AMF communities associated to Vitis vinifera in an Italian vineyard subjected to integrated pest management at two different phenological stages.

Vitis vinifera L. is an economically important crop that can be influenced by soil microorganisms, including arbuscular mycorrhizal fungi (AMF), that establish symbiotic associations with its roots. AMF have beneficial effects on grapevine performance improving water use efficiency and replant success. Most grapevine varieties are susceptible to various diseases, and integrated pest management (IPM) is one of the emerging approaches to perform pest control. In the present study, we examined the AMF communities present in the soil associated to the roots of V. vinifera cv. Pinot Noir (comparing them to those present in a soil not affected by grapevine roots), in a vineyard subjected to IPM at two different phenological stages, using 454 Roche sequencing technology. We proposed a new approach to analyze sequencing data. Most of the taxa were included in the family Glomeraceae. In particular, Glomus sp. Rhizophagus sp. and Septoglomus viscosum were present. The family Archeosporaceae was represented only by the genus Archeospora sp. Different AMF communities were found in the two soils and the importance of the phenological stage in regulating AMF biodiversity was assessed.

Metaproteomic characterization of theVitis vinifera rhizosphere.

The rhizosphere is a hotspot of microbial activity where the release of root exudates stimulates bacterial density and diversity. The majority of the bacterial cells in soil are viable, unculturable, but active. Proteomic tools could be useful in gaining information about microbial community activity and to better understand the real interactions between roots and soil. The aim of this work was to characterize the bacterial community associated with Vitis vinifera cv. Pinot Noir roots using a metaproteome approach. Our results confirmed the large potential of proteomics in describing the environmental microbial communities and their activities: in particular, we showed that bacteria belonging to Streptomyces, Bacillus, Bradyrhizobium, Burkholderia and Pseudomonas genera are the most active in protein expression. Concerning the biological activity of these genera in the rhizosphere, we observed the exclusive presence of the phosphorus metabolic process and the regulation of primary metabolic processes. To our knowledge, this is the first study reporting the rhizosphere proteome of V. vinifera, describing the bacterial community structure and activity of an important ecosystem for the Italian landscape, agriculture and economy.

Transcript analysis of stress defence genes in a white poplar clone inoculated with the arbuscular mycorrhizal fungus Glomus mosseae and grown on a polluted soil.

In this study we investigated if the symbiosis with the arbuscular mycorrhizal fungus Glomus mosseae, which contributes to alleviate heavy metal stress in plants, may affect the transcription of genes involved in the stress defence in the white poplar clone 'AL35' grown on a multimetal (Cu and Zn) contaminated soil. The results obtained showed that the symbiosis with G. mosseae reduced transcript abundance of genes involved in antioxidant defence in leaves and roots of 'AL35' plants grown on the heavy metal-polluted soil. Moreover, the interaction between this poplar clone and the arbuscular mycorrhizal fungus induced the gene coding for phytochelatin synthase in leaves, whereas the expression of genes involved in heavy metal homeostasis did not change in roots. The present results suggest that, in presence of high levels of heavy metals, inoculation with G. mosseae may confer to 'AL35' a more efficient control of the oxidant level. Moreover, in mycorrhizal plants heavy metal chelation pathways appear involved in the defence strategies in leaves, whereas in roots they do not seem to contribute to increase the plant tolerance of heavy metals.

Interactions between Pseudomonas putida UW4 and Gigaspora rosea BEG9 and their consequences for the growth of cucumber under salt-stress conditions.

AIMS: After the determination of the toxic but nonlethal concentration of NaCl for cucumber, we examined the interaction between an ACC (1-aminocyclopropane-1-carboxylate) deaminase producing bacterial strain and an arbuscular mycorrhizal fungus (AMF) and their effects on cucumber growth under salinity. METHODS AND RESULTS: In the first experiment, cucumber seedlings were exposed to 0.1, 50, 100 or 200 mmol l(-1) NaCl, and plant biomass and leaf area were measured. While seeds exposed to 200 mmol l(-1) NaCl did not germinate, plant growth and leaf size were reduced by 50 or 100 mmol l(-1) salt. The latter salt cancentration caused plant death in 1 month. In the second experiment, seeds were inoculated with the ACC deaminase-producing strain Pseudomonas putida UW4 (AcdS(+)), its mutant unable to produce the enzyme (AcdS(-)), or the AMF Gigaspora rosea BEG9, individually or in combination and exposed to 75 mmol l(-1) salt. Plant morphometric and root architectural parameters, mycorrhizal and bacterial colonization and the influence of each micro-organism on the photosynthetic efficiency were evaluated. The AcdS(+) strain or the AMF, inoculated alone, increased plant growth, affected root architecture and improved photosynthetic activity. Mycorrhizal colonization was inhibited by each bacterial strain. CONCLUSIONS: Salinity negatively affects cucumber growth and health, but root colonization by ACC deaminase-producing bacteria or arbuscular mycorrhizal fungi can improve plant tolerance to such stressful condition. SIGNIFICANCE AND IMPACT OF THE STUDY: Arbuscular mycorrhizal fungus and bacterial ACC deaminase may ameliorate plant growth under stressful conditions. It was previously shown that, under optimal growth conditions, Ps. putida UW4 AcdS(+) increases root colonization by Gi. rosea resulting in synergistic effects on cucumber growth. These results suggest that while in optimal conditions ACC deaminase is mainly involved in the bacteria/fungus interactions, while under stressful conditions this enzyme plays a role in plant/bacterium interactions. This finding is relevant from an ecological and an applicative point of view.

Clonal differences in survival capacity, copper and zinc accumulation, and correlation with leaf polyamine levels in poplar: a large-scale field trial on heavily polluted soil.

Three ex situ collections of poplar clones from natural populations of Populus alba and P. nigra growing in northern Italy were assessed for their genetic dissimilarity (GD) by means of amplified fragment length polymorphism (AFLP). The high GD evidenced within populations was exploited for screening 168 clones in a field trial on heavy metal-polluted soil. After one growth season, clonal differences in plant survival and growth were observed. On the basis of performance, six clones were singled out, and used to evaluate copper and zinc accumulation in different organs. Clonal differences in metal concentrations were most evident for leaves and stems; one clone of P. alba (AL35) had a distinctly higher concentration of both metals in the roots. Leaf polyamine (putrescine, spermidine, spermine) profiles correlated with tissue metal concentrations, depending on the clone, plant organ and metal. In particular, the high metal-accumulating clone AL35 exhibited a dramatically higher concentration of free and conjugated putrescine. Overall, the results indicate that, given the high GD of Populus even within populations, it is possible to identify genotypes best suited for soil clean-up, and useful also for investigating physiological markers associated with high metal accumulation/tolerance.

Vertebroplasty in the treatment of osteoporosis vertebral fractures: report on 52 cases.

BACKGROUND: Percutaneous vertebroplasty (PV) is largely employed in vertebral body compression fractures (VCF). PURPOSE: To evaluate the efficacy of PV on pain relief and functional status, and its complications rate. MATERIALS AND METHODS: A prospective observational study was conducted by the Division of Internal Medicine of St. Croce and Carle Hospital. INCLUSION CRITERIA: Diagnosis of osteoporosis, intense back pain, unresponsive to conservative treatment, associated with radiological evidence of recent VCF. Pain control and functional improvement were respectively assessed using Visual Analogue Scale (VAS) and Activity of Daily Living scale (ADL) on admission, 24 h after PV and at follow-up. PV complications were detected by an immediate computed tomography (CT) scan on the vertebra treated as well as the vertebrae above and below the treated level(s) and by CT chest scan to exclude pulmonary emboli. A magnetic resonance imaging (MRI) follow-up at 6 or 12 months was performed. RESULTS: Fifty-two (46 with primary osteoporosis) patients were enrolled (mean age 73.18 yr, range 44-92). Median follow-up was 20.4 months (range 6-24). Treated vertebrae were 124. VAS, mean value was 9.05 (range 6-10) before treatment, 5.95 (range 2-8) at 24 h after PV and 4.94 (range 2-9) at follow-up (p<0.001). Before PV, 18 patients (34.6%) were functionally impaired vs 8 patients (15.3%) at follow-up (p<0.003). Control MRI evidenced 9 (17.3%) new VCF adjacent and 13 (25%) non-adjacent to treated vertebras. There was one case of discitis. Seven cases (13%) of cement leakage in para-vertebral space were observed. CONCLUSION: PV is safe and effective in immediate pain reduction and functional improvement and at a median term follow-up.

Pulmonary arteriovenous malformations: percutaneous treatment preserving parenchyma in high-flow fistulae.

PURPOSE: The aim of our study was to illustrate the benefits of percutaneous treatment by embolisation of high-flow pulmonary arteriovenous malformations (PAVM) in patients suffering from hereditary haemorrhagic telangiectasia (HHT; Rendu-Osler-Weber disease). MATERIALS AND METHODS: From December 2001 to February 2007, we embolised 60 PAVMS in 35 procedures performed on 30 patients, all referred by the HHT centre in Crema, and enrolled in a screening programme of HHT families. All patients underwent clinical evaluation, contrast-enhanced ultrasound (CEUS) and spiral computed tomography (CT). Embolisation was made with nonmagnetic metallic coils via femoral venous access; an endovascular Amplatzer device was used in one patient only. RESULTS: All embolisations were performed without difficulty. One patient only developed partial temporary aphasia, which resolved in 72 H. At spiral-CT follow-up, we generally demonstrated exclusion from circulation of treated PAVMS and regression of clinical symptoms. In the case of new lesions or recanalisation, further embolisation was possible: CONCLUSIONS: Percutaneous embolisation has recently become the initial treatment option in PAVM owing to its good results and minimal invasiveness compared with thoracotomy. Our experience is in agreement with the literature: the procedure has a low complication rate, provides very good technical and clinical results and avoids resection of healthy pulmonary parenchyma.

Intra-arterial hepatic chemotherapy: management of liver tumors by percutaneous port-a-cath positioning.

In the past, intrahepatic arterial locoregional chemotherapy was performed by surgical approach via gastroduodenal artery; early use of percutaneously placed arterial port was complicated by clotting and bleeding in 50% of pts. More recently, permanent catheters were positioned percutaneously in GDA by Japanese group and fixed to the artery by means of bucrylate in order to reduce dislocation. We present the technique and the preliminary results of percutaneous implantation of intraarterial catheters connected to a subcutaneous infusion reservoir for prolonged regional chemotherapy of hepatic tumors. Two hundred patients underwent to percutaneous arterial port implant, for loco-regional chemotherapy for liver primary or metastatic tumors. Catheter dislodgments were observed in 14,5%, but in 90% the catheters could be reinserted. No case of catheter related mortality was registered. Percutaneous positioning of arterial port is a safe and effective technique to deliver loco-regional treatment for hepatic tumors. Complication rates are similar to the surgical series and to other percutaneous interventional radiological reports. This percutaneous approach in the hands of a skilled team allows intra-arterial infusion in a wide percentage of pts, improving the accuracy of clinical trials by a faster and optimal balanced comparison between systemic and arterial arm.

Nuclear changes in pathogen-infected tomato roots.

We have investigated nuclear changes induced in tomato (Lycopersicon esculentum) plant roots by two different pathogens, a phytoplasma of the stolbur group and the soil-borne fungus Phytophthora nicotianae var. parasitica, using light and electron microscopy as well as flow cytometry. Our results show that both pathogens strongly influenced nuclear structure, causing pyknosis and chromatolysis, and induced variations in proportion of nuclear populations with different DNA content, increasing the 2C and decreasing the 4C nuclear populations. These latter results suggest a block of the endoreduplication process in the presynthetic phase of the host cell cycle. Moreover, in pathogen-infected roots, nuclei of the same DNA content were less fluorescent, and therefore had a lower DNA content, compared to those of controls, as confirmed by morphological analyses. Our findings suggest that different stimuli may evoke similar nuclear changes, and confirm the usefulness of flow cytometry as a tool to recognize the stress conditions related to the presence of a pathogen.

The nucleus of differentiated root plant cells: modifications induced by arbuscular mycorrhizal fungi.

The nuclei of plant cells show marked differences in chromatin organisation, related to their DNA content, which ranges from the type with large strands of condensed chromatin (reticulate or chromonematic nuclei) to one with mostly decondensed chromatin (chromocentric or diffuse nuclei). A loosening of the chromatin structure generally occurs in actively metabolising cells, such as differentiating and secretory cells, in relation to their high transcriptional activity. Endoreduplication may occur, especially in plants with a small genome, which increases the availability of nuclear templates, the synthesis of DNA, and probably regulates gene expression. Here we describe structural and quantitative changes of the chromatin and their relationship with transcription that occur in differentiated cells following an increase of their metabolism. The nuclei of root cortical cells of three plants with different 2C DNA content (Allium porrum, Pisum sativum and Lycopersicon esculentum) and their modifications induced by arbuscular mycorrhization, which strongly increase the metabolic activity of colonised cells, are taken as examples.