Effects of ageing on peroxidase activity and localization in radish (Raphanus sativus L.) seeds.

Peroxidase activity was assayed in crude extracts of integument, cotyledons and embryo axis of radish seeds, deteriorated under accelerated ageing conditions. Over five days of ageing, in which germination decreased from 100 to 52%, the enzyme activity in integument was higher than that in other seed parts, increasing in the first days of ageing and then decreasing sharply in extremely aged seeds. Polyacrylamide gel electrophoresis analysis showed four peroxidase isoenzymes with MM of 98, 52.5, 32.8 and 29.5 kDa in the embryo axis of unaged seeds, and only the 32.8 and 29.5 kDa MM isoforms in the integument and cotyledons. In these parts of the seed, only the 29.5 kDa MM isoenzyme increased in activity in early days of ageing and decreased there-after. In the embryo axis, the 29.5 kDa MM isoenzyme activity increased slowly in the first day of ageing, while the 98 and 52.5 kDa MM isoenzyme activities disappeared. A cytochemical localization of peroxidase activity in the various tissues showed that main differences between unaged and extremely aged seeds occurred in the embryo axis.

Structural and histochemical changes during seed development of Brassica macrocarpa Guss.

During seed formation of Brassica macrocarpa the development of the embryo precedes that of the integuments; structural changes and histochemical changes are associated. Esterases, acid phosphatases, phenols and starch follow a sigmoid pattern, increasing during embryogenesis and decreasing during seed maturation. In the mature seed, esterase activity is localized in the embryo and in the cells of the mucilaginous, aleuronic and hyaline layers. Acid phosphatases are present in the mucilaginous cells, mainly in the column, the cell walls delimiting intercellular spaces of the cortical cylinder and the adhesion areas of the cotyledons. Phenols are scanty in the root apex, mucilaginous cells and the palisade layer, and abundant in the pigmented layer. Starch is absent in ripe seeds which have lipid and protein reserves. The major classes of storage proteins have molecular weights of 21, 22, 27 and 30 KD and accumulate in the late stages prior to complete drying. Esterases and acid phosphatases in mucilaginous cells of the seed integument suggest that these enzymes are involved in hydrolytic processes occurring prior to germination and that mucilages have a metabolic function in seed-soil interactions.

Effects of simulated acid rain on pollen physiology and ultrastructure in the apple.

Viability, germination and tube length were investigated in pollen grains of field-grown 'Summerred' apple trees (Malus domestica Borkh) exposed to deionized water, rainfall or simulated acid rain at pH 5.6, 4.0 and 3.0. Pollen viability and germination significantly decreased with lower values of pH and with increasing number of treatments. The effects of pH 5.6 and natural rainfall were not significant. Electron microscope investigation of vegetative pollen cells of plants exposed to acid rain at pH 4.0 and 3.0 showed modified features in mitochondria, plastids and endoplasmic reticulum.

Differential staining for cellulosic and modified plant cell walls.

A simple method to enhance the staining of cell wall components for fluorescence microscopy is described. In stems of Nicotiana tabacum and needles of Pinus eldarica lignin, the cuticle and unsaturated lipids are indicated by a purple-red fluorescence while pectocellulosic components fluoresce pale blue.

The in-vitro response of pollen germination and tube length to different types of acidity.

Pollen germination and tube growth are among the most sensitive responses to atmospheric pollution. Both these are inhibited by the acidity of the growth medium. Pollen grains from two species (Pinus cembra L. and Sambucus nigra L.) were germinated in media over a range of pHs (5.0, 4.5, 4.0, 3.5, 3.0 and 2.5) and six types of acidity (H(2)SO(4), HNO(3), H(2)SO(4): HNO(3) in 1:1, 2:1, 3:1 and 5:1 ratio). Pollen of the Gymnosperm is shown to be more resistant to acidity in the medium. Sulphuric acid alone and the ratio 2:1 with nitric acid are demonstrated to be the more harmful for P. cembra and S. nigra, respectively. The latter species was sensitive to all mixtures, particularly in respect to germination percentage.

[Oral vaccination in the control of feral rabies]. / La vaccinazione orale nel controllo della rabbia silvestre.

The authors briefly report the results of laboratory and epidemiological investigations on living modified and inactivated antirabies vaccines, started in 1975 and carried out in collaboration with public health authorities and scientific institutions. The antirabies oral vaccination of foxes, using a live and modified vaccine (SADB19 Tüb.) began in Brescia province (Val Camonica) in 1984 and was extended in 1985 to Bolzano and Trento provinces. Since July 1986 no more cases of rabies have been observed in Italy. The problems related to the distribution in the territory of live and modified antirabies vaccines, the immunological value of inactivated vaccines, the connections between sylvatic rabies and bat rabies (or pseudorabies), are discussed.

A quantitative cytochemical method for phosphofructokinase in plant tissues.

A quantitative cytochemical method for the demonstration of phosphofructokinase has been successfully applied to a range of plant tissues. The findings indicate that this enzyme system may be assayed as an indicator of glycolytic activity in plant cells, and furthermore tha the very high endogenous phosphoenolpyruvate concentrations may not be rate limiting in vivo.

[Control of wildlife rabies in North-Eastern Italy]. / Le contrôle de la rage selvatique dans le nord-est de l'Italie.

The authors describe the propagation of wildlife rabies in the Bolzano province of north-eastern Italy in 1977 by means of the crossing of the Italian-Austrian border, and the disappearance of the infection after a decrease in fox density. They establish a relationship between the intensity of fox decrease at the beginning of rabies contamination of the territory and during the following years and the final disappearance of the infection. In order to show indirectly the supported thesis, they take into consideration the results found in the Udine province nearby, where the struggle resulted in failure because of lack of motivation, organization and funds. They studied at the same time, the development of wildlife rabies on the border of Venetian regions and Austria, which is a steep mountainous barrier 300 km long. During four years, rabies entered Italy from Austria six times. Two times into territory already undergoing fox-decreasing programmes, and kept under control. In the last case, the infection did not propagate, striking only one fox that crossed the border.

[Control and eradication of ovine and caprine brucellosis in Italy]. / Contrôle et éradication de la brucellose ovine et caprine en Italie.

The prevention of ovine and caprine brucellosis in Italy is carried out in accordance with Regulation No 33 of 23 January 1968 and with Government Decree of 4 June 1968. The Regulation also provides in addition to sanitary measures, the vaccination of all livestock aged from 3 to 7 months with strain Rev. 1 of Br. melitensis. From the last trimester of 1968 until the end of 1974 3489514 young animals were vaccinated, which corresponds approximately to 50% of the animals today in the zones where the "revisation" was undertaken. An important decrease in the number of abortions was observed, with many epizootical advantages. During the same period a considerable decrease in human cases of brucellosis was observed; from the 19300 cases announced from 1965 to 1968 (yearly average: 4825) the figure fell to 18988 cases for the period 1969-1974 (yearly average: 3164).