Carotenoids accumulation

Carotenoid accumulation during fruit ripening in tomato has been studied extensively and is a good model system to elucidate the regulation of the process. During ripening the concentration of carotenoids increases between 10 and 15-fold due mainly to a 500-fold increase in the concentration of lycopene (Fraser et al, 1994 Table 13.5). Accumulation of lycopene begins... 

HAUPTMANN R, ESCHENFELDT w H, ENGLISH J and BRINKHAUS F L (1997) Enhanced carotenoid accumulation in storage organs of genetically engineered plants , US patent 5618988. 

Plant phytoene synthase (Psy) has been used in a variety of transgenics. As noted above, P yl over-expression under a strong constitutive promoter caused a decrease in carotenoid accumulation, probably due to transcription silencing. Similarly, over-expression of the gene sequence backward (antisense) also silenced activity. In another approach to over-expression of tomato 1 in fruits, a synthetic alternative in which the third position of each codon was changed in order to avoid transcriptional silencing was successful in conditioning an increase in carotenoid accumulation. 

The availability of precursor IPP may ultimately be most influential over accumulation of carotenoid metabolites. While over-expression of DXS and DXR in color complementation systems leads to hyperaccumulation of carotenoids (discussed in Section 5.3.3.3), over-expression of plant Dxs genes has not always been effective. Over-expression of DXS resulted in increased carotenoid accumulation in transgenic tomato and Arabidopsis, but over-expression of daffodil DXS in rice endosperm did not increase pigment accumulation. ... 

Gallagher, C.E., Cervantes-Cervantes, M., and Wurtzel, E.T., Surrogate biochemistry use of Escherichia coli to identify plant cDNAs that impact metabolic engineering of carotenoid accumulation, AppZ. Microbiol. Biotechnol. 60, 713, 2003. 

Matthews, P.D. and Wurtzel, E.T., Metabolic engineering of carotenoid accumulation in Escherichia coli by modulation of the isoprenoid precursor pool with expression of deoxyxylulose phosphate synthase, Appl. Microbiol. Biotechnol. 53, 396, 2000. 

Carotenoids accumulating in the human body are obtained exclusively from our diet. Out of almost 50 carotenoids present in a typical human diet, about 14 are absorbed into the blood (Khachik et al., 1997), and only two of them—lutein and zeaxanthin (Figure 15.1)—accumulate in the retina (Bernstein et al., 2001 Bone and Landrum, 1992 Bone et al., 1988, 1997 Davies and Morland, 2004 Khachik et al., 1997, 2002). Lutein and zeaxanthin are particularly concentrated in photoreceptor axons and inner plexiform layer in the area including and surrounding... 

In another study of carotenoid accumulation, cultured ARPE-19 cells were treated with a lipophilic extract from tomatoes solubilized in ethanol and injected into the culture medium for 24 h. The extract, containing 3-carotene, lycopene, and lutein at relative ratios of 23, 13, and 1, respectively, led to internalization of carotenoids at ratios of 9, 1.3, and 1, respectively (Chichili et al., 2006). These results indicate preferential accumulation of (3-carotene and lutein over lycopene in ARPE-19 cells. 

Casagrande, S., Costantini, D., Fanfani, A., Tagliavini, J., and Dell Omo, G. 2007. Patterns of serum carotenoid accumulation and skin colour variation in kestrel nestlings in relation to breeding conditions and different terms of carotenoid supplementation. J. Comp. Physiol. B 177 237-245. 

McGraw, K. J., Nolan, P. M., and Crino, O. L. 2006b. Carotenoid accumulation strategies for becoming a colorful house finch Analyses of plasma and liver pigments in wild molting birds. Fund. Ecol. 20 678-688. 

Wang, G.-Y. and Keasbng, J.D. (2002) Amplification of HMG-CoA reductase production enhances carotenoid accumulation in Neurospora crassa. Metabolic Engineering, 4, 193-201. 

The third phase of carotenoid accumulation is explored by the observation of a sequential increase of carotenoids following photo-induction. Because synthesis of sterols is not increased after illumination, Bindel et al.12) concluded that the photoregulation takes place between farnesylpyrophosphate and the colored carotenoids, at least for Fusarium. 

Because plants are able to synthesize carotenoids de novo, the carotenoid composition of plant foods is enriched by the presence of small or trace amounts of biosynthetic precursors, along with derivatives of the main components. Although commonly thought of as plant pigments, carotenoids are also encountered in some animal foods. Animals are incapable of carotenoid biosynthesis thus their carotenoids need to be derived from the diet. Selectively or unselectively absorbed, carotenoids accumulate in animal tissues unchanged or slightly modified into typical animal carotenoids. 

Marty I, Bureau S, Sarkissian G, Gouble B, Audergon JM and Albagnac G. 2005. Ethylene regulation of carotenoid accumulation and carotenogenic gene expression in colour-contrasted apricot varieties (Prunus armeniaca). J Exp Bot 56(417) 1877-1886. 

Rodrigo M and Zacarias L. 2007. Effect of postharvest ethylene treatment on carotenoid accumulation and the expression of carotenoid biosynthetic genes in the flavedo of orange (Citrus sinensis L. Osbeck) fruit. Postharvest Biol Technol 43 14-22. 

Because of their considerable role in human wellfare, carotenoids have been measured not only in plants as primary sources and in human and animal tissues but also in a wide variety of other matrices to find new and economical sources for carotenoids. Thus, the carotenoid accumulation capacity of algae and microalgae have been vigorously investigated. A validated liquid chromatography-electrospray mass spectrometry method have been developed and employed for the separation and quantitative determination of... 

Fong N. J. C., Burgess M. L., Barrow K. D., and Glenn D. R. (2001) Carotenoid accumulation in the psychrotrophic bacterium Arthrobacter agilis in response to thermal and salt stress. Appl. Microbiol. Biotechnol. 56, 750-756. 

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