Glycine Rich Proteins (GRPs) are induced at different developmental stages and in specific plant tissues. Recently, we described a novel Arabidopsis gene encoding a short glycine-rich domain protein (AtGRDP1). This gene is involved in abiotic stress responsiveness; the Atgrdpl-null mutant seeds were more sensitive to stress, while the opposite phenotype was achieved by AtGRDP1 overexpression. In this study, we analyzed the phenotype of the fruits produced by Arabidopsis Atgrdpl mutants and 355::AtGRDP1 overexpression lines. Our analyses revealed important changes in silique length, seed number, seed weight and morphology in the analyzed lines. In particular, Atgrdpl mutant lines exhibited several defects including short siliques, a diminished number of seeds per silique, and a reduction in seed size and weight as compared to Col-0. The overexpression of the AtGRDP1 gene also generated phenotypes with alterations in size of silique, number of seeds per silique, and size and weight of the seed. In addition, the expression analysis of AtGRDPI gene showed that it was expressed in floral and fruit organs, with the highest expression level in mature siliques. The alterations in the siliques and seeds traits in the Atgrdpl mutant line, as well as the phenotypes observed in AtGRDP1 overexpression lines, suggest a role of the AtGRDP1 gene in the Arabidopsis fruit development. (C) 2017 Elsevier Inc. All rights reserved.