BACKGROUND A high ratio of blank fruit in hazelnut (Corylus heterophylla Fisch) is a very common phenomenon that causes serious yield losses in northeast China. The development of blank fruit in the Corylus genus is known to be associated with embryo abortion. However, little is known about the molecular mechanisms responsible for embryo abortion during the nut development stage. Genomic inform...

The plant life cycle is characterized by the alternation of generations between a diploid sporophyte and a haploid gametophyte. The sporophyte functions to produce spores, which then develop into gametophytes. The differentiated gametophytes in turn produce either the male gametes (sperm) or female gametes (egg cells). In contrast to lower plant species, in which the gametophyte is the dominant...

Genetic studies of embryo, ovule and flower development in Arabidopsis thaliana have led to the independent isolation of different mutant alleles of a single gene (SIN1/SUS1/CAF, now renamed DCL1) that encodes a complex RNA-processing enzyme. DCL1 shows similarity to the Dicer group of genes, which are required for RNA silencing in Drosophila and Caenorhabditis. These recent findings identify a...

Meiosis is a central feature in the reproductive program of plants and all other sexually reproducing eukaryotes. In plants such as Arabidopsis thaliana, reproduction initiates during the development of the male (anther) and female (ovule) reproductive structures from somatic tissue. During anther development, a group of cells differentiate to form archesporial cells, which in turn give rise to...

The number of ovules per flower varies over several orders of magnitude among angiosperms. Here we consider evidence that stochastic uncertainty in pollen receipt and ovule fertilization has been a selective factor in the evolution of ovule number per flower. We hypothesize that stochastic variation in floral mating success creates an advantage to producing many ovules per flower because a plan...

Genes that control ovule identity were first identified in Petunia. Co-suppression of both FLORAL BINDING PROTEIN 7 (FBP7) and FBP11, two D-lineage genes, resulted in the homeotic transformation of ovules into carpelloid structures. Later in Arabidopsis it was shown that three genes, SHATTERPROOF1 (SHP1), SHP2, and SEEDSTICK (STK), redundantly control ovule identity, because in the stk shp1 shp...

A genetic approach has resulted in an extensive framework for the methodical analysis of ovule development. The most recent progress was accomplished in the areas of primordium formation and integument morphogenesis. Furthermore, systematic screens have identified a number of gametophytic mutations disrupting several distinct steps of embryo sac ontogenesis.

In flowering plants the gynoecium is the female reproductive structure. In Arabidopsis thaliana ovules initiate within the developing gynoecium from meristematic tissue located along the margins of the floral carpels. When fertilized the ovules will develop into seeds. SEUSS (SEU) and AINTEGUMENTA (ANT) encode transcriptional regulators that are critical for the proper formation of ovules from ...

BACKGROUND AND AIMS The evolution of seeds together with the mechanisms related to their dispersal into the environment represented a turning point in the evolution of plants. Seeds are produced by gymnosperms and angiosperms but only the latter have an ovary to be transformed into a fruit. Yet some gymnosperms produce fleshy structures attractive to animals, thus behaving like fruits from a fu...