|Jin, Wei - ISU|
|Horner, Harry - ISU|
Submitted to: Botanical Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 5, 1996
Publication Date: N/A
Technical Abstract: A new genic male-sterile soybean mutant was shown to have developmental similarities related to callase production, to two already described soybean genic male-sterile mutants, ms2 and ms3. However this new mutant is genetically different from all known soybean male-sterile mutants, including ms2 and ms3. Southern blots showed that the callase gene is present in both normal and sterile lines and the mapping of this gene is being carried out. Northern blots showed a reduction in callase mRNA in the sterile line, which suggests that transcription may be affected. In situ hybridization studies are being conducted to determine in which tissue and at which developmental stage the transcription occurs. Antibodies for callase are being used to locate the site of callase production in the anther tissues of the normal line, and to determine whether translation and/or post-translation are/is affected in the mutant. Ultrastructural abnormalities in the sterile anthers were evident during the tetrad stage. Tapetal cell cytoplasm became disorganized and highly vacuolate; many organelles were disrupted, and ER profiles increased. The cytoplasm of microspores in the tetrads was normal up to this time; however, plastids developed dense bodies and surrounding callose was not degraded, in contrast to normal tetrads where the callose dissolved. The mutant tetrads of microspores aborted while encased in callose, producing completely sterile anthers. These results suggest that there may be many different factors that regulate callase synthesis in male sterile systems of different taxa.