TETRASPORE is required for male meiotic cytokinesis in Arabidopsis thaliana

Development ◽  
1997 ◽  
Vol 124 (13) ◽  
pp. 2645-2657 ◽  
Author(s):  
M. Spielman ◽  
D. Preuss ◽  
F.L. Li ◽  
W.E. Browne ◽  
R.J. Scott ◽  
...  

In flowering plants, male meiosis occurs in the microsporocyte to produce four microspores, each of which develops into a pollen grain. Here we describe four mutant alleles of TETRASPORE (TES), a gene essential for microsporocyte cytokinesis in Arabidopsis thaliana. Following failure of male meiotic cytokinesis in tes mutants, all four microspore nuclei remain within the same cytoplasm, with some completing their developmental programmes to form functional pollen nuclei. Both of the mitotic divisions seen in normal pollen development take place in tes mutants, including the asymmetric division required for the differentiation of gametes; some tes grains perform multiple asymmetric divisions in the same cytoplasm. tes pollen shows a variety of abnormalities subsequent to the cytokinetic defect, including fusion of nuclei, formation of ectopic internal walls, and disruptions to external wall patterning. In addition, ovules fertilized by tes pollen often abort, possibly because of excess paternal genomes in the endosperm. Thus tes mutants not only reveal a gene specific to male meiosis, but aid investigation of a wide range of processes in pollen development and function.

2004 ◽  
Vol 40 (6) ◽  
pp. 979-995 ◽  
Author(s):  
Jeremy Preston ◽  
Janet Wheeler ◽  
Joshua Heazlewood ◽  
Song Feng Li ◽  
Roger W. Parish

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 596 ◽  
Author(s):  
Susheel Sagar Bhat ◽  
Dawid Bielewicz ◽  
Artur Jarmolowski ◽  
Zofia Szweykowska-Kulinska

N6-methyladenosine (m6A) is known to occur in plant and animal messenger RNAs (mRNAs) since the 1970s. However, the scope and function of this modification remained un-explored till very recently. Since the beginning of this decade, owing to major technological breakthroughs, the interest in m6A has peaked again. Similar to animal mRNAs, plant mRNAs are also m6A methylated, within a specific sequence motif which is conserved across these kingdoms. m6A has been found to be pivotal for plant development and necessary for processes ranging from seed germination to floral development. A wide range of proteins involved in methylation of adenosine have been identified alongside proteins that remove or identify m6A. This review aims to put together the current knowledge regarding m6A in Arabidopsis thaliana.


2005 ◽  
Vol 60 (7-8) ◽  
pp. 572-576 ◽  
Author(s):  
Atsumi Shimada ◽  
Hisakazu Yamane ◽  
Yasuo Kimura

Application of indole-3-acetic acid (IAA) with a pollen growth inhibitor, aspterric acid (AA), results in the recovery of normal pollen development. In contrast, application of gibberellin (GA3) with AA do not induce normal pollen growth. In addition, application of different concentrations of IAA with AA shortens the period of growth from bolting to first flowering as compared to that treated with AA alone. Furthermore, stem length and number of flower bud treated with IAA and AA were similar to those of control. These results suggest, that IAA may play an important role in reproductive growth of A. thaliana.


2020 ◽  
Author(s):  
Swee-Suak Ko ◽  
Min-Jeng Li ◽  
Yi-Cheng Ho ◽  
Chun-Ping Yu ◽  
Ting-Ting Yang ◽  
...  

AbstractGAMYB, UDT1, TIP2/bHLH142, TDR, and EAT1/DTD are important transcription factors (TFs) that play a crucial role during rice pollen development. This study demonstrates that bHLH142 acts downstream of UDT1 and GAMYB and works as a “hub” in these two pollen pathways. We show that GAMYB modulates bHLH142 expression through specific binding to the MYB motif of bHLH142 promoter during early stage of pollen development; while TDR acts as a transcriptional repressor of the GAMYB modulation of bHLH142 by binding to the E-box close to the MYB motif on the promoter. The up- and down-regulation of TFs highlights the importance that a tight, precise, and coordinated regulation among these TFs is essential for normal pollen development. Most notably, this study illustrates the regulatory pathways of GAMYB and UDT1 that rely on bHLH142 in a direct and an indirect manner, respectively, and function in different tissues with distinct biological functions during pollen development. This study advances our understanding of the molecular mechanisms of rice pollen development.HighlightGAMYB can directly modulate the transactivation of the bHLH142, but the modulation is repressed by TDR to keep the homeostasis of bHLH142 gene expression to ensure normal pollen development.


2016 ◽  
pp. 126-129
Author(s):  
M. Makarenko ◽  
◽  
D. Hovsyeyev ◽  
L. Sydoryk ◽  
◽  
...  

Different kinds of physiological stress cause mass changes in the cells, including the changes in the structure and function of the protein complexes and in separate molecules. The protein functions is determined by its folding (the spatial conclusion), which depends on the functioning of proteins of thermal shock- molecular chaperons (HSPs) or depends on the stress proteins, that are high-conservative; specialized proteins that are responsible for the correct proteinaceous folding. The family of the molecular chaperones/ chaperonins/ Hsp60 has a special place due to the its unique properties of activating the signaling cascades through the system of Toll-like receptors; it also stimulates the cells to produce anti- inflammatory cytokines, defensins, molecules of cell adhesion and the molecules of MHC; it functions as the intercellular signaling molecule. The pathological role of Hsp60 is established in a wide range of illnesses, from diabetes to atherosclerosis, where Hsp60 takes part in the regulation of both apoptosis and the autoimmune processes. The presence of the HSPs was found in different tissues that are related to the reproductive system. Key words: molecular chaperons (HSPs), Toll-like receptors, reproductive function, natural auto antibody.


2012 ◽  
Vol 6 (1-3) ◽  
pp. 243-259 ◽  
Author(s):  
Yohan Yoo

This article demonstrates the need for the iconic status and function of Buddhist scripture to receive more attention by illuminating how lay Korean Buddhists try to appropriate the power of sutras. The oral and aural aspects of scripture, explained by Wilfred Cantwell Smith, provide only a limited understanding of the characteristics of scripture. It should be noted that, before modern times, most lay people, not only in Buddhist cultures but also in Christian and other traditions, neither had the chance to recite scriptures nor to listen to their recitations regularly. Several clear examples demonstrate contemporary Korean Buddhists’ acceptance of the iconic status of sutras and their attempt to appropriate the power and status of those sacred texts. In contemporary Korea, lay Buddhists try to claim the power of scriptures in their daily lives by repeating and possessing them. Twenty-first century lay believers who cannot read or recite in a traditional style have found new methods of repetition, such as internet programs for copying sacred texts and for playing recordings of their recitations. In addition, many Korean Buddhists consider the act of having sutras in one’s possession to be an effective way of accessing the sacred status and power of these texts. Hence, various ways of possessing them have been developed in a wide range of products, from fancy gilded sutras to sneakers embroidered with mantras.


Author(s):  
Erik Gray

Love begets poetry; poetry begets love. These two propositions have seemed evident to thinkers and poets across the Western literary tradition. Plato writes that “anyone that love touches instantly becomes a poet.” And even today, when poetry has largely disappeared from the mainstream of popular culture, it retains its romantic associations. But why should this be so—what are the connections between poetry and erotic love that lead us to associate them so strongly with one another? An examination of different theories of both love and poetry across the centuries reveals that the connection between them is not merely an accident of cultural history—the result of our having grown up hearing, or hearing about, love poetry—but something more intrinsic. Even as definitions of them have changed, the two phenomena have consistently been described in parallel terms. Love is characterized by paradox. Above all, it is both necessarily public, because interpersonal, and intensely private; hence it both requires expression and resists it. In poetry, especially lyric poetry, which features its own characteristic paradoxes and silences, love finds a natural outlet. This study considers both the theories and the love poems themselves, bringing together a wide range of examples from different eras in order to examine the major structures that love and poetry share. It does not aim to be a comprehensive history of Western love poetry, but an investigation into the meaning and function of recurrent tropes, forms, and images employed by poets to express and describe erotic love.


2017 ◽  
Vol 2017 ◽  
pp. 1-20 ◽  
Author(s):  
Jun Ma ◽  
Shinji Nakata ◽  
Akihito Yoshida ◽  
Yukio Tamura

Full-scale tests on a one-story steel frame structure with a typical precast cladding system using ambient and free vibration methods are described in detail. The cladding system is primarily composed of ALC (Autoclaved Lightweight Concrete) external wall cladding panels, gypsum plasterboard interior linings, and window glazing systems. Ten test cases including the bare steel frame and the steel frame with addition of different parts of the precast cladding system are prepared for detailed investigations. The amplitude-dependent dynamic characteristics of the test cases including natural frequencies and damping ratios determined from the tests are presented. The effects of the ALC external wall cladding panels, the gypsum plasterboard interior linings, and the window glazing systems on the stiffness and structural damping of the steel frame are discussed in detail. The effect of the precast cladding systems on the amplitude dependency of the dynamic characteristics and the tendencies of the dynamic parameters with respect to the structural response amplitude are investigated over a wide range. Furthermore, results estimated from the ambient vibration method are compared with those from the free vibration tests to evaluate the feasibility of the ambient vibration method.


2021 ◽  
Vol 1 ◽  
pp. 3219-3228
Author(s):  
Koray Benli ◽  
Jonathan Luntz ◽  
Diann Brei ◽  
Wonhee Kim ◽  
Paul Alexander ◽  
...  

AbstractPneumatically activated systems enable myriad types of highly functional inflatables employing a wide range of architectural approaches affecting their form and function, making systematic conceptual design difficult. A new architectural class of pneumatically activated systems, constrained layer inflatable systems, consists of hierarchically architected flat layers of thin airtight bladders that are internally and/or externally constrained to generate a variety of functionalities. The highly hierarchical architectural structure of constrained layer inflatable systems coincides with the hierarchy of produced functions, providing an opportunity for the development of a functional architectural decomposition, capturing the inherent relationship between architectural and functional hierarchies. The basis of the approach is conveyed through the design of an example constrained layer inflatable system. This approach empowers the systematic understanding of the interrelated architectural and functional breakdown of constrained layer inflatable systems, enabling designers to iteratively analyze, synthesize, and re-synthesize the components of the system improving existing designs and exploring new concepts.


2021 ◽  
Author(s):  
Jiuxiao Ruan ◽  
Huhui Chen ◽  
Tao Zhu ◽  
Yaoguang Yu ◽  
Yawen Lei ◽  
...  

Abstract In flowering plants, repression of the seed maturation program is essential for the transition from the seed to the vegetative phase, but the underlying mechanisms remain poorly understood. The B3-domain protein VIVIPAROUS1/ABSCISIC ACID-INSENSITIVE3-LIKE 1 (VAL1) is involved in repressing the seed maturation program. Here we uncovered a molecular network triggered by the plant hormone brassinosteroid (BR) that inhibits the seed maturation program during the seed-to-seedling transition in Arabidopsis (Arabidopsis thaliana). val1-2 mutant seedlings treated with a BR biosynthesis inhibitor form embryonic structures, whereas BR signaling gain-of-function mutations rescue the embryonic structure trait. Furthermore, the BR-activated transcription factors BRI1-EMS-SUPPRESSOR 1 and BRASSINAZOLE-RESISTANT 1 bind directly to the promoter of AGAMOUS-LIKE15 (AGL15), which encodes a transcription factor involved in activating the seed maturation program, and suppress its expression. Genetic analysis indicated that BR signaling is epistatic to AGL15 and represses the seed maturation program by downregulating AGL15. Finally, we showed that the BR-mediated pathway functions synergistically with the VAL1/2-mediated pathway to ensure the full repression of the seed maturation program. Together, our work uncovered a mechanism underlying the suppression of the seed maturation program, shedding light on how BR promotes seedling growth.


Sign in / Sign up

Export Citation Format

Share Document