0000000000542568
AUTHOR
Sergio G. Nebauer
Plant hormones and Agrobacterium tumefaciens strain 82.139 induce efficient plant regeneration in the cardenolide-producing plant Digitalis minor
Summary Shoot formation in explants of Digitalis minor was achieved, through axillary bud proliferation and adventitious bud differentiation, by varying the amount and source of plant hormones. Shoot regeneration was also obtained after infection of D. minor with the wild-type Agrobacterium tumefaciens strain 82.139, which induced shooty tumours. These shoots were not transgenic, as revealed by nopaline assays and the use of a C58pMP90/T139GUS-INT strain harbouring the intron inactivated gusA gene. Plants were easily rooted and transplanted into the greenhouse. Shoot cultures of D. minor accumulated up to 226 μg cardenolides per g dry mass when cultured on agar-solidified medium. Cardenolid…
Crocus sativus L. Ecotypes from Mediterranean Countries: Phenological, Morpho-Productive, Qualitative and Genetic Traits
The characterization of C. sativus ecotypes is of great interest for preserving them from a possible genetic erosion due to the decrease of European cultivation surface. In this study, we evaluated four ecotypes from Italy (Sardinia and Abruzzo), Spain (Castilla-La Mancha), and Greece (Kozani) in order to detect the existence of variability and promote the biodiversity of this crop. Thirty-one traits related to saffron flowering, flower morphology, production of spice and daughter corms, vegetative development (leaf and corm traits), and spice quality, were evaluated. In addition, a genetic analysis through three PCR-based approaches, SSRs, RAPD, and SRAP was assessed. Results highlighted a…
RAPD variation within and among natural populations of outcrossing willow-leaved foxglove (Digitalis obscura L.)
Random amplified polymorphic DNA (RAPD) markers were used to assess levels and patterns of genetic diversity in Digitalis obscura L. (Scrophulariaceae), an outcrossing cardenolide-producing medicinal plant species. A total of 50 plants from six natural populations on the Iberian Peninsula were analysed by six arbitrarily chosen decamer primers resulting in 96 highly reproducible RAPD bands. To avoid bias in parameter estimation, analyses of population genetic structure were restricted to bands (35 of 96) whose observed frequencies were less than 1–3/n in each population. The analysis of molecular variance (AMOVA) with distances among individuals corrected for the dominant nature of RAPDs (g…
Cardenolide variation within and among natural populations of Digitalis obscura
Summary Cardenolide content in 49 wild-growing Digitalis obscura plants from six natural populations on the Iberian Peninsula was determined by HPLC. Series A and B glycosides were the predominant cardenolides in all samples, but absolute values varied among and within populations. Hierarchic analysis of variance showed that the proportion of variation attributable to individuals was significantly higher than that attributable to population differences. Furthermore, analyses from greenhouse-grown plants, generated from seeds collected from selected parental genotypes, attributed nearly all the variability in cardenolide content to single plants. Some individual plants showed a leaf content …
The targeted overexpression of SlCDF4 in the fruit enhances tomato size and yield involving gibberellin signalling
AbstractTomato is one of the most widely cultivated vegetable crops and a model for studying fruit biology. Although several genes involved in the traits of fruit quality, development and size have been identified, little is known about the regulatory genes controlling its growth. In this study, we characterized the role of the tomato SlCDF4 gene in fruit development, a cycling DOF-type transcription factor highly expressed in fruits. The targeted overexpression of SlCDF4 gene in the fruit induced an increased yield based on a higher amount of both water and dry matter accumulated in the fruits. Accordingly, transcript levels of genes involved in water transport and cell division and expans…
Genetic diversity and structure of natural and managed populations of Cedrus atlantica (Pinaceae) assessed using random amplified polymorphic DNA
Cedrus atlantica (Pinaceae) is a large and exceptionally long-lived conifer native to the Rif and Atlas Mountains of North Africa. To assess levels and patterns of genetic diversity of this species, samples were obtained throughout the natural range in Morocco and from a forest plantation in Arbúcies, Girona (Spain) and analyzed using RAPD markers. Within-population genetic diversity was high and comparable to that revealed by isozymes. Managed populations harbored levels of genetic variation similar to those found in their natural counterparts. Genotypic analyses of molecular variance (AMOVA) found that most variation was within populations, but significant differentiation was also found b…
Population genetic study in the Balearic endemic plant speciesDigitalis minor(Scrophulariaceae) using RAPD markers
Digitalis minor (Scrophulariaceae) is a cardenolide-producing plant endemic to the eastern Balearic Islands (Mallorca, Menorca, and Cabrera) that occurs in two morphologically distinct varieties: D. minor var. minor (pubescent) and D. minor var. palaui (glabrous). Levels and patterns of genetic diversity in 162 individuals from 17 D. minor populations across the entire geographic range were assessed using random amplified polymorphic DNA (RAPD) markers. Comigrating RAPD fragments tested were found to be homologous by Southern hybridization in both var. minor and var. palaui. To avoid bias in parameter estimation, analyses of population genetic structure were restricted to those RAPD bands t…
An assessment of genetic relationships within the genus Digitalis based on PCR-generated RAPD markers
RAPD markers were used to study inter-specific variation among six species of the genus Digitalis: D. obscura, D. lanata, D. grandiflora, D. purpurea, D. thapsi and D. dubia, and the hybrid D. excelsior (D. purpurea×D. grandiflora). A total of 91 highly reproducible bands amplified with four arbitrarily chosen decamer primers were obtained. Homology of the co-emigrating RAPD markers was tested by blot hybridisation and sequencing of selected bands. The application of a range of statistical approaches for RAPD data analysis, including distance and parsimony methods, family clustering and the analysis of molecular variance (AMOVA), indicated that these molecular markers were taxonomically inf…
Ectopic expression of the AtCDF1 transcription factor in potato enhances tuber starch and amino acid contents and yield under open field conditions
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Phosphoglycerate Kinases Are Co-Regulated to Adjust Metabolism and to Optimize Growth
[EN] In plants, phosphoglycerate kinase (PGK) converts 1,3-bisphosphoglycerate into 3-phosphoglycerate in glycolysis but also participates in the reverse reaction in gluconeogenesis and the Calvin-Benson cycle. In the databases, we found three genes that encode putative PGKs. Arabidopsis (Arabidopsis thaliana) PGK1 was localized exclusively in the chloroplasts of photosynthetic tissues, while PGK2 was expressed in the chloroplast/plastid of photosynthetic and nonphotosynthetic cells. PGK3 was expressed ubiquitously in the cytosol of all studied cell types. Measurements of carbohydrate content and photosynthetic activities in PGK mutants and silenced lines corroborated that PGK1 was the phot…
Cryopreservation of Digitalis obscura selected genotypes by encapsulation-dehydration
Shoot-tips from several genotypes of the cardenolide-producing perennial shrub Digitalis obscura L. were successfully cryopreserved using the encapsulation-dehydration technique. Precultivation on MS medium containing 0.5 M sucrose, followed by 2.5 h dehydration (final weight 30 %) induced shoot regrowth in 42 % of cryopreserved shoot-tips. Cold-hardening of the in vitro cultures before sucrose treatment dramatically increased shoot recovery up to 86 %. The optimized cryopreservation protocol was then employed using different shoot cultures from five D. obscura genotypes. Responses to cryopreservation depended mainly on the genotype, best results being obtained when shoot tips from HU3 and …
Phosphoglycerate dehydrogenase genes differentially affect Arabidopsis metabolism and development.
[EN] Unlike animals, plants possess diverse L-serine (Ser) biosynthetic pathways. One of them, the Phosphorylated Pathway of Serine Biosynthesis (PPSB) has been recently described as essential for embryo, pollen and root development, and required for ammonium and sulfur assimilation. The first and rate limiting step of PPSB is the reaction catalyzed by the enzyme phosphoglycerate dehydrogenase (PGDH). In Arabidopsis, the PGDH family consists of three genes, PGDH1, PGDH2 and PGDH3. PGDH1 is characterized as being the essential gene of the family. However, the biological significance of PGDH2 and PGDH3 remains unknown. In this manuscript, we have functionally characterized PGDH2 and PGDH3. Ph…
Ongoing Evolution in the Genus Crocus: Diversity of Flowering Strategies on the Way to Hysteranthy
[EN] Species of the genus Crocus are found over a wide range of climatic areas. In natural habitats, these geophytes diverge in the flowering strategies. This variability was assessed by analyzing the flowering traits of the Spanish collection of wild crocuses, preserved in the Bank of Plant Germplasm of Cuenca. Plants of the seven Spanish species were analyzed both in their natural environments (58 native populations) and in common garden experiments (112 accessions). Differences among species observed in the native habitats were maintained under uniform environmental conditions, suggesting a genetic basis for flowering mechanisms. Two eco-morphological types, autumn- and spring-flowering …