Combined microscopy and molecular analyses show phloem occlusions and cell wall modifications in tomato leaves in response to 'Candidatus Phytoplasma solani'.

Callose deposition, phloem-protein conformational changes and cell wall thickening are calcium-mediated occlusions occurring in the plant sieve elements in response to different biotic and abiotic stresses. However, the significance of these structures in plant-phytoplasma interactions requires in-depth investigations. We adopted a novel integrated approach, based on the combined use of microscopic and molecular analyses, to investigate the structural modifications induced in tomato leaf tissues in presence of phytoplasmas, focusing on vascular bundles and on the occlusion structures. Phloem hyperplasia and string-like arrangement of xylem vessels were found in infected vascular tissue. The diverse occlusion structures were differentially modulated in the phloem in response to phytoplasma infection. Callose amount was higher in midribs from infected plants than in healthy ones. Callose was observed at sieve plates but not at pore-plasmodesma units. A putative callose synthase gene encoding a protein with high similarity to Arabidopsis CalS7, responsible for callose deposition at sieve plates, was upregulated in symptomatic leaves, indicating a modulation in the response to stolbur infection. P-proteins showed configuration changes in infected sieve elements, exhibiting condensation of the filaments. The transcripts for a putative P-protein 2 and a sieve element occlusion-related protein were localized in the phloem but only the first one was modulated in the infected tissues.

Welfare indicators during broiler slaughtering.

1. The aim of this study was to identify the most relevant welfare indicators for unloading, lairage, stunning, killing and post-mortem inspection in a poultry slaughter plant. Different indicators were unloading duration, lairage time, environmental variables in the lairage facilities, shackling time and electrical variables used in the water bath. 2. Lairage time did not correlate strongly with dead on arrival. Heat stress was limited by means of ventilation systems, correct cage placement and appropriate stocking density per crate. The acceptable shackling period was about 30 s. 3. The presence of a corneal reflex showed that an animal was alive, while spontaneous wing flapping, spontaneous eye blinking and response to a painful stimulus were regarded as indicators of stunning efficiency. 4. It was concluded that the presence of recent traumatic injuries during the post-mortem inspection could be a valid means to establish whether corrective measures concerning the handling, transport and loading procedures should be taken.

Acquired Tolerance in Apricot Plants that Stably Recovered from European Stone Fruit Yellows.

European stone fruit yellows (ESFY) is one of the most destructive phytoplasma diseases of plum, apricot, and peach in Europe. Conventional preventive defense strategies have been ineffective. Because apricot cultivars with innate-constitutive resistance against ESFY are not available, the aim of this more than 20-year-long study was to seek acquired resistance or tolerance. In the first experiment, we surveyed an orchard with seven apricot cultivars for 12 years in an area of northern Italy with a high rate of natural occurrence of ESFY. Of the diseased plants, a few (8.7%) became completely symptomless but retained the phytoplasma, as confirmed by polymerase chain reaction (PCR). In the second experiment, we grafted buds from two stably recovered plants and from two nonrecovered plants onto 'Rubira' peach. Over the next 9 years in an orchard with a high rate of natural infection, 93.0% of the "nonrecovered clones" became diseased but only 1.5% of the plants grafted with the two "recovered clones" developed ESFY symptoms. According to PCR analyses, all of the exposed test plants were ESFY-infected, whether they were derived from recovered or nonrecovered mothers. This could indicate that epigenetic changes occurred in recovered plants due to a graft-transmissible memory. Based on the results attained from the two described experiments, we propose that an acquired tolerance that occurred in stably recovered apricot trees was graft transmitted from two tolerant apricot clones. In contrast, we did not demonstrate a cross-protection process based on protectant avirulent phytoplasma strains that suppress severe strains.

Pseudo aneurysm of the external carotid artery: report of a case.

The authors report a case of left otorrhagia in a 1-year-old male infant in the presence of a mass involving the parotideal and upper cervical regions, which had appeared after an infection of the upper airways. Non-invasive techniques, such as echography and CT scan, provided useful but contradicting information. Surgery allowed us to define the diagnosis of mycotic aneurysm of the external carotid artery. The authors, after pointing out the extreme rarity of such a pathology, discuss the ethiopathogenetic theories, the clinical features, the diagnosis and the surgical and medical treatment of the disease. Concerning surgery ligation of the external carotid artery is the treatment of choice, since distally the blood flow is provided by a conspicuous collateral circle and because a possible postoperative septic dissemination is avoided.