Arabidopsis TSO1 regulates directional processes in cells during floral organogenesis

• Published in: Genetics (Austin) Vol. 150; no. 1; pp. 411 - 423
• Main Authors: Hauser, B.A. (University of California, Davis.), Villanueva, J.M, Gasser, C.S
• Format: Journal Article
• Language: English
• Published: United States Genetics Soc America 01.09.1998; Genetics Society of America
• Subjects: ALLELES; ANDROECIUM; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - ultrastructure; ARABIDOPSIS THALIANA; CALYX; Cell division; COROLLA; FEMALES; FERTILITY; Flowers & plants; FRUITING; GENES; Genes, Plant; Genetics; GROWTH; GYNOECIUM; Microscopy, Electron, Scanning; MORPHOGENESIS; MUTANTS; MUTATION; OVA; OVULES; PLANT ANATOMY; POLLEN TUBES; SEED MORPHOLOGY; SEED SET; SEEDS; STAMENS
• ISSN: 0016-6731; 1943-2631; 1943-2631
• DOI: 10.1093/genetics/150.1.411

Flowers of the previously described Arabidopsis tso1-1 mutant had aberrant, highly reduced organs in place of petals, stamens, and carpels. Cells of tso1-1 flowers had division defects, including failure in cytokinesis, partial cell wall formation, and elevated nuclear DNA content. We describe here two new tso1 alleles (tso1-3 and tso1-4), which caused defects in ovule development, but had little effect on gross floral morphology. Early ovule development occurred normally in tso1-3 and tso1-4, but the shapes and alignments of integument cells became increasingly more disordered as development progressed. tso1-3 ovules usually lacked embryo sacs due to a failure to form megaspore mother cells. The cell division defects described for the strong tso1-1 mutant were rarely observed in tso1-3 ovules. The aberrations in tso1-3 mutants primarily resulted from a failure in directional expansion of cells and/or coordination of this process among adjacent cells. Effects of tso1-3 appeared to be independent of effects of other ovule development mutations, with the exception of leunig, which exhibited a synergistic interaction. The data are consistent with TSO1 acting in processes governing directional movement of cellular components, indicating a likely role for TSO1 in cytoskeletal function.