Pollen development in orchids 4. Cytoskeleton and ultrastructure of the unequal pollen mitosis inPhalaenopsis

PROTOPLASMA ◽  
1992 ◽  
Vol 167 (3-4) ◽  
pp. 183-192 ◽  
Author(s):  
R. C. Brown ◽  
B. E. Lemmon
Keyword(s):  
Pollen Development ◽  
Pollen Mitosis

Pollen development in orchids

1991 ◽  
Vol 99 (2) ◽  
pp. 273-281 ◽  
Author(s):  
R. C. BROWN ◽  
B. E. LEMMON
Keyword(s):  
Plasma Membrane ◽  
Nuclear Envelope ◽  
Pollen Development ◽  
Nuclear Migration ◽  
Pollen Mitosis ◽  
Polar Structure ◽  
Microtubular Cytoskeleton ◽  
Distal Surface

Cytoplasmic preparation for the unequal first mitosis in non-vacuolate pollen of moth orchids (Phalaenopsis) includes reorganization of the microtubular cytoskeleton and nuclear migration. Following meiotic cytokinesis, both microtubules and F-actin are unpolarized in microspores of persistent tetrads. Microtubules radiate from the centrally located nucleus and F-actin forms a reticulate pattern in the cytoplasm. Polarization of the microspores is marked by a dramatic reorganization of microtubules while the pattern of F-actin remains unchanged. We describe a novel system of microtubules at the generative pole (GPMS), which forms a polar structure structure at the distal surface and marks the path of nuclear migration prior to pollen mitosis. The GPMS consists of numerous microtubules that extend between the plasma membrane and nuclear envelope. The nucleus becomes displaced toward the generative pole and flattened in association with microtubules of the GPMS. Initiation of the GPMS is marked by a localized proliferation of ER and clearing of large organelles from the generative pole.

scholarly journals Unequal plastid distribution during the development of the male gametophyte of angiosperms

2014 ◽  
Vol 50 (1-2) ◽  
pp. 321-327 ◽  
Author(s):  
R. Hagemann
Keyword(s):  
Pollen Development ◽  
Male Gametophyte ◽  
Pollen Mitosis ◽  
Plastid Inheritance ◽  
Simple Mechanism ◽  
Plastid Distribution ◽  
The Difference

The difference between the uniparental maternal and biparental type of plastid inheritance is based upon a relatively simple mechanism. In the uniparental type plastids are excluded from the generative or siperm cells during the firts pollen mitosis or during pollen development. In some angiosperms this exclusion is completely lacking or carried out partially.

Resolution of Channels in the Exine by Translocation of Colloidal Iron

1971 ◽  
Vol 29 ◽  
pp. 352-353
Author(s):  
John R. Rowley
Keyword(s):  
Phosphate Buffer ◽  
Pollen Development ◽  
Osmium Tetroxide ◽  
Pollen Grains ◽  
Deionized Water ◽  
Colloidal Iron ◽  
Fixed Material ◽  
Epilobium Angustifolium ◽  
Untreated Material ◽  
Microspore Mitosis

The morphology of the exine of many pollen grains, at the time of flowering, is such that one can suppose that transport of substances through the exine occurred during pollen development. Holes or channels, microscopic to submicroscopic, are described for a large number of grains. An inner part of the exine of Epilobium angustifolium L. and E. montanum L., which may be referred to as the endexine, has irregularly shaped channels early in pollen development although by microspore mitosis there is no indication of such channeling in chemically fixed material. The nucleus in microspores used in the experiment reported here was in prophase of microspore mitosis and the endexine, while lamellated in untreated grains, did not contain irregularly shaped channels. Untreated material from the same part of the inflorescence as iron treated stamens was examined following fixation with 0.1M glutaraldehyde in cacodylate-HCl buffer at pH 6.9 (315 milliosmoles) for 24 hrs, 4% formaldehyde in phosphate buffer at pH 7.2 (1,300 milliosmoles) for 12 hrs, 1% glutaraldehyde mixed with 0.1% osmium tetroxide for 20 min, osmium tetroxide in deionized water for 2 hrs and 1% glutaraldehyde mixed with 4% formaldehyde in 0.1M cacodylate-HCl buffer at pH 6.9 for two hrs.

Dynamic Changes in Activity and Distribution of Proteasome During Pollen Development of Pinus bungeana

2012 ◽  
Vol 47 (2) ◽  
pp. 141-148
Author(s):  
Jiang Liping ◽  
Dong Xiaoling ◽  
Li Xue ◽  
Gao Yuan ◽  
Sheng Xianyong
Keyword(s):  
Pollen Development ◽  
Dynamic Changes ◽  
Pinus Bungeana

scholarly journals OseIF3h Regulates Plant Growth and Pollen Development at Translational Level Presumably through Interaction with OsMTA2

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1101
Author(s):  
Yuqing Huang ◽  
Peng Zheng ◽  
Xuejiao Liu ◽  
Hao Chen ◽  
Jumin Tu
Keyword(s):  
Plant Growth ◽  
Translation Initiation ◽  
Pollen Development ◽  
Messenger Rna ◽  
Protein Biosynthesis ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Sequencing Data ◽  
Knock Out ◽  
Translational Level

The initiation stage of protein biosynthesis is a sophisticated process tightly regulated by numerous initiation factors and their associated components. However, the mechanism underlying translation initiation has not been completely understood in rice. Here, we showed knock-out mutation of the rice eukaryotic translation initiation factor 3 subunit h (OseIF3h) resulted in plant growth retardation and seed-setting rate reduction as compared to the wild type. Further investigation demonstrated an interaction between OseIF3h and OsMTA2 (mRNA adenosine methylase 2), a rice homolog of METTL3 (methyltransferase-like 3) in mammals, which provided new insight into how N6-methyladenosine (m6A) modification of messenger RNA (mRNA) is engaged in the translation initiation process in monocot species. Moreover, the RIP-seq (RNA immunoprecipitation sequencing) data suggested that OseIF3h was involved in multiple biological processes, including photosynthesis, cellular metabolic process, precursor metabolites, and energy generation. Therefore, we infer that OseIF3h interacts with OsMTA2 to target a particular subset of genes at translational level, regulating plant growth and pollen development.

A novel Arabidopsis gene RGAT1 is required for GA‐mediated tapetum and pollen development

2021 ◽  
Author(s):  
Qian Qian ◽  
Yuhua Yang ◽  
Wenbin Zhang ◽  
Yilong Hu ◽  
Yuge Li ◽  
...  
Keyword(s):  
Pollen Development ◽  
Arabidopsis Gene
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