Submitted to: International Conference on Genetics and Cellular Biology
Publication Type: Abstract Only
Publication Acceptance Date: 5/17/2001
Publication Date: 5/17/2001
Citation: AINKSTER, Y., ELIAN, T., MITLEMAN, L., SZABO, L.J., BUSHNELL, W.R. PYCNIAL NECTAR OF RUST FUNGI INDUCES CAP FORMATION ON PYCNIOSPORES OF OPPOSITE MATING TYPE. INTERNATIONAL CONFERENCE ON GENETICS AND CELLULAR BIOLOGY. 2001. Abstract p. 9. Interpretive Summary:
Technical Abstract: Pycnial nectar transferred between pycnia of opposite mating type induced formation of a cap on one end of pycniospores. The caps stained with India ink, or labeled with colloidal gold or wheat germ agglutinin conjugated with fluorescein isothiocyanate. The polar caps developed with seven species of Puccinia and four Uromyces. Interspecific transfer of pycnial nectar induced pycniospore caps in a mating type manner in most cases. Nectar contained a complex of high molecular weight proteins larger than 100 kDa which was able to induce cap formation in a native polyacrylamide gel bio-assay. In SDS denaturing gels, 6-7 polypeptides ranging in size from 14-70 kDa were observed. Pycniospores that were removed from a pycnium and induced to form caps by pycniospore-free nectar of opposite mating type did not induce aecia when returned to the original pycnium, demonstrating that cap formation alone was not sufficient for completion of the mating process. These results indicate that nectar from several rust species contain high molecular weight cap-inducing proteins which are mating type-specific and induce pycniospore cap formation as an early event associated with processes leading to fertilization.