Ovule discounting denotes the reduction in the number of ovules available for cross-fertilization due to the interference of inferior pollen. Traditionally, ovule discounting has been discussed solely from the perspective of compromised outcrossing opportunities as a result of selfing, but the principle is more general. Here, we extend its applicability beyond the simple contrast between selfin...

Land plants are characterised by haplo-diploid life cycles, and developing ovules are the organs in which the haploid and diploid generations coexist. Recently it has been shown that hormones such as auxin and cytokinins play important roles in ovule development and patterning. The establishment and regulation of auxin levels in cells is predominantly determined by the activity of the auxin eff...

Ovule development in Arabidopsis involves the formation of three morphologically defined proximal-distal pattern elements. Integuments arise from the central pattern element. Analysis of Bell 1 (Bel 1) mutant ovules indicated that BEL1 was required for integument development. Cloning of the BEL1 locus reveals that it encodes a homeodomain transcription factor. Prior to integument initiation, BE...

Self-pollination results in significantly lower seed set than cross-pollination in tristylous Narcissus triandrus. We investigated structural and functional aspects of pollen-pistil interactions and ovule-seed development following cross- and self-pollination to assess the timing and mechanism of self-sterility. Ovule development within an ovary was asynchronous at anthesis. There were no signi...

Tissue specific expression of transgenes in plant species has several advantages over constitutive expression. Identification of ovule specific promoters would be useful in genetic engineering of plants with a variety of desirable traits such as genetically engineered parthenocarpy, female sterile plants or seedless fruits. Relative inaccessibility and difficulty in harvesting adequate amounts ...

The purpose of the present study was to determine the nature of the photoreceptor that controls the light-dependent development of the peanut ovule and embryo, and to determine whether this photoreceptor activity is located in the ovular or the embryonic tissue. Peanut ovules were aseptically excised from surface sterilized gynophores (pegs) and cultured in darkness, continuous far red (FR), or...

In Arabidopsis, different combinations of ABC organ identity proteins interact in the presence of SEPALLATA (SEP) proteins to regulate floral organ differentiation. Ectopic expression of SEP3 in combination with class A and B or B and C genes is sufficient to homeotically convert vegetative leaves into petal-like organs and bracts into stamen-like structures, respectively. Recently, it has been...

Gibberellins (GAs) are plant hormones that regulate most plant life cycle aspects, including flowering and fruit development. Here, we demonstrate the implication of GAs in ovule development. DELLA proteins, negative GA response regulators, act as positive factors for ovule integument development in a mechanism that involves transcription factor ABERRANT TESTA SHAPE (ATS). The seeds of the dell...

Angiosperm ovules consist of three proximal-distal domains – the nucellus, chalaza and funiculus – demarcated by developmental fate and specific gene expression. Mutation in three paralogous class III homeodomain leucine zipper (HD-ZIPIII) genes leads to aberrations in ovule integument development. Expression of WUSCHEL (WUS) is normally confined to the nucellar domain, but in this triple mutan...