title: Suspensor length determines developmental progression of the embryo in Arabidopsis.
abstract: The first structure that differentiates during plant embryogenesis is the extra-embryonic suspensor that positions the embryo in the lumen of the seed. A central role in nutrient transport has been ascribed to the suspensor in species with prominent suspensor structures. Little is known, however, about what impact the size of the rather simple Arabidopsis (Arabidopsis thaliana) suspensor has on embryogenesis. Here, we describe mutations in the predicted exo-polygalacturonase gene NIMNA (NMA) that lead to cell elongation defects in the early embryo and markedly reduced suspensor length. Mutant nma embryos develop slower than wild-type embryos, and we could observe a similar developmental delay in another mutant with shorter suspensors. Interestingly, for both genes, the paternal allele has a stronger influence on the embryonic phenotype. We conclude that the length of the suspensor is crucial for fast developmental progression of the embryo in Arabidopsis.
authors.affiliation: Department of Cell Biology, Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076 Tuebingen, Germany.
authors.forename: Yashodar
authors.initials: Y
authors.lastname: Babu
authors.forename: Thomas
authors.initials: T
authors.lastname: Musielak
authors.forename: Agnes
authors.initials: A
authors.lastname: Henschen
authors.forename: Martin
authors.initials: M
authors.lastname: Bayer
mesh_terms: D017360:Arabidopsis / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D006026:Glycoside Hydrolases / Q000235:genetics; D053592:Interleukin-1 Receptor-Associated Kinases / Q000235:genetics; D009154:Mutation; D030821:Plants, Genetically Modified; D011096:Polygalacturonase / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000235:genetics; D012639:Seeds / Q000033:anatomy & histology / Q000166:cytology* / Q000254:growth & development* / Q000648:ultrastructure
chemical_list: D029681:Arabidopsis Proteins; D053592:Interleukin-1 Receptor-Associated Kinases; C539498:SSP protein, Arabidopsis; D006026:Glycoside Hydrolases; C586314:NIMNA protein, Arabidopsis; D011096:Polygalacturonase