ABSTRACT
Self-, cross- and non-pollinated styles of Petunia hybrida were treated with 3-3'-diaminobenzidine for the ultrastructural localization of peroxidase activity. Wall peroxidases were absent in cross-pollinated styles, but they were detectable as an osmiophilic deposit on the cell walls of the outer portion of the transmitting tissue in self- and non-pollinated styles. The cell layer showing peroxidase activity was thicker in the self-pollinated styles than in the non-pollinated ones. In accordance with current hypotheses on the mechanism involved in pollen incompatibility process, it is suggested: that wall peroxidases present in the cells of the outer portion of the transmitting tissue are involved in the gametophytic self-incompatibility of Petunia; that self-pollination causes an increase in the number of cells involved in the rejection process; that non-pollinated styles, which are characterized by the presence of cell wall peroxidases in the outer portion of the transmitting tissue, are 'prepared' to a certain extent for the rejection of incompatible pollen tubes. The removal of peroxidase activity thus seems to be an important step in the compatible pollination process.
Subject(s)
Fertilization , Peroxidases/metabolism , Plants/enzymology , Cell Wall/enzymology , Cell Wall/ultrastructure , Microscopy, Electron , Plants/ultrastructureABSTRACT
Immunological techniques are useful to clarify the sistematic scheme utilized for mushrooms. By comparing the various fruiting portions, a different composition in protein was observed in the cell wall of spores, pileus and stipe. The differences were present both in Agaricus bisporus and in Pleurotus ostreatus. The results indicate that a well definite choice of the utilized portions is necessary for comparative studies. In the Basidiomycetes the meiospores represent the more useful development stage to carry out immunological comparisons.
Subject(s)
Agaricales/immunology , Basidiomycota/immunology , Fungal Proteins/analysis , Membrane Proteins/analysis , Polyporaceae/immunology , Cell Wall/immunology , Fluorescent Antibody Technique , Immunodiffusion , Species Specificity , Spores, Fungal/immunologyABSTRACT
The ultrastructure of the generative cell of the pollen grain has been studied in two different plants: Mirabilis jalapa L., where variegation is transmitted only by the egg cell, and Pelargonium zonale AIT., where variegation can be transmitted also by the pollen grain. It was found that only in Pelargonium zonale AIT. does the male generative cell possesses a great number of proplastids.
