutritional value and high market price. In the present study, we used morphological and molecular markers to estimate genetic diversity within the landrace. Morphological analysis was based on characteristics of the seed. Molecular analysis was performed using simple sequence repeat (SSR) molecular markers in a high-resolution melting (HRM) approach. ‘Samos’ and ‘Demetra’, two of the most widely cultivated commercial lentil varieties in Greece, were used for comparisons. Morphological analysis was performed with 584 seeds randomly selected from a lot. Analysis of seed dimensions and colour distributed the samples in different categories and highlighted the phenotypic variability in ‘Eglouvis’ lentil seeds. Genetic variability was estimated from 91 individual DNA samples with 11 SSR markers using HRM analysis. Genotyping was based upon the shape of the melting curves and the difference plots; all polymerase chain reaction products were also run on agarose gels. Genetic distances of individuals and principal coordinates analysis suggested that ‘Eglouvis’ landrace has a unique genetic background that significantly differs from ‘Samos’ and ‘Demetra’ and no overlapping could be detected. Genetic variability within the ‘Eglouvis’ landrace can be considered in targeted breeding programs as a significant phytogenetic resource of lentils in Greece.

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