Secondary metabolites cytokinins

Terpenoids, which are also known as isoprenoids, constitute the most abundant and structurally diverse group of plant secondary metabolites, consisting of more than 40,000 different chemical structures. The isoprenoid biosynthetic pathway generates both primary and secondary metabolites that are of great importance to plant growth and survival. Among the primary metabolites produced by this pathway are phytohormones, such as gibberellic acid (GA), abscisic acid (ABA), and cytokinins the carotenoids, such as chlorophylls and plastoquinones involved in photosynthesis the ubiquinones required for respiration and the sterols that influence membrane stmcture (see also Steroid and Triterpene Biosynthesis) (Fig. 1). Monoterpenoids (CIO), sesquiterpenoids (Cl5), diterpenoids (C20), and... 

Poly(c -l,4-isoprene) belongs to the family of polyisoprenoids, which are the most structurally diverse and abundant natural products known, with more than 23,000 primary and secondary metabolites. This huge family comprises, for example, sterols which display not only structural functions (control of biological membrane fluidity) but also hormonal functions (steroid hormones). Key phyto-hormones, such as abscisic acid, gibberellins and cytokinins, are isoprenoids too. Moreover, isoprenoids are used in protein prenylation, which is a key step in the activation and the localization of metabolic enzymes in many organisms. The first common step of all isoprenoid biosynthesis pathways is the formation of isopentenyl diphosphate (IPP). ... 

In order to improve yields and productivities of secondary metabolites in plant cell culture s it is essential the selection of the most elEcient plant growth regulators (auxins, cytokinins, gibberellic acid and abscicic acid) and the relationship between diem [74, 75]. 

In earlier work, [ H]-[9R]Z was supplied to the transpiration stream of both de-rooted and intact blue lupin (Lupinusangustifolius L.) plants [2]. Features of this work included (1) the very low proportion of [9R]Z which moved to the seed, although [9R]Z reached the pod walls in significant amounts and tended to be conserved therein (2) the direct lateral movement of [9R]Z and/or related cytokinins from xylem to bark (all tissues outside secondary xylem) (3) the detection of a metabolite, or closely related metabolites, of unknown nucleotide-like structure in pod walls, stem bark and developing lateral shoots. For convenience, the metabolites were all designated U-NT (meaning unknown nucleotides), because all... 

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