The aim of this study was to discover genes involved in grape secondary metabolism pathways by stimulating their production in grape cell suspension cultures. Among numerous elicitors tested, methyl jasmonate (MeJA) induced the production of a wide range of sesquiterpenes in Cabernet Sauvignon cell suspension cultures derived from berries. The efficacy of MeJA in the induction of sesquiterpenes production is strictly dependent upon the density of cells in cell suspension at the moment of elicitor addition. We also found that jasmonic acid (JA) as MeJA activate sesquiterpene synthesis, but when salicylic acid (SA) was added in addition to MeJA, sesquiterpenes were not produced. Microarray analyses on the induced cultures confirmed the activation of sesquiterpenes biosynthetic pathway by MeJA and JA and the inhibition effect of SA: two terpene synthases on the gene chip were upregulated in the MeJA and JA treated cells. Microarray data also indicated that genes from tannins and stilbenes pathways are differentially expressed in response to the treatments. Tannins accumulated to higher levels in the MeJA- and JA-treated cell suspension cultures and the expressions of pathway key genes was more than 2-fold higher in the MeJA and JA treatments than the control and MeJA+SA cells. Stilbenes accumulated in all three treatments, but the levels correlated mostly with the expression of stilbene synthase (STS2). The results of this work confirm that an inducible cell culture system is a powerful tool for functional genomics studies as we can associate specific genes from biosynthesis pathways with changes in metabolite production. We are now working towards the functional characterisation of terpene synthases, modifying enzymes and transport proteins associated with volatile production in grapes. We have also identified several transcription factors that have expression patterns matching the induction patterns seen for the three pathways described above. These are also targets of future work as they may help us understand the regulation of these secondary metabolite pathways in grape berries.
Secondary metabolite biosynthesis in elicited grape cell suspensions
D'ONOFRIO, CLAUDIO;
2007-01-01
Abstract
The aim of this study was to discover genes involved in grape secondary metabolism pathways by stimulating their production in grape cell suspension cultures. Among numerous elicitors tested, methyl jasmonate (MeJA) induced the production of a wide range of sesquiterpenes in Cabernet Sauvignon cell suspension cultures derived from berries. The efficacy of MeJA in the induction of sesquiterpenes production is strictly dependent upon the density of cells in cell suspension at the moment of elicitor addition. We also found that jasmonic acid (JA) as MeJA activate sesquiterpene synthesis, but when salicylic acid (SA) was added in addition to MeJA, sesquiterpenes were not produced. Microarray analyses on the induced cultures confirmed the activation of sesquiterpenes biosynthetic pathway by MeJA and JA and the inhibition effect of SA: two terpene synthases on the gene chip were upregulated in the MeJA and JA treated cells. Microarray data also indicated that genes from tannins and stilbenes pathways are differentially expressed in response to the treatments. Tannins accumulated to higher levels in the MeJA- and JA-treated cell suspension cultures and the expressions of pathway key genes was more than 2-fold higher in the MeJA and JA treatments than the control and MeJA+SA cells. Stilbenes accumulated in all three treatments, but the levels correlated mostly with the expression of stilbene synthase (STS2). The results of this work confirm that an inducible cell culture system is a powerful tool for functional genomics studies as we can associate specific genes from biosynthesis pathways with changes in metabolite production. We are now working towards the functional characterisation of terpene synthases, modifying enzymes and transport proteins associated with volatile production in grapes. We have also identified several transcription factors that have expression patterns matching the induction patterns seen for the three pathways described above. These are also targets of future work as they may help us understand the regulation of these secondary metabolite pathways in grape berries.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
