Rafael Font

Heavy metals and arsenic uptake by wild vegetation in the Guadiamar river area after the toxic spill of the Aznalcóllar mine.

On 25 April 1998, approximately 4.5 hm(3) of pyritic sludge, containing 5000 mg of As kg(-1) among other pollutants, was spilled into the Agrio and Guadiamar rivers and the surrounding agricultural areas (Aznalcóllar, Seville, Southern Spain). Many trace metals such as Pb, Cu, Zn, Cd, Tl, Sb and As reached the Doñana National Park, the largest wetland area in Europe, affecting soils, different plant and animal species. In order to recuperate the affected lands by employing plants capable of accumulating high levels of contaminants in shoots, periodical field surveys have been made to identify the metal-tolerant species that are spontaneously growing in the polluted soils, and are able to uptake one or various of the contaminants. Among the 99 different plant species studied, Anchusa azurea, Beta vulgaris, Chamaemelum fuscatum, Convolvulus arvensis, Cynodon dactylon, Diplotaxis virgata, Erodium aethiopicum, Lavatera cretica, Malva nicaeensis, Silybum marianum and, above all, Amaranthus blitoides highlight as the most promising to be used in the remediation of the affected area.

Modulation of genotoxicity and cytotoxicity by radish grown in metal-contaminated soils

Members of the Brassicaceae family are known for their anticarcinogenic and genetic material protective effects. However, many of the species of this family accumulate high amounts of metals, which is an undesirable feature. Radish (Raphanus sativus L.) has shown to accumulate metals in roots to a higher extent than others members of Brassicaceae. The main objectives of this work are (i) to study the distribution of the accumulated As, Pb and Cd in radish plants and (ii) to establish the genotoxic, antigenotoxic and cytotoxic activities of the root and shoot of this vegetable. Results indicate that (i) the shoots of radish accumulate higher concentrations of metal(oid)s than roots; (ii) the shoots were genotoxic at the different concentrations studied, with the root showing such genotoxic effect only at the highest concentration assayed; (iii) the antigenotoxic potential of radish is reduced in plants with high metal content and (iv) the tumouricide activities of the radish plants were negatively correlated to their metal(oid) contents. An interaction between metal(oid)s and the isotyocianates (hydrolysis products of the glucosinolates) contained in the radish is suggested as the main modulator agents of the genotoxic activity of the plants grown in contaminated soils with metal(oid)s.

Glucosinolate assessment in Brassica oleracea leaves by near-infrared spectroscopy

Glucosinolates and their hydrolysis products are of great concern because they are responsible for many of both the beneficial and harmful properties of glucosinolate-containing plants. Cabbage ( Brassica oleracea L.) is a species highly consumed as a leaf vegetable in many countries showing high qualitative and quantitative differences in glucosinolate composition among cultivars. The standard analytical techniques for determining glucosinolate composition using conventional methods lead to high costs, labour input and delays, all of which affect both the availability of data and the taking of swift decisions. In contrast, near-infrared spectroscopy (NIRS) has emerged as a rapid and cost-effective technique of analysis for many agro-food products. In this work we test the potential of NIRS for screening the total glucosinolates (t-GSL), gluconapin (GNA), gluconasturtiin (GNAST) and neoglucobrassicin (NGBS) contents of cabbage leaf cultivars coming from Portugal and Spain. NIRS calibrations resulted in coefficients of determination and standard deviation to standard error of cross-validation ratio of 0·83 and 2·38 for t-GSL; 0·70 and 1·85 for GNA; 0·62 and 1·63 for GNAST; and 0·60 and 1·58 for NGBS, respectively. An examination of the loadings of the equation for t-GSL suggested that O-H groups of water, C-H combinations of the methylene group and also N-H groups of amides were the molecular associations most strongly used in modelling total glucosinolates. It was concluded that NIRS shows a high potential as an analytical method for total and individual glucosinolate routine analysis in cabbage.

An approach to the phytochemical profiling of rocket [Eruca sativa (Mill.) Thell].

BACKGROUND Eruca sativa (rocket) contains a wide range of compounds with nutraceutical and organoleptical properties. This research aimed to characterise the nutraceutical interest of four rocket accessions by analysis of glucosinolates, isothiocyanates, phenolics, carotenoids and carbohydrates. Different methods based on chromatographic separation with ultraviolet absorbance or mass spectrometry detection were used. RESULTS The total content of glucosinolates ranged from 14.02 to 28.24 µmol g(-1) of dry weight. Glucoraphanin represented up to 52% of the total glucosinolates in leaves of one accession. Accessions showed differences in the hydrolysis of glucoraphanin to the isothiocyanate sulforaphane. No correlation between these compounds was observed, which insisted differences in the myrosinase activity within accessions. Rocket leaves had variable phenolic profiles represented by quercetin-3-glucoside, rutin, myricetin, quercetin and ferulic and p-coumaric acids. A high variability was observed for the total carotenoids ranged from 16.2 to 275 µg g(-1) with lutein as the main carotenoid. Glucose was the predominant sugar, representing >70% of the total soluble carbohydrates. CONCLUSIONS Some accessions could be candidates for future breeding programmes because of their pattern of beneficial compounds for human health. However, further research is essential to evaluate the biological activity of these accessions before designing functional food.

Inheritance of high oleic acid content in the seed oil of mutant Ethiopian mustard lines and its relationship with erucic acid content

Ethiopian mustard (Brassica carinata) genotypes with different contents of oleic acid (C18:1) in the seed oil could be useful for food and industrial applications. The objectives of the present research were to study the inheritance of high C18:1 in the seed oil of different lines of Ethiopian mustard and its relationship with erucic acid content (C22:1). The low C18: I/high C22:1 mutant line L-1806, the high C18: I/high C22:1 mutant line L-482, the high C18: 1/low C22:1 mutant line L-2890 and the low C18:1/very high C22:1 mutant line L-1630 were isolated after a chemical mutagen treatment of C-101 seeds (about 94 g C18:1/kg and 450 g C22:1/kg). The high C18:1/zero C22:1 line L-25X-1 was obtained by interspecific crosses of Ethiopian mustard with rapeseed and Indian mustard. Plants of lines L-2890 x C-101, L-482 x L-2890, L-1630 x L-25X-1, L-1630 x L-2890 and L-482 x L-1806 were reciprocally crossed and F 2 and the BC 1 F 1 generations were obtained. Cytoplasmic effects were not observed in any of the crosses. The segregation pattern in F 2 and BC 1 F 1 populations differed in the crosses studied. The inheritance of C18:1 content in crosses segregating for this fatty acid was that expected for one (crosses between L-482xL-1806), two (L-2890xC-101) or three (L-1630 x L-2890, L-1630 x L-25X-1 and L-482 x 2890) loci. Oleic acid segregation indicated control of accumulation by two segregating genetic systems, one acting on chain elongation from C18:1 to C22:1 and the other involving desaturation from C18:1 to linoleic acid (C18:2). Accumulations of C18:1 and C22:1 were influenced by the same loci (Ml, M2, El and E2), which control the chain elongation steps leading from C18:1 to C22:1. In addition, C18:1 was influenced by one additional locus (tentatively named OL) involved in control of desaturation of C18:1 to form C18:2. The genetic constitution of the parent lines would be OlOlE 1 E 1 E 2 E 2 m 1 m 1 m 2 m 2 for L-2890, OlOlE 1 E 1 E 2 E 2 M 1 M 1 M 2 M 2 for C-101, ololE 1 E 1 E 2 E 2 M 1 M 1 M 2 M 2 for L-1630, OlOle 1 e 1 e 2 e 2 M 1 M 1 M 2 M 2 for L-25X-1, ol1ol1E 1 E 1 E 2 E 2 M 1 M 1 M 2 M 2 for L-482 and Ol1Ol1E 1 E 1 E 2 E 1 M 1 M 1 M 2 M 2 for L-1806. Transgressive recombinants were obtained from the cross L-1630 x L-25X-1, with about three-fold increase of the C18:1 content ofthe parents (> 643 g/kg) and free of C22:1 content, which represent a high potential for commercial exploitation.

Genetic control of intermediate erucic acid content in the seed oil of the mutant ethiopian mustard line L-935

Chemical-mutagen treatment of Ethiopian mustard (Brassica carinata A. Braun) line C-101 seeds (which contained about 441 g/kg C22:1) led to isolation of a mutant, L-935, which contained about 190g/kg erucic acid (intermediate C22:1) in the seed oil. The objective was to determine the inheritance of the intermediate C22:1 level in this mutant. The mutant L-935 was reciprocally crossed to C-101 and to the mutant line L-2890 (which contained 112 g/kg C22:1:low). The F 1 , F 2 and BC 1 F 1 generations were obtained. Cytoplasmic effects were not observed in any of the crosses. The analysis of the fatty acid composition in the F 2 populations from the crosses of L-935 with C-101 revealed a segregation pattern fitting a ratio 1:2:1 for intermediate, high and very high C22:1 content. The segregation patterns fitted a one-locus (designated M2) model with two alleles (M 2 and m,) and with partial dominance of high over intermediate C22:1 content. The segregating generations of the crosses L-935×L-2890 showed a strong transgressive segregation with C22:1 values ranged from 1.3-406.5 g/kg. The analyses of the F 2 , BC 1 F 1 and F 3 generations indicated that the combination of alleles at two loci, Ml and M2 controlled the transgressive segregation for C22:1 content. The proposed genotypes (C22:1 content) for each parent were as follows: L-935 (190 g/kg C22:1)=MMm i m i EEEE; L-2890 (112 g/kg C22: \)=mmmmEEEE; and C-101 (441 g/kg C22:1)= MMMMEEEE.