Subunits of forming pollen exine and Ubisch bodies as seen in freeze substitutedLedebouria socialis Roth (Hyacinthaceae)

PROTOPLASMA ◽  
1994 ◽  
Vol 182 (1-2) ◽  
pp. 10-14 ◽  
Author(s):  
M. W. Hess ◽  
Andrea Frosch
Keyword(s):  
Pollen Exine ◽  
Ubisch Bodies

Ultrastructural aspects of gymnosperms reproductive organs tissues due to their functional condition

1978 ◽  
Vol 36 (2) ◽  
pp. 440-441
Author(s):  
G. M. Kozubov
Keyword(s):  
Metabolic Activity ◽  
Functional Condition ◽  
Reproductive Organs ◽  
Considerable Change ◽  
Complicated Structure ◽  
Tetrad Stage ◽  
Ubisch Bodies ◽  
Similar Organization ◽  
Female Reproductive Organs ◽  
High Metabolic Activity

The ultrastructure of reproductive organs of pine, spruce, larch and ginkgo was investigated. It was found that the male reproductive organs possess similar organization. The most considerable change in the ultrastructure of the microsporocytes occur in meiosis. Sporoderm is being laid at the late tetrad stage. The cells of the male gameto-phyte are distinguished according to the metabolic activity of the or- ganells. They are most weakly developed in the spermiogenic cell. Ta-petum of the gymnosperms is of the periplasmodic - secretorial type. The Ubisch bodies which possess similar structure in the types investigated but are specific in details in different species are produced in tapetum.Parietal and subepidermal layers are distinguished for their high metabolic activity and are capable of the autonomous photosynthesis. Female reproductive organs differ more greatly in their struture and have the most complicated structure in primitive groups. On the first stages of their formation the inner cells of nucellus are transformed into the nucellar tapetum in which the structures similar to the Ubisch bodies taking part in the formation of the sporoderm of female gametophyte have been found.

Absence of Callose and Tetrad in the Microsporogenesis of Pandanus odoratissimus with Well-formed Pollen Exine

1991 ◽  
Vol 67 (1) ◽  
pp. 29-33 ◽  
Author(s):  
K. PERIASAMY ◽  
J. AMALATHAS
Keyword(s):  
Pollen Exine ◽  
Pandanus Odoratissimus

The Ultrastructure and Ontogeny of Pollen in Helleborus Foetidus L

1968 ◽  
Vol 3 (2) ◽  
pp. 161-174
Author(s):  
P. ECHLIN ◽  
H. GODWIN
Keyword(s):  
Cell Wall ◽  
Tapetal Cell ◽  
Pollen Grains ◽  
Ultrastructural Level ◽  
Low Molecular Weight ◽  
Cell Organelles ◽  
Helleborus Foetidus ◽  
Ubisch Bodies ◽  
Ubisch Body ◽  
Development Proceeds

The ontogeny of the tapetum and Ubisch bodies in Helleborus foetidus L. has been examined at the ultrastructural level, and their development has been closely linked with that of the sporogenous cell and pollen grains. During development the tapetum passes through successive phases of synthesis, maturity and senescence, ending in complete dissolution. During the anabolic phase of growth, precursors of the Ubisch bodies are formed as spheroidal vesicles of medium electron density within the tapetal cytoplasm; they are associated with a zone of radiating ribosomes, which, as development proceeds, can clearly be seen to be situated on strands of endoplasmic reticulum. The callose special wall round the microspores and the tapetal cell wall now disintegrate and the pro-Ubisch bodies are extruded through the cell membrance of the tapetal cells, where they remain on the surface of the anther cavity and soon become irregularly coated with sporopollenin. Deposition of sporopollenin continues on the Ubisch bodies at the same time as upon the exines of the developing pollen grains. In both cases, the later stages of sporopollenin deposition are associated with electron-transparent layers of unit-membrane dimensions appearing in section as white lines of uniform thickness. Continuing deposition of sporopollenin leads to the formation of compound or aggregate Ubisch bodies. It is conjectured that the sporopollenin is synthesized from the compounds of low molecular weight released into the anther loculus by the breakdown of the callose special wall and the tapetal cell wall. The final stages of tapetal autolysis involve the disappearance of all the cell organelles. An attempt is made to relate the findings to those described in other recent studies on Ubisch body formation and to combine them in a common ontogenetic pattern.

OsFLA1 encodes a fasciclin-like arabinogalactan protein and affects pollen exine development in rice

2022 ◽  
Author(s):  
Yao Deng ◽  
Yingchun Wan ◽  
Weichi Liu ◽  
Lisha Zhang ◽  
Kai Zhou ◽  
...  
Keyword(s):  
Arabinogalactan Protein ◽  
Pollen Exine

PRIMULINE INDUCED FLUORESCENCE OF THE FIRST EXINE ELEMENTS AND UBISCH BODIES IN IPOMOEA AND LILIUM

Sporopollenin ◽  
1971 ◽  
pp. 108-129 ◽  
Author(s):  
L. Waterkeyn ◽  
A. Bienfait
Keyword(s):  
Ubisch Bodies

scholarly journals Molecular regulation ofZmMs7required for maize male fertility and development of a dominant male-sterility system in multiple species

2020 ◽  
Vol 117 (38) ◽  
pp. 23499-23509 ◽  
Author(s):  
Xueli An ◽  
Biao Ma ◽  
Meijuan Duan ◽  
Zhenying Dong ◽  
Ruogu Liu ◽  
...  
Keyword(s):  
Male Sterility ◽  
Seed Production ◽  
Target Genes ◽  
Hybrid Seed ◽  
Molecular Regulation ◽  
Dominant Male ◽  
Hybrid Seed Production ◽  
Maize Breeding ◽  
Pollen Exine ◽  
Multiple Species

Understanding the molecular basis of male sterility and developing practical male-sterility systems are essential for heterosis utilization and commercial hybrid seed production in crops. Here, we report molecular regulation by genic male-sterility genemaize male sterility 7(ZmMs7) and its application for developing a dominant male-sterility system in multiple species.ZmMs7is specifically expressed in maize anthers, encodes a plant homeodomain (PHD) finger protein that functions as a transcriptional activator, and plays a key role in tapetal development and pollen exine formation. ZmMs7 can interact with maize nuclear factor Y (NF-Y) subunits to form ZmMs7-NF-YA6-YB2-YC9/12/15 protein complexes that activate target genes by directly binding to CCAAT box in their promoter regions. Premature expression ofZmMs7in maize by an anther-specific promoterp5126results in dominant and complete male sterility but normal vegetative growth and female fertility. Early expression ofZmMs7downstream genes induced by prematurely expressed ZmMs7 leads to abnormal tapetal development and pollen exine formation inp5126-ZmMs7maize lines. Thep5126-ZmMs7transgenic rice andArabidopsisplants display similar dominant male sterility. Meanwhile, themCherrygene coupled withp5126-ZmMs7facilitates the sorting of dominant sterility seeds based on fluorescent selection. In addition, both thems7-6007recessive male-sterility line andp5126-ZmMs7Mdominant male-sterility line are highly stable under different genetic germplasms and thus applicable for hybrid maize breeding. Together, our work provides insight into the mechanisms of anther and pollen development and a promising technology for hybrid seed production in crops.

POLLEN EXINE SUBSTRUCTURE. I. LILIUM LONGIFLORUM

1985 ◽  
Vol 72 (8) ◽  
pp. 1274-1283 ◽  
Author(s):  
Darlene Southworth
Keyword(s):  
Lilium Longiflorum ◽  
Pollen Exine

scholarly journals IRREGULAR POLLEN EXINE1 Is a Novel Factor in Anther Cuticle and Pollen Exine Formation

2016 ◽  
Vol 173 (1) ◽  
pp. 307-325 ◽  
Author(s):  
Xiaoyang Chen ◽  
Hua Zhang ◽  
Huayue Sun ◽  
Hongbing Luo ◽  
Li Zhao ◽  
...  
Keyword(s):  
Pollen Exine ◽  
Anther Cuticle

scholarly journals Cytochrome P450 Family Member CYP704B2 Catalyzes the ω -Hydroxylation of Fatty Acids and Is Required for Anther Cutin Biosynthesis and Pollen Exine Formation in Rice

2010 ◽  
Vol 22 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Hui Li ◽  
Franck Pinot ◽  
Vincent Sauveplane ◽  
Danièle Werck-Reichhart ◽  
Patrik Diehl ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Cytochrome P450 ◽  
Family Member ◽  
Pollen Exine ◽  
Cytochrome P450 Family
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