CONTRIBUTION TO THE EMBRYOLOGY OF HOPPEA DICHOTOMA WILLD. (GENTIANACEAE)

1961 ◽  
Vol 39 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Govindappa D. Arekal
Keyword(s):  
Cell Wall ◽  
Female Gametophyte ◽  
Embryo Sac ◽  
Cell Wall Formation ◽  
Polygonum Type ◽  
Wall Formation ◽  
Embryo Sac Development ◽  
In Series ◽  
Second Period

The mode of embryo sac development in Hoppea dichotoma Willd. conforms to the Polygonum type. No integumentary tapetum is organized around the female gametophyte. The organization of the endosperm follows the nuclear type. Simultaneous cell wall formation occurs throughout the endosperm when the embryo is at the 4- to 6-celled stage. The development of the embryo is assigned to the second period, V megarchetype and group 11 in series C′ in the system of embryogenic classification of Souèges. The endosperm and embryo of Gentianaceae are compared with those of Menyanthaceae.

scholarly journals Development of Female Gametophyte in Gladiolus italicus Miller (Iridaceae)

Caryologia ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 91-97
Author(s):  
Ciler Kartal ◽  
Nuran Ekici ◽  
Almina Kargacıoğlu ◽  
Hazal Nurcan Ağırman
Keyword(s):  
Light Microscopy ◽  
Female Gametophyte ◽  
Embryo Sac ◽  
Polygonum Type ◽  
Gametophyte Development ◽  
Embryo Sac Development ◽  
Secondary Nucleus ◽  
Microscopy Techniques ◽  
Female Gametophyte Development ◽  
First Time

In this study gynoecium, megasporogenesis, megagametogenesis and female gametophyte of Gladiolus italicus Miller were examined cytologically and histologically by using light microscopy techniques. Ovules of G. italicus are of anatropous, bitegmic and crassinucellate type. Embryo sac development is of monosporic Polygonum type. Polar nuclei fuse before fertilization to form a secondary nucleus near the antipodals. The female gametophyte development of G. italicus was investigated for the first time with this study.

Megagametophyte development in Hordeum vulgare. 1. Early megagametogenesis and the nature of cell wall formation

1985 ◽  
Vol 63 (12) ◽  
pp. 2164-2171 ◽  
Author(s):  
D. D. Cass ◽  
D. J. Peteya ◽  
B. L. Robertson
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Embryo Sac ◽  
Cell Wall Formation ◽  
Wall Formation ◽  
Growing Cell ◽  
Transmission Electron ◽  
Nuclear Stage ◽  
Functional Megaspore ◽  
Dictyosome Vesicles

Megagametophyte development in barley (Hordeum vulgare 'Atsel') was studied using Nomarski-interference optics and transmission electron microscopy. Stages described include the functional megaspore to cell wall formation. Aspects of the transition from the free nuclear stage of the embryo sac to the cellular embryo sac indicate involvement of elongate cell plates associated with clusters of microtubules. Initial cell walls among micropylar and chalazal nuclei are composed of beads derived from dictyosome vesicles. Fusion of growing cell plates occurs, especially within the antipodal apparatus.

Embryology of Polygonatum (Asparagaceae) and its systematic significance

Phytotaxa ◽  
2018 ◽  
Vol 350 (3) ◽  
pp. 235
Author(s):  
YUAN-YUAN SONG ◽  
YUN-YUN ZHAO ◽  
JIA-XI LIU
Keyword(s):  
Female Gametophyte ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Mature Pollen ◽  
Polygonum Type ◽  
Male And Female ◽  
Systematic Significance ◽  
Embryo Sac Development

In this study, we systematically studied the microsporogenesis, megasporogenesis, as well as development of male and female gametophyte of Polygonatum macropodum and P. sibiricum using the conventional paraffin sectioning technique. Our results showed that 1) microsporocytes cytokinesis is of the successive type; 2) microspore tetrads are tetragonal or tetrahedral; 3) mature pollen grains are two-celled or three-celled; 4) ovary is superior and trilocular, with axile placentas bearing 4–6 anatropous per locule; 5) ovules are anatropous, crassinucellate and bitegmic, with micropyle formed by the inner integument; 6) megaspore tetrads are linear or T-shaped; 7) embryo sac development is typically of Polygonum-type. The embryological features of Polygonatum support its inclusion of Asparagaceae in Asparagales.

Ethylene effects on cambial activity and cell wall formation in hypocotyls of Picea abies seedlings

1991 ◽  
Vol 82 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Barbro S. M. Ingemarsson ◽  
Leif Eklund ◽  
Lennart Eliasson
Keyword(s):  
Cell Wall ◽  
Picea Abies ◽  
Cambial Activity ◽  
Cell Wall Formation ◽  
Wall Formation

Arabidopsis Callose Synthase Gene GSL8 is Required for Cell Wall Formation and Establishment and Maintenance of Quiescent Center

2014 ◽  
Vol 48 (4) ◽  
pp. 389-397
Author(s):  
Liu Lin ◽  
Quan Xianqing ◽  
Zhao Xiaomei ◽  
Huang Lihua ◽  
Feng Shangcai ◽  
...  
Keyword(s):  
Cell Wall ◽  
Quiescent Center ◽  
Cell Wall Formation ◽  
Callose Synthase ◽  
Wall Formation

scholarly journals MYB Transcription Factors and Its Regulation in Secondary Cell Wall Formation and Lignin Biosynthesis during Xylem Development

2021 ◽  
Vol 22 (7) ◽  
pp. 3560
Author(s):  
Ruixue Xiao ◽  
Chong Zhang ◽  
Xiaorui Guo ◽  
Hui Li ◽  
Hai Lu
Keyword(s):  
Cell Wall ◽  
Transcription Factors ◽  
Secondary Wall ◽  
Secondary Cell Wall ◽  
Lignin Biosynthesis ◽  
Cell Wall Formation ◽  
Long Distance ◽  
Secondary Cell Wall Formation ◽  
Myb Transcription Factors ◽  
Wall Formation

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.

Embryological studies in the compositae, I. Sporogenesis, Gametogenesis, and Embryogeny in Cotula australis (Less.) Hook. F

1962 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
GL Davis
Keyword(s):  
Mother Cell ◽  
Megaspore Mother Cell ◽  
Embryo Sac ◽  
Subsequent Development ◽  
Pollen Grains ◽  
Archesporial Cell ◽  
Polygonum Type ◽  
Wall Formation ◽  
Chalazal Megaspore

Cotula australis has a discoid heterogamous capitulum in which the outermost three whorls of florets are female and naked. The bisexual disk florets are fully fertile and have a four-lobed corolla with four shortly epipetalous stamens. The anthers contain only two microsporangia. Wall formation and microsporogenesis are described and the pollen grains are shed at the three-celled condition. The ovule is teguinucellate and the hypodermal archesporial cell develops directly as the megaspore mother cell. Megasporogenesis is normal and the monosporio embryo sac develops from the chalazal megaspore. Breakdown of the nucellar epidermis takes place when the embryo sac is binucleate and its subsequent development follows the Polygonum type. The synergids extend deeply into the micropyle and one persists until late in embryogeny as a haustorium. The development of the embryo is of the Asterad type, and the endosperm is cellular. C. coronopifolia agrees with C. australis in the presence of only two microsporangia in each anther and the development of a synergid haustorium.

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