Herbicidal potential of ophiobolins produced by Drechslera gigantea

Drechslera gigantea, a potential mycoherbicide of grass weeds, was isolated in Florida from naturally infected large crabgrass (Digitaria sanguinalis); it produces phytotoxic metabolites in liquid culture. The main metabolite was identified by spectroscopic methods and optical properties as ophiobolin A (1), a well-known phytotoxic sesterterpene produced by several phytopathogenic fungi of important crops and already extensively studied for its interesting biological activities. The other three minor metabolites proved to be related to ophiobolin A and were identified using the same techniques as 6-epi-ophiobolin A and 3-anhydro-6-epi-ophiobolin A (2 and 3) and ophiobolin I (4). Assayed on punctured detached leaves of several grass and dicotyledon weeds, ophiobolin A proved to be on average more phytotoxic as compared to the other related compounds. Some structural features appear to be important for the phytoxicity, such as the hydroxy group at C-3, the stereochemistry at C-6, and the aldehyde group at C-7. Furthermore, grass weeds usually proved to be more sensitive to the phytotoxins than dicotyledons, on which ophiobolin A caused the appearance of large necrosis even at the lowest concentration assayed. This is the first report about the production of ophiobolins from D. gigantea and of the proposed use as potential natural herbicides against grass weeds.     

Trabectedin and Plitidepsin: Drugs from the Sea that Strike the Tumor Microenvironment

The prevailing paradigm states that cancer cells acquire multiple genetic mutations in oncogenes or tumor suppressor genes whose respective activation/up-regulation or loss of function serve to impart aberrant properties, such as hyperproliferation or inhibition of cell death. However, a tumor is now considered as an organ-like structure, a complex system composed of multiple cell types (e.g., tumor cells, inflammatory cells, endothelial cells, fibroblasts, etc.) all embedded in an inflammatory stroma. All these components influence each other in a complex and dynamic cross-talk, leading to tumor cell survival and progression. As the microenvironment has such a crucial role in tumor pathophysiology, it represents an attractive target for cancer therapy. In this review, we describe the mechanism of action of trabectedin and plitidepsin as an example of how these specific drugs of marine origin elicit their antitumor activity not only by targeting tumor cells but also the tumor microenvironment.     

The use of Lactobacillus pentosus 1MO to shorten the debittering process time of black table olives (Cv. Itrana and Leccino): a pilot-scale application

Fifty lactobacilli isolated from black table olive brines were evaluated for their salt tolerance, resistance to oleuropein and verbascoside, and ability to grow in modified filter-sterilized brines. A strain of Lactobacillus pentosus was selected and used as a starter to ferment, in pilot plant, black olives (Itrana and Leccino cv.) in brines modified for pH, carbohydrate, and growth factor concentrations, at 28 degrees C. The temperature-controlled fermentation of Leccino cv. olives resulted in obtaining ready-to-eat, high-quality table olives in a reduced-time process. HPLC analysis of phenolic compounds from fermented olives showed a decrease of oleuropein, a glucoside secoiridoid responsible for the bitter taste of olive drupes, and an increase of the hydroxytyrosol concentration. The selected strain of L. pentosus (1MO) allowed the reduction of the debittering phase period to 8 days.     

Evaluation of the effectiveness of soil-applied plant derivatives of Meliaceae species on nitrogen availability to peach trees

We assessed the effect of soil-applied derivatives of melia (Melia azedarach L.) and neem (Azadirachta indica A. Juss) on nitrogen (N) soil availability, root uptake and peach (Prunus persica L.) growth. First we evaluated the effectiveness of experimentally prepared amendments made with fresh ground melia leaves or commercial neem cake incorporated into the soil as nitrification inhibitors, then we evaluated the effect of fresh ground melia fruits and neem cake on growth and N root uptake of potted peach trees, and on soil microbial respiration. Soil-applied fresh ground melia leaves at 10 and 20 g kg⁻¹ of soil as well as commercial neem cake (10 g kg⁻¹) were ineffective in decreasing the level of mineral N after soil application of urea-N as a source of mineral N, rather they increased soil concentration of nitric N and ammonium N. The incorporation into the soil of fresh ground melia fruits (at 20 and 40 g kg⁻¹) and neem cake (at 10 and 20 g kg⁻¹) increased N concentration in leaves of GF677 peach × almond (Prunus amygdalus) hybrid rootstock alone or grafted with one-year-old variety Rome Star peach trees. An increase in microbial respiration, leaf green color and plant biomass compared to the control trees were also observed. The Meliaceae derivatives did not affect, in the short term (7 days), N root uptake efficiency, as demonstrated by the use of stable isotope ¹⁵N, rather they promoted in the long term an increase of soil N availability, N leaf concentration and plant growth.     

Agronomic and qualitative characteristics of ten bread wheat hybrids produced using a chemical hybridizing agent

Summary Ten experimental hybrids derived from the crossing of representative Italian pure-line varieties were grown at three locations in 1984–85. The amount of F₁ seed produced from the crossings ranged from 1.5 up to 4 kg per plot of 20 m². Hybrid purity was on average 88% when estimated through the growout test and 82% when estimated through acid polyacrylamide gel electrophoresis (A-PAGE) of gliadin.All the hybrids showed high-parent heterosis for plant height. Grain yield was higher in the hybrids (71.1 q/ha) than in the female parents (66.5 q/ha); the range of mid-parent heterosis being-10% to +17%. Four hybrids showed standard heterosis (yield advantage). The highest value (+6%) was obtained with the combinations Chiarano x Leopardo and Claudia x Leopardo. Among yield components, the number of spikelets/spike proved to be an important trait and may explain the superiority of the hybrids over the traditional varieties.The bread-making quality appeared intermediate to that of the parents or closer to that of the poorest parental variety.     

Volatile compounds and phenolic composition of virgin olive oil: optimization of temperature and time of exposure of olive pastes to air contact during the mechanical extraction process

The operative conditions of malaxation such as temperature and time of exposure of olive pastes to air contact (TEOPAC) affect volatile and phenolic composition of virgin olive oil (VOO) and, as a consequence, its sensory and healthy qualities. In this paper, optimal temperature and TEOPAC during malaxation were studied, in lab scale, in two Italian cultivars using phenolic compounds, volatile composition, and sensory analysis of VOO as markers. The optimal temperature and TEOPAC, selected by response surface modeling,were cultivar-dependent being 30 min of TEOPAC at the lowest temperature investigated (22 degrees C) and 0 min of TEOPAC at 26 degrees C for Frantoio and Moraiolo cultivars, respectively.     

Extremely potent antifeedant neo-clerodane derivatives of scutecyprol A

Two known neo-clerodane diterpenoids, scutecyprol A (1) and scutalbin C (2), have been isolated from the acetone extract of the aerial parts of Scutellaria sieberi. The antifeedant activity of scutecyprol A (1), of its 15-oxo derivative (3), and of several halohydrins (4-9), synthesized starting from compounds 1 and 3, against Spodoptera littoralis have been determined and structure-antifeedant relationships are discussed.     

A simple molecular approach for identifying a rare Acronychia (Rutaceae) provides new insights on its multiple hybrid origins

Hybridization plays an important role in the evolution of plant diversity. Nonetheless, it is often difficult to clearly ascertain hybrid origin by assessing morphological characters alone. Acronychia littoralis (Rutaceae) is a recently described rare tree from littoral rainforests in eastern Australia. Two forms have been tentatively distinguished on the basis of different leaf morphology however, because of the variability of the discriminatory characters across populations (and in some cases across single individuals), compiling data on the exact distribution of each form has been a difficult process. To further complicate matters, some of these distinguishing morphological characters are intermediate between those of closely related, sympatric species. As a result, simple molecular techniques were developed to assist the development of adequate conservation and management strategies for A. littoralis and to better understand its evolutionary history. Sequence data from the ITS2 region were obtained and haplotype specific primers that distinguished the two forms and the related taxa were developed. Sequence data suggest that the two forms of A. littoralis are each of hybrid origin but both involve different parental taxa. The findings provide a perspective on the evolutionary dynamics of the local rainforest flora and highlight the need for phylogenetic evaluation of rare taxa where there is taxonomic ambiguity.     

Olive mill wastewater spreading and AMF inoculation effects in a low-input semi-arid Mediterranean crop succession

ABSTRACT

The study aimed to evaluate, in a marginal semi-arid Mediterranean agro-ecosystem (Sicily-Italy), the effects of arbuscular mycorrhizal fungi (AMF) inoculation and raw olive mill wastewater (OMW) (40 and 80 m³ ha^?1) on forage (durum wheat-snail medick intercropping) yield, and grain production of broad bean and chickpea. AMF inoculation significantly increased (+13.6%) forage dry biomass and durum wheat nitrogen (+22.8%) and phosphorus (+32.5%) uptake. AMF inoculation, significantly promoted broad bean phosphorus uptake (+11.5%) and root nodule number (+13.9%) in the absence of OMW. OMW spreading reduced weeds in the forage (?31.3%), root nodule number (?29.7%) and dry weight (?22.7%) in broad bean. OMW also significantly increased snail medick dry biomass (+19.3%) as compared to control treatments (0, 40 and 80 m³ H₂O ha^?1, average production 361 g m^?2), and broad bean grain yield with a production of 2.46 ± 0.12 and 1.94 ± 0.09 Mg ha^?1 with and without OMW, respectively. During the experiment AMF colonization was not affected by OMW volumes. The results obtained showed that in a marginal Mediterranean agro-ecosystem: 1) OMW, notwithstanding spreading volumes, is a valuable amendment to maximize legume yield while 2) AMF inoculation is a valuable practice to improve biomass production and N and P uptake in wheat.     

Synthesis of pyrazole derivatives and their evaluation as photosynthetic electron transport inhibitors

Two series of new pyrazoles, namely six pyrazolo[1,5-a][1,3,5]triazine-2,4-dione and four pyrazolo[1,5-c][1,3,5]thiadiazine-2-one derivatives, were synthesized as potential inhibitors of the photosynthetic electron transport chain at the photosystem II level. The compounds were confirmed by 1H NMR, elemental, and IR analyses. Their biological activity was evaluated in vivo upon both the growth of blue-green algae and the photosynthetic oxygen evolution by eukaryotic algae and in vitro as the ability to interfere with light-driven reduction of ferricyanide by isolated spinach chloroplasts. Some compounds exhibited remarkable inhibitory properties, comparable to those of the reference commercial herbicides lenacil, diuron, and hexazinone. Results suggest that the substitution of triazine with thiadiazine ring may act as amplifier for herbicidal activity.