Explore the vast range of titles available.

Tomato fruit has assumed the status of ‘functional food’ due to the association between its consumption and a reduced likelihood of certain types of cancers and CVD. The nutraceutical value of tomatoes can be affected by the cultivation conditions, e.g. the phytochemical content of the fruits may increase with the establishment of beneficial mycorrhizal symbioses in the plants. A multidisciplinary study was carried out to gain knowledge on the antioxidant, oestrogenic/anti-oestrogenic and genotoxic activity of tomato fruits produced by mycorrhizal plants. The present results showed that the symbiosis positively affected the growth and mineral nutrient content of tomato plants and enhanced the nutritional and nutraceutical value of tomato fruits through modifications of plant secondary metabolism, which led to increased levels of lycopene in fruits obtained from mycorrhizal plants, compared with controls. Moreover, such changes did not result in the production of mutagenic compounds, since tomato extracts induced no in vitro genotoxic effects. Fruit extracts, both hydrophilic and the lipophilic fractions, originating from mycorrhizal plants strongly inhibited 17-β-oestradiol–human oestrogen receptor binding, showing significantly higher anti-oestrogenic power compared with controls. The present study shows that beneficial plant symbionts, such as mycorrhizal fungi, can lead to the production of safe and high-quality food, which is an important societal issue strongly demanded by both consumers and producers.

The nucellus is a maternal tissue that embeds and feeds the developing embryo and secondary endosperm. During seed development, the cells of the nucellus suffer a degenerative process soon after fertilization as the cellular endosperm expands and accumulates reserves. Nucellar cell degeneration has been considered to be a form of developmentally programmed cell death (PCD). It was investigated whether or not this degenerative process is characterized by apoptotic hallmarks. Evidence showed that cell death is mostly localized in the border region of the tissue adjacent to the expanding endosperm. Cell death is accompanied by profound changes in the morphology of the nuclei and by a huge degradation of nuclear DNA. Moreover, an increase of activity of different classes of proteinases is reported, and the induction of caspase-like proteases sensitive to specific inhibitors was detected. Nucellar caspase-like proteases are characterized by an acid pH optimum suggesting a possible localization in the vacuole.

Gibberellins in the embryo-suspensor system have been considered so far only in Phaseolus coccineus. We present in this report the localization of gibberellin-like substances in the suspensors of Tropaeolum majus L. and Cytisus laburnum L. The total gibberellin activity (expressed as gibberellic-acid equivalent in the α-amylase bioassay) in 2000 suspensors (106 mg fresh weight; FW) of C. laburnum and in 600 suspensors (236 mg FW) of T. majus were 50.9 μg g(-1) FW and 8.9 μg g(-1) FW respectively.

Crude particulate homogenates from leaves of barley (Hordeum vulgare L.), rice (Oryza sativa L.), leaf-beet (Beta vulgaris var. cicla L.) and pumpkin (Cucurbita pepo L.) cotyledons were separated on sucrose density gradients. The peroxisomal fractions appeared at a buoyant density of 1.25 g·cm-3 and contained most of the activities of catalase (EC 1.11.1.6), and hydroxypyruvate reductase (EC 1.1.1.81) on the gradients. In peroxisomal fractions from detached leaves and green cotyledons incubated in permanent darkness we detected the presence of isocitrate lyase (EC 4.1.3.1) and malate synthase (EC 4.1.3.2), key enzymes of the glyoxylate cycle, and β-oxidation activity (except in pumpkin). As proposed by H. Gut and P. Matile (1988, Planta 176, 548—550) the glyoxylate cycle may be functional during leaf senescence, and the presence of two key enzymes indicates a transition from leaf peroxisome to glyoxysome; for pumpkin cotyledons in particular a double transition occurs (glyoxysome to leaf peroxisome during greening, and leaf peroxisome to glyoxysome during senescence).

Free abscisic acid (ABA) content in suspensors, embryos, and integuments was determined during seed development of Phaseolus coccineus. A highly specific and sensitive solid-phase radioimmunoassay based on a monoclonal antibody raised against free (S)-ABA was used for ABA quantification. Very small amounts of ABA were detected in the suspensor during initial stages of development; later two peaks of ABA occurred. Levels of ABA in the embryo and integument show a coincident triphasic distribution: two maxima in ABA content occurred when the embryo was 11 to 12 and 15 to 16 millimeters in length; later, when the embryo was 19 to 20 millimeters long, a further increase was observed. The role of ABA in runner bean seeds is discussed in relation to the development of the different seed tissues.

Analysis of extracts from 6300 (1.2 grams fresh weight) Phaseolus coccineus suspensors by combined gas chromatography-mass spectrometry has demonstrated the presence of five C19-gibberellins, $\\text{GA}_{1}$, GA4, $\\text{GA}_{5}$, $\\text{GA}_{6}$, $\\text{GA}_{8}$, and one $\\text{C}_{20}$-GA, $\\text{GA}_{44}$. The major GAs present were $\\text{GA}_{1}$ and $\\text{GA}_{8}$. Data are discussed in relation to previous results obtained in P. coccineus seed as well as in the embryo-suspensor system.

The effects of 10 growth regulators on the development of 2 bulbous iris cultivars are reported. Particularly effective were treatments with GA₃ and growth retardants. Early flowering was promoted by GA₃ in cv. \"Prof. Blaauw \"without effects on flower quality. The role of gibberellins on iris flowering and their possible use in iris forcing are discussed. Sono riportati gli effetti di dieci regolatori di crescita sullo sviluppo di due cultivar di iris bulboso. Sono risultati particolarmente attivi GA₃ ed i ritardanti di crescita. GA₃ stimola precoce fioritura nella cv Prof. Blaauw senza effetti deleteri sulla qualità del fiore. È inoltre discusso il ruolo delle gibberelline sulla fioritura dell'iris ed il loro possibile uso nella forzatura di questa specie.

Gibberellins (GAs) in suspensors and embryos of Phaseolus coccineus seeds at the heart stage of embryo development were analyzed by combined gas chromatography-mass spectrometry (GC-MS). From the suspensor four C19-GAs, GA1, GA4, GA5s, GA6, and one C20 GA, GA44, were identified. From the embryo, five C19- GAs GA1, GA4, GA5, GA6, GA60 and two C20 GAs, GA19, and GA44 were identified. The data, in relation to previous results, suggest a dependence of the embryo on the suspensor during early stages of development