Environmental control of gametogenesis in Laminaria saccharina. II. Correlation of nitrate and phosphate concentrations with gametogenesis and selected metabolites

1973 ◽  
Vol 51 (5) ◽  
pp. 829-839 ◽  
Author(s):  
Stephen I. C. Hsiao ◽  
Louis D. Druehl
Keyword(s):  
Female Gametophyte ◽  
Environmental Control ◽  
Male Gametophyte ◽  
Axenic Culture ◽  
Nutrient Concentrations ◽  
Growth Morphology ◽  
Laminaria Saccharina ◽  
Synthetic Seawater ◽  
Sexual Fusion ◽  
Seawater Medium

The gametophyte growth, morphology, gametogenesis, and metabolites of Laminaria saccharina (L.) Lamouroux were studied in different cyncentrations of nitrate and phosphate in axenic culture, using a synthetic seawater medium under optimal light and temperature conditions.Nitrate and phosphate were required for the various stages of gametophyte development and gametogenesis. Under nitrate and phosphate concentrations optimal for growth and gametogenesis, maximum quantities of DNA, RNA, protein, and carbohydrate, and low quantities of lipid were produced. Further, nutrient concentrations which gave rise to the greatest fertility also gave rise to the highest ratios of RNA/DNA and protein/RNA.Antheridial production occurred over a wider range of nitrate and phosphate concentrations than oogonial production. Further, percentage fertility was greater for the male gametophyte. This indicated that the female gametophyte was the limiting agent in sexual fusion.

Seed production and gametophyte formation in Agave tequilana and Agave americana

Botany ◽  
2008 ◽  
Vol 86 (11) ◽  
pp. 1343-1353 ◽  
Author(s):  
Rocio E. Escobar-Guzmán ◽  
Flor Zamudio Hernández ◽  
Katia Gil Vega ◽  
June Simpson
Keyword(s):  
Seed Production ◽  
Female Gametophyte ◽  
Male Gametophyte ◽  
Raw Material ◽  
Low Fertility ◽  
Agave Tequilana ◽  
Genetic Incompatibility ◽  
Gametophyte Development ◽  
Agave Americana ◽  
Female Gametophyte Development

Agave tequilana Weber var. azul is the raw material used in the production of tequila. This species has a life cycle of approximately 6–8 years; however, owing to the practice of removing the inflorescence to conserve accumulated sugar reserves, the main form of reproduction is asexual. Little attention has, therefore, been paid to the process of flowering and the factors leading to low levels of germination and seedling viability have not been investigated in detail. The objective of this study was to document gametophyte development, seed production, and germination in A. tequilana under different pollination treatments and in an interspecies cross with Agave americana L. Seed production and germination efficiency was low for both A. tequilana and A. americana under the different pollination treatments, although interspecies crosses did produce some viable seeds. Development of the male gametophyte in both species is of the successive type, producing pollen grains with dicolpate morphology. Female gametophyte development is of the Polygonum monosporic type. The results obtained suggest that genetic incompatibility, inbreeding effects, factors affecting pollen development and germination, or errors in female gametophyte development may contribute to the low fertility observed for A. tequilana and A. americana.

scholarly journals Epigenetic Regulation of Plant Gametophyte Development

2019 ◽  
Vol 20 (12) ◽  
pp. 3051 ◽  
Author(s):  
Vasily V. Ashapkin ◽  
Lyudmila I. Kutueva ◽  
Nadezhda I. Aleksandrushkina ◽  
Boris F. Vanyushin
Keyword(s):  
Mother Cell ◽  
Female Gametophyte ◽  
Male Gametophyte ◽  
Endosperm Development ◽  
Epigenetic Changes ◽  
Gametophyte Development ◽  
Daughter Cells ◽  
Second Stage ◽  
Somatic Tissues ◽  
Mother Cells

Unlike in animals, the reproductive lineage cells in plants differentiate from within somatic tissues late in development to produce a specific haploid generation of the life cycle—male and female gametophytes. In flowering plants, the male gametophyte develops within the anthers and the female gametophyte—within the ovule. Both gametophytes consist of only a few cells. There are two major stages of gametophyte development—meiotic and post-meiotic. In the first stage, sporocyte mother cells differentiate within the anther (pollen mother cell) and the ovule (megaspore mother cell). These sporocyte mother cells undergo two meiotic divisions to produce four haploid daughter cells—male spores (microspores) and female spores (megaspores). In the second stage, the haploid spore cells undergo few asymmetric haploid mitotic divisions to produce the 3-cell male or 7-cell female gametophyte. Both stages of gametophyte development involve extensive epigenetic reprogramming, including siRNA dependent changes in DNA methylation and chromatin restructuring. This intricate mosaic of epigenetic changes determines, to a great extent, embryo and endosperm development in the future sporophyte generation.

A MICROBIOLOGICAL ASSAY FOR BIOTIN IN SEAWATER

1963 ◽  
Vol 9 (3) ◽  
pp. 403-409 ◽  
Author(s):  
N. J. Antia
Keyword(s):  
Growth Response ◽  
Marine Bacterium ◽  
Microbiological Assay ◽  
Synthetic Seawater ◽  
Seawater Samples ◽  
Seawater Medium

A method is described for the direct bioassay of biotin in seawater samples. The assay organism is an unidentified marine bacterium that shows a growth response, in enriched seawater medium, proportional to dissolved biotin concentration in the range 3–12 μμg/ml. The growth was measured turbidimetrically with a spectrophotometer. The effective assay range was extended successfully to higher biotin levels by making appropriate dilutions in synthetic seawater.

scholarly journals Attractive and repulsive interactions between female and male gametophytes in Arabidopsis pollen tube guidance

Development ◽  
2000 ◽  
Vol 127 (20) ◽  
pp. 4511-4518 ◽  
Author(s):  
K.K. Shimizu ◽  
K. Okada
Keyword(s):  
Pollen Tube ◽  
Female Gametophyte ◽  
Inclusive Fitness ◽  
Male Gametophyte ◽  
Pollen Tubes ◽  
Interspecific Crosses ◽  
Pollen Tube Guidance ◽  
Normal Number ◽  
Mutant Female ◽  
Diploid Cells

Sexual reproduction in plants, unlike that of animals, requires the action of multicellular haploid gametophytes. The male gametophyte (pollen tube) is guided to a female gametophyte through diploid sporophytic cells in the pistil. While interactions between the pollen tube and diploid cells have been described, little is known about the intercellular recognition systems between the pollen tube and the female gametophyte. In particular, the mechanisms that enable only one pollen tube to interact with each female gametophyte, thereby preventing polysperm, are not understood. We isolated female gametophyte mutants named magatama (maa) from Arabidopsis thaliana by screening for siliques containing half the normal number of mature seeds. In maa1 and maa3 mutants, in which the development of the female gametophyte was delayed, pollen tube guidance was affected. Pollen tubes were directed to mutant female gametophytes, but they lost their way just before entering the micropyle and elongated in random directions. Moreover, the mutant female gametophytes attracted two pollen tubes at a high frequency. To explain the interaction between gametophytes, we propose a monogamy model in which a female gametophyte emits two attractants and prevents polyspermy. This prevention process by the female gametophyte could increase a plant's inclusive fitness by facilitating the fertilization of sibling female gametophytes. In addition, repulsion between pollen tubes might help prevent polyspermy. The reproductive isolations observed in interspecific crosses in Brassicaceae are also consistent with the monogamy model.

Genesis of megaspore and microspore as well as development of female gametophyte and male gametophyte in Liriope spicata (Thunberg) Loureiro

2014 ◽  
Vol 301 (1) ◽  
pp. 139-149 ◽  
Author(s):  
Cai-Yan Shi ◽  
Yun-Yun Zhao ◽  
Duo Chen ◽  
Hong-Na Chen ◽  
Jia-Xi Liu
Keyword(s):  
Female Gametophyte ◽  
Male Gametophyte

scholarly journals CrRLK1L receptor-like kinases HERCULES RECEPTOR KINASE 1 and ANJEA are female determinants of pollen tube reception

2018 ◽  
Author(s):  
Sergio Galindo-Trigo ◽  
Noel Blanco-Touriñán ◽  
Thomas A. DeFalco ◽  
Eloise S. Wells ◽  
Julie E Gray ◽  
...  
Keyword(s):  
Pollen Tube ◽  
Female Gametophyte ◽  
Male Gametophyte ◽  
Oxygen Species ◽  
Receptor Kinase ◽  
In Planta ◽  
Filiform Apparatus ◽  
Synergid Cell ◽  
Receptor Kinases ◽  
Type Receptor

AbstractCommunication between the gametophytes is vital for angiosperm fertilisation. Multiple CrRLK1L-type receptor kinases prevent premature pollen tube burst, while another CrRLK1L protein, FERONIA (FER), is required for pollen tube burst in the female gametophyte. We report here the identification of two additional CrRLK1L homologues, HERCULES RECEPTOR KINASE 1 (HERK1) and ANJEA (ANJ), which act redundantly to promote pollen tube burst at the synergid cells. HERK1 and ANJ localise to the filiform apparatus of the synergid cells in unfertilised ovules, and in herk1 anj mutants a majority of ovules remain unfertilised due to pollen tube overgrowth, together indicating that HERK1 and ANJ act as female determinants for fertilisation. As in fer mutants, the synergid cell-specific, endomembrane protein NORTIA (NTA) is not relocalised after pollen tube reception; however, unlike fer mutants, reactive oxygen species levels are unaffected in herk1 anj double mutants. Both ANJ and HERK1 associate with FER and its proposed co-receptor LORELEI (LRE) in planta. Together, our data indicate that HERK1 and ANJ act with FER to mediate female-male gametophyte interactions during plant fertilisation.

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