BackgroundSolanum elaeagnifolium, an invasive weed of the Solanaceae family, is poorly studied although it poses a significant threat to crops. Here the analysis of the transcriptome of S. elaeagnifolium is presented, as a means to explore the biology of this species and to identify genes related to its adaptation to environmental stress. One of the basic mechanisms by which plants respond to environmental stress is through the synthesis of specific secondary metabolites that protect the plant from herbivores and microorganisms, or serve as signaling molecules. One important such group of secondary metabolites are terpenes.ResultsBy next-generation sequencing, the flower/leaf transcriptome of S. elaeagnifolium was sequenced and de novo assembled into 75,618 unigenes. Among the unigenes identified, several corresponded to genes involved in terpene biosynthesis; these included terpene synthases (TPSs) and genes of the mevalonate (MVA) and the methylerythritol phosphate (MEP) pathways. Functional characterization of two of the TPSs showed that one produced the sesquiterpene (E)-caryophyllene and the second produced the monoterpene camphene. Analysis of wounded S. elaeagnifolium leaves has shown significant increase of the concentration of (E)-caryophyllene and geranyl linalool, two terpenes implicated in stress responses. The increased production of (E)-caryophyllene was matched to the induced expression of the corresponding TPS gene. Wounding also led to the increased expression of the putative 1-deoxy-D-xylulose-5-phosphate synthase 2 (DXS2) gene, a key enzyme of the MEP pathway, corroborating the overall increased output of terpene biosynthesis.ConclusionsThe reported S. elaeagnifolium de novo transcriptome provides a valuable sequence database that could facilitate study of this invasive weed and contribute to our understanding of the highly diverse Solanaceae family. Analysis of genes and pathways involved in the plant’s interaction with the environment will help to elucidate the mechanisms that underly the intricate features of this unique Solanum species.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1738-3) contains supplementary material, which is available to authorized users.

Peppers are the fourth most important vegetable in the global food economy. Greek pepper cultivars 'Florinis' and 'Karatzova' are especially popular because of the signature red color and sweet taste of the fruits. The economic interest in 'Florinis' peppers has led to many adulteration events. In that aspect, genetic profiles of 'Florinis', a 'Florinis'-type and 'Karatzova' peppers, were studied using Inter Simple Sequence Repeats (ISSR) molecular markers and an automated fragment detection system. Biochemical parameters, such as total dietary fiber, total phenolic and lycopene contents, and sugar profile that affect the fruit organoleptic and nutritional properties were evaluated. The molecular protocol established during this study may successfully discriminate the original 'Florinis' cultivar from the 'Florinis'-type peppers. 'Karatzova' cultivar, which fruits are similar to 'Florinis', presented also a unique profile. The biochemical evaluation revealed that 'Florinis' peppers had the highest sweetness index and total phenolic content. Such an analysis could be used for the discrimination of pepper cultivars sharing common morphological traits ensuring the unique identity of each cultivar and protecting farmers and consumers from fraud.