This paper presents an approach to simultaneously analyze polyacetylenes, carotenoids, and polysaccharides in carrot (Daucus carota L.) roots by means of Raman spectroscopy. The components were measured in situ in the plant tissue without any preliminary sample preparation. The analysis is based on the intensive and characteristic key bands observed in the Raman spectrum of carrot root. The molecular structures of the main carrot polyacetylenes, falcarinol and falcarindiol, are similar, but their Raman spectra exhibit specific differences demonstrated by the shift of their -C[triple bond]C- mode from 2258 to 2252 cm(-)(1), respectively. Carotenoids can be identified by -C=C- stretching vibrations (about 1520 and 1155 cm(-)(1)) of the conjugated system of their polyene chain, whereas the characteristic Raman band at 478 cm(-)(1) indicates the skeletal vibration mode of starch molecule. The other polysaccharide, pectin, can be identified by the characteristic band at 854 cm(-)(1), which is due to the -C-O-C- skeletal mode of alpha-anomer carbohydrates. The Raman mapping technique applied here has revealed detailed information regarding the relative distribution of polyacetylenes, carotenoids, starch, and pectin in the investigated plant tissues. The distribution of these components varies among various carrot cultivars, and especially a significant difference can be seen between cultivated carrot and the wild relative D. carota ssp. maritimus.

C17-polyacetylenes (PAs) are a prominent group of oxylipins and are primarily produced by plants of the families Apiaceae, Araliaceae, and Asteraceae, respectively. Recent studies on the biological activity of polyacetylenes have indicated their potential to improve human health due to anticancer, antifungal, antibacterial, anti-inflammatory, and serotogenic effects. These findings suggest targeting vegetables with elevated levels of bisacetylenic oxylipins, such as falcarinol, by breeding studies. Due to the abundant availability, high diversity of cultivars, worldwide experience, and high agricultural yields, in particular, carrot (Daucus carota L.) genotypes are a very promising target vegetable. This paper provides a review on falcarinol-type C17-polyacetylenes in carrots and a perspective on their potential as a future contributor to improving human health and well-being.

SummaryMaternally inherited defects in the formation of male¯ower organs leading to cytoplasmic male sterility (CMS) indicate an involvement of mitochondrial genes in the control of¯ower formation. In the`carpeloid' CMS type of carrot, stamens are replaced by carpels. The¯orets thus resemble well-investigated homeotic ower mutants of Arabidopsis and Antirrhinum, in which organ identity is impaired because of the mutation of speci®c nuclear MADS box genes. We have isolated ®ve cDNAs encoding MADS box proteins (DcMADS1±5) from a¯ower-speci®c library of carrot. Structural features deduced from their sequence and transcript patterns in unmodi®ed carrot¯owers determined by in situ hybridisation relate them to known MADS box transcription factors involved in speci®cation of¯ower organs. In`carpeloid' CMS¯ow-ers, we detected a distinctly reduced expression of DcMADS2 and DcMADS3, homologues of the Antirrhinum genes GLOBOSA and DEFICIENS. Our data strongly suggest that the`carpeloid' CMS phenotype is caused by a cytoplasmic (mitochondrial) effect on the expression of two MADS box factors specifying organ development at whorls 2 and 3 of carrot¯owers.

Raman spectroscopy can be used for sensitive detection of carotenoids in living tissue and Raman mapping provides further information about their spatial distribution in the measured plant sample. In this work, the relative content and distribution of the main carrot (Daucus carota L.) root carotenoids, alpha-, beta-carotene, lutein and lycopene were assessed using near-infrared Fourier transform Raman spectroscopy. The pigments were measured simultaneously in situ in root sections without any preliminary sample preparation. The Raman spectra obtained from carrots of different origin and root colour had intensive bands of carotenoids that could be assigned to beta-carotene (1,520 cm(-1)), lycopene (1,510 cm(-1)) and alpha-carotene/lutein (1,527 cm(-1)). The Raman mapping technique revealed detailed information regarding the relative content and distribution of these carotenoids. The level of beta-carotene was heterogeneous across root sections of orange, yellow, red and purple roots, and in the secondary phloem increased gradually from periderm towards the core, but declined fast in cells close to the vascular cambium. alpha-carotene/lutein were deposited in younger cells with a higher rate than beta-carotene while lycopene in red carrots accumulated throughout the whole secondary phloem at the same level. The results indicate developmental regulation of carotenoid genes in carrot root and that Raman spectroscopy can supply essential information on carotenogenesis useful for molecular investigations on gene expression and regulation.