Hypothesis: Sex allocation theory predicts that the pollen–ovule ratio should increase linearly with increasing seed size among seed plants (Charnov, 1982). Data examined: We retrieved data for the pollen–ovule ratio, seed size, and possible confounding variables (ovule number, plant height, mating system) from a database and additional literature for 299 gymnosperm plant species of the German ...

Hypothesis: Sex allocation theory predicts that the pollen-ovule ratio should increase linearly with increasing seed size among seed plants (Charnov 1982). Data examined: We retrieved data for pollen-ovule ratio, seed size and possible confounding variables (ovule number, plant height, mating system) from a database and additional literature for 299 angyosperm plant species of the German flora....

We have recently developed a new generic seed crystal that has been used successfully to fabricate any oriented, single grain (RE)-Ba-Cu-O bulk superconductor by a cold seeding technique. In this paper we report the chemical, structural and microstructural properties of these seed crystals, including the variation of melting point, crystallographic parameters and volume fraction of Mg-rich incl...

Seed development is a complex process that requires coordinated integration of many genetic, metabolic, and physiological pathways and environmental cues. Different cell cycle types, such as asymmetric cell division, acytokinetic mitosis, mitotic cell division, and endoreduplication, frequently occur in sequential yet overlapping manner during the development of the embryo and the endosperm, se...

Flowering plants, like placental mammals, have an extensive maternal contribution toward progeny development. Plants are distinguished from animals by a genetically active haploid phase of growth and development between meiosis and fertilization, called the gametophyte. Flowering plants are further distinguished by the process of double fertilization that produces sister progeny, the endosperm ...

In Arabidopsis (Arabidopsis thaliana), ethylene responses are mediated by a family of five receptors that have both overlapping and nonoverlapping roles. In this study, we used loss-of-function mutants for each receptor isoform to determine the role of individual isoforms in seed germination under salt stress. From this analysis, we found subfunctionalization of the receptors in the control of ...

Climate change is accelerating plant developmental transitions coordinated with the seasons in temperate environments. To understand the importance of these timing advances for a stable life history strategy, we constructed a full life cycle model of Arabidopsis thaliana. Modelling and field data reveal that a cryptic function of flowering time control is to limit seed set of winter annuals to ...

MicroRNAs have emerged in recent years as important regulators of cell function in both normal and diseased cells. MiRNAs coordinately regulate large suites of target genes by mRNA degradation and/or translational inhibition. The mRNA target specificities of miRNAs in animals are primarily encoded within a 7 nt "seed region" mapping to positions 2-8 at the molecule's 5' end. We here combine com...

OBJECTIVE This retrospective study compared the advantages and disadvantages of iodine-125 (125I) seed implantation and pancreaticoduodenectomy (PD) in the treatment of pancreatic cancer. METHODS Patients with diagnosed pancreatic cancer who were treated with 125125I seed implantation (30 patients) or PD (30 patients) in our hospital were evaluated for operative time, bleeding, liver function...

Abscisic acid (ABA) and gibberellin (GA) are two antagonistic phytohormones that regulate seed germination in response to biotic and abiotic environmental stresses. We demonstrate here that MOTHER OF FT AND TFL1 (MFT), which encodes a phosphatidylethanolamine-binding protein, regulates seed germination via the ABA and GA signaling pathways in Arabidopsis thaliana. MFT is specifically induced in...