Studies on the Sporogenous Lineage in the Moss Timmiella barbuloides IX. Development of the Tapetum

Abstract

KeywordsMosses, cytoskeleton, immunofluorescence, microtubules, meiosis.TEM and immunofluorescence studies of monoplastidic meiosis in cryptogams (Brown and Lem-For TEM, capsules at various stages of development were fixed in 2 % glutaraldehyde + 1 % paraformaldehyde in phosphate buffer (0.05 M, pH 7.4) for 2 h at room temperature, post-fixed in 1 % osmium tetroxide in the same buffer, dehydrated through graded ethanol solutions and propylene oxide, and embedded in Spurr's resin. Ultra-thin sections were sequentially stained with 5 % uranyl acetate I!l 50 % ethanol and lead citrate, and examined in a Philips CM12 electron microscope.Studies on the Sporogenous Lineage in the Moss Timmiella barbuloides VII. Bot. Acta 106 (1993) 351

A seasonal cycle of cell wall structure is accompanied by a cyclical rearrangement of cortical microtubules in fusiform cambial cells within taproots of Aesculus hippocastanum (Hippocastanaceae)

“…Furthermore, Barnett (1981) illustrated ' vesicular material ' within the middle lamella between enlarging cells in the active cambial zone of Aesculus shoot. The presence of similar structures within cell walls has also been noted within the outer tangential walls of adaxial epidermal cells of the grass ligule (Chaffey, 1995), and within tapetal cells of a moss (Gambardella et al, 1994). In both these instances, the vesicular bodies were inferred to be related to the secretory processes taking place within those systems.…”

Spore morphology of some Orthotrichaceae Arn. species (Bryophyta) from Turkey

“…It is also a potential source of information regarding the evolutionary processes, which may lead to the definition of biological or taxonomic boundaries (Carrion et al 1995). In some recent papers (Sorsa and Koponen 1973, Vitt and Hamilton 1974, Boros and Járai-Komlódi 1975, Olesen and Mogensen 1978, Brown and Lemmon 1988, Blackmore and Barnes 1991, Gambardella et al 1994, Carrion et al 1995, Estebanez et al 1997, Luizi-Ponzo and Barth 1998, 1999, Khoshravesh and Kazempour Osaloo 2007, Savaroglu and Potoglu Erkara 2008, Medina et al 2009, Aşçı et al 2010, Caldeira et al 2013, the intine structure and the spore external morphology have proven useful in characterizing moss taxa at the generic and specific levels. There is, however, still required research in this area.…”

Sporogenesis in Physcomitrium patens: Intergenerational collaboration and the development of the spore wall and aperture

“…The polarity of spores is prominent throughout sporogenesis in P. patens and is apparent in the production of a structurally distinct distal wall and a proximal wall where the aperture is constructed. As in other mosses, the aperture is trilaesurate and extends across the proximal spore surface along the contact faces of the four spores in the tetrad (Brown and Lemmon, 1981;Gambardella et al, 1994;Brown et al, 2015). The moss aperture is complex and in P. patens includes a modified irregular perine, thin interrupted exine, highly thickened intine, and a specialized central disc-like pad that contains callose (Schuette et al, 2009).…”

“…Aspects of spore development in mosses have been reported in diverse taxa, including Sphagnum ( Brown et al, 1982 ), Andreaea ( Brown and Lemmon, 1984 ), Andreaeobryum ( Polevova et al, 2022 ), and Takakia ( Renzaglia et al, 1997 ), the sister taxa to peristomate mosses. Among bryopsid mosses, sporogenesis has been examined in scattered taxa, including Trematodon ( Brown and Lemmon, 1981 ), Ditrichum ( Brown and Lemmon, 1980 ), Timmiella ( Gambardella et al, 1993 ; Gambardella et al, 1994 ), Archidium ( Brown and Lemmon, 1985 ), and Amblystegium ( Brown and Lemmon, 1982 ). As intimated by Wallace et al (2011) , several critical questions regarding spore wall development in P. patens remain unanswered, including the derivation of sporopollenin-containing layers and aperture development.…”