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Flax (Linum usitatissimum L.) is a common fiber and oilseed crop considered as a valuable functional food since it constitutes one of the key sources of ?-3 fatty acids, phenylpropanoids (lignans) and mucilage [1]. During the last years there has been an increasing interest in dietary human consumption of flaxseeds in order to improve the nutritional and health status. In our laboratory we are interested in the study of phenylpropanoids metabolism. The main class of phenylpropanoids found in flax are lignans, diphenolic compounds displaying a broad range of biological activities such as antioxidant, cytotoxic, antifungal, antiviral, and phytoestrogenic [2; 3]. These phenolic compounds are of great interest for pharmaceutical, cosmetic and food industry. With the aim to identify and select the cultivar with the highest production of metabolites, the phenylpropanoid content of 7 flax cultivars (Linoal, Valoal, Natural, Festival, Merlin, Solal, Kaolin) and the expression level of key genes (PAL, Phenylalanine ammonia-lyase and 4CL, 4-Coumarate:CoA ligase) involved in their biosynthesis were compared. Moreover, the cultivar showing either the highest level of phenylpropanoids production and the highest level of expression of two key biosynthetic genes were chosen to start the production of flax cell cultures in order to improve the accumulation of bioactive compounds. In fact, it has been reported that plant cell cultures represent a promising system to optimize the production of valuable secondary metabolites [4]. Results. The 1H-NMR metabolite profiling of leaves (Fig.1) showed the presence of flavonoids, isoorientin, luteolin, apigenin and isovitexin, whereas seeds showed mainly lignans compounds. Real-Time PCR approach was used to evaluate the relative expression level of PAL and 4CL, representing two genes in the first part of phenylpropanoid biosynthetic pathway. Among the cultivars analysed, we found that Valoal and Solal are those with the highest expression level of PAL and 4CL both in leaves and in seeds (Fig.2). The determination of the specific activity of PAL and 4CL enzymes was in agreement with gene expression data, highlighting Valoal and Solal as the cultivars with the highest phenylpropanoids production. On the basis of these results Valoal was selected to start the production of in vitro cell cultures. To verify if in this system the ability to produce bioactive compounds was maintained we performed both biochemical and 1H-NMR analysis on the cultured cells. Preliminary analysis showed that flax cell cultures mainly produce compounds belonging to lignans, resembling the secondary metabolites identified in flax seeds. To increase the performance of flax cell cultures two strategies were used: a) the optimization of the medium composition and b) the use of some elicitors such as yeast extract, salicylic acid and methyl-jasmonate. Conclusion. The results obtained from flax leaves and seeds highlighted the presence of flavonoids and lignans with demonstrated antioxidant, antinflamatory, chemopreventive properties on human. The molecular analysis performed on the general phenylpropanoid pathway could help to better understand the biosynthesis of these compounds. Moreover, the preliminary results from the in vitro cultured cells suggest that this system is able to produce lignans as secondary metabolites resembling the flax seeds tissue. This finding is particularly encouraging since lignans have phytoestrogenic and cancer chemopreventive properties [5].

Solanum lycopersicum represents an important dietary source of bioactive compounds including the antioxidants flavonoids and phenolic acids. We previously identified two genotypes (IL7-3 and IL12-4) carrying loci from the wild species Solanum pennellii, which increased antioxidants in the fruit. Successively, these lines were crossed and two genotypes carrying both introgressions at the homozygous condition (DHO88 and DHO88-SL) were selected. The amount of total antioxidant compounds was increased in DHOs compared to both ILs and the control genotype M82. In order to understand the genetic mechanisms underlying the positive interaction between the two wild regions pyramided in DHO genotypes, detailed analyses of the metabolites accumulated in the fruit were carried out by colorimetric methods and LC/MS/MS. These analyses evidenced a lower content of flavonoids in DHOs and in ILs, compared to M82. By contrast, in the DHOs the relative content of phenolic acids increased, particularly the fraction of hexoses, thus evidencing a redirection of the phenylpropanoid flux towards the biosynthesis of phenolic acid glycosides in these genotypes. In addition, the line DHO88 exhibited a lower content of free phenolic acids compared to M82. Interestingly, the two DHOs analyzed differ in the size of the wild region on chromosome 12. Genes mapping in the introgression regions were further investigated. Several genes of the phenylpropanoid biosynthetic pathway were identified, such as one 4-coumarate:CoA ligase and two UDP-glycosyltransferases in the region 12-4 and one chalcone isomerase and one UDP-glycosyltransferase in the region 7-3. Transcriptomic analyses demonstrated a different expression of the detected genes in the ILs and in the DHOs compared to M82.These analyses, combined with biochemical analyses, suggested a central role of the 4-coumarate:CoA ligase in redirecting the phenylpropanoid pathways towards the biosynthesis of phenolic acids in the pyramided lines. Moreover, analyses here carried out suggest the presence in the introgression regions of novel regulatory proteins, such as one Myb4 detected on chromosome 7 and one bHLH detected in chromosome 12. Overall our data indicates that structural and regulatory genes identified in this study might have a key role for the manipulation of the phenylpropanoid metabolic pathway in tomato fruit.