Comparative anatomy and histochemistry of the association of Puccinia poarum with its alternate hosts.

The relationship of the macrocyclic rust fungus PUccinia poarum with its pycnial-aecial host, Tussilago fapfaPa, and its uredial-telial host, Poa ppatensis, has been investigated, using light microscopy, electron microscopy and micro-autoradiography. Aspects of the morp- hology and ontogeny of spores and sari, which were previously disputed, have been clarified. Monokaryotic hyphae grow more densely in the intercellular spaces of Tussilago leaves than the dikaryotic intercellular hyphae on Poa. Although ultrastructurally sbnilar, monokaryotic hyphae differ from dikaryotic hyphae in their interaction with host cell walls, often growing embedded in wall material which may project into the host cells. The frequency of penetration of Poa mesophyll cells by haustoria of the dikaryon is greater than that of Tussilago cells by the relatively undifferentiated intracellular hyphae of the monokaryon. Intracellular hyphae differ from haustoria in their irregular growth, septation, lack of a neck-band or markedly constricted neck, the deposition of host wall-like material in the external matrix bounded by the invaginated host plasmalemma and in the association of callose reactions \vith intracellular hyphae and adjacent parts of host walls. Monokaryotic and dikaryotic infections differ also in the changes induced in the organization and ultrastructure of their respective host cells. Intracellular hyphae in bundle sheath, xylem parenchyma, transfer cells of phloem parenchyma and companion cells, give the monokaryon of P. poaPUm direct access to nutrients translocated in vascular tissue of Tussilago. Bundle sheath cells of Poa contain unusually long haustoria but· there is no penetration of the endodermis and vascular tissue by the dikaryon. After uptake of tritiated glycerol by infected tissue, microautoradiographic investigation shows radioactivity to be concentrated in sporulation structures, haustoria and, in the case of Poa, in host nuclei. Cells of uninfected tissues differ from those of infected tissue in accumulation of label in chloroplasts. These studies contribute to an understanding of the physiological interaction of P. poaPUm with its alternate hosts

ANTIOXIDATIVE EFFECT OF HELIOTROPIUM EUROPIUM ALCOHOLIC LEAVES EXTRACT IN ALBINO MALE RATS EXPOSED TO OXIDATIVE STRESS.

The present study aimed to investigate someAntioxidant effects of alcoholic leaves extract of Heliotropium by measurement some antioxidant levels such as (glutathione and superoxide dismutase activity ),and the levels of Malondialdehyde (MDA), and peroxy nitrate radical( ONOO._ )and somebiochemical parameter such as total protein, albumin and urea in male rats exposed to oxidative stress by hydrogen peroxide (0.5% )in drinking water throughout the experimental period (30) days, and comparison these effects with the effects of the vitamin C as well known anti-oxidant . For purpose of this study preliminary experiments were carried out to find the most effective dose of Heliotropiumextract and was found (300) mg / kg of body weight. (35) male albino rats(4-5) months and( 245-280gm weight) were divided to (7) groups both Group included (5) rats as follows: The control group, hydrogen peroxide (H2O2 group,, Heliotropium extract group. H2O2+ Heliotropium extract group. (Heliotropium) Extract + Vitamin C group, .H2O2 + Vitamin C group. H2O2+ extract of Heliotropium + vitamin C group, The results of study showed that the oxidative stress by hydrogen peroxide led to a significant decrease in the concentration of glutathione activity of the enzyme SOD, total protein and albumin when compared with the control group. And a significant increase in the concentration of MDA, peroxynitrate radical and urea. Where the treatment of animals with Heliotropium + H2O2 led to a significant increase in the concentration of glutathione, SOD activity, total protein and albumin compared with a group of hydrogen peroxide. And a significant decrease in the concentration of MDA peroxy nitrite radical and urea compared with a group of hydrogen peroxide. The treatment of animals exposed to oxidative stress with vitamin C (250 mg / kg of body weight) for 30 days showed a significant increase in the concentration of glutathione enzyme SOD activity, total protein and albumin when compared with hydrogen peroxide. And a significant decrease in the concentration of MDA and peroxynitrite radical. And non-significant differences in the concentration of urea compared with a group of hydrogen peroxide. Well the treatment of animals with vitamin C and extract of Heliotropium has led to a significant increase in the concentration of glutathione SOD activity total protein and albumin when compared with a hydrogen peroxide group, and a significant decrease in the concentration of MDA, peroxy nitrite radicals and urea compared with hydrogen peroxide