Reproductive cross-talk: seed development in flowering plants

Abstract

Flowering plants have evolved to be a predominant life form on earth. A common principle of flowering plants and probably one of the main reasons for their evolutionary success is the rapid development of an embryo next to a supporting tissue called the endosperm. The embryo and the endosperm are protected by surrounding maternal tissues, the integuments, and the trinity of integuments, embryo and endosperm comprise the plant seed. For proper seed development, these three structures have to develop in a highly controlled and co-ordinated manner, representing a paradigm for cell-cell communication during development. Communication pathways between the endosperm and the seed coat are now beginning to be unravelled. Moreover, recently isolated mutants affecting plant reproduction have allowed a genetic dissection of seed development, and revealed that the embryo plays a previously unrecognized yet important role in co-ordinating seed development.

Networks controlling seed size in Arabidopsis

“…37 Arabidopsis seed development (see Fig. 1) starts after a 38 double-fertilization event (for a complete seed develop-39 ment review, see Nowack et al 2010;Becker et al 2014).…”

Comprehensive Tissue-Specific Transcriptome Analysis Reveals Distinct Regulatory Programs during Early Tomato Fruit Development

“…6, B-G). Cluster 6 contained many genes related to cell division and spanned multiple seed tissues, possibly reflecting the need to coordinate nuclear division and cell proliferation across the embryo, endosperm, seed coat, and tissues surrounding the seed upon fertilization (Nowack et al, 2010). Another gene set, cluster 5, indicates a spatial focus of hormone-related gene expression and suggests the coregulation of genes involved in controlling the levels of auxin in seed tissues.…”

“…Following pollination, the ovules, which are attached to the central septum via placental tissue, form seeds, with double fertilization of the egg and central cells producing the diploid embryo and triploid endosperm, respectively. Each seed is surrounded by a seed coat that is derived from the integuments that enclose the embryo sac (Nowack et al, 2010). Coinciding with seed initiation, the placenta, septum, and pericarp undergo rapid cell division, and the placenta proliferates to fill the locular cavity (Gillaspy et al, 1993).…”

Evaluation of Interspecific-Interploid Hybrids (F1) and Back Crosses (BC1) in Hylocereus Species (Cactaceae)

“…Endosperm dysfunction was the primary reason for hybrid abortion in a range of Angiosperm families (Brink & Cooper, 1947). Nowack et al (2010) showed that the fertilized egg transmits a signal for development, but it cannot continue without the fertilization of the central cell. On the basis of this hypothesis, Cisneros et al (2011) postulate, for vine cacti, that: 1) double fertilization happened but the zygote aborted, resulting in empty seeds due to post-zygotic barriers; 2) endosperm formation is necessary (and double fertilization is required) for normal seed coat development, but the presence of an embryo is not essential for the development of a normal black seed coat; and 3) increased genome dosage in the polyploid results in reduced seed viability, which may be attributable to a maternal/paternal imbalance or a lack of double fertilization.…”