Antonio De Haro

A plant genetically modified that accumulates Pb is especially promising for phytoremediation.

From a number of wild plant species growing on soils highly contaminated by heavy metals in Eastern Spain, Nicotiana glauca R. Graham (shrub tobacco) was selected for biotechnological modification, because it showed the most appropriate properties for phytoremediation. This plant has a wide geographic distribution, is fast-growing with a high biomass, and is repulsive to herbivores. Following Agrobacterium mediated transformation, the induction and overexpression of a wheat gene encoding phytochelatin synthase (TaPCS1) in this particular plant greatly increased its tolerance to metals such as Pb and Cd, developing seedling roots 160% longer than wild type plants. In addition, seedlings of transformed plants grown in mining soils containing high levels of Pb (1572 ppm) accumulated double concentration of this heavy metal than wild type. These results indicate that the transformed N. glauca represents a highly promising new tool for use in phytoremediation efforts.

Variability of Some Physico‐chemical Characters in Desi and Kabuli Chickpea Types

A collection of 50 chickpea accessions (26 kabuli and 24 desi types) was evaluated for 2 years for eight physico-chemical seed characters : 100-seed weight, hydration capacity, hydration index, coat thickness and contents of protein, oil, acid detergent fibre (ADF) and starch. Significant differences were found between desi and kabuli types for the majority of the characters. The variance component due to the genotype x year interaction was important for the hydration index, starch and protein content, showing the importance of the year effect on genotypic expression of these characters. One kabuli accession and five desi accessions with high and stable protein content were selected. There was no overlap between the variation limits of desi and kabuli for coat thickness and ADF content. There were high positive and significant correlations between seed weight and oil content for both types of chickpea.

Salicylic acid increases tolerance to oxidative stress induced by hydrogen peroxide accumulation in leaves of cadmium-exposed flax (Linum usitatissimum L.)

The aim of this study is to investigate the impacts of exogenous salicylic acid (SA) pretreatments on hydrogen peroxide (H2O2) accumulation, protein oxidation, and H2O2-scavenging enzymes in leaves of Cd-treated flax seedlings. Cd-enhanced H2O2 levels were related to increased activities of guaiacol peroxidase (POX, EC 1.11.1.7) and ascorbate peroxidase (APX, EC 1.11.1.11), and were independent of changes in catalase (CAT, EC 1.11.1.6) and superoxide dismutase (SOD, EC 1.15.1.1) activities. In control flax seedlings, exogenous SA pretreatments inhibited the activity of CAT, resulted in an enhanced production of H2O2 suggesting that SA requires H2O2 to initiate an oxidative stress. However, although leaves of Cd-free flax seedlings pretreated with SA accumulated in vivo H2O2 by 1.2-fold compared with leaves of Cd-only exposed ones; the damage to growth and proteins after the exposure to Cd was significantly less, indicating that SA can regulate the Cd-induced oxidative stress. Moreover, the Cd-treated seedlings primed with SA exhibited a higher level of total antioxidant capacities and increased activities of H2O2-detoxifying enzymes.

Identification of as Accumulation Plant Species Growing on Highly Contaminated Soils

Soils from the alluvial flats of the Turia River, Valencia, Spain, which were highly contaminated by decades of industrial activity, were surveyed for native plant species that could be candidates useful in phytoremediation. Concentrations of heavy metals and arsenic (As) in soils reached 25,000 mg Kg−1 Pb, 12,000 mg Kg−1 Zn, 70 mg Kg−1 Cd, and 13500 mg Kg−1 As. The predominant vegetation was collected and species identified. Soil samples and the corresponding plant shoots were analyzed to determine the amount of As accumulated by the various plant species. Several were able to tolerate more than 1000 mg Kg−1 As in the soil. Bassia scoparia (Chenopodiaceae) survive in soil with 8375 mg Kg−1 As. Arsenic accumulation in shoots of the various plant species investigated ranged from 0.1 to 107 mg Kg−1 dw. Bassia scoparia (Chenopodiaceae), Inula viscosa (Asteraceae), Solanum nigrum (Solanaceae), and Hirschfeldia incana (Brassicaceae) had the highest values for As accumulation.

Intraspecific breeding for reduced glucosinolate content in Ethiopian mustard (Brassica carinata A. Braun)

A total of six Ethiopian mustard ( Brassica carinata A. Braun) lines showing reduced levels of total glucosinolate content were developed through two different approaches. In the first case, eight lines with good agronomic performance under southern-Spanish conditions were first evaluated during two years for glucosinolate content, and a pedigree selection was then performed during three further generations. The line N2-142, with an average glucosinolate content of 82 μmoles g-1 seed, was developed from the original line C-49, with an average glucosinolate content of 115 μmoles g-1 seed. In the second case, chemical mutagenesis (EMS 1% v/v) was applied to seeds from the line C- 101, with an average glucosinolate content of 125 μmoles g- 1 seed. Five mutant lines showing an average glucosinolate content between 20 and 30 μmoles g-1 seed lower than the wild line C-101 were isolated in the M_3 or M_4 generation. The reduced glucosinolate content of these mutants was confirmed by developing and analysing the M_5 generation. Previous results in B. juncea suggest that a further reduction of total glucosinolate content might be achieved through genetic recombination between the different lines developed in this work.

Exogenous salicylic acid protects phospholipids against cadmium stress in flax (Linum usitatissimum L.)

Salicylic acid (SA) promotes plant defense responses against toxic metal stresses. The present study addressed the hypothesis that 8-h SA pretreatment, would alter membrane lipids in a way that would protect against Cd toxicity. Flax seeds were pre-soaked for 8h in SA (0, 250 and 1000µM) and then subjected, at seedling stage, to cadmium (Cd) stress. At 100µM CdCl2, significant decreases in the percentages of phosphatidylcholine (PC), phosphatidylglycerol (PG), phosphatidylethanolamine (PE) and monogalactosyldiacylglycerol (MGDG) and changes in their relative fatty acid composition were observed in Cd-treated roots in comparison with controls. However, in roots of 8-h SA pretreated plantlets, results showed that the amounts of PC and PE were significantly higher as compared to non-pretreated plantlets. Additionally, in both lipid classes, the proportion of linolenic acid (18:3) increased upon the pretreatment with SA. This resulted in a significant increase in the fatty acid unsaturation ratio of the root PC and PE classes. As the exogenous application of SA was found to be protective of flax lipid metabolism, the possible mechanisms of protection against Cd stress in flax roots were discussed.

Application of near-infrared reflectance spectroscopy to estimate the bulk density of Ethiopian mustard seeds

This study was conducted to test the applicability of NIRS to estimate the bulk density of Ethiopian mustard seeds. A set of samples from the 1992 crop with bulk density values between 262 and 676 kg m -3 was used to develop a calibration equation for this trait. The best equation was obtained by using the original log (1/R) spectra, without any mathematical pretreatment, and modified partial least squares (MPLS) regression. The coefficient of determination in external validation (r 2 ) was 0.92, which indicated a high reliability in the estimation of bulk density by NIRS. This equation was successively expanded with new samples from the 1993 and 1994 crops. The calibration equation developed in 1994, including 356 samples from the 1992, 1993 and 1994 crops, was validated with a total of 362 samples from the 1995 crop, ranging from 204 to 697 kg m -3 . The r 2 was 0.92, indicating the high robustness of the 3-year calibration equation to estimate the bulk density of samples from populations not represented in the calibration set. A 3-year calibration was also developed by multiple linear regression (MLR) and a restriction to 19 wavelengths available in common filter instruments, resulting in an r 2 = 0.88 in the validation with samples from 1995, which suggests that this trait may be also accurately estimated in filter instruments. This study demonstrated that the bulk density of Ethiopian mustard seeds can be easily and accurately estimated by NIRS, which facilitates the rapid identification of undesirable low bulk density samples in routine analysis.

Variability in the Content of Gamma-Linolenic Acid and Other Fatty Acids of the Seed Oil of Germplasm of Wild and Cultivated Borage (Borago officinalis L.)

SURMMARY Two hundred and six Borago officinalis L. (Boraginaceae) accessions of cultivated and wild germplasm collections from different origins were evaluated for gamma-linolenic acid (GLA) and other fatty acids and seeds characters. GLA showed an important range of variation, from 8.7% to 28.6% of the seed oil. Oleic, linoleic and erucic acid also showed wide ranges of variation. White flowered cultivated genotypes had higher contents of GLA than blue flowered wild material collected in Spain. Blue flowered germplasm from Northern Europe showed higher values of erucic acid. No correlation was found between oil content and GLA. In spite of the positive correlation between GLA and erucic acid, genotypes with high oil and GLA content and low levels of erucic acid content could be identified for breeding purposes.

An efficient method for screening seed colour in Ethiopian mustard using visible reflectance spectroscopy and multivariate analysis

SummarySeed colour is considered as an important breeding objective in Ethiopian mustard and other Brassica species, but its measurement is usually subjective rather than objective. For this reason we studied the potential of visible reflectance spectroscopy (VRS) combined with factorial analysis and multivariate calibration to predict seed colour in seeds of Ethiopian mustard. A total of 8331 samples were screened in the range 400–2500 nm with a near infra-red reflectance spectroscopy (NIRS) spectrophotometer. A common factor analysis was performed using 1148 samples and spectral data from 400 to 700 nm. It was found that four common factors explained 99.9% of the variance. Three of these factors were associated with colour characteristics of the seeds. Factor 1 separated yellow, yellow-brown and brown seeded samples, factor 3 separated brown from reddish-brown samples and factor 4 separated complete yellow from greenish-yellow samples. Calibration equations were developed for each factor, which allowed seed colour in those samples not included in factor analysis to be predicted. This study demonstrated that seed colour prediction can be incorporated into NIRS routine analysis with instruments that incorporate the visible spectral region.

Boraginaceae as Potential Sources of Gamma-Linolenic Acid

Gamma linolenic acid (GLA, 18:3 Δ6, 9, 12) is an essential fatty acid in demand for its clinical and pharmaceutical applications. The most common commercial source of GLA for pharmaceutical use has been the oil of evening primrose seeds, Oenothera biennis (Galwey and Shirlin, 1990; del Rio et al., 1993). A possible alternative GLA source is the seed of borage, Borago officinalis, which is characterized by high oil content (24-34% as compared to 14-25% in Oenothera), with high GLA (23% as compared to 10.5%) and low erucic acid composition (Janick et al., 1989; del Rio et al., 1993). Additional advantages of borage are its annual life cycle and larger seeds as compared to Oenothera (Galwey and Shirlin, 1990). In addition to borage, other genera of the Boraginaceae, or borage family, also represent potential sources for GLA (Galwey and Shirlin, 1990; del Rio et al., 1993; de Haro and del Rio, 1998).