Morphological analysis of seed shape in Arabidopsis thaliana reveals altered polarity in mutants of the ethylene signaling pathway

• Published in: Journal of plant physiology 2008-06, Vol.165 (9), p.911-919
• Main Authors: Robert, Céline, Noriega, Arturo, Tocino, Ángel, Cervantes, Emilio
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Arabidopsis; Arabidopsis - anatomy & histology; Arabidopsis - cytology; Arabidopsis - genetics; Arabidopsis thaliana; Biological and medical sciences; Cell physiology; Cell Polarity; Curvature; Ethylene; Ethylenes - metabolism; Fundamental and applied biological sciences. Psychology; genetic variation; Genotype; imbibition; Molecular and cellular biology; Mutation - genetics; plant morphology; Polarity; Seed; seeds; Seeds - anatomy & histology; Seeds - cytology; Signal Transduction; Software; Water
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2007.10.005

The shape of Arabidopsis thaliana dry seed is described here as a prolate spheroid. The accuracy of this approximation is discussed. Considering its limitations, it allows a geometric approximation to the analysis of changes occurring in seed shape during imbibition prior to seed germination as well as the differences in shape between genotypes and their changes during imbibition. The triple mutant ein2-1, ers1-2, etr1-7 presents notable alterations in seed shape. In addition, seeds of this and other mutants in the ethylene signaling pathway ( ctr1-1, eto1-1, etr1-1, ein2-1) show different response to imbibition than the wild type. Imbibed seeds of the wild type increase their asymmetry compared with the dry seeds. This is detected by the relative changes in the curvature values in both poles. Thus, during imbibition of the wild-type seeds, the reduction in curvature values observed in the basal pole gives them an ovoid shape. In contrast, in the seeds of the ethylene mutants, reduction in curvature values occurs in both basal and apical poles, and its shape remains as a prolate spheroid. Our data indicate that the ethylene signaling pathway is involved, in general, in the complex regulation of seed shape and, in particular, in the establishment of polarity in seeds, controlling curvature values in the seed poles.